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guile/module/slib/slib.info
Keisuke Nishida 9ddacf866c Import SLIB 2d1.
2001-04-14 11:24:45 +00:00

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This is slib.info, produced by makeinfo version 4.0 from slib.texi.
INFO-DIR-SECTION The Algorithmic Language Scheme
START-INFO-DIR-ENTRY
* SLIB: (slib). Scheme Library
END-INFO-DIR-ENTRY
This file documents SLIB, the portable Scheme library.
Copyright (C) 1993 Todd R. Eigenschink
Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000 Aubrey
Jaffer
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.
Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that this permission notice may be stated in a
translation approved by the author.

File: slib.info, Node: Top, Next: The Library System, Prev: (dir), Up: (dir)
"SLIB" is a portable library for the programming language "Scheme". It
provides a platform independent framework for using "packages" of
Scheme procedures and syntax. As distributed, SLIB contains useful
packages for all Scheme implementations. Its catalog can be
transparently extended to accomodate packages specific to a site,
implementation, user, or directory.
* Menu:
* The Library System:: How to use and customize.
* Scheme Syntax Extension Packages::
* Textual Conversion Packages::
* Mathematical Packages::
* Database Packages::
* Other Packages::
* About SLIB:: Install, etc.
* Index::

File: slib.info, Node: The Library System, Next: Scheme Syntax Extension Packages, Prev: Top, Up: Top
The Library System
******************
* Menu:
* Feature:: SLIB names.
* Requesting Features::
* Library Catalogs::
* Catalog Compilation::
* Built-in Support::
* About this manual::

File: slib.info, Node: Feature, Next: Requesting Features, Prev: The Library System, Up: The Library System
Feature
=======
SLIB denotes "features" by symbols. SLIB maintains a list of features
supported by the Scheme "session". The set of features provided by a
session may change over time. Some features are properties of the
Scheme implementation being used. The following features detail what
sort of numbers are available from an implementation.
* 'inexact
* 'rational
* 'real
* 'complex
* 'bignum
Other features correspond to the presence of sets of Scheme procedures
or syntax (macros).
- Function: provided? feature
Returns `#t' if FEATURE is supported by the current Scheme session.
- Procedure: provide feature
Informs SLIB that FEATURE is supported. Henceforth `(provided?
FEATURE)' will return `#t'.
(provided? 'foo) => #f
(provide 'foo)
(provided? 'foo) => #t

File: slib.info, Node: Requesting Features, Next: Library Catalogs, Prev: Feature, Up: The Library System
Requesting Features
===================
SLIB creates and maintains a "catalog" mapping features to locations of
files introducing procedures and syntax denoted by those features.
At the beginning of each section of this manual, there is a line like
`(require 'FEATURE)'. The Scheme files comprising SLIB are cataloged
so that these feature names map to the corresponding files.
SLIB provides a form, `require', which loads the files providing the
requested feature.
- Procedure: require feature
* If `(provided? FEATURE)' is true, then `require' just returns
an unspecified value.
* Otherwise, if FEATURE is found in the catalog, then the
corresponding files will be loaded and an unspecified value
returned.
Subsequently `(provided? FEATURE)' will return `#t'.
* Otherwise (FEATURE not found in the catalog), an error is
signaled.
The catalog can also be queried using `require:feature->path'.
- Function: require:feature->path feature
* If FEATURE is already provided, then returns `#t'.
* Otherwise, if FEATURE is in the catalog, the path or list of
paths associated with FEATURE is returned.
* Otherwise, returns `#f'.

File: slib.info, Node: Library Catalogs, Next: Catalog Compilation, Prev: Requesting Features, Up: The Library System
Library Catalogs
================
At the start of a session no catalog is present, but is created with the
first catalog inquiry (such as `(require 'random)'). Several sources
of catalog information are combined to produce the catalog:
* standard SLIB packages.
* additional packages of interest to this site.
* packages specifically for the variety of Scheme which this session
is running.
* packages this user wants to always have available. This catalog
is the file `homecat' in the user's "HOME" directory.
* packages germane to working in this (current working) directory.
This catalog is the file `usercat' in the directory to which it
applies. One would typically `cd' to this directory before
starting the Scheme session.
Catalog files consist of one or more "association list"s. In the
circumstance where a feature symbol appears in more than one list, the
latter list's association is retrieved. Here are the supported formats
for elements of catalog lists:
`(FEATURE . <symbol>)'
Redirects to the feature named <symbol>.
`(FEATURE . "<path>")'
Loads file <path>.
`(FEATURE source "<path>")'
`slib:load's the Scheme source file <path>.
`(FEATURE compiled "<path>" ...)'
`slib:load-compiled's the files <path> ....
The various macro styles first `require' the named macro package, then
just load <path> or load-and-macro-expand <path> as appropriate for the
implementation.
`(FEATURE defmacro "<path>")'
`defmacro:load's the Scheme source file <path>.
`(FEATURE macro-by-example "<path>")'
`defmacro:load's the Scheme source file <path>.
`(FEATURE macro "<path>")'
`macro:load's the Scheme source file <path>.
`(FEATURE macros-that-work "<path>")'
`macro:load's the Scheme source file <path>.
`(FEATURE syntax-case "<path>")'
`macro:load's the Scheme source file <path>.
`(FEATURE syntactic-closures "<path>")'
`macro:load's the Scheme source file <path>.
Here is an example of a `usercat' catalog. A Program in this directory
can invoke the `run' feature with `(require 'run)'.
;;; "usercat": SLIB catalog additions for SIMSYNCH. -*-scheme-*-
(
(simsynch . "../synch/simsynch.scm")
(run . "../synch/run.scm")
(schlep . "schlep.scm")
)

File: slib.info, Node: Catalog Compilation, Next: Built-in Support, Prev: Library Catalogs, Up: The Library System
Catalog Compilation
===================
SLIB combines the catalog information which doesn't vary per user into
the file `slibcat' in the implementation-vicinity. Therefore `slibcat'
needs change only when new software is installed or compiled. Because
the actual pathnames of files can differ from installation to
installation, SLIB builds a separate catalog for each implementation it
is used with.
The definition of `*SLIB-VERSION*' in SLIB file `require.scm' is
checked against the catalog association of `*SLIB-VERSION*' to
ascertain when versions have changed. I recommend that the definition
of `*SLIB-VERSION*' be changed whenever the library is changed. If
multiple implementations of Scheme use SLIB, remember that recompiling
one `slibcat' will fix only that implementation's catalog.
The compilation scripts of Scheme implementations which work with SLIB
can automatically trigger catalog compilation by deleting `slibcat' or
by invoking a special form of `require':
- Procedure: require 'new-catalog
This will load `mklibcat', which compiles and writes a new
`slibcat'.
Another special form of `require' erases SLIB's catalog, forcing it to
be reloaded the next time the catalog is queried.
- Procedure: require #f
Removes SLIB's catalog information. This should be done before
saving an executable image so that, when restored, its catalog
will be loaded afresh.
Each file in the table below is descibed in terms of its file-system
independent "vicinity" (*note Vicinity::). The entries of a catalog in
the table override those of catalogs above it in the table.
`implementation-vicinity' `slibcat'
This file contains the associations for the packages comprising
SLIB, the `implcat' and the `sitecat's. The associations in the
other catalogs override those of the standard catalog.
`library-vicinity' `mklibcat.scm'
creates `slibcat'.
`library-vicinity' `sitecat'
This file contains the associations specific to an SLIB
installation.
`implementation-vicinity' `implcat'
This file contains the associations specific to an implementation
of Scheme. Different implementations of Scheme should have
different `implementation-vicinity'.
`implementation-vicinity' `mkimpcat.scm'
if present, creates `implcat'.
`implementation-vicinity' `sitecat'
This file contains the associations specific to a Scheme
implementation installation.
`home-vicinity' `homecat'
This file contains the associations specific to an SLIB user.
`user-vicinity' `usercat'
This file contains associations effecting only those sessions whose
"working directory" is `user-vicinity'.

File: slib.info, Node: Built-in Support, Next: About this manual, Prev: Catalog Compilation, Up: The Library System
Built-in Support
================
The procedures described in these sections are supported by all
implementations as part of the `*.init' files or by `require.scm'.
* Menu:
* Require:: Module Management
* Vicinity:: Pathname Management
* Configuration:: Characteristics of Scheme Implementation
* Input/Output:: Things not provided by the Scheme specs.
* Legacy::
* System:: LOADing, EVALing, ERRORing, and EXITing

File: slib.info, Node: Require, Next: Vicinity, Prev: Built-in Support, Up: Built-in Support
Require
-------
- Variable: *features*
Is a list of symbols denoting features supported in this
implementation. *FEATURES* can grow as modules are `require'd.
*FEATURES* must be defined by all implementations (*note
Porting::).
Here are features which SLIB (`require.scm') adds to *FEATURES*
when appropriate.
* 'inexact
* 'rational
* 'real
* 'complex
* 'bignum
For each item, `(provided? 'FEATURE)' will return `#t' if that
feature is available, and `#f' if not.
- Variable: *modules*
Is a list of pathnames denoting files which have been loaded.
- Variable: *catalog*
Is an association list of features (symbols) and pathnames which
will supply those features. The pathname can be either a string
or a pair. If pathname is a pair then the first element should be
a macro feature symbol, `source', or `compiled'. The cdr of the
pathname should be either a string or a list.
In the following functions if the argument FEATURE is not a symbol it
is assumed to be a pathname.
- Function: provided? feature
Returns `#t' if FEATURE is a member of `*features*' or `*modules*'
or if FEATURE is supported by a file already loaded and `#f'
otherwise.
- Procedure: require feature
FEATURE is a symbol. If `(provided? FEATURE)' is true `require'
returns. Otherwise, if `(assq FEATURE *catalog*)' is not `#f',
the associated files will be loaded and `(provided? FEATURE)' will
henceforth return `#t'. An unspecified value is returned. If
FEATURE is not found in `*catalog*', then an error is signaled.
- Procedure: require pathname
PATHNAME is a string. If PATHNAME has not already been given as
an argument to `require', PATHNAME is loaded. An unspecified
value is returned.
- Procedure: provide feature
Assures that FEATURE is contained in `*features*' if FEATURE is a
symbol and `*modules*' otherwise.
- Function: require:feature->path feature
Returns `#t' if FEATURE is a member of `*features*' or `*modules*'
or if FEATURE is supported by a file already loaded. Returns a
path if one was found in `*catalog*' under the feature name, and
`#f' otherwise. The path can either be a string suitable as an
argument to load or a pair as described above for *catalog*.

File: slib.info, Node: Vicinity, Next: Configuration, Prev: Require, Up: Built-in Support
Vicinity
--------
A vicinity is a descriptor for a place in the file system. Vicinities
hide from the programmer the concepts of host, volume, directory, and
version. Vicinities express only the concept of a file environment
where a file name can be resolved to a file in a system independent
manner. Vicinities can even be used on "flat" file systems (which have
no directory structure) by having the vicinity express constraints on
the file name. On most systems a vicinity would be a string. All of
these procedures are file system dependent.
These procedures are provided by all implementations.
- Function: make-vicinity path
Returns the vicinity of PATH for use by `in-vicinity'.
- Function: program-vicinity
Returns the vicinity of the currently loading Scheme code. For an
interpreter this would be the directory containing source code.
For a compiled system (with multiple files) this would be the
directory where the object or executable files are. If no file is
currently loading it the result is undefined. *Warning:*
`program-vicinity' can return incorrect values if your program
escapes back into a `load'.
- Function: library-vicinity
Returns the vicinity of the shared Scheme library.
- Function: implementation-vicinity
Returns the vicinity of the underlying Scheme implementation. This
vicinity will likely contain startup code and messages and a
compiler.
- Function: user-vicinity
Returns the vicinity of the current directory of the user. On most
systems this is `""' (the empty string).
- Function: home-vicinity
Returns the vicinity of the user's "HOME" directory, the directory
which typically contains files which customize a computer
environment for a user. If scheme is running without a user (eg.
a daemon) or if this concept is meaningless for the platform, then
`home-vicinity' returns `#f'.
- Function: in-vicinity vicinity filename
Returns a filename suitable for use by `slib:load',
`slib:load-source', `slib:load-compiled', `open-input-file',
`open-output-file', etc. The returned filename is FILENAME in
VICINITY. `in-vicinity' should allow FILENAME to override
VICINITY when FILENAME is an absolute pathname and VICINITY is
equal to the value of `(user-vicinity)'. The behavior of
`in-vicinity' when FILENAME is absolute and VICINITY is not equal
to the value of `(user-vicinity)' is unspecified. For most systems
`in-vicinity' can be `string-append'.
- Function: sub-vicinity vicinity name
Returns the vicinity of VICINITY restricted to NAME. This is used
for large systems where names of files in subsystems could
conflict. On systems with directory structure `sub-vicinity' will
return a pathname of the subdirectory NAME of VICINITY.

File: slib.info, Node: Configuration, Next: Input/Output, Prev: Vicinity, Up: Built-in Support
Configuration
-------------
These constants and procedures describe characteristics of the Scheme
and underlying operating system. They are provided by all
implementations.
- Constant: char-code-limit
An integer 1 larger that the largest value which can be returned by
`char->integer'.
- Constant: most-positive-fixnum
In implementations which support integers of practically unlimited
size, MOST-POSITIVE-FIXNUM is a large exact integer within the
range of exact integers that may result from computing the length
of a list, vector, or string.
In implementations which do not support integers of practically
unlimited size, MOST-POSITIVE-FIXNUM is the largest exact integer
that may result from computing the length of a list, vector, or
string.
- Constant: slib:tab
The tab character.
- Constant: slib:form-feed
The form-feed character.
- Function: software-type
Returns a symbol denoting the generic operating system type. For
instance, `unix', `vms', `macos', `amiga', or `ms-dos'.
- Function: slib:report-version
Displays the versions of SLIB and the underlying Scheme
implementation and the name of the operating system. An
unspecified value is returned.
(slib:report-version) => slib "2d1" on scm "5b1" on unix |
- Function: slib:report
Displays the information of `(slib:report-version)' followed by
almost all the information neccessary for submitting a problem
report. An unspecified value is returned.
- Function: slib:report #t
provides a more verbose listing.
- Function: slib:report filename
Writes the report to file `filename'.
(slib:report)
=>
slib "2d1" on scm "5b1" on unix |
(implementation-vicinity) is "/home/jaffer/scm/"
(library-vicinity) is "/home/jaffer/slib/"
(scheme-file-suffix) is ".scm"
loaded *features* :
trace alist qp sort
common-list-functions macro values getopt
compiled
implementation *features* :
bignum complex real rational
inexact vicinity ed getenv
tmpnam abort transcript with-file
ieee-p1178 rev4-report rev4-optional-procedures hash
object-hash delay eval dynamic-wind
multiarg-apply multiarg/and- logical defmacro
string-port source current-time record
rev3-procedures rev2-procedures sun-dl string-case
array dump char-ready? full-continuation
system
implementation *catalog* :
(i/o-extensions compiled "/home/jaffer/scm/ioext.so")
...

File: slib.info, Node: Input/Output, Next: Legacy, Prev: Configuration, Up: Built-in Support
Input/Output
------------
These procedures are provided by all implementations.
- Procedure: file-exists? filename
Returns `#t' if the specified file exists. Otherwise, returns
`#f'. If the underlying implementation does not support this
feature then `#f' is always returned.
- Procedure: delete-file filename
Deletes the file specified by FILENAME. If FILENAME can not be
deleted, `#f' is returned. Otherwise, `#t' is returned.
- Procedure: tmpnam
Returns a pathname for a file which will likely not be used by any
other process. Successive calls to `(tmpnam)' will return
different pathnames.
- Procedure: current-error-port
Returns the current port to which diagnostic and error output is
directed.
- Procedure: force-output
- Procedure: force-output port
Forces any pending output on PORT to be delivered to the output
device and returns an unspecified value. The PORT argument may be
omitted, in which case it defaults to the value returned by
`(current-output-port)'.
- Procedure: output-port-width
- Procedure: output-port-width port
Returns the width of PORT, which defaults to
`(current-output-port)' if absent. If the width cannot be
determined 79 is returned.
- Procedure: output-port-height
- Procedure: output-port-height port
Returns the height of PORT, which defaults to
`(current-output-port)' if absent. If the height cannot be
determined 24 is returned.

File: slib.info, Node: Legacy, Next: System, Prev: Input/Output, Up: Built-in Support
Legacy
------
These procedures are provided by all implementations.
- Function: identity x
IDENTITY returns its argument.
Example:
(identity 3)
=> 3
(identity '(foo bar))
=> (foo bar)
(map identity LST)
== (copy-list LST)
The following procedures were present in Scheme until R4RS (*note
Language changes: (r4rs)Notes.). They are provided by all SLIB
implementations.
- Constant: t
Derfined as `#t'.
- Constant: nil
Defined as `#f'.
- Function: last-pair l
Returns the last pair in the list L. Example:
(last-pair (cons 1 2))
=> (1 . 2)
(last-pair '(1 2))
=> (2)
== (cons 2 '())

File: slib.info, Node: System, Prev: Legacy, Up: Built-in Support
System
------
These procedures are provided by all implementations.
- Procedure: slib:load-source name
Loads a file of Scheme source code from NAME with the default
filename extension used in SLIB. For instance if the filename
extension used in SLIB is `.scm' then `(slib:load-source "foo")'
will load from file `foo.scm'.
- Procedure: slib:load-compiled name
On implementations which support separtely loadable compiled
modules, loads a file of compiled code from NAME with the
implementation's filename extension for compiled code appended.
- Procedure: slib:load name
Loads a file of Scheme source or compiled code from NAME with the
appropriate suffixes appended. If both source and compiled code
are present with the appropriate names then the implementation
will load just one. It is up to the implementation to choose
which one will be loaded.
If an implementation does not support compiled code then
`slib:load' will be identical to `slib:load-source'.
- Procedure: slib:eval obj
`eval' returns the value of OBJ evaluated in the current top level
environment. *Note Eval:: provides a more general evaluation
facility.
- Procedure: slib:eval-load filename eval
FILENAME should be a string. If filename names an existing file,
the Scheme source code expressions and definitions are read from
the file and EVAL called with them sequentially. The
`slib:eval-load' procedure does not affect the values returned by
`current-input-port' and `current-output-port'.
- Procedure: slib:warn arg1 arg2 ...
Outputs a warning message containing the arguments.
- Procedure: slib:error arg1 arg2 ...
Outputs an error message containing the arguments, aborts
evaluation of the current form and responds in a system dependent
way to the error. Typical responses are to abort the program or
to enter a read-eval-print loop.
- Procedure: slib:exit n
- Procedure: slib:exit
Exits from the Scheme session returning status N to the system.
If N is omitted or `#t', a success status is returned to the
system (if possible). If N is `#f' a failure is returned to the
system (if possible). If N is an integer, then N is returned to
the system (if possible). If the Scheme session cannot exit an
unspecified value is returned from `slib:exit'.

File: slib.info, Node: About this manual, Prev: Built-in Support, Up: The Library System
About this manual
=================
* Entries that are labeled as Functions are called for their return
values. Entries that are labeled as Procedures are called
primarily for their side effects.
* Examples in this text were produced using the `scm' Scheme
implementation.
* At the beginning of each section, there is a line that looks like
`(require 'feature)'. Include this line in your code prior to
using the package.

File: slib.info, Node: Scheme Syntax Extension Packages, Next: Textual Conversion Packages, Prev: The Library System, Up: Top
Scheme Syntax Extension Packages
********************************
* Menu:
* Defmacro:: Supported by all implementations
* R4RS Macros:: 'macro
* Macro by Example:: 'macro-by-example
* Macros That Work:: 'macros-that-work
* Syntactic Closures:: 'syntactic-closures
* Syntax-Case Macros:: 'syntax-case
Syntax extensions (macros) included with SLIB. Also *Note Structures::.
* Fluid-Let:: 'fluid-let
* Yasos:: 'yasos, 'oop, 'collect

File: slib.info, Node: Defmacro, Next: R4RS Macros, Prev: Scheme Syntax Extension Packages, Up: Scheme Syntax Extension Packages
Defmacro
========
Defmacros are supported by all implementations.
- Function: gentemp
Returns a new (interned) symbol each time it is called. The symbol
names are implementation-dependent
(gentemp) => scm:G0
(gentemp) => scm:G1
- Function: defmacro:eval e
Returns the `slib:eval' of expanding all defmacros in scheme
expression E.
- Function: defmacro:load filename
FILENAME should be a string. If filename names an existing file,
the `defmacro:load' procedure reads Scheme source code expressions
and definitions from the file and evaluates them sequentially.
These source code expressions and definitions may contain defmacro
definitions. The `macro:load' procedure does not affect the values
returned by `current-input-port' and `current-output-port'.
- Function: defmacro? sym
Returns `#t' if SYM has been defined by `defmacro', `#f' otherwise.
- Function: macroexpand-1 form
- Function: macroexpand form
If FORM is a macro call, `macroexpand-1' will expand the macro
call once and return it. A FORM is considered to be a macro call
only if it is a cons whose `car' is a symbol for which a
`defmacro' has been defined.
`macroexpand' is similar to `macroexpand-1', but repeatedly
expands FORM until it is no longer a macro call.
- Macro: defmacro name lambda-list form ...
When encountered by `defmacro:eval', `defmacro:macroexpand*', or
`defmacro:load' defines a new macro which will henceforth be
expanded when encountered by `defmacro:eval',
`defmacro:macroexpand*', or `defmacro:load'.
Defmacroexpand
--------------
`(require 'defmacroexpand)'
- Function: defmacro:expand* e
Returns the result of expanding all defmacros in scheme expression
E.

File: slib.info, Node: R4RS Macros, Next: Macro by Example, Prev: Defmacro, Up: Scheme Syntax Extension Packages
R4RS Macros
===========
`(require 'macro)' is the appropriate call if you want R4RS
high-level macros but don't care about the low level implementation. If
an SLIB R4RS macro implementation is already loaded it will be used.
Otherwise, one of the R4RS macros implemetations is loaded.
The SLIB R4RS macro implementations support the following uniform
interface:
- Function: macro:expand sexpression
Takes an R4RS expression, macro-expands it, and returns the result
of the macro expansion.
- Function: macro:eval sexpression
Takes an R4RS expression, macro-expands it, evals the result of the
macro expansion, and returns the result of the evaluation.
- Procedure: macro:load filename
FILENAME should be a string. If filename names an existing file,
the `macro:load' procedure reads Scheme source code expressions and
definitions from the file and evaluates them sequentially. These
source code expressions and definitions may contain macro
definitions. The `macro:load' procedure does not affect the
values returned by `current-input-port' and `current-output-port'.

File: slib.info, Node: Macro by Example, Next: Macros That Work, Prev: R4RS Macros, Up: Scheme Syntax Extension Packages
Macro by Example
================
`(require 'macro-by-example)'
A vanilla implementation of `Macro by Example' (Eugene Kohlbecker,
R4RS) by Dorai Sitaram, (dorai@cs.rice.edu) using `defmacro'.
* generating hygienic global `define-syntax' Macro-by-Example macros
*cheaply*.
* can define macros which use `...'.
* needn't worry about a lexical variable in a macro definition
clashing with a variable from the macro use context
* don't suffer the overhead of redefining the repl if `defmacro'
natively supported (most implementations)
Caveat
------
These macros are not referentially transparent (*note Macros:
(r4rs)Macros.). Lexically scoped macros (i.e., `let-syntax' and
`letrec-syntax') are not supported. In any case, the problem of
referential transparency gains poignancy only when `let-syntax' and
`letrec-syntax' are used. So you will not be courting large-scale
disaster unless you're using system-function names as local variables
with unintuitive bindings that the macro can't use. However, if you
must have the full `r4rs' macro functionality, look to the more
featureful (but also more expensive) versions of syntax-rules available
in slib *Note Macros That Work::, *Note Syntactic Closures::, and *Note
Syntax-Case Macros::.
- Macro: define-syntax keyword transformer-spec
The KEYWORD is an identifier, and the TRANSFORMER-SPEC should be
an instance of `syntax-rules'.
The top-level syntactic environment is extended by binding the
KEYWORD to the specified transformer.
(define-syntax let*
(syntax-rules ()
((let* () body1 body2 ...)
(let () body1 body2 ...))
((let* ((name1 val1) (name2 val2) ...)
body1 body2 ...)
(let ((name1 val1))
(let* (( name2 val2) ...)
body1 body2 ...)))))
- Macro: syntax-rules literals syntax-rule ...
LITERALS is a list of identifiers, and each SYNTAX-RULE should be
of the form
`(PATTERN TEMPLATE)'
where the PATTERN and TEMPLATE are as in the grammar above.
An instance of `syntax-rules' produces a new macro transformer by
specifying a sequence of hygienic rewrite rules. A use of a macro
whose keyword is associated with a transformer specified by
`syntax-rules' is matched against the patterns contained in the
SYNTAX-RULEs, beginning with the leftmost SYNTAX-RULE. When a
match is found, the macro use is trancribed hygienically according
to the template.
Each pattern begins with the keyword for the macro. This keyword
is not involved in the matching and is not considered a pattern
variable or literal identifier.

File: slib.info, Node: Macros That Work, Next: Syntactic Closures, Prev: Macro by Example, Up: Scheme Syntax Extension Packages
Macros That Work
================
`(require 'macros-that-work)'
`Macros That Work' differs from the other R4RS macro implementations
in that it does not expand derived expression types to primitive
expression types.
- Function: macro:expand expression
- Function: macwork:expand expression
Takes an R4RS expression, macro-expands it, and returns the result
of the macro expansion.
- Function: macro:eval expression
- Function: macwork:eval expression
`macro:eval' returns the value of EXPRESSION in the current top
level environment. EXPRESSION can contain macro definitions.
Side effects of EXPRESSION will affect the top level environment.
- Procedure: macro:load filename
- Procedure: macwork:load filename
FILENAME should be a string. If filename names an existing file,
the `macro:load' procedure reads Scheme source code expressions and
definitions from the file and evaluates them sequentially. These
source code expressions and definitions may contain macro
definitions. The `macro:load' procedure does not affect the
values returned by `current-input-port' and `current-output-port'.
References:
The `Revised^4 Report on the Algorithmic Language Scheme' Clinger and
Rees [editors]. To appear in LISP Pointers. Also available as a
technical report from the University of Oregon, MIT AI Lab, and Cornell.
Macros That Work. Clinger and Rees. POPL '91.
The supported syntax differs from the R4RS in that vectors are allowed
as patterns and as templates and are not allowed as pattern or template
data.
transformer spec ==> (syntax-rules literals rules)
rules ==> ()
| (rule . rules)
rule ==> (pattern template)
pattern ==> pattern_var ; a symbol not in literals
| symbol ; a symbol in literals
| ()
| (pattern . pattern)
| (ellipsis_pattern)
| #(pattern*) ; extends R4RS
| #(pattern* ellipsis_pattern) ; extends R4RS
| pattern_datum
template ==> pattern_var
| symbol
| ()
| (template2 . template2)
| #(template*) ; extends R4RS
| pattern_datum
template2 ==> template
| ellipsis_template
pattern_datum ==> string ; no vector
| character
| boolean
| number
ellipsis_pattern ==> pattern ...
ellipsis_template ==> template ...
pattern_var ==> symbol ; not in literals
literals ==> ()
| (symbol . literals)
Definitions
-----------
Scope of an ellipsis
Within a pattern or template, the scope of an ellipsis (`...') is
the pattern or template that appears to its left.
Rank of a pattern variable
The rank of a pattern variable is the number of ellipses within
whose scope it appears in the pattern.
Rank of a subtemplate
The rank of a subtemplate is the number of ellipses within whose
scope it appears in the template.
Template rank of an occurrence of a pattern variable
The template rank of an occurrence of a pattern variable within a
template is the rank of that occurrence, viewed as a subtemplate.
Variables bound by a pattern
The variables bound by a pattern are the pattern variables that
appear within it.
Referenced variables of a subtemplate
The referenced variables of a subtemplate are the pattern
variables that appear within it.
Variables opened by an ellipsis template
The variables opened by an ellipsis template are the referenced
pattern variables whose rank is greater than the rank of the
ellipsis template.
Restrictions
------------
No pattern variable appears more than once within a pattern.
For every occurrence of a pattern variable within a template, the
template rank of the occurrence must be greater than or equal to the
pattern variable's rank.
Every ellipsis template must open at least one variable.
For every ellipsis template, the variables opened by an ellipsis
template must all be bound to sequences of the same length.
The compiled form of a RULE is
rule ==> (pattern template inserted)
pattern ==> pattern_var
| symbol
| ()
| (pattern . pattern)
| ellipsis_pattern
| #(pattern)
| pattern_datum
template ==> pattern_var
| symbol
| ()
| (template2 . template2)
| #(pattern)
| pattern_datum
template2 ==> template
| ellipsis_template
pattern_datum ==> string
| character
| boolean
| number
pattern_var ==> #(V symbol rank)
ellipsis_pattern ==> #(E pattern pattern_vars)
ellipsis_template ==> #(E template pattern_vars)
inserted ==> ()
| (symbol . inserted)
pattern_vars ==> ()
| (pattern_var . pattern_vars)
rank ==> exact non-negative integer
where V and E are unforgeable values.
The pattern variables associated with an ellipsis pattern are the
variables bound by the pattern, and the pattern variables associated
with an ellipsis template are the variables opened by the ellipsis
template.
If the template contains a big chunk that contains no pattern
variables or inserted identifiers, then the big chunk will be copied
unnecessarily. That shouldn't matter very often.

File: slib.info, Node: Syntactic Closures, Next: Syntax-Case Macros, Prev: Macros That Work, Up: Scheme Syntax Extension Packages
Syntactic Closures
==================
`(require 'syntactic-closures)'
- Function: macro:expand expression
- Function: synclo:expand expression
Returns scheme code with the macros and derived expression types of
EXPRESSION expanded to primitive expression types.
- Function: macro:eval expression
- Function: synclo:eval expression
`macro:eval' returns the value of EXPRESSION in the current top
level environment. EXPRESSION can contain macro definitions.
Side effects of EXPRESSION will affect the top level environment.
- Procedure: macro:load filename
- Procedure: synclo:load filename
FILENAME should be a string. If filename names an existing file,
the `macro:load' procedure reads Scheme source code expressions and
definitions from the file and evaluates them sequentially. These
source code expressions and definitions may contain macro
definitions. The `macro:load' procedure does not affect the
values returned by `current-input-port' and `current-output-port'.
Syntactic Closure Macro Facility
--------------------------------
A Syntactic Closures Macro Facility
by Chris Hanson
9 November 1991
This document describes "syntactic closures", a low-level macro
facility for the Scheme programming language. The facility is an
alternative to the low-level macro facility described in the `Revised^4
Report on Scheme.' This document is an addendum to that report.
The syntactic closures facility extends the BNF rule for TRANSFORMER
SPEC to allow a new keyword that introduces a low-level macro
transformer:
TRANSFORMER SPEC := (transformer EXPRESSION)
Additionally, the following procedures are added:
make-syntactic-closure
capture-syntactic-environment
identifier?
identifier=?
The description of the facility is divided into three parts. The
first part defines basic terminology. The second part describes how
macro transformers are defined. The third part describes the use of
"identifiers", which extend the syntactic closure mechanism to be
compatible with `syntax-rules'.
Terminology
...........
This section defines the concepts and data types used by the syntactic
closures facility.
* "Forms" are the syntactic entities out of which programs are
recursively constructed. A form is any expression, any
definition, any syntactic keyword, or any syntactic closure. The
variable name that appears in a `set!' special form is also a
form. Examples of forms:
17
#t
car
(+ x 4)
(lambda (x) x)
(define pi 3.14159)
if
define
* An "alias" is an alternate name for a given symbol. It can appear
anywhere in a form that the symbol could be used, and when quoted
it is replaced by the symbol; however, it does not satisfy the
predicate `symbol?'. Macro transformers rarely distinguish
symbols from aliases, referring to both as identifiers.
* A "syntactic" environment maps identifiers to their meanings.
More precisely, it determines whether an identifier is a syntactic
keyword or a variable. If it is a keyword, the meaning is an
interpretation for the form in which that keyword appears. If it
is a variable, the meaning identifies which binding of that
variable is referenced. In short, syntactic environments contain
all of the contextual information necessary for interpreting the
meaning of a particular form.
* A "syntactic closure" consists of a form, a syntactic environment,
and a list of identifiers. All identifiers in the form take their
meaning from the syntactic environment, except those in the given
list. The identifiers in the list are to have their meanings
determined later. A syntactic closure may be used in any context
in which its form could have been used. Since a syntactic closure
is also a form, it may not be used in contexts where a form would
be illegal. For example, a form may not appear as a clause in the
cond special form. A syntactic closure appearing in a quoted
structure is replaced by its form.
Transformer Definition
......................
This section describes the `transformer' special form and the
procedures `make-syntactic-closure' and `capture-syntactic-environment'.
- Syntax: transformer expression
Syntax: It is an error if this syntax occurs except as a
TRANSFORMER SPEC.
Semantics: The EXPRESSION is evaluated in the standard transformer
environment to yield a macro transformer as described below. This
macro transformer is bound to a macro keyword by the special form
in which the `transformer' expression appears (for example,
`let-syntax').
A "macro transformer" is a procedure that takes two arguments, a
form and a syntactic environment, and returns a new form. The
first argument, the "input form", is the form in which the macro
keyword occurred. The second argument, the "usage environment",
is the syntactic environment in which the input form occurred.
The result of the transformer, the "output form", is automatically
closed in the "transformer environment", which is the syntactic
environment in which the `transformer' expression occurred.
For example, here is a definition of a push macro using
`syntax-rules':
(define-syntax push
(syntax-rules ()
((push item list)
(set! list (cons item list)))))
Here is an equivalent definition using `transformer':
(define-syntax push
(transformer
(lambda (exp env)
(let ((item
(make-syntactic-closure env '() (cadr exp)))
(list
(make-syntactic-closure env '() (caddr exp))))
`(set! ,list (cons ,item ,list))))))
In this example, the identifiers `set!' and `cons' are closed in
the transformer environment, and thus will not be affected by the
meanings of those identifiers in the usage environment `env'.
Some macros may be non-hygienic by design. For example, the
following defines a loop macro that implicitly binds `exit' to an
escape procedure. The binding of `exit' is intended to capture
free references to `exit' in the body of the loop, so `exit' must
be left free when the body is closed:
(define-syntax loop
(transformer
(lambda (exp env)
(let ((body (cdr exp)))
`(call-with-current-continuation
(lambda (exit)
(let f ()
,@(map (lambda (exp)
(make-syntactic-closure env '(exit)
exp))
body)
(f))))))))
To assign meanings to the identifiers in a form, use
`make-syntactic-closure' to close the form in a syntactic
environment.
- Function: make-syntactic-closure environment free-names form
ENVIRONMENT must be a syntactic environment, FREE-NAMES must be a
list of identifiers, and FORM must be a form.
`make-syntactic-closure' constructs and returns a syntactic closure
of FORM in ENVIRONMENT, which can be used anywhere that FORM could
have been used. All the identifiers used in FORM, except those
explicitly excepted by FREE-NAMES, obtain their meanings from
ENVIRONMENT.
Here is an example where FREE-NAMES is something other than the
empty list. It is instructive to compare the use of FREE-NAMES in
this example with its use in the `loop' example above: the examples
are similar except for the source of the identifier being left
free.
(define-syntax let1
(transformer
(lambda (exp env)
(let ((id (cadr exp))
(init (caddr exp))
(exp (cadddr exp)))
`((lambda (,id)
,(make-syntactic-closure env (list id) exp))
,(make-syntactic-closure env '() init))))))
`let1' is a simplified version of `let' that only binds a single
identifier, and whose body consists of a single expression. When
the body expression is syntactically closed in its original
syntactic environment, the identifier that is to be bound by
`let1' must be left free, so that it can be properly captured by
the `lambda' in the output form.
To obtain a syntactic environment other than the usage
environment, use `capture-syntactic-environment'.
- Function: capture-syntactic-environment procedure
`capture-syntactic-environment' returns a form that will, when
transformed, call PROCEDURE on the current syntactic environment.
PROCEDURE should compute and return a new form to be transformed,
in that same syntactic environment, in place of the form.
An example will make this clear. Suppose we wanted to define a
simple `loop-until' keyword equivalent to
(define-syntax loop-until
(syntax-rules ()
((loop-until id init test return step)
(letrec ((loop
(lambda (id)
(if test return (loop step)))))
(loop init)))))
The following attempt at defining `loop-until' has a subtle bug:
(define-syntax loop-until
(transformer
(lambda (exp env)
(let ((id (cadr exp))
(init (caddr exp))
(test (cadddr exp))
(return (cadddr (cdr exp)))
(step (cadddr (cddr exp)))
(close
(lambda (exp free)
(make-syntactic-closure env free exp))))
`(letrec ((loop
(lambda (,id)
(if ,(close test (list id))
,(close return (list id))
(loop ,(close step (list id)))))))
(loop ,(close init '())))))))
This definition appears to take all of the proper precautions to
prevent unintended captures. It carefully closes the
subexpressions in their original syntactic environment and it
leaves the `id' identifier free in the `test', `return', and
`step' expressions, so that it will be captured by the binding
introduced by the `lambda' expression. Unfortunately it uses the
identifiers `if' and `loop' within that `lambda' expression, so if
the user of `loop-until' just happens to use, say, `if' for the
identifier, it will be inadvertently captured.
The syntactic environment that `if' and `loop' want to be exposed
to is the one just outside the `lambda' expression: before the
user's identifier is added to the syntactic environment, but after
the identifier loop has been added.
`capture-syntactic-environment' captures exactly that environment
as follows:
(define-syntax loop-until
(transformer
(lambda (exp env)
(let ((id (cadr exp))
(init (caddr exp))
(test (cadddr exp))
(return (cadddr (cdr exp)))
(step (cadddr (cddr exp)))
(close
(lambda (exp free)
(make-syntactic-closure env free exp))))
`(letrec ((loop
,(capture-syntactic-environment
(lambda (env)
`(lambda (,id)
(,(make-syntactic-closure env '() `if)
,(close test (list id))
,(close return (list id))
(,(make-syntactic-closure env '()
`loop)
,(close step (list id)))))))))
(loop ,(close init '())))))))
In this case, having captured the desired syntactic environment,
it is convenient to construct syntactic closures of the
identifiers `if' and the `loop' and use them in the body of the
`lambda'.
A common use of `capture-syntactic-environment' is to get the
transformer environment of a macro transformer:
(transformer
(lambda (exp env)
(capture-syntactic-environment
(lambda (transformer-env)
...))))
Identifiers
...........
This section describes the procedures that create and manipulate
identifiers. Previous syntactic closure proposals did not have an
identifier data type - they just used symbols. The identifier data
type extends the syntactic closures facility to be compatible with the
high-level `syntax-rules' facility.
As discussed earlier, an identifier is either a symbol or an "alias".
An alias is implemented as a syntactic closure whose "form" is an
identifier:
(make-syntactic-closure env '() 'a)
=> an "alias"
Aliases are implemented as syntactic closures because they behave just
like syntactic closures most of the time. The difference is that an
alias may be bound to a new value (for example by `lambda' or
`let-syntax'); other syntactic closures may not be used this way. If
an alias is bound, then within the scope of that binding it is looked
up in the syntactic environment just like any other identifier.
Aliases are used in the implementation of the high-level facility
`syntax-rules'. A macro transformer created by `syntax-rules' uses a
template to generate its output form, substituting subforms of the
input form into the template. In a syntactic closures implementation,
all of the symbols in the template are replaced by aliases closed in
the transformer environment, while the output form itself is closed in
the usage environment. This guarantees that the macro transformation
is hygienic, without requiring the transformer to know the syntactic
roles of the substituted input subforms.
- Function: identifier? object
Returns `#t' if OBJECT is an identifier, otherwise returns `#f'.
Examples:
(identifier? 'a)
=> #t
(identifier? (make-syntactic-closure env '() 'a))
=> #t
(identifier? "a")
=> #f
(identifier? #\a)
=> #f
(identifier? 97)
=> #f
(identifier? #f)
=> #f
(identifier? '(a))
=> #f
(identifier? '#(a))
=> #f
The predicate `eq?' is used to determine if two identifers are
"the same". Thus `eq?' can be used to compare identifiers exactly
as it would be used to compare symbols. Often, though, it is
useful to know whether two identifiers "mean the same thing". For
example, the `cond' macro uses the symbol `else' to identify the
final clause in the conditional. A macro transformer for `cond'
cannot just look for the symbol `else', because the `cond' form
might be the output of another macro transformer that replaced the
symbol `else' with an alias. Instead the transformer must look
for an identifier that "means the same thing" in the usage
environment as the symbol `else' means in the transformer
environment.
- Function: identifier=? environment1 identifier1 environment2
identifier2
ENVIRONMENT1 and ENVIRONMENT2 must be syntactic environments, and
IDENTIFIER1 and IDENTIFIER2 must be identifiers. `identifier=?'
returns `#t' if the meaning of IDENTIFIER1 in ENVIRONMENT1 is the
same as that of IDENTIFIER2 in ENVIRONMENT2, otherwise it returns
`#f'. Examples:
(let-syntax
((foo
(transformer
(lambda (form env)
(capture-syntactic-environment
(lambda (transformer-env)
(identifier=? transformer-env 'x env 'x)))))))
(list (foo)
(let ((x 3))
(foo))))
=> (#t #f)
(let-syntax ((bar foo))
(let-syntax
((foo
(transformer
(lambda (form env)
(capture-syntactic-environment
(lambda (transformer-env)
(identifier=? transformer-env 'foo
env (cadr form))))))))
(list (foo foo)
(foobar))))
=> (#f #t)
Acknowledgements
................
The syntactic closures facility was invented by Alan Bawden and
Jonathan Rees. The use of aliases to implement `syntax-rules' was
invented by Alan Bawden (who prefers to call them "synthetic names").
Much of this proposal is derived from an earlier proposal by Alan
Bawden.

File: slib.info, Node: Syntax-Case Macros, Next: Fluid-Let, Prev: Syntactic Closures, Up: Scheme Syntax Extension Packages
Syntax-Case Macros
==================
`(require 'syntax-case)'
- Function: macro:expand expression
- Function: syncase:expand expression
Returns scheme code with the macros and derived expression types of
EXPRESSION expanded to primitive expression types.
- Function: macro:eval expression
- Function: syncase:eval expression
`macro:eval' returns the value of EXPRESSION in the current top
level environment. EXPRESSION can contain macro definitions.
Side effects of EXPRESSION will affect the top level environment.
- Procedure: macro:load filename
- Procedure: syncase:load filename
FILENAME should be a string. If filename names an existing file,
the `macro:load' procedure reads Scheme source code expressions and
definitions from the file and evaluates them sequentially. These
source code expressions and definitions may contain macro
definitions. The `macro:load' procedure does not affect the
values returned by `current-input-port' and `current-output-port'.
This is version 2.1 of `syntax-case', the low-level macro facility
proposed and implemented by Robert Hieb and R. Kent Dybvig.
This version is further adapted by Harald Hanche-Olsen
<hanche@imf.unit.no> to make it compatible with, and easily usable
with, SLIB. Mainly, these adaptations consisted of:
* Removing white space from `expand.pp' to save space in the
distribution. This file is not meant for human readers anyway...
* Removed a couple of Chez scheme dependencies.
* Renamed global variables used to minimize the possibility of name
conflicts.
* Adding an SLIB-specific initialization file.
* Removing a couple extra files, most notably the documentation (but
see below).
If you wish, you can see exactly what changes were done by reading the
shell script in the file `syncase.sh'.
The two PostScript files were omitted in order to not burden the SLIB
distribution with them. If you do intend to use `syntax-case',
however, you should get these files and print them out on a PostScript
printer. They are available with the original `syntax-case'
distribution by anonymous FTP in
`cs.indiana.edu:/pub/scheme/syntax-case'.
In order to use syntax-case from an interactive top level, execute:
(require 'syntax-case)
(require 'repl)
(repl:top-level macro:eval)
See the section Repl (*note Repl::) for more information.
To check operation of syntax-case get
`cs.indiana.edu:/pub/scheme/syntax-case', and type
(require 'syntax-case)
(syncase:sanity-check)
Beware that `syntax-case' takes a long time to load - about 20s on a
SPARCstation SLC (with SCM) and about 90s on a Macintosh SE/30 (with
Gambit).
Notes
-----
All R4RS syntactic forms are defined, including `delay'. Along with
`delay' are simple definitions for `make-promise' (into which `delay'
expressions expand) and `force'.
`syntax-rules' and `with-syntax' (described in `TR356') are defined.
`syntax-case' is actually defined as a macro that expands into calls
to the procedure `syntax-dispatch' and the core form `syntax-lambda';
do not redefine these names.
Several other top-level bindings not documented in TR356 are created:
* the "hooks" in `hooks.ss'
* the `build-' procedures in `output.ss'
* `expand-syntax' (the expander)
The syntax of define has been extended to allow `(define ID)', which
assigns ID to some unspecified value.
We have attempted to maintain R4RS compatibility where possible. The
incompatibilities should be confined to `hooks.ss'. Please let us know
if there is some incompatibility that is not flagged as such.
Send bug reports, comments, suggestions, and questions to Kent Dybvig
(dyb@iuvax.cs.indiana.edu).
Note from maintainer
--------------------
Included with the `syntax-case' files was `structure.scm' which
defines a macro `define-structure'. There is no documentation for this
macro and it is not used by any code in SLIB.

File: slib.info, Node: Fluid-Let, Next: Yasos, Prev: Syntax-Case Macros, Up: Scheme Syntax Extension Packages
Fluid-Let
=========
`(require 'fluid-let)'
- Syntax: fluid-let `(BINDINGS ...)' FORMS...
(fluid-let ((VARIABLE INIT) ...)
EXPRESSION EXPRESSION ...)
The INITs are evaluated in the current environment (in some
unspecified order), the current values of the VARIABLEs are saved, the
results are assigned to the VARIABLEs, the EXPRESSIONs are evaluated
sequentially in the current environment, the VARIABLEs are restored to
their original values, and the value of the last EXPRESSION is returned.
The syntax of this special form is similar to that of `let', but
`fluid-let' temporarily rebinds existing VARIABLEs. Unlike `let',
`fluid-let' creates no new bindings; instead it _assigns_ the values of
each INIT to the binding (determined by the rules of lexical scoping)
of its corresponding VARIABLE.

File: slib.info, Node: Yasos, Prev: Fluid-Let, Up: Scheme Syntax Extension Packages
Yasos
=====
`(require 'oop)' or `(require 'yasos)'
`Yet Another Scheme Object System' is a simple object system for
Scheme based on the paper by Norman Adams and Jonathan Rees: `Object
Oriented Programming in Scheme', Proceedings of the 1988 ACM Conference
on LISP and Functional Programming, July 1988 [ACM #552880].
Another reference is:
Ken Dickey. Scheming with Objects `AI Expert' Volume 7, Number 10
(October 1992), pp. 24-33.
* Menu:
* Yasos terms:: Definitions and disclaimer.
* Yasos interface:: The Yasos macros and procedures.
* Setters:: Dylan-like setters in Yasos.
* Yasos examples:: Usage of Yasos and setters.

File: slib.info, Node: Yasos terms, Next: Yasos interface, Prev: Yasos, Up: Yasos
Terms
-----
"Object"
Any Scheme data object.
"Instance"
An instance of the OO system; an "object".
"Operation"
A METHOD.
_Notes:_
The object system supports multiple inheritance. An instance can
inherit from 0 or more ancestors. In the case of multiple
inherited operations with the same identity, the operation used is
that from the first ancestor which contains it (in the ancestor
`let'). An operation may be applied to any Scheme data
object--not just instances. As code which creates instances is
just code, there are no "classes" and no meta-ANYTHING. Method
dispatch is by a procedure call a la CLOS rather than by `send'
syntax a la Smalltalk.
_Disclaimer:_
There are a number of optimizations which can be made. This
implementation is expository (although performance should be quite
reasonable). See the L&FP paper for some suggestions.

File: slib.info, Node: Yasos interface, Next: Setters, Prev: Yasos terms, Up: Yasos
Interface
---------
- Syntax: define-operation `('opname self arg ...`)' DEFAULT-BODY
Defines a default behavior for data objects which don't handle the
operation OPNAME. The default behavior (for an empty
DEFAULT-BODY) is to generate an error.
- Syntax: define-predicate opname?
Defines a predicate OPNAME?, usually used for determining the
"type" of an object, such that `(OPNAME? OBJECT)' returns `#t' if
OBJECT has an operation OPNAME? and `#f' otherwise.
- Syntax: object `((NAME SELF ARG ...) BODY)' ...
Returns an object (an instance of the object system) with
operations. Invoking `(NAME OBJECT ARG ...' executes the BODY of
the OBJECT with SELF bound to OBJECT and with argument(s) ARG....
- Syntax: object-with-ancestors `(('ancestor1 init1`)' ...`)'
operation ...
A `let'-like form of `object' for multiple inheritance. It
returns an object inheriting the behaviour of ANCESTOR1 etc. An
operation will be invoked in an ancestor if the object itself does
not provide such a method. In the case of multiple inherited
operations with the same identity, the operation used is the one
found in the first ancestor in the ancestor list.
- Syntax: operate-as component operation self arg ...
Used in an operation definition (of SELF) to invoke the OPERATION
in an ancestor COMPONENT but maintain the object's identity. Also
known as "send-to-super".
- Procedure: print obj port
A default `print' operation is provided which is just `(format
PORT OBJ)' (*note Format::) for non-instances and prints OBJ
preceded by `#<INSTANCE>' for instances.
- Function: size obj
The default method returns the number of elements in OBJ if it is
a vector, string or list, `2' for a pair, `1' for a character and
by default id an error otherwise. Objects such as collections
(*note Collections::) may override the default in an obvious way.

File: slib.info, Node: Setters, Next: Yasos examples, Prev: Yasos interface, Up: Yasos
Setters
-------
"Setters" implement "generalized locations" for objects associated
with some sort of mutable state. A "getter" operation retrieves a
value from a generalized location and the corresponding setter
operation stores a value into the location. Only the getter is named -
the setter is specified by a procedure call as below. (Dylan uses
special syntax.) Typically, but not necessarily, getters are access
operations to extract values from Yasos objects (*note Yasos::).
Several setters are predefined, corresponding to getters `car', `cdr',
`string-ref' and `vector-ref' e.g., `(setter car)' is equivalent to
`set-car!'.
This implementation of setters is similar to that in Dylan(TM)
(`Dylan: An object-oriented dynamic language', Apple Computer Eastern
Research and Technology). Common LISP provides similar facilities
through `setf'.
- Function: setter getter
Returns the setter for the procedure GETTER. E.g., since
`string-ref' is the getter corresponding to a setter which is
actually `string-set!':
(define foo "foo")
((setter string-ref) foo 0 #\F) ; set element 0 of foo
foo => "Foo"
- Syntax: set place new-value
If PLACE is a variable name, `set' is equivalent to `set!'.
Otherwise, PLACE must have the form of a procedure call, where the
procedure name refers to a getter and the call indicates an
accessible generalized location, i.e., the call would return a
value. The return value of `set' is usually unspecified unless
used with a setter whose definition guarantees to return a useful
value.
(set (string-ref foo 2) #\O) ; generalized location with getter
foo => "FoO"
(set foo "foo") ; like set!
foo => "foo"
- Procedure: add-setter getter setter
Add procedures GETTER and SETTER to the (inaccessible) list of
valid setter/getter pairs. SETTER implements the store operation
corresponding to the GETTER access operation for the relevant
state. The return value is unspecified.
- Procedure: remove-setter-for getter
Removes the setter corresponding to the specified GETTER from the
list of valid setters. The return value is unspecified.
- Syntax: define-access-operation getter-name
Shorthand for a Yasos `define-operation' defining an operation
GETTER-NAME that objects may support to return the value of some
mutable state. The default operation is to signal an error. The
return value is unspecified.

File: slib.info, Node: Yasos examples, Prev: Setters, Up: Yasos
Examples
--------
;;; These definitions for PRINT and SIZE are
;;; already supplied by
(require 'yasos)
(define-operation (print obj port)
(format port
(if (instance? obj) "#<instance>" "~s")
obj))
(define-operation (size obj)
(cond
((vector? obj) (vector-length obj))
((list? obj) (length obj))
((pair? obj) 2)
((string? obj) (string-length obj))
((char? obj) 1)
(else
(error "Operation not supported: size" obj))))
(define-predicate cell?)
(define-operation (fetch obj))
(define-operation (store! obj newValue))
(define (make-cell value)
(object
((cell? self) #t)
((fetch self) value)
((store! self newValue)
(set! value newValue)
newValue)
((size self) 1)
((print self port)
(format port "#<Cell: ~s>" (fetch self)))))
(define-operation (discard obj value)
(format #t "Discarding ~s~%" value))
(define (make-filtered-cell value filter)
(object-with-ancestors
((cell (make-cell value)))
((store! self newValue)
(if (filter newValue)
(store! cell newValue)
(discard self newValue)))))
(define-predicate array?)
(define-operation (array-ref array index))
(define-operation (array-set! array index value))
(define (make-array num-slots)
(let ((anArray (make-vector num-slots)))
(object
((array? self) #t)
((size self) num-slots)
((array-ref self index)
(vector-ref anArray index))
((array-set! self index newValue)
(vector-set! anArray index newValue))
((print self port)
(format port "#<Array ~s>" (size self))))))
(define-operation (position obj))
(define-operation (discarded-value obj))
(define (make-cell-with-history value filter size)
(let ((pos 0) (most-recent-discard #f))
(object-with-ancestors
((cell (make-filtered-call value filter))
(sequence (make-array size)))
((array? self) #f)
((position self) pos)
((store! self newValue)
(operate-as cell store! self newValue)
(array-set! self pos newValue)
(set! pos (+ pos 1)))
((discard self value)
(set! most-recent-discard value))
((discarded-value self) most-recent-discard)
((print self port)
(format port "#<Cell-with-history ~s>"
(fetch self))))))
(define-access-operation fetch)
(add-setter fetch store!)
(define foo (make-cell 1))
(print foo #f)
=> "#<Cell: 1>"
(set (fetch foo) 2)
=>
(print foo #f)
=> "#<Cell: 2>"
(fetch foo)
=> 2

File: slib.info, Node: Textual Conversion Packages, Next: Mathematical Packages, Prev: Scheme Syntax Extension Packages, Up: Top
Textual Conversion Packages
***************************
* Menu:
* Precedence Parsing::
* Format:: Common-Lisp Format
* Standard Formatted I/O:: Posix printf and scanf
* Programs and Arguments::
* HTML::
* HTML Tables:: Databases meet HTML
* HTTP and CGI:: Serve WWW sites
* URI:: Uniform Resource Identifier |
* Printing Scheme:: Nicely
* Time and Date::
* Vector Graphics::
* Schmooz:: Documentation markup for Scheme programs

File: slib.info, Node: Precedence Parsing, Next: Format, Prev: Textual Conversion Packages, Up: Textual Conversion Packages
Precedence Parsing
==================
`(require 'precedence-parse)' or `(require 'parse)'
This package implements:
* a Pratt style precedence parser;
* a "tokenizer" which congeals tokens according to assigned classes
of constituent characters;
* procedures giving direct control of parser rulesets;
* procedures for higher level specification of rulesets.
* Menu:
* Precedence Parsing Overview::
* Ruleset Definition and Use::
* Token definition::
* Nud and Led Definition::
* Grammar Rule Definition::

File: slib.info, Node: Precedence Parsing Overview, Next: Ruleset Definition and Use, Prev: Precedence Parsing, Up: Precedence Parsing
Precedence Parsing Overview
---------------------------
This package offers improvements over previous parsers.
* Common computer language constructs are concisely specified.
* Grammars can be changed dynamically. Operators can be assigned
different meanings within a lexical context.
* Rulesets don't need compilation. Grammars can be changed
incrementally.
* Operator precedence is specified by integers.
* All possibilities of bad input are handled (1) and return as much
structure as was parsed when the error occured; The symbol `?' is
substituted for missing input.
Here are the higher-level syntax types and an example of each.
Precedence considerations are omitted for clarity. See *Note Grammar
Rule Definition:: for full details.
- Grammar: nofix bye exit
bye
calls the function `exit' with no arguments.
- Grammar: prefix - negate
- 42
Calls the function `negate' with the argument `42'.
- Grammar: infix - difference
x - y
Calls the function `difference' with arguments `x' and `y'.
- Grammar: nary + sum
x + y + z
Calls the function `sum' with arguments `x', `y', and `y'.
- Grammar: postfix ! factorial
5 !
Calls the function `factorial' with the argument `5'.
- Grammar: prestfix set set!
set foo bar
Calls the function `set!' with the arguments `foo' and `bar'.
- Grammar: commentfix /* */
/* almost any text here */
Ignores the comment delimited by `/*' and `*/'.
- Grammar: matchfix { list }
{0, 1, 2}
Calls the function `list' with the arguments `0', `1', and `2'.
- Grammar: inmatchfix ( funcall )
f(x, y)
Calls the function `funcall' with the arguments `f', `x', and `y'.
- Grammar: delim ;
set foo bar;
delimits the extent of the restfix operator `set'.
---------- Footnotes ----------
(1) How do I know this? I parsed 250kbyte of random input (an e-mail
file) with a non-trivial grammar utilizing all constructs.

File: slib.info, Node: Ruleset Definition and Use, Next: Token definition, Prev: Precedence Parsing Overview, Up: Precedence Parsing
Ruleset Definition and Use
--------------------------
- Variable: *syn-defs*
A grammar is built by one or more calls to `prec:define-grammar'.
The rules are appended to *SYN-DEFS*. The value of *SYN-DEFS* is
the grammar suitable for passing as an argument to `prec:parse'.
- Constant: *syn-ignore-whitespace*
Is a nearly empty grammar with whitespace characters set to group
0, which means they will not be made into tokens. Most rulesets
will want to start with `*syn-ignore-whitespace*'
In order to start defining a grammar, either
(set! *syn-defs* '())
or
(set! *syn-defs* *syn-ignore-whitespace*)
- Function: prec:define-grammar rule1 ...
Appends RULE1 ... to *SYN-DEFS*. `prec:define-grammar' is used to
define both the character classes and rules for tokens.
Once your grammar is defined, save the value of `*syn-defs*' in a
variable (for use when calling `prec:parse').
(define my-ruleset *syn-defs*)
- Function: prec:parse ruleset delim
- Function: prec:parse ruleset delim port
The RULESET argument must be a list of rules as constructed by
`prec:define-grammar' and extracted from *SYN-DEFS*.
The token DELIM may be a character, symbol, or string. A
character DELIM argument will match only a character token; i.e. a
character for which no token-group is assigned. A symbols or
string will match only a token string; i.e. a token resulting from
a token group.
`prec:parse' reads a RULESET grammar expression delimited by DELIM
from the given input PORT. `prec:parse' returns the next object
parsable from the given input PORT, updating PORT to point to the
first character past the end of the external representation of the
object.
If an end of file is encountered in the input before any
characters are found that can begin an object, then an end of file
object is returned. If a delimiter (such as DELIM) is found
before any characters are found that can begin an object, then
`#f' is returned.
The PORT argument may be omitted, in which case it defaults to the
value returned by `current-input-port'. It is an error to parse
from a closed port.

File: slib.info, Node: Token definition, Next: Nud and Led Definition, Prev: Ruleset Definition and Use, Up: Precedence Parsing
Token definition
----------------
- Function: tok:char-group group chars chars-proc
The argument CHARS may be a single character, a list of
characters, or a string. Each character in CHARS is treated as
though `tok:char-group' was called with that character alone.
The argument CHARS-PROC must be a procedure of one argument, a
list of characters. After `tokenize' has finished accumulating
the characters for a token, it calls CHARS-PROC with the list of
characters. The value returned is the token which `tokenize'
returns.
The argument GROUP may be an exact integer or a procedure of one
character argument. The following discussion concerns the
treatment which the tokenizing routine, `tokenize', will accord to
characters on the basis of their groups.
When GROUP is a non-zero integer, characters whose group number is
equal to or exactly one less than GROUP will continue to
accumulate. Any other character causes the accumulation to stop
(until a new token is to be read).
The GROUP of zero is special. These characters are ignored when
parsed pending a token, and stop the accumulation of token
characters when the accumulation has already begun. Whitespace
characters are usually put in group 0.
If GROUP is a procedure, then, when triggerd by the occurence of
an initial (no accumulation) CHARS character, this procedure will
be repeatedly called with each successive character from the input
stream until the GROUP procedure returns a non-false value.
The following convenient constants are provided for use with
`tok:char-group'.
- Constant: tok:decimal-digits
Is the string `"0123456789"'.
- Constant: tok:upper-case
Is the string consisting of all upper-case letters
("ABCDEFGHIJKLMNOPQRSTUVWXYZ").
- Constant: tok:lower-case
Is the string consisting of all lower-case letters
("abcdefghijklmnopqrstuvwxyz").
- Constant: tok:whitespaces
Is the string consisting of all characters between 0 and 255 for
which `char-whitespace?' returns true.

File: slib.info, Node: Nud and Led Definition, Next: Grammar Rule Definition, Prev: Token definition, Up: Precedence Parsing
Nud and Led Definition
----------------------
This section describes advanced features. You can skip this section
on first reading.
The "Null Denotation" (or "nud") of a token is the procedure and
arguments applying for that token when "Left", an unclaimed parsed
expression is not extant.
The "Left Denotation" (or "led") of a token is the procedure,
arguments, and lbp applying for that token when there is a "Left", an
unclaimed parsed expression.
In his paper,
Pratt, V. R. Top Down Operator Precendence. `SIGACT/SIGPLAN
Symposium on Principles of Programming Languages', Boston, 1973,
pages 41-51
the "left binding power" (or "lbp") was an independent property of
tokens. I think this was done in order to allow tokens with NUDs but
not LEDs to also be used as delimiters, which was a problem for
statically defined syntaxes. It turns out that _dynamically binding_
NUDs and LEDs allows them independence.
For the rule-defining procedures that follow, the variable TK may be a
character, string, or symbol, or a list composed of characters,
strings, and symbols. Each element of TK is treated as though the
procedure were called for each element.
Character TK arguments will match only character tokens; i.e.
characters for which no token-group is assigned. Symbols and strings
will both match token strings; i.e. tokens resulting from token groups.
- Function: prec:make-nud tk sop arg1 ...
Returns a rule specifying that SOP be called when TK is parsed.
If SOP is a procedure, it is called with TK and ARG1 ... as its
arguments; the resulting value is incorporated into the expression
being built. Otherwise, `(list SOP ARG1 ...)' is incorporated.
If no NUD has been defined for a token; then if that token is a string,
it is converted to a symbol and returned; if not a string, the token is
returned.
- Function: prec:make-led tk sop arg1 ...
Returns a rule specifying that SOP be called when TK is parsed and
LEFT has an unclaimed parsed expression. If SOP is a procedure,
it is called with LEFT, TK, and ARG1 ... as its arguments; the
resulting value is incorporated into the expression being built.
Otherwise, LEFT is incorporated.
If no LED has been defined for a token, and LEFT is set, the parser
issues a warning.

File: slib.info, Node: Grammar Rule Definition, Prev: Nud and Led Definition, Up: Precedence Parsing
Grammar Rule Definition
-----------------------
Here are procedures for defining rules for the syntax types introduced
in *Note Precedence Parsing Overview::.
For the rule-defining procedures that follow, the variable TK may be a
character, string, or symbol, or a list composed of characters,
strings, and symbols. Each element of TK is treated as though the
procedure were called for each element.
For procedures prec:delim, ..., prec:prestfix, if the SOP argument is
`#f', then the token which triggered this rule is converted to a symbol
and returned. A false SOP argument to the procedures prec:commentfix,
prec:matchfix, or prec:inmatchfix has a different meaning.
Character TK arguments will match only character tokens; i.e.
characters for which no token-group is assigned. Symbols and strings
will both match token strings; i.e. tokens resulting from token groups.
- Function: prec:delim tk
Returns a rule specifying that TK should not be returned from
parsing; i.e. TK's function is purely syntactic. The end-of-file
is always treated as a delimiter.
- Function: prec:nofix tk sop
Returns a rule specifying the following actions take place when TK
is parsed:
* If SOP is a procedure, it is called with no arguments; the
resulting value is incorporated into the expression being
built. Otherwise, the list of SOP is incorporated.
- Function: prec:prefix tk sop bp rule1 ...
Returns a rule specifying the following actions take place when TK
is parsed:
* The rules RULE1 ... augment and, in case of conflict, override
rules currently in effect.
* `prec:parse1' is called with binding-power BP.
* If SOP is a procedure, it is called with the expression
returned from `prec:parse1'; the resulting value is
incorporated into the expression being built. Otherwise, the
list of SOP and the expression returned from `prec:parse1' is
incorporated.
* The ruleset in effect before TK was parsed is restored; RULE1
... are forgotten.
- Function: prec:infix tk sop lbp bp rule1 ...
Returns a rule declaring the left-binding-precedence of the token
TK is LBP and specifying the following actions take place when TK
is parsed:
* The rules RULE1 ... augment and, in case of conflict, override
rules currently in effect.
* One expression is parsed with binding-power LBP. If instead a
delimiter is encountered, a warning is issued.
* If SOP is a procedure, it is applied to the list of LEFT and
the parsed expression; the resulting value is incorporated
into the expression being built. Otherwise, the list of SOP,
the LEFT expression, and the parsed expression is
incorporated.
* The ruleset in effect before TK was parsed is restored; RULE1
... are forgotten.
- Function: prec:nary tk sop bp
Returns a rule declaring the left-binding-precedence of the token
TK is BP and specifying the following actions take place when TK
is parsed:
* Expressions are parsed with binding-power BP as far as they
are interleaved with the token TK.
* If SOP is a procedure, it is applied to the list of LEFT and
the parsed expressions; the resulting value is incorporated
into the expression being built. Otherwise, the list of SOP,
the LEFT expression, and the parsed expressions is
incorporated.
- Function: prec:postfix tk sop lbp
Returns a rule declaring the left-binding-precedence of the token
TK is LBP and specifying the following actions take place when TK
is parsed:
* If SOP is a procedure, it is called with the LEFT expression;
the resulting value is incorporated into the expression being
built. Otherwise, the list of SOP and the LEFT expression is
incorporated.
- Function: prec:prestfix tk sop bp rule1 ...
Returns a rule specifying the following actions take place when TK
is parsed:
* The rules RULE1 ... augment and, in case of conflict, override
rules currently in effect.
* Expressions are parsed with binding-power BP until a
delimiter is reached.
* If SOP is a procedure, it is applied to the list of parsed
expressions; the resulting value is incorporated into the
expression being built. Otherwise, the list of SOP and the
parsed expressions is incorporated.
* The ruleset in effect before TK was parsed is restored; RULE1
... are forgotten.
- Function: prec:commentfix tk stp match rule1 ...
Returns rules specifying the following actions take place when TK
is parsed:
* The rules RULE1 ... augment and, in case of conflict, override
rules currently in effect.
* Characters are read until and end-of-file or a sequence of
characters is read which matches the _string_ MATCH.
* If STP is a procedure, it is called with the string of all
that was read between the TK and MATCH (exclusive).
* The ruleset in effect before TK was parsed is restored; RULE1
... are forgotten.
Parsing of commentfix syntax differs from the others in several
ways. It reads directly from input without tokenizing; It calls
STP but does not return its value; nay any value. I added the STP
argument so that comment text could be echoed.
- Function: prec:matchfix tk sop sep match rule1 ...
Returns a rule specifying the following actions take place when TK
is parsed:
* The rules RULE1 ... augment and, in case of conflict, override
rules currently in effect.
* A rule declaring the token MATCH a delimiter takes effect.
* Expressions are parsed with binding-power `0' until the token
MATCH is reached. If the token SEP does not appear between
each pair of expressions parsed, a warning is issued.
* If SOP is a procedure, it is applied to the list of parsed
expressions; the resulting value is incorporated into the
expression being built. Otherwise, the list of SOP and the
parsed expressions is incorporated.
* The ruleset in effect before TK was parsed is restored; RULE1
... are forgotten.
- Function: prec:inmatchfix tk sop sep match lbp rule1 ...
Returns a rule declaring the left-binding-precedence of the token
TK is LBP and specifying the following actions take place when TK
is parsed:
* The rules RULE1 ... augment and, in case of conflict, override
rules currently in effect.
* A rule declaring the token MATCH a delimiter takes effect.
* Expressions are parsed with binding-power `0' until the token
MATCH is reached. If the token SEP does not appear between
each pair of expressions parsed, a warning is issued.
* If SOP is a procedure, it is applied to the list of LEFT and
the parsed expressions; the resulting value is incorporated
into the expression being built. Otherwise, the list of SOP,
the LEFT expression, and the parsed expressions is
incorporated.
* The ruleset in effect before TK was parsed is restored; RULE1
... are forgotten.

File: slib.info, Node: Format, Next: Standard Formatted I/O, Prev: Precedence Parsing, Up: Textual Conversion Packages
Format (version 3.0)
====================
`(require 'format)'
* Menu:
* Format Interface::
* Format Specification::

File: slib.info, Node: Format Interface, Next: Format Specification, Prev: Format, Up: Format
Format Interface
----------------
- Function: format destination format-string . arguments
An almost complete implementation of Common LISP format description
according to the CL reference book `Common LISP' from Guy L.
Steele, Digital Press. Backward compatible to most of the
available Scheme format implementations.
Returns `#t', `#f' or a string; has side effect of printing
according to FORMAT-STRING. If DESTINATION is `#t', the output is
to the current output port and `#t' is returned. If DESTINATION
is `#f', a formatted string is returned as the result of the call.
NEW: If DESTINATION is a string, DESTINATION is regarded as the
format string; FORMAT-STRING is then the first argument and the
output is returned as a string. If DESTINATION is a number, the
output is to the current error port if available by the
implementation. Otherwise DESTINATION must be an output port and
`#t' is returned.
FORMAT-STRING must be a string. In case of a formatting error
format returns `#f' and prints a message on the current output or
error port. Characters are output as if the string were output by
the `display' function with the exception of those prefixed by a
tilde (~). For a detailed description of the FORMAT-STRING syntax
please consult a Common LISP format reference manual. For a test
suite to verify this format implementation load `formatst.scm'.
Please send bug reports to `lutzeb@cs.tu-berlin.de'.
Note: `format' is not reentrant, i.e. only one `format'-call may
be executed at a time.

File: slib.info, Node: Format Specification, Prev: Format Interface, Up: Format
Format Specification (Format version 3.0)
-----------------------------------------
Please consult a Common LISP format reference manual for a detailed
description of the format string syntax. For a demonstration of the
implemented directives see `formatst.scm'.
This implementation supports directive parameters and modifiers (`:'
and `@' characters). Multiple parameters must be separated by a comma
(`,'). Parameters can be numerical parameters (positive or negative),
character parameters (prefixed by a quote character (`''), variable
parameters (`v'), number of rest arguments parameter (`#'), empty and
default parameters. Directive characters are case independent. The
general form of a directive is:
DIRECTIVE ::= ~{DIRECTIVE-PARAMETER,}[:][@]DIRECTIVE-CHARACTER
DIRECTIVE-PARAMETER ::= [ [-|+]{0-9}+ | 'CHARACTER | v | # ]
Implemented CL Format Control Directives
........................................
Documentation syntax: Uppercase characters represent the corresponding
control directive characters. Lowercase characters represent control
directive parameter descriptions.
`~A'
Any (print as `display' does).
`~@A'
left pad.
`~MINCOL,COLINC,MINPAD,PADCHARA'
full padding.
`~S'
S-expression (print as `write' does).
`~@S'
left pad.
`~MINCOL,COLINC,MINPAD,PADCHARS'
full padding.
`~D'
Decimal.
`~@D'
print number sign always.
`~:D'
print comma separated.
`~MINCOL,PADCHAR,COMMACHARD'
padding.
`~X'
Hexadecimal.
`~@X'
print number sign always.
`~:X'
print comma separated.
`~MINCOL,PADCHAR,COMMACHARX'
padding.
`~O'
Octal.
`~@O'
print number sign always.
`~:O'
print comma separated.
`~MINCOL,PADCHAR,COMMACHARO'
padding.
`~B'
Binary.
`~@B'
print number sign always.
`~:B'
print comma separated.
`~MINCOL,PADCHAR,COMMACHARB'
padding.
`~NR'
Radix N.
`~N,MINCOL,PADCHAR,COMMACHARR'
padding.
`~@R'
print a number as a Roman numeral.
`~:@R'
print a number as an "old fashioned" Roman numeral.
`~:R'
print a number as an ordinal English number.
`~R' |
print a number as a cardinal English number.
`~P'
Plural.
`~@P'
prints `y' and `ies'.
`~:P'
as `~P but jumps 1 argument backward.'
`~:@P'
as `~@P but jumps 1 argument backward.'
`~C'
Character.
`~@C'
prints a character as the reader can understand it (i.e. `#\'
prefixing).
`~:C'
prints a character as emacs does (eg. `^C' for ASCII 03).
`~F'
Fixed-format floating-point (prints a flonum like MMM.NNN).
`~WIDTH,DIGITS,SCALE,OVERFLOWCHAR,PADCHARF'
`~@F'
If the number is positive a plus sign is printed.
`~E'
Exponential floating-point (prints a flonum like MMM.NNN`E'EE).
`~WIDTH,DIGITS,EXPONENTDIGITS,SCALE,OVERFLOWCHAR,PADCHAR,EXPONENTCHARE'
`~@E'
If the number is positive a plus sign is printed.
`~G'
General floating-point (prints a flonum either fixed or
exponential).
`~WIDTH,DIGITS,EXPONENTDIGITS,SCALE,OVERFLOWCHAR,PADCHAR,EXPONENTCHARG'
`~@G'
If the number is positive a plus sign is printed.
`~$'
Dollars floating-point (prints a flonum in fixed with signs
separated).
`~DIGITS,SCALE,WIDTH,PADCHAR$'
`~@$'
If the number is positive a plus sign is printed.
`~:@$'
A sign is always printed and appears before the padding.
`~:$'
The sign appears before the padding.
`~%'
Newline.
`~N%'
print N newlines.
`~&'
print newline if not at the beginning of the output line.
`~N&'
prints `~&' and then N-1 newlines.
`~|'
Page Separator.
`~N|'
print N page separators.
`~~'
Tilde.
`~N~'
print N tildes.
`~'<newline>
Continuation Line.
`~:'<newline>
newline is ignored, white space left.
`~@'<newline>
newline is left, white space ignored.
`~T'
Tabulation.
`~@T'
relative tabulation.
`~COLNUM,COLINCT'
full tabulation.
`~?'
Indirection (expects indirect arguments as a list).
`~@?'
extracts indirect arguments from format arguments.
`~(STR~)'
Case conversion (converts by `string-downcase').
`~:(STR~)'
converts by `string-capitalize'.
`~@(STR~)'
converts by `string-capitalize-first'.
`~:@(STR~)'
converts by `string-upcase'.
`~*'
Argument Jumping (jumps 1 argument forward).
`~N*'
jumps N arguments forward.
`~:*'
jumps 1 argument backward.
`~N:*'
jumps N arguments backward.
`~@*'
jumps to the 0th argument.
`~N@*'
jumps to the Nth argument (beginning from 0)
`~[STR0~;STR1~;...~;STRN~]'
Conditional Expression (numerical clause conditional).
`~N['
take argument from N.
`~@['
true test conditional.
`~:['
if-else-then conditional.
`~;'
clause separator.
`~:;'
default clause follows.
`~{STR~}'
Iteration (args come from the next argument (a list)).
`~N{'
at most N iterations.
`~:{'
args from next arg (a list of lists).
`~@{'
args from the rest of arguments.
`~:@{'
args from the rest args (lists).
`~^'
Up and out.
`~N^'
aborts if N = 0
`~N,M^'
aborts if N = M
`~N,M,K^'
aborts if N <= M <= K
Not Implemented CL Format Control Directives
............................................
`~:A'
print `#f' as an empty list (see below).
`~:S'
print `#f' as an empty list (see below).
`~<~>'
Justification.
`~:^'
(sorry I don't understand its semantics completely)
Extended, Replaced and Additional Control Directives
....................................................
`~MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHD'
`~MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHX'
`~MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHO'
`~MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHB'
`~N,MINCOL,PADCHAR,COMMACHAR,COMMAWIDTHR'
COMMAWIDTH is the number of characters between two comma
characters.
`~I'
print a R4RS complex number as `~F~@Fi' with passed parameters for
`~F'.
`~Y'
Pretty print formatting of an argument for scheme code lists.
`~K'
Same as `~?.'
`~!'
Flushes the output if format DESTINATION is a port.
`~_'
Print a `#\space' character
`~N_'
print N `#\space' characters.
`~/'
Print a `#\tab' character
`~N/'
print N `#\tab' characters.
`~NC'
Takes N as an integer representation for a character. No arguments
are consumed. N is converted to a character by `integer->char'. N
must be a positive decimal number.
`~:S'
Print out readproof. Prints out internal objects represented as
`#<...>' as strings `"#<...>"' so that the format output can always
be processed by `read'.
`~:A'
Print out readproof. Prints out internal objects represented as
`#<...>' as strings `"#<...>"' so that the format output can always
be processed by `read'.
`~Q'
Prints information and a copyright notice on the format
implementation.
`~:Q'
prints format version.
`~F, ~E, ~G, ~$'
may also print number strings, i.e. passing a number as a string
and format it accordingly.
Configuration Variables
.......................
Format has some configuration variables at the beginning of
`format.scm' to suit the systems and users needs. There should be no
modification necessary for the configuration that comes with SLIB. If
modification is desired the variable should be set after the format
code is loaded. Format detects automatically if the running scheme
system implements floating point numbers and complex numbers.
FORMAT:SYMBOL-CASE-CONV
Symbols are converted by `symbol->string' so the case type of the
printed symbols is implementation dependent.
`format:symbol-case-conv' is a one arg closure which is either
`#f' (no conversion), `string-upcase', `string-downcase' or
`string-capitalize'. (default `#f')
FORMAT:IOBJ-CASE-CONV
As FORMAT:SYMBOL-CASE-CONV but applies for the representation of
implementation internal objects. (default `#f')
FORMAT:EXPCH
The character prefixing the exponent value in `~E' printing.
(default `#\E')
Compatibility With Other Format Implementations
...............................................
SLIB format 2.x:
See `format.doc'.
SLIB format 1.4:
Downward compatible except for padding support and `~A', `~S',
`~P', `~X' uppercase printing. SLIB format 1.4 uses C-style
`printf' padding support which is completely replaced by the CL
`format' padding style.
MIT C-Scheme 7.1:
Downward compatible except for `~', which is not documented
(ignores all characters inside the format string up to a newline
character). (7.1 implements `~a', `~s', ~NEWLINE, `~~', `~%',
numerical and variable parameters and `:/@' modifiers in the CL
sense).
Elk 1.5/2.0:
Downward compatible except for `~A' and `~S' which print in
uppercase. (Elk implements `~a', `~s', `~~', and `~%' (no
directive parameters or modifiers)).
Scheme->C 01nov91:
Downward compatible except for an optional destination parameter:
S2C accepts a format call without a destination which returns a
formatted string. This is equivalent to a #f destination in S2C.
(S2C implements `~a', `~s', `~c', `~%', and `~~' (no directive
parameters or modifiers)).
This implementation of format is solely useful in the SLIB context
because it requires other components provided by SLIB.

File: slib.info, Node: Standard Formatted I/O, Next: Programs and Arguments, Prev: Format, Up: Textual Conversion Packages
Standard Formatted I/O
======================
* Menu:
* Standard Formatted Output:: 'printf
* Standard Formatted Input:: 'scanf
stdio
-----
`(require 'stdio)'
`require's `printf' and `scanf' and additionally defines the symbols:
- Variable: stdin
Defined to be `(current-input-port)'.
- Variable: stdout
Defined to be `(current-output-port)'.
- Variable: stderr
Defined to be `(current-error-port)'.

File: slib.info, Node: Standard Formatted Output, Next: Standard Formatted Input, Prev: Standard Formatted I/O, Up: Standard Formatted I/O
Standard Formatted Output
-------------------------
`(require 'printf)'
- Procedure: printf format arg1 ...
- Procedure: fprintf port format arg1 ...
- Procedure: sprintf str format arg1 ...
- Procedure: sprintf #f format arg1 ...
- Procedure: sprintf k format arg1 ...
Each function converts, formats, and outputs its ARG1 ...
arguments according to the control string FORMAT argument and
returns the number of characters output.
`printf' sends its output to the port `(current-output-port)'.
`fprintf' sends its output to the port PORT. `sprintf'
`string-set!'s locations of the non-constant string argument STR
to the output characters.
Two extensions of `sprintf' return new strings. If the first
argument is `#f', then the returned string's length is as many
characters as specified by the FORMAT and data; if the first
argument is a non-negative integer K, then the length of the
returned string is also bounded by K.
The string FORMAT contains plain characters which are copied to
the output stream, and conversion specifications, each of which
results in fetching zero or more of the arguments ARG1 .... The
results are undefined if there are an insufficient number of
arguments for the format. If FORMAT is exhausted while some of the
ARG1 ... arguments remain unused, the excess ARG1 ... arguments
are ignored.
The conversion specifications in a format string have the form:
% [ FLAGS ] [ WIDTH ] [ . PRECISION ] [ TYPE ] CONVERSION
An output conversion specifications consist of an initial `%'
character followed in sequence by:
* Zero or more "flag characters" that modify the normal
behavior of the conversion specification.
`-'
Left-justify the result in the field. Normally the
result is right-justified.
`+'
For the signed `%d' and `%i' conversions and all inexact
conversions, prefix a plus sign if the value is positive.
` '
For the signed `%d' and `%i' conversions, if the result
doesn't start with a plus or minus sign, prefix it with
a space character instead. Since the `+' flag ensures
that the result includes a sign, this flag is ignored if
both are specified.
`#'
For inexact conversions, `#' specifies that the result
should always include a decimal point, even if no digits
follow it. For the `%g' and `%G' conversions, this also
forces trailing zeros after the decimal point to be
printed where they would otherwise be elided.
For the `%o' conversion, force the leading digit to be
`0', as if by increasing the precision. For `%x' or
`%X', prefix a leading `0x' or `0X' (respectively) to
the result. This doesn't do anything useful for the
`%d', `%i', or `%u' conversions. Using this flag
produces output which can be parsed by the `scanf'
functions with the `%i' conversion (*note Standard
Formatted Input::).
`0'
Pad the field with zeros instead of spaces. The zeros
are placed after any indication of sign or base. This
flag is ignored if the `-' flag is also specified, or if
a precision is specified for an exact converson.
* An optional decimal integer specifying the "minimum field
width". If the normal conversion produces fewer characters
than this, the field is padded (with spaces or zeros per the
`0' flag) to the specified width. This is a _minimum_ width;
if the normal conversion produces more characters than this,
the field is _not_ truncated.
Alternatively, if the field width is `*', the next argument
in the argument list (before the actual value to be printed)
is used as the field width. The width value must be an
integer. If the value is negative it is as though the `-'
flag is set (see above) and the absolute value is used as the
field width.
* An optional "precision" to specify the number of digits to be
written for numeric conversions and the maximum field width
for string conversions. The precision is specified by a
period (`.') followed optionally by a decimal integer (which
defaults to zero if omitted).
Alternatively, if the precision is `.*', the next argument in
the argument list (before the actual value to be printed) is
used as the precision. The value must be an integer, and is
ignored if negative. If you specify `*' for both the field
width and precision, the field width argument precedes the
precision argument. The `.*' precision is an enhancement. C
library versions may not accept this syntax.
For the `%f', `%e', and `%E' conversions, the precision
specifies how many digits follow the decimal-point character.
The default precision is `6'. If the precision is
explicitly `0', the decimal point character is suppressed.
For the `%g' and `%G' conversions, the precision specifies how
many significant digits to print. Significant digits are the
first digit before the decimal point, and all the digits
after it. If the precision is `0' or not specified for `%g'
or `%G', it is treated like a value of `1'. If the value
being printed cannot be expressed accurately in the specified
number of digits, the value is rounded to the nearest number
that fits.
For exact conversions, if a precision is supplied it
specifies the minimum number of digits to appear; leading
zeros are produced if necessary. If a precision is not
supplied, the number is printed with as many digits as
necessary. Converting an exact `0' with an explicit
precision of zero produces no characters.
* An optional one of `l', `h' or `L', which is ignored for
numeric conversions. It is an error to specify these
modifiers for non-numeric conversions.
* A character that specifies the conversion to be applied.
Exact Conversions
.................
`d', `i'
Print an integer as a signed decimal number. `%d' and `%i'
are synonymous for output, but are different when used with
`scanf' for input (*note Standard Formatted Input::).
`o'
Print an integer as an unsigned octal number.
`u'
Print an integer as an unsigned decimal number.
`x', `X'
Print an integer as an unsigned hexadecimal number. `%x'
prints using the digits `0123456789abcdef'. `%X' prints
using the digits `0123456789ABCDEF'.
Inexact Conversions
...................
`f'
Print a floating-point number in fixed-point notation.
`e', `E'
Print a floating-point number in exponential notation. `%e'
prints `e' between mantissa and exponont. `%E' prints `E'
between mantissa and exponont.
`g', `G'
Print a floating-point number in either fixed or exponential
notation, whichever is more appropriate for its magnitude.
Unless an `#' flag has been supplied, trailing zeros after a
decimal point will be stripped off. `%g' prints `e' between
mantissa and exponont. `%G' prints `E' between mantissa and
exponent.
`k', `K'
Print a number like `%g', except that an SI prefix is output
after the number, which is scaled accordingly. `%K' outputs
a space between number and prefix, `%k' does not.
Other Conversions
.................
`c'
Print a single character. The `-' flag is the only one which
can be specified. It is an error to specify a precision.
`s'
Print a string. The `-' flag is the only one which can be
specified. A precision specifies the maximum number of
characters to output; otherwise all characters in the string
are output.
`a', `A'
Print a scheme expression. The `-' flag left-justifies the
output. The `#' flag specifies that strings and characters
should be quoted as by `write' (which can be read using
`read'); otherwise, output is as `display' prints. A
precision specifies the maximum number of characters to
output; otherwise as many characters as needed are output.
_Note:_ `%a' and `%A' are SLIB extensions.
`%'
Print a literal `%' character. No argument is consumed. It
is an error to specifiy flags, field width, precision, or
type modifiers with `%%'.

File: slib.info, Node: Standard Formatted Input, Prev: Standard Formatted Output, Up: Standard Formatted I/O
Standard Formatted Input
------------------------
`(require 'scanf)'
- Function: scanf-read-list format
- Function: scanf-read-list format port
- Function: scanf-read-list format string
- Macro: scanf format arg1 ...
- Macro: fscanf port format arg1 ...
- Macro: sscanf str format arg1 ...
Each function reads characters, interpreting them according to the
control string FORMAT argument.
`scanf-read-list' returns a list of the items specified as far as
the input matches FORMAT. `scanf', `fscanf', and `sscanf' return
the number of items successfully matched and stored. `scanf',
`fscanf', and `sscanf' also set the location corresponding to ARG1
... using the methods:
symbol
`set!'
car expression
`set-car!'
cdr expression
`set-cdr!'
vector-ref expression
`vector-set!'
substring expression
`substring-move-left!'
The argument to a `substring' expression in ARG1 ... must be a
non-constant string. Characters will be stored starting at the
position specified by the second argument to `substring'. The
number of characters stored will be limited by either the position
specified by the third argument to `substring' or the length of the
matched string, whichever is less.
The control string, FORMAT, contains conversion specifications and
other characters used to direct interpretation of input sequences.
The control string contains:
* White-space characters (blanks, tabs, newlines, or formfeeds)
that cause input to be read (and discarded) up to the next
non-white-space character.
* An ordinary character (not `%') that must match the next
character of the input stream.
* Conversion specifications, consisting of the character `%', an
optional assignment suppressing character `*', an optional
numerical maximum-field width, an optional `l', `h' or `L'
which is ignored, and a conversion code.
Unless the specification contains the `n' conversion character
(described below), a conversion specification directs the
conversion of the next input field. The result of a conversion
specification is returned in the position of the corresponding
argument points, unless `*' indicates assignment suppression.
Assignment suppression provides a way to describe an input field
to be skipped. An input field is defined as a string of
characters; it extends to the next inappropriate character or
until the field width, if specified, is exhausted.
_Note:_ This specification of format strings differs from the
`ANSI C' and `POSIX' specifications. In SLIB, white space
before an input field is not skipped unless white space
appears before the conversion specification in the format
string. In order to write format strings which work
identically with `ANSI C' and SLIB, prepend whitespace to all
conversion specifications except `[' and `c'.
The conversion code indicates the interpretation of the input
field; For a suppressed field, no value is returned. The
following conversion codes are legal:
`%'
A single % is expected in the input at this point; no value
is returned.
`d', `D'
A decimal integer is expected.
`u', `U'
An unsigned decimal integer is expected.
`o', `O'
An octal integer is expected.
`x', `X'
A hexadecimal integer is expected.
`i'
An integer is expected. Returns the value of the next input
item, interpreted according to C conventions; a leading `0'
implies octal, a leading `0x' implies hexadecimal; otherwise,
decimal is assumed.
`n'
Returns the total number of bytes (including white space)
read by `scanf'. No input is consumed by `%n'.
`f', `F', `e', `E', `g', `G'
A floating-point number is expected. The input format for
floating-point numbers is an optionally signed string of
digits, possibly containing a radix character `.', followed
by an optional exponent field consisting of an `E' or an `e',
followed by an optional `+', `-', or space, followed by an
integer.
`c', `C'
WIDTH characters are expected. The normal
skip-over-white-space is suppressed in this case; to read the
next non-space character, use `%1s'. If a field width is
given, a string is returned; up to the indicated number of
characters is read.
`s', `S'
A character string is expected The input field is terminated
by a white-space character. `scanf' cannot read a null
string.
`['
Indicates string data and the normal
skip-over-leading-white-space is suppressed. The left
bracket is followed by a set of characters, called the
scanset, and a right bracket; the input field is the maximal
sequence of input characters consisting entirely of
characters in the scanset. `^', when it appears as the first
character in the scanset, serves as a complement operator and
redefines the scanset as the set of all characters not
contained in the remainder of the scanset string.
Construction of the scanset follows certain conventions. A
range of characters may be represented by the construct
first-last, enabling `[0123456789]' to be expressed `[0-9]'.
Using this convention, first must be lexically less than or
equal to last; otherwise, the dash stands for itself. The
dash also stands for itself when it is the first or the last
character in the scanset. To include the right square
bracket as an element of the scanset, it must appear as the
first character (possibly preceded by a `^') of the scanset,
in which case it will not be interpreted syntactically as the
closing bracket. At least one character must match for this
conversion to succeed.
The `scanf' functions terminate their conversions at end-of-file,
at the end of the control string, or when an input character
conflicts with the control string. In the latter case, the
offending character is left unread in the input stream.

File: slib.info, Node: Programs and Arguments, Next: HTML, Prev: Standard Formatted I/O, Up: Textual Conversion Packages
Program and Arguments
=====================
* Menu:
* Getopt:: Command Line option parsing
* Command Line:: A command line reader for Scheme shells
* Parameter lists:: 'parameters
* Getopt Parameter lists:: 'getopt-parameters
* Filenames:: 'glob or 'filename
* Batch:: 'batch

File: slib.info, Node: Getopt, Next: Command Line, Prev: Programs and Arguments, Up: Programs and Arguments
Getopt
------
`(require 'getopt)'
This routine implements Posix command line argument parsing. Notice
that returning values through global variables means that `getopt' is
_not_ reentrant.
- Variable: *optind*
Is the index of the current element of the command line. It is
initially one. In order to parse a new command line or reparse an
old one, *OPTING* must be reset.
- Variable: *optarg*
Is set by getopt to the (string) option-argument of the current
option.
- Procedure: getopt argc argv optstring
Returns the next option letter in ARGV (starting from `(vector-ref
argv *optind*)') that matches a letter in OPTSTRING. ARGV is a
vector or list of strings, the 0th of which getopt usually
ignores. ARGC is the argument count, usually the length of ARGV.
OPTSTRING is a string of recognized option characters; if a
character is followed by a colon, the option takes an argument
which may be immediately following it in the string or in the next
element of ARGV.
*OPTIND* is the index of the next element of the ARGV vector to be
processed. It is initialized to 1 by `getopt.scm', and `getopt'
updates it when it finishes with each element of ARGV.
`getopt' returns the next option character from ARGV that matches
a character in OPTSTRING, if there is one that matches. If the
option takes an argument, `getopt' sets the variable *OPTARG* to
the option-argument as follows:
* If the option was the last character in the string pointed to
by an element of ARGV, then *OPTARG* contains the next
element of ARGV, and *OPTIND* is incremented by 2. If the
resulting value of *OPTIND* is greater than or equal to ARGC,
this indicates a missing option argument, and `getopt'
returns an error indication.
* Otherwise, *OPTARG* is set to the string following the option
character in that element of ARGV, and *OPTIND* is
incremented by 1.
If, when `getopt' is called, the string `(vector-ref argv
*optind*)' either does not begin with the character `#\-' or is
just `"-"', `getopt' returns `#f' without changing *OPTIND*. If
`(vector-ref argv *optind*)' is the string `"--"', `getopt'
returns `#f' after incrementing *OPTIND*.
If `getopt' encounters an option character that is not contained in
OPTSTRING, it returns the question-mark `#\?' character. If it
detects a missing option argument, it returns the colon character
`#\:' if the first character of OPTSTRING was a colon, or a
question-mark character otherwise. In either case, `getopt' sets
the variable GETOPT:OPT to the option character that caused the
error.
The special option `"--"' can be used to delimit the end of the
options; `#f' is returned, and `"--"' is skipped.
RETURN VALUE
`getopt' returns the next option character specified on the command
line. A colon `#\:' is returned if `getopt' detects a missing
argument and the first character of OPTSTRING was a colon `#\:'.
A question-mark `#\?' is returned if `getopt' encounters an option
character not in OPTSTRING or detects a missing argument and the
first character of OPTSTRING was not a colon `#\:'.
Otherwise, `getopt' returns `#f' when all command line options
have been parsed.
Example:
#! /usr/local/bin/scm
;;;This code is SCM specific.
(define argv (program-arguments))
(require 'getopt)
(define opts ":a:b:cd")
(let loop ((opt (getopt (length argv) argv opts)))
(case opt
((#\a) (print "option a: " *optarg*))
((#\b) (print "option b: " *optarg*))
((#\c) (print "option c"))
((#\d) (print "option d"))
((#\?) (print "error" getopt:opt))
((#\:) (print "missing arg" getopt:opt))
((#f) (if (< *optind* (length argv))
(print "argv[" *optind* "]="
(list-ref argv *optind*)))
(set! *optind* (+ *optind* 1))))
(if (< *optind* (length argv))
(loop (getopt (length argv) argv opts))))
(slib:exit)
Getopt-
-------
- Function: getopt- argc argv optstring
The procedure `getopt--' is an extended version of `getopt' which
parses "long option names" of the form `--hold-the-onions' and
`--verbosity-level=extreme'. `Getopt--' behaves as `getopt'
except for non-empty options beginning with `--'.
Options beginning with `--' are returned as strings rather than
characters. If a value is assigned (using `=') to a long option,
`*optarg*' is set to the value. The `=' and value are not
returned as part of the option string.
No information is passed to `getopt--' concerning which long
options should be accepted or whether such options can take
arguments. If a long option did not have an argument, `*optarg'
will be set to `#f'. The caller is responsible for detecting and
reporting errors.
(define opts ":-:b:")
(define argc 5)
(define argv '("foo" "-b9" "--f1" "--2=" "--g3=35234.342" "--"))
(define *optind* 1)
(define *optarg* #f)
(require 'qp)
(do ((i 5 (+ -1 i)))
((zero? i))
(define opt (getopt-- argc argv opts))
(print *optind* opt *optarg*)))
-|
2 #\b "9"
3 "f1" #f
4 "2" ""
5 "g3" "35234.342"
5 #f "35234.342"

File: slib.info, Node: Command Line, Next: Parameter lists, Prev: Getopt, Up: Programs and Arguments
Command Line
------------
`(require 'read-command)'
- Function: read-command port
- Function: read-command
`read-command' converts a "command line" into a list of strings
suitable for parsing by `getopt'. The syntax of command lines
supported resembles that of popular "shell"s. `read-command'
updates PORT to point to the first character past the command
delimiter.
If an end of file is encountered in the input before any
characters are found that can begin an object or comment, then an
end of file object is returned.
The PORT argument may be omitted, in which case it defaults to the
value returned by `current-input-port'.
The fields into which the command line is split are delimited by
whitespace as defined by `char-whitespace?'. The end of a command
is delimited by end-of-file or unescaped semicolon (<;>) or
<newline>. Any character can be literally included in a field by
escaping it with a backslach (<\>).
The initial character and types of fields recognized are:
`\'
The next character has is taken literally and not interpreted
as a field delimiter. If <\> is the last character before a
<newline>, that <newline> is just ignored. Processing
continues from the characters after the <newline> as though
the backslash and <newline> were not there.
`"'
The characters up to the next unescaped <"> are taken
literally, according to [R4RS] rules for literal strings
(*note Strings: (r4rs)Strings.).
`(', `%''
One scheme expression is `read' starting with this character.
The `read' expression is evaluated, converted to a string
(using `display'), and replaces the expression in the returned
field.
`;'
Semicolon delimits a command. Using semicolons more than one
command can appear on a line. Escaped semicolons and
semicolons inside strings do not delimit commands.
The comment field differs from the previous fields in that it must
be the first character of a command or appear after whitespace in
order to be recognized. <#> can be part of fields if these
conditions are not met. For instance, `ab#c' is just the field
ab#c.
`#'
Introduces a comment. The comment continues to the end of
the line on which the semicolon appears. Comments are
treated as whitespace by `read-dommand-line' and backslashes
before <newline>s in comments are also ignored.
- Function: read-options-file filename
`read-options-file' converts an "options file" into a list of
strings suitable for parsing by `getopt'. The syntax of options
files is the same as the syntax for command lines, except that
<newline>s do not terminate reading (only <;> or end of file).
If an end of file is encountered before any characters are found
that can begin an object or comment, then an end of file object is
returned.

File: slib.info, Node: Parameter lists, Next: Getopt Parameter lists, Prev: Command Line, Up: Programs and Arguments
Parameter lists
---------------
`(require 'parameters)'
Arguments to procedures in scheme are distinguished from each other by
their position in the procedure call. This can be confusing when a
procedure takes many arguments, many of which are not often used.
A "parameter-list" is a way of passing named information to a
procedure. Procedures are also defined to set unused parameters to
default values, check parameters, and combine parameter lists.
A PARAMETER has the form `(parameter-name value1 ...)'. This format
allows for more than one value per parameter-name.
A PARAMETER-LIST is a list of PARAMETERs, each with a different
PARAMETER-NAME.
- Function: make-parameter-list parameter-names
Returns an empty parameter-list with slots for PARAMETER-NAMES.
- Function: parameter-list-ref parameter-list parameter-name
PARAMETER-NAME must name a valid slot of PARAMETER-LIST.
`parameter-list-ref' returns the value of parameter PARAMETER-NAME
of PARAMETER-LIST.
- Function: remove-parameter parameter-name parameter-list
Removes the parameter PARAMETER-NAME from PARAMETER-LIST.
`remove-parameter' does not alter the argument PARAMETER-LIST.
If there are more than one PARAMETER-NAME parameters, an error is
signaled.
- Procedure: adjoin-parameters! parameter-list parameter1 ...
Returns PARAMETER-LIST with PARAMETER1 ... merged in.
- Procedure: parameter-list-expand expanders parameter-list
EXPANDERS is a list of procedures whose order matches the order of
the PARAMETER-NAMEs in the call to `make-parameter-list' which
created PARAMETER-LIST. For each non-false element of EXPANDERS
that procedure is mapped over the corresponding parameter value
and the returned parameter lists are merged into PARAMETER-LIST.
This process is repeated until PARAMETER-LIST stops growing. The
value returned from `parameter-list-expand' is unspecified.
- Function: fill-empty-parameters defaulters parameter-list
DEFAULTERS is a list of procedures whose order matches the order
of the PARAMETER-NAMEs in the call to `make-parameter-list' which
created PARAMETER-LIST. `fill-empty-parameters' returns a new
parameter-list with each empty parameter replaced with the list
returned by calling the corresponding DEFAULTER with
PARAMETER-LIST as its argument.
- Function: check-parameters checks parameter-list
CHECKS is a list of procedures whose order matches the order of
the PARAMETER-NAMEs in the call to `make-parameter-list' which
created PARAMETER-LIST.
`check-parameters' returns PARAMETER-LIST if each CHECK of the
corresponding PARAMETER-LIST returns non-false. If some CHECK
returns `#f' a warning is signaled. |
In the following procedures ARITIES is a list of symbols. The elements
of `arities' can be:
`single'
Requires a single parameter.
`optional'
A single parameter or no parameter is acceptable.
`boolean'
A single boolean parameter or zero parameters is acceptable.
`nary'
Any number of parameters are acceptable.
`nary1'
One or more of parameters are acceptable.
- Function: parameter-list->arglist positions arities parameter-list |
Returns PARAMETER-LIST converted to an argument list. Parameters
of ARITY type `single' and `boolean' are converted to the single
value associated with them. The other ARITY types are converted
to lists of the value(s). |
POSITIONS is a list of positive integers whose order matches the
order of the PARAMETER-NAMEs in the call to `make-parameter-list'
which created PARAMETER-LIST. The integers specify in which
argument position the corresponding parameter should appear.

File: slib.info, Node: Getopt Parameter lists, Next: Filenames, Prev: Parameter lists, Up: Programs and Arguments
Getopt Parameter lists
----------------------
`(require 'getopt-parameters)'
- Function: getopt->parameter-list argc argv optnames arities types
aliases desc ... |
Returns ARGV converted to a parameter-list. OPTNAMES are the
parameter-names. ARITIES and TYPES are lists of symbols |
corresponding to OPTNAMES. |
|
ALIASES is a list of lists of strings or integers paired with |
elements of OPTNAMES. Each one-character string will be treated |
as a single `-' option by `getopt'. Longer strings will be |
treated as long-named options (*note getopt-: Getopt.). |
|
If the ALIASES association list has only strings as its `car's, |
then all the option-arguments after an option (and before the next |
option) are adjoined to that option. |
|
If the ALIASES association list has integers, then each (string) |
option will take at most one option-argument. Unoptioned |
arguments are collected in a list. A `-1' alias will take the |
last argument in this list; `+1' will take the first argument in |
the list. The aliases -2 then +2; -3 then +3; ... are tried so |
long as a positive or negative consecutive alias is found and |
arguments remain in the list. Finally a `0' alias, if found, |
absorbs any remaining arguments. |
|
In all cases, if unclaimed arguments remain after processing, a |
warning is signaled and #f is returned. |
- Function: getopt->arglist argc argv optnames positions arities types
defaulters checks aliases desc ... |
Like `getopt->parameter-list', but converts ARGV to an
argument-list as specified by OPTNAMES, POSITIONS, ARITIES, TYPES,
DEFAULTERS, CHECKS, and ALIASES. If the options supplied violate |
the ARITIES or CHECKS constraints, then a warning is signaled and |
#f is returned. |
These `getopt' functions can be used with SLIB relational databases.
For an example, *Note make-command-server: Database Utilities.
If errors are encountered while processing options, directions for using
the options (and argument strings DESC ...) are printed to |
`current-error-port'. |
(begin
(set! *optind* 1)
(getopt->parameter-list
2
'("cmd" "-?")
'(flag number symbols symbols string flag2 flag3 num2 num3)
'(boolean optional nary1 nary single boolean boolean nary nary)
'(boolean integer symbol symbol string boolean boolean integer integer)
'(("flag" flag)
("f" flag)
("Flag" flag2)
("B" flag3)
("optional" number)
("o" number)
("nary1" symbols)
("N" symbols)
("nary" symbols)
("n" symbols)
("single" string)
("s" string)
("a" num2)
("Abs" num3))))
-|
Usage: cmd [OPTION ARGUMENT ...] ...
-f, --flag
-o, --optional=<number>
-n, --nary=<symbols> ...
-N, --nary1=<symbols> ...
-s, --single=<string>
--Flag
-B
-a <num2> ...
--Abs=<num3> ...
ERROR: getopt->parameter-list "unrecognized option" "-?"

File: slib.info, Node: Filenames, Next: Batch, Prev: Getopt Parameter lists, Up: Programs and Arguments
Filenames
---------
`(require 'filename)' or `(require 'glob)'
- Function: filename:match?? pattern
- Function: filename:match-ci?? pattern
Returns a predicate which returns a non-false value if its string
argument matches (the string) PATTERN, false otherwise. Filename
matching is like "glob" expansion described the bash manpage,
except that names beginning with `.' are matched and `/'
characters are not treated specially.
These functions interpret the following characters specially in
PATTERN strings:
`*'
Matches any string, including the null string.
`?'
Matches any single character.
`[...]'
Matches any one of the enclosed characters. A pair of
characters separated by a minus sign (-) denotes a range; any
character lexically between those two characters, inclusive,
is matched. If the first character following the `[' is a
`!' or a `^' then any character not enclosed is matched. A
`-' or `]' may be matched by including it as the first or
last character in the set.
- Function: filename:substitute?? pattern template
- Function: filename:substitute-ci?? pattern template
Returns a function transforming a single string argument according
to glob patterns PATTERN and TEMPLATE. PATTERN and TEMPLATE must
have the same number of wildcard specifications, which need not be
identical. PATTERN and TEMPLATE may have a different number of
literal sections. If an argument to the function matches PATTERN
in the sense of `filename:match??' then it returns a copy of
TEMPLATE in which each wildcard specification is replaced by the
part of the argument matched by the corresponding wildcard
specification in PATTERN. A `*' wildcard matches the longest
leftmost string possible. If the argument does not match PATTERN
then false is returned.
TEMPLATE may be a function accepting the same number of string
arguments as there are wildcard specifications in PATTERN. In the
case of a match the result of applying TEMPLATE to a list of the
substrings matched by wildcard specifications will be returned,
otherwise TEMPLATE will not be called and `#f' will be returned.
((filename:substitute?? "scm_[0-9]*.html" "scm5c4_??.htm")
"scm_10.html")
=> "scm5c4_10.htm"
((filename:substitute?? "??" "beg?mid?end") "AZ")
=> "begAmidZend"
((filename:substitute?? "*na*" "?NA?") "banana")
=> "banaNA"
((filename:substitute?? "?*?" (lambda (s1 s2 s3) (string-append s3 s1))) "ABZ")
=> "ZA"
- Function: replace-suffix str old new
STR can be a string or a list of strings. Returns a new string
(or strings) similar to `str' but with the suffix string OLD
removed and the suffix string NEW appended. If the end of STR
does not match OLD, an error is signaled.
(replace-suffix "/usr/local/lib/slib/batch.scm" ".scm" ".c")
=> "/usr/local/lib/slib/batch.c"

File: slib.info, Node: Batch, Prev: Filenames, Up: Programs and Arguments
Batch
-----
`(require 'batch)'
The batch procedures provide a way to write and execute portable scripts
for a variety of operating systems. Each `batch:' procedure takes as
its first argument a parameter-list (*note Parameter lists::). This
parameter-list argument PARMS contains named associations. Batch
currently uses 2 of these:
`batch-port'
The port on which to write lines of the batch file.
`batch-dialect'
The syntax of batch file to generate. Currently supported are:
* unix
* dos
* vms
* amigados
* system
* *unknown*
`batch.scm' uses 2 enhanced relational tables (*note Database
Utilities::) to store information linking the names of
`operating-system's to `batch-dialect'es.
- Function: batch:initialize! database
Defines `operating-system' and `batch-dialect' tables and adds the
domain `operating-system' to the enhanced relational database
DATABASE.
- Variable: batch:platform
Is batch's best guess as to which operating-system it is running
under. `batch:platform' is set to `(software-type)' (*note
Configuration::) unless `(software-type)' is `unix', in which case
finer distinctions are made.
- Function: batch:call-with-output-script parms file proc
PROC should be a procedure of one argument. If FILE is an
output-port, `batch:call-with-output-script' writes an appropriate
header to FILE and then calls PROC with FILE as the only argument.
If FILE is a string, `batch:call-with-output-script' opens a
output-file of name FILE, writes an appropriate header to FILE,
and then calls PROC with the newly opened port as the only
argument. Otherwise, `batch:call-with-output-script' acts as if
it was called with the result of `(current-output-port)' as its
third argument.
The rest of the `batch:' procedures write (or execute if
`batch-dialect' is `system') commands to the batch port which has been
added to PARMS or `(copy-tree PARMS)' by the code:
(adjoin-parameters! PARMS (list 'batch-port PORT))
- Function: batch:command parms string1 string2 ...
Calls `batch:try-command' (below) with arguments, but signals an
error if `batch:try-command' returns `#f'.
These functions return a non-false value if the command was successfully
translated into the batch dialect and `#f' if not. In the case of the
`system' dialect, the value is non-false if the operation suceeded.
- Function: batch:try-command parms string1 string2 ...
Writes a command to the `batch-port' in PARMS which executes the
program named STRING1 with arguments STRING2 ....
- Function: batch:try-chopped-command parms arg1 arg2 ... list
breaks the last argument LIST into chunks small enough so that the
command:
ARG1 ARG2 ... CHUNK
fits withing the platform's maximum command-line length.
`batch:try-chopped-command' calls `batch:try-command' with the
command and returns non-false only if the commands all fit and
`batch:try-command' of each command line returned non-false.
- Function: batch:run-script parms string1 string2 ...
Writes a command to the `batch-port' in PARMS which executes the
batch script named STRING1 with arguments STRING2 ....
_Note:_ `batch:run-script' and `batch:try-command' are not the
same for some operating systems (VMS).
- Function: batch:comment parms line1 ...
Writes comment lines LINE1 ... to the `batch-port' in PARMS.
- Function: batch:lines->file parms file line1 ...
Writes commands to the `batch-port' in PARMS which create a file
named FILE with contents LINE1 ....
- Function: batch:delete-file parms file
Writes a command to the `batch-port' in PARMS which deletes the
file named FILE.
- Function: batch:rename-file parms old-name new-name
Writes a command to the `batch-port' in PARMS which renames the
file OLD-NAME to NEW-NAME.
In addition, batch provides some small utilities very useful for writing
scripts:
- Function: truncate-up-to path char
- Function: truncate-up-to path string
- Function: truncate-up-to path charlist
PATH can be a string or a list of strings. Returns PATH sans any
prefixes ending with a character of the second argument. This can
be used to derive a filename moved locally from elsewhere.
(truncate-up-to "/usr/local/lib/slib/batch.scm" "/")
=> "batch.scm"
- Function: string-join joiner string1 ...
Returns a new string consisting of all the strings STRING1 ... in
order appended together with the string JOINER between each
adjacent pair.
- Function: must-be-first list1 list2
Returns a new list consisting of the elements of LIST2 ordered so
that if some elements of LIST1 are `equal?' to elements of LIST2,
then those elements will appear first and in the order of LIST1.
- Function: must-be-last list1 list2
Returns a new list consisting of the elements of LIST1 ordered so
that if some elements of LIST2 are `equal?' to elements of LIST1,
then those elements will appear last and in the order of LIST2.
- Function: os->batch-dialect osname
Returns its best guess for the `batch-dialect' to be used for the
operating-system named OSNAME. `os->batch-dialect' uses the
tables added to DATABASE by `batch:initialize!'.
Here is an example of the use of most of batch's procedures:
(require 'database-utilities)
(require 'parameters)
(require 'batch)
(require 'glob)
(define batch (create-database #f 'alist-table))
(batch:initialize! batch)
(define my-parameters
(list (list 'batch-dialect (os->batch-dialect batch:platform))
(list 'platform batch:platform)
(list 'batch-port (current-output-port)))) ;gets filled in later
(batch:call-with-output-script
my-parameters
"my-batch"
(lambda (batch-port)
(adjoin-parameters! my-parameters (list 'batch-port batch-port))
(and
(batch:comment my-parameters
"================ Write file with C program.")
(batch:rename-file my-parameters "hello.c" "hello.c~")
(batch:lines->file my-parameters "hello.c"
"#include <stdio.h>"
"int main(int argc, char **argv)"
"{"
" printf(\"hello world\\n\");"
" return 0;"
"}" )
(batch:command my-parameters "cc" "-c" "hello.c")
(batch:command my-parameters "cc" "-o" "hello"
(replace-suffix "hello.c" ".c" ".o"))
(batch:command my-parameters "hello")
(batch:delete-file my-parameters "hello")
(batch:delete-file my-parameters "hello.c")
(batch:delete-file my-parameters "hello.o")
(batch:delete-file my-parameters "my-batch")
)))
Produces the file `my-batch':
#!/bin/sh
# "my-batch" script created by SLIB/batch Sun Oct 31 18:24:10 1999
# ================ Write file with C program.
mv -f hello.c hello.c~
rm -f hello.c
echo '#include <stdio.h>'>>hello.c
echo 'int main(int argc, char **argv)'>>hello.c
echo '{'>>hello.c
echo ' printf("hello world\n");'>>hello.c
echo ' return 0;'>>hello.c
echo '}'>>hello.c
cc -c hello.c
cc -o hello hello.o
hello
rm -f hello
rm -f hello.c
rm -f hello.o
rm -f my-batch
When run, `my-batch' prints:
bash$ my-batch
mv: hello.c: No such file or directory
hello world

File: slib.info, Node: HTML, Next: HTML Tables, Prev: Programs and Arguments, Up: Textual Conversion Packages
HTML
====
`(require 'html-form)'
- Function: html:atval txt
Returns a string with character substitutions appropriate to send
TXT as an "attribute-value".
- Function: html:plain txt
Returns a string with character substitutions appropriate to send
TXT as an "plain-text".
- Function: html:meta name content |
Returns a tag of meta-information suitable for passing as the |
third argument to `html:head'. The tag produced is `<META |
NAME="NAME" CONTENT="CONTENT">'. The string or symbol NAME can be |
`author', `copyright', `keywords', `description', `date', |
`robots', .... |
|
- Function: html:http-equiv name content |
Returns a tag of HTTP information suitable for passing as the |
third argument to `html:head'. The tag produced is `<META |
HTTP-EQUIV="NAME" CONTENT="CONTENT">'. The string or symbol NAME |
can be `Expires', `PICS-Label', `Content-Type', `Refresh', .... |
|
- Function: html:meta-refresh delay uri |
- Function: html:meta-refresh delay |
Returns a tag suitable for passing as the third argument to |
`html:head'. If URI argument is supplied, then DELAY seconds after |
displaying the page with this tag, Netscape or IE browsers will |
fetch and display URI. Otherwise, DELAY seconds after displaying |
the page with this tag, Netscape or IE browsers will fetch and |
redisplay this page. |
|
- Function: html:head title backlink tags ...
- Function: html:head title backlink
- Function: html:head title
Returns header string for an HTML page named TITLE. If BACKLINK |
is a string, it is used verbatim between the `H1' tags; otherwise |
TITLE is used. If string arguments TAGS ... are supplied, then |
they are included verbatim within the <HEAD> section. |
- Function: html:body body ...
Returns HTML string to end a page.
- Function: html:pre line1 line ...
Returns the strings LINE1, LINES as "PRE"formmated plain text
(rendered in fixed-width font). Newlines are inserted between
LINE1, LINES. HTML tags (`<tag>') within LINES will be visible
verbatim.
- Function: html:comment line1 line ...
Returns the strings LINE1 as HTML comments.
HTML Forms
==========
- Function: html:form method action body ... |
The symbol METHOD is either `get', `head', `post', `put', or
`delete'. The strings BODY form the body of the form. |
`html:form' returns the HTML "form".
- Function: html:hidden name value |
Returns HTML string which will cause NAME=VALUE in form. |
|
- Function: html:checkbox pname default |
Returns HTML string for check box. |
|
- Function: html:text pname default size ... |
Returns HTML string for one-line text box. |
|
- Function: html:text-area pname default-list |
Returns HTML string for multi-line text box. |
|
- Function: html:select pname arity default-list foreign-values |
Returns HTML string for pull-down menu selector. |
|
- Function: html:buttons pname arity default-list foreign-values |
Returns HTML string for any-of selector. |
|
- Function: form:submit submit-label command |
- Function: form:submit submit-label |
The string or symbol SUBMIT-LABEL appears on the button which |
submits the form. If the optional second argument COMMAND is |
given, then `*command*=COMMAND' and `*button*=SUBMIT-LABEL' are |
set in the query. Otherwise, `*command*=SUBMIT-LABEL' is set in |
the query. |
|
- Function: form:image submit-label image-src |
The IMAGE-SRC appears on the button which submits the form. |
|
- Function: form:reset |
Returns a string which generates a "reset" button. |
|
- Function: form:element pname arity default-list foreign-values |
Returns a string which generates an INPUT element for the field |
named PNAME. The element appears in the created form with its |
representation determined by its ARITY and domain. For domains |
which are foreign-keys: |
|
`single' |
select menu |
|
`optional' |
select menu |
|
`nary' |
check boxes |
|
`nary1' |
check boxes |
|
If the foreign-key table has a field named `visible-name', then |
the contents of that field are the names visible to the user for |
those choices. Otherwise, the foreign-key itself is visible. |
|
For other types of domains: |
|
`single' |
text area |
|
`optional' |
text area |
|
`boolean' |
check box |
|
`nary' |
text area |
|
`nary1' |
text area |
|
- Function: form:delimited pname doc aliat arity default-list |
foreign-values |
Returns a HTML string for a form element embedded in a line of a |
delimited list. Apply map `form:delimited' to the list returned by |
`command->p-specs'. |
|
- Function: command->p-specs rdb command-table command |
The symbol COMMAND-TABLE names a command table in the RDB
relational database. The symbol COMMAND names a key in |
COMMAND-TABLE. |
`command->p-specs' returns a list of lists of PNAME, DOC, ALIAT, |
ARITY, DEFAULT-LIST, and FOREIGN-VALUES. The returned list has |
one element for each parameter of command COMMAND. |
This example demonstrates how to create a HTML-form for the `build'
command.
(require (in-vicinity (implementation-vicinity) "build.scm"))
(call-with-output-file "buildscm.html"
(lambda (port)
(display
(string-append
(html:head 'commands)
(html:body
(sprintf #f "<H2>%s:</H2><BLOCKQUOTE>%s</BLOCKQUOTE>\\n" |
(html:plain 'build) |
(html:plain ((comtab 'get 'documentation) 'build))) |
(html:form |
'post |
(or "http://localhost:8081/buildscm" "/cgi-bin/build.cgi") |
(apply html:delimited-list |
(apply map form:delimited |
(command->p-specs build '*commands* 'build))) |
(form:submit 'build) |
(form:reset)))) |
port)))

File: slib.info, Node: HTML Tables, Next: HTTP and CGI, Prev: HTML, Up: Textual Conversion Packages
HTML Tables
===========
`(require 'db->html)'
- Function: html:table options row ... |
|
- Function: html:caption caption align |
- Function: html:caption caption |
ALIGN can be `top' or `bottom'. |
- Function: html:heading columns
Outputs a heading row for the currently-started table.
- Function: html:href-heading columns uris |
Outputs a heading row with column-names COLUMNS linked to URIs |
URIS. |
- Function: html:linked-row-converter k foreigns |
The positive integer K is the primary-key-limit (number of
primary-keys) of the table. FOREIGNS is a list of the filenames of
foreign-key field pages and #f for non foreign-key fields.
`html:linked-row-converter' returns a procedure taking a row for |
its single argument. This returned procedure returns the html |
string for that table row. |
- Function: table-name->filename table-name
Returns the symbol TABLE-NAME converted to a filename.
- Function: table->linked-html caption db table-name match-key1 ... |
Returns HTML string for DB table TABLE-NAME. Every foreign-key |
value is linked to the page (of the table) defining that key. |
The optional MATCH-KEY1 ... arguments restrict actions to a subset
of the table. *Note match-key: Table Operations.
- Function: table->linked-page db table-name index-filename arg ... |
Returns a complete HTML page. The string INDEX-FILENAME names the
page which refers to this one.
The optional ARGS ... arguments restrict actions to a subset of
the table. *Note match-key: Table Operations.
- Function: catalog->html db caption arg ...
Returns HTML string for the catalog table of DB.
HTML editing tables |
------------------- |
|
A client can modify one row of an editable table at a time. For any |
change submitted, these routines check if that row has been modified |
during the time the user has been editing the form. If so, an error |
page results. |
|
The behavior of edited rows is: |
|
* If no fields are changed, then no change is made to the table. |
|
* If the primary keys equal null-keys (parameter defaults), and no |
other user has modified that row, then that row is deleted. |
|
* If only primary keys are changed, there are non-key fields, and no |
row with the new keys is in the table, then the old row is deleted |
and one with the new keys is inserted. |
|
* If only non-key fields are changed, and that row has not been |
modified by another user, then the row is changed to reflect the |
fields. |
|
* If both keys and non-key fields are changed, and no row with the |
new keys is in the table, then a row is created with the new keys |
and fields. |
|
* If fields are changed, all fields are primary keys, and no row with |
the new keys is in the table, then a row is created with the new |
keys. |
|
After any change to the table, a `sync-database' of the database is |
performed. |
|
- Function: command:modify-table table-name null-keys update delete |
retrieve |
- Function: command:modify-table table-name null-keys update delete |
- Function: command:modify-table table-name null-keys update |
- Function: command:modify-table table-name null-keys |
Returns procedure (of DB) which returns procedure to modify row of |
TABLE-NAME. NULL-KEYS is the list of "null" keys which indicate |
that the row is to be deleted. Optional arguments UPDATE, DELETE, |
and RETRIEVE default to the `row:update', `row:delete', and |
`row:retrieve' of TABLE-NAME in DB. |
|
- Function: command:make-editable-table rdb table-name arg ... |
Given TABLE-NAME in RDB, creates parameter and `*command*' tables |
for editing one row of TABLE-NAME at a time. |
`command:make-editable-table' returns a procedure taking a row |
argument which returns the HTML string for editing that row. |
|
Optional ARGS are expressions (lists) added to the call to |
`command:modify-table'. |
|
The domain name of a column determines the expected arity of the |
data stored in that column. Domain names ending in: |
|
`*' |
have arity `nary'; |
|
`+' |
have arity `nary1'. |
|
- Function: html:editable-row-converter k names edit-point |
edit-converter |
The positive integer K is the primary-key-limit (number of |
primary-keys) of the table. NAMES is a list of the field-names. |
EDIT-POINT is the list of primary-keys denoting the row to edit |
(or #f). EDIT-CONVERTER is the procedure called with K, NAMES, |
and the row to edit. |
|
`html:editable-row-converter' returns a procedure taking a row for |
its single argument. This returned procedure returns the html |
string for that table row. |
|
Each HTML table constructed using `html:editable-row-converter' |
has first K fields (typically the primary key fields) of each row |
linked to a text encoding of these fields (the result of calling |
`row->anchor'). The page so referenced typically allows the user |
to edit fields of that row. |
HTML databases
--------------
- Function: db->html-files db dir index-filename caption |
DB must be a relational database. DIR must be #f or a non-empty
string naming an existing sub-directory of the current directory.
`db->html-files' creates an html page for each table in the |
database DB in the sub-directory named DIR, or the current |
directory if DIR is #f. The top level page with the catalog of |
tables (captioned CAPTION) is written to a file named |
INDEX-FILENAME. |
- Function: db->html-directory db dir index-filename |
- Function: db->html-directory db dir |
DB must be a relational database. DIR must be a non-empty string
naming an existing sub-directory of the current directory or one
to be created. The optional string INDEX-FILENAME names the
filename of the top page, which defaults to `index.html'.
`db->html-directory' creates sub-directory DIR if neccessary, and |
calls `(db->html-files DB DIR INDEX-FILENAME DIR)'. The `file:' |
URI of INDEX-FILENAME is returned. |
- Function: db->netscape db dir index-filename
- Function: db->netscape db dir
`db->netscape' is just like `db->html-directory', but calls |
`browse-url-netscape' with the uri for the top page after the |
pages are created.

File: slib.info, Node: HTTP and CGI, Next: URI, Prev: HTML Tables, Up: Textual Conversion Packages
|
HTTP and CGI
============
`(require 'http)' or `(require 'cgi)'
|
- Function: http:header alist
Returns a string containing lines for each element of ALIST; the
`car' of which is followed by `: ', then the `cdr'.
- Function: http:content alist body ...
Returns the concatenation of strings BODY with the `(http:header
ALIST)' and the `Content-Length' prepended.
- Variable: *http:byline*
String appearing at the bottom of error pages.
- Function: http:error-page status-code reason-phrase html-string ...
STATUS-CODE and REASON-PHRASE should be an integer and string as
specified in `RFC 2068'. The returned page (string) will show the
STATUS-CODE and REASON-PHRASE and any additional HTML-STRINGS ...;
with *HTTP:BYLINE* or SLIB's default at the bottom.
- Function: http:forwarding-page title delay uri html-string ... |
The string or symbol TITLE is the page title. DELAY is a |
non-negative integer. The HTML-STRINGS ... are typically used to |
explain to the user why this page is being forwarded. |
|
`http:forwarding-page' returns an HTML string for a page which |
automatically forwards to URI after DELAY seconds. The returned |
page (string) contains any HTML-STRINGS ... followed by a manual |
link to URI, in case the browser does not forward automatically. |
|
- Function: http:serve-query serve-proc input-port output-port
reads the "URI" and "query-string" from INPUT-PORT. If the query
is a valid `"POST"' or `"GET"' query, then `http:serve-query' calls
SERVE-PROC with three arguments, the REQUEST-LINE, QUERY-STRING,
and HEADER-ALIST. Otherwise, `http:serve-query' calls SERVE-PROC
with the REQUEST-LINE, #f, and HEADER-ALIST.
If SERVE-PROC returns a string, it is sent to OUTPUT-PORT. If
SERVE-PROC returns a list, then an error page with number 525 and
strings from the list. If SERVE-PROC returns #f, then a `Bad
Request' (400) page is sent to OUTPUT-PORT.
Otherwise, `http:serve-query' replies (to OUTPUT-PORT) with
appropriate HTML describing the problem.
This example services HTTP queries from PORT-NUMBER:
(define socket (make-stream-socket AF_INET 0))
(and (socket:bind socket port-number) ; AF_INET INADDR_ANY
(socket:listen socket 10) ; Queue up to 10 requests.
(dynamic-wind
(lambda () #f)
(lambda ()
(do ((port (socket:accept socket) (socket:accept socket)))
(#f)
(let ((iport (duplicate-port port "r"))
(oport (duplicate-port port "w")))
(http:serve-query build:serve iport oport)
(close-port iport)
(close-port oport))
(close-port port)))
(lambda () (close-port socket))))
- Function: cgi:serve-query serve-proc
reads the "URI" and "query-string" from `(current-input-port)'.
If the query is a valid `"POST"' or `"GET"' query, then
`cgi:serve-query' calls SERVE-PROC with three arguments, the
REQUEST-LINE, QUERY-STRING, and HEADER-ALIST. Otherwise,
`cgi:serve-query' calls SERVE-PROC with the REQUEST-LINE, #f, and
HEADER-ALIST.
If SERVE-PROC returns a string, it is sent to
`(current-input-port)'. If SERVE-PROC returns a list, then an
error page with number 525 and strings from the list. If
SERVE-PROC returns #f, then a `Bad Request' (400) page is sent to
`(current-input-port)'.
Otherwise, `cgi:serve-query' replies (to `(current-input-port)')
with appropriate HTML describing the problem.
- Function: make-query-alist-command-server rdb command-table |
- Function: make-query-alist-command-server rdb command-table #t |
Returns a procedure of one argument. When that procedure is called
with a QUERY-ALIST (as returned by `uri:decode-query', the value |
of the `*command*' association will be the command invoked in |
COMMAND-TABLE. If `*command*' is not in the QUERY-ALIST then the |
value of `*suggest*' is tried. If neither name is in the |
QUERY-ALIST, then the literal value `*default*' is tried in |
COMMAND-TABLE. |
|
If optional third argument is non-false, then the command is called |
with just the parameter-list; otherwise, command is called with the |
arguments described in its table. |
|

File: slib.info, Node: URI, Next: Printing Scheme, Prev: HTTP and CGI, Up: Textual Conversion Packages
|
URI |
=== |
|
`(require 'uri)' |
|
Implements "Uniform Resource Identifiers" (URI) as described in RFC |
2396. |
|
- Function: make-uri |
- Function: make-uri fragment |
- Function: make-uri query fragment |
- Function: make-uri path query fragment |
- Function: make-uri authority path query fragment |
- Function: make-uri scheme authority path query fragment |
Returns a Uniform Resource Identifier string from component |
arguments. |
|
- Function: html:anchor name |
Returns a string which defines this location in the (HTML) file as |
NAME. The hypertext `<A HREF="#NAME">' will link to this point. |
|
(html:anchor "(section 7)") |
=> |
"<A NAME=\"(section%207)\"></A>" |
|
- Function: html:link uri highlighted |
Returns a string which links the HIGHLIGHTED text to URI. |
|
(html:link (make-uri "(section 7)") "section 7") |
=> |
"<A HREF=\"#(section%207)\">section 7</A>" |
|
- Function: html:base uri |
Returns a string specifying the "base" URI of a document, for |
inclusion in the HEAD of the document (*note head: HTML.). |
|
- Function: html:isindex prompt |
Returns a string specifying the search PROMPT of a document, for |
inclusion in the HEAD of the document (*note head: HTML.). |
|
- Function: uri->tree uri-reference base-tree ... |
Returns a list of 5 elements corresponding to the parts (SCHEME |
AUTHORITY PATH QUERY FRAGMENT) of string URI-REFERENCE. Elements |
corresponding to absent parts are #f. |
|
The PATH is a list of strings. If the first string is empty, then |
the path is absolute; otherwise relative. |
|
If the AUTHORITY component is a "Server-based Naming Authority", |
then it is a list of the USERINFO, HOST, and PORT strings (or #f). |
For other types of AUTHORITY components the AUTHORITY will be a |
string. |
|
(uri->tree "http://www.ics.uci.edu/pub/ietf/uri/#Related") |
=> |
(http "www.ics.uci.edu" ("" "pub" "ietf" "uri" "") #f "Related") |
|
`uric:' prefixes indicate procedures dealing with URI-components. |
|
- Function: uric:encode uri-component allows |
Returns a copy of the string URI-COMPONENT in which all "unsafe" |
octets (as defined in RFC 2396) have been `%' "escaped". |
`uric:decode' decodes strings encoded by `uric:encode'. |
|
- Function: uric:decode uri-component |
Returns a copy of the string URI-COMPONENT in which each `%' |
escaped characters in URI-COMPONENT is replaced with the character |
it encodes. This routine is useful for showing URI contents on |
error pages. |

File: slib.info, Node: Printing Scheme, Next: Time and Date, Prev: URI, Up: Textual Conversion Packages
|
Printing Scheme
===============
* Menu:
* Generic-Write:: 'generic-write
* Object-To-String:: 'object->string
* Pretty-Print:: 'pretty-print, 'pprint-file

File: slib.info, Node: Generic-Write, Next: Object-To-String, Prev: Printing Scheme, Up: Printing Scheme
Generic-Write
-------------
`(require 'generic-write)'
`generic-write' is a procedure that transforms a Scheme data value
(or Scheme program expression) into its textual representation and
prints it. The interface to the procedure is sufficiently general to
easily implement other useful formatting procedures such as pretty
printing, output to a string and truncated output.
- Procedure: generic-write obj display? width output
OBJ
Scheme data value to transform.
DISPLAY?
Boolean, controls whether characters and strings are quoted.
WIDTH
Extended boolean, selects format:
#f
single line format
integer > 0
pretty-print (value = max nb of chars per line)
OUTPUT
Procedure of 1 argument of string type, called repeatedly with
successive substrings of the textual representation. This
procedure can return `#f' to stop the transformation.
The value returned by `generic-write' is undefined.
Examples:
(write obj) == (generic-write obj #f #f DISPLAY-STRING)
(display obj) == (generic-write obj #t #f DISPLAY-STRING)
where
DISPLAY-STRING ==
(lambda (s) (for-each write-char (string->list s)) #t)

File: slib.info, Node: Object-To-String, Next: Pretty-Print, Prev: Generic-Write, Up: Printing Scheme
Object-To-String
----------------
`(require 'object->string)'
- Function: object->string obj
Returns the textual representation of OBJ as a string.
- Function: object->limited-string obj limit
Returns the textual representation of OBJ as a string of length at
most LIMIT.

File: slib.info, Node: Pretty-Print, Prev: Object-To-String, Up: Printing Scheme
Pretty-Print
------------
`(require 'pretty-print)'
- Procedure: pretty-print obj
- Procedure: pretty-print obj port
`pretty-print's OBJ on PORT. If PORT is not specified,
`current-output-port' is used.
Example:
(pretty-print '((1 2 3 4 5) (6 7 8 9 10) (11 12 13 14 15)
(16 17 18 19 20) (21 22 23 24 25)))
-| ((1 2 3 4 5)
-| (6 7 8 9 10)
-| (11 12 13 14 15)
-| (16 17 18 19 20)
-| (21 22 23 24 25))
- Procedure: pretty-print->string obj |
- Procedure: pretty-print->string obj width |
Returns the string of OBJ `pretty-print'ed in WIDTH columns. If |
WIDTH is not specified, `(output-port-width)' is used. |
|
Example: |
(pretty-print->string '((1 2 3 4 5) (6 7 8 9 10) (11 12 13 14 15) |
(16 17 18 19 20) (21 22 23 24 25))) |
=> |
"((1 2 3 4 5) |
(6 7 8 9 10) |
(11 12 13 14 15) |
(16 17 18 19 20) |
(21 22 23 24 25)) |
" |
(pretty-print->string '((1 2 3 4 5) (6 7 8 9 10) (11 12 13 14 15) |
(16 17 18 19 20) (21 22 23 24 25)) |
16) |
=> |
"((1 2 3 4 5) |
(6 7 8 9 10) |
(11 |
12 |
13 |
14 |
15) |
(16 |
17 |
18 |
19 |
20) |
(21 |
22 |
23 |
24 |
25)) |
" |
|
`(require 'pprint-file)'
- Procedure: pprint-file infile
- Procedure: pprint-file infile outfile
Pretty-prints all the code in INFILE. If OUTFILE is specified,
the output goes to OUTFILE, otherwise it goes to
`(current-output-port)'.
- Function: pprint-filter-file infile proc outfile
- Function: pprint-filter-file infile proc
INFILE is a port or a string naming an existing file. Scheme
source code expressions and definitions are read from the port (or
file) and PROC is applied to them sequentially.
OUTFILE is a port or a string. If no OUTFILE is specified then
`current-output-port' is assumed. These expanded expressions are
then `pretty-print'ed to this port.
Whitepsace and comments (introduced by `;') which are not part of
scheme expressions are reproduced in the output. This procedure
does not affect the values returned by `current-input-port' and
`current-output-port'.
`pprint-filter-file' can be used to pre-compile macro-expansion and
thus can reduce loading time. The following will write into
`exp-code.scm' the result of expanding all defmacros in `code.scm'.
(require 'pprint-file)
(require 'defmacroexpand)
(defmacro:load "my-macros.scm")
(pprint-filter-file "code.scm" defmacro:expand* "exp-code.scm")

File: slib.info, Node: Time and Date, Next: Vector Graphics, Prev: Printing Scheme, Up: Textual Conversion Packages
Time and Date
=============
* Menu:
* Time Zone::
* Posix Time:: 'posix-time
* Common-Lisp Time:: 'common-lisp-time
If `(provided? 'current-time)':
The procedures `current-time', `difftime', and `offset-time' deal with
a "calendar time" datatype which may or may not be disjoint from other
Scheme datatypes.
- Function: current-time
Returns the time since 00:00:00 GMT, January 1, 1970, measured in
seconds. Note that the reference time is different from the
reference time for `get-universal-time' in *Note Common-Lisp
Time::.
- Function: difftime caltime1 caltime0
Returns the difference (number of seconds) between twe calendar
times: CALTIME1 - CALTIME0. CALTIME0 may also be a number.
- Function: offset-time caltime offset
Returns the calendar time of CALTIME offset by OFFSET number of
seconds `(+ caltime offset)'.

File: slib.info, Node: Time Zone, Next: Posix Time, Prev: Time and Date, Up: Time and Date
Time Zone
---------
(require 'time-zone)
- Data Format: TZ-string
POSIX standards specify several formats for encoding time-zone
rules.
:<pathname>
If the first character of <pathname> is `/', then <pathname>
specifies the absolute pathname of a tzfile(5) format
time-zone file. Otherwise, <pathname> is interpreted as a
pathname within TZFILE:VICINITY (/usr/lib/zoneinfo/) naming a
tzfile(5) format time-zone file.
<std><offset>
The string <std> consists of 3 or more alphabetic characters.
<offset> specifies the time difference from GMT. The <offset>
is positive if the local time zone is west of the Prime
Meridian and negative if it is east. <offset> can be the
number of hours or hours and minutes (and optionally seconds)
separated by `:'. For example, `-4:30'.
<std><offset><dst>
<dst> is the at least 3 alphabetic characters naming the local
daylight-savings-time.
<std><offset><dst><doffset>
<doffset> specifies the offset from the Prime Meridian when
daylight-savings-time is in effect.
The non-tzfile formats can optionally be followed by transition
times specifying the day and time when a zone changes from
standard to daylight-savings and back again.
,<date>/<time>,<date>/<time>
The <time>s are specified like the <offset>s above, except
that leading `+' and `-' are not allowed.
Each <date> has one of the formats:
J<day>
specifies the Julian day with <day> between 1 and 365.
February 29 is never counted and cannot be referenced.
<day>
This specifies the Julian day with n between 0 and 365.
February 29 is counted in leap years and can be
specified.
M<month>.<week>.<day>
This specifies day <day> (0 <= <day> <= 6) of week
<week> (1 <= <week> <= 5) of month <month> (1 <= <month>
<= 12). Week 1 is the first week in which day d occurs
and week 5 is the last week in which day <day> occurs.
Day 0 is a Sunday.
- Data Type: time-zone
is a datatype encoding how many hours from Greenwich Mean Time the
local time is, and the "Daylight Savings Time" rules for changing
it.
- Function: time-zone TZ-string
Creates and returns a time-zone object specified by the string
TZ-STRING. If `time-zone' cannot interpret TZ-STRING, `#f' is
returned.
- Function: tz:params caltime tz
TZ is a time-zone object. `tz:params' returns a list of three
items:
0. An integer. 0 if standard time is in effect for timezone TZ
at CALTIME; 1 if daylight savings time is in effect for
timezone TZ at CALTIME.
1. The number of seconds west of the Prime Meridian timezone TZ
is at CALTIME.
2. The name for timezone TZ at CALTIME.
`tz:params' is unaffected by the default timezone; inquiries can be
made of any timezone at any calendar time.
The rest of these procedures and variables are provided for POSIX
compatability. Because of shared state they are not thread-safe.
- Function: tzset
Returns the default time-zone.
- Function: tzset tz
Sets (and returns) the default time-zone to TZ.
- Function: tzset TZ-string
Sets (and returns) the default time-zone to that specified by
TZ-STRING.
`tzset' also sets the variables *TIMEZONE*, DAYLIGHT?, and TZNAME.
This function is automatically called by the time conversion
procedures which depend on the time zone (*note Time and Date::).
- Variable: *timezone*
Contains the difference, in seconds, between Greenwich Mean Time
and local standard time (for example, in the U.S. Eastern time
zone (EST), timezone is 5*60*60). `*timezone*' is initialized by
`tzset'.
- Variable: daylight?
is `#t' if the default timezone has rules for "Daylight Savings
Time". _Note:_ DAYLIGHT? does not tell you when Daylight Savings
Time is in effect, just that the default zone sometimes has
Daylight Savings Time.
- Variable: tzname
is a vector of strings. Index 0 has the abbreviation for the
standard timezone; If DAYLIGHT?, then index 1 has the abbreviation
for the Daylight Savings timezone.

File: slib.info, Node: Posix Time, Next: Common-Lisp Time, Prev: Time Zone, Up: Time and Date
Posix Time
----------
(require 'posix-time)
- Data Type: Calendar-Time
is a datatype encapsulating time.
- Data Type: Coordinated Universal Time
(abbreviated "UTC") is a vector of integers representing time:
0. seconds (0 - 61)
1. minutes (0 - 59)
2. hours since midnight (0 - 23)
3. day of month (1 - 31)
4. month (0 - 11). Note difference from
`decode-universal-time'.
5. the number of years since 1900. Note difference from
`decode-universal-time'.
6. day of week (0 - 6)
7. day of year (0 - 365)
8. 1 for daylight savings, 0 for regular time
- Function: gmtime caltime
Converts the calendar time CALTIME to UTC and returns it.
- Function: localtime caltime tz
Returns CALTIME converted to UTC relative to timezone TZ.
- Function: localtime caltime
converts the calendar time CALTIME to a vector of integers
expressed relative to the user's time zone. `localtime' sets the
variable *TIMEZONE* with the difference between Coordinated
Universal Time (UTC) and local standard time in seconds (*note
tzset: Time Zone.).
- Function: gmktime univtime
Converts a vector of integers in GMT Coordinated Universal Time
(UTC) format to a calendar time.
- Function: mktime univtime
Converts a vector of integers in local Coordinated Universal Time
(UTC) format to a calendar time.
- Function: mktime univtime tz
Converts a vector of integers in Coordinated Universal Time (UTC)
format (relative to time-zone TZ) to calendar time.
- Function: asctime univtime
Converts the vector of integers CALTIME in Coordinated Universal
Time (UTC) format into a string of the form `"Wed Jun 30 21:49:08
1993"'.
- Function: gtime caltime
- Function: ctime caltime
- Function: ctime caltime tz
Equivalent to `(asctime (gmtime CALTIME))', `(asctime (localtime
CALTIME))', and `(asctime (localtime CALTIME TZ))', respectively.

File: slib.info, Node: Common-Lisp Time, Prev: Posix Time, Up: Time and Date
Common-Lisp Time
----------------
- Function: get-decoded-time
Equivalent to `(decode-universal-time (get-universal-time))'.
- Function: get-universal-time
Returns the current time as "Universal Time", number of seconds
since 00:00:00 Jan 1, 1900 GMT. Note that the reference time is
different from `current-time'.
- Function: decode-universal-time univtime
Converts UNIVTIME to "Decoded Time" format. Nine values are
returned:
0. seconds (0 - 61)
1. minutes (0 - 59)
2. hours since midnight
3. day of month
4. month (1 - 12). Note difference from `gmtime' and
`localtime'.
5. year (A.D.). Note difference from `gmtime' and `localtime'.
6. day of week (0 - 6)
7. #t for daylight savings, #f otherwise
8. hours west of GMT (-24 - +24)
Notice that the values returned by `decode-universal-time' do not
match the arguments to `encode-universal-time'.
- Function: encode-universal-time second minute hour date month year
- Function: encode-universal-time second minute hour date month year
time-zone
Converts the arguments in Decoded Time format to Universal Time
format. If TIME-ZONE is not specified, the returned time is
adjusted for daylight saving time. Otherwise, no adjustment is
performed.
Notice that the values returned by `decode-universal-time' do not
match the arguments to `encode-universal-time'.

File: slib.info, Node: Vector Graphics, Next: Schmooz, Prev: Time and Date, Up: Textual Conversion Packages
Vector Graphics
===============
* Menu:
* Tektronix Graphics Support::

File: slib.info, Node: Tektronix Graphics Support, Prev: Vector Graphics, Up: Vector Graphics
Tektronix Graphics Support
--------------------------
_Note:_ The Tektronix graphics support files need more work, and are
not complete.
Tektronix 4000 Series Graphics
..............................
The Tektronix 4000 series graphics protocol gives the user a 1024 by
1024 square drawing area. The origin is in the lower left corner of the
screen. Increasing y is up and increasing x is to the right.
The graphics control codes are sent over the current-output-port and
can be mixed with regular text and ANSI or other terminal control
sequences.
- Procedure: tek40:init
- Procedure: tek40:graphics
- Procedure: tek40:text
- Procedure: tek40:linetype linetype
- Procedure: tek40:move x y
- Procedure: tek40:draw x y
- Procedure: tek40:put-text x y str
- Procedure: tek40:reset
Tektronix 4100 Series Graphics
..............................
The graphics control codes are sent over the current-output-port and
can be mixed with regular text and ANSI or other terminal control
sequences.
- Procedure: tek41:init
- Procedure: tek41:reset
- Procedure: tek41:graphics
- Procedure: tek41:move x y
- Procedure: tek41:draw x y
- Procedure: tek41:point x y number
- Procedure: tek41:encode-x-y x y
- Procedure: tek41:encode-int number

File: slib.info, Node: Schmooz, Prev: Vector Graphics, Up: Textual Conversion Packages
Schmooz
=======
"Schmooz" is a simple, lightweight markup language for interspersing
Texinfo documentation with Scheme source code. Schmooz does not create
the top level Texinfo file; it creates `txi' files which can be
imported into the documentation using the Texinfo command `@include'.
`(require 'schmooz)' defines the function `schmooz', which is used to
process files. Files containing schmooz documentation should not
contain `(require 'schmooz)'.
- Procedure: schmooz filenamescm ...
FILENAMEscm should be a string ending with `scm' naming an
existing file containing Scheme source code. `schmooz' extracts
top-level comments containing schmooz commands from FILENAMEscm
and writes the converted Texinfo source to a file named
FILENAMEtxi.
- Procedure: schmooz filenametexi ...
- Procedure: schmooz filenametex ...
- Procedure: schmooz filenametxi ...
FILENAME should be a string naming an existing file containing
Texinfo source code. For every occurrence of the string `@include
FILENAMEtxi' within that file, `schmooz' calls itself with the
argument `FILENAMEscm'.
Schmooz comments are distinguished (from non-schmooz comments) by
their first line, which must start with an at-sign (@) preceded by one
or more semicolons (;). A schmooz comment ends at the first subsequent
line which does _not_ start with a semicolon. Currently schmooz
comments are recognized only at top level.
Schmooz comments are copied to the Texinfo output file with the
leading contiguous semicolons removed. Certain character sequences
starting with at-sign are treated specially. Others are copied
unchanged.
A schmooz comment starting with `@body' must be followed by a Scheme
definition. All comments between the `@body' line and the definition
will be included in a Texinfo definition, either a `@defun' or a
`@defvar', depending on whether a procedure or a variable is being
defined.
Within the text of that schmooz comment, at-sign followed by `0' will
be replaced by `@code{procedure-name}' if the following definition is
of a procedure; or `@var{variable}' if defining a variable.
An at-sign followed by a non-zero digit will expand to the variable
citation of that numbered argument: `@var{argument-name}'.
If more than one definition follows a `@body' comment line without an
intervening blank or comment line, then those definitions will be
included in the same Texinfo definition using `@defvarx' or `@defunx',
depending on whether the first definition is of a variable or of a
procedure.
Schmooz can figure out whether a definition is of a procedure if it
is of the form:
`(define (<identifier> <arg> ...) <expression>)'
or if the left hand side of the definition is some form ending in a
lambda expression. Obviously, it can be fooled. In order to force
recognition of a procedure definition, start the documentation with
`@args' instead of `@body'. `@args' should be followed by the argument
list of the function being defined, which may be enclosed in
parentheses and delimited by whitespace, (as in Scheme), enclosed in
braces and separated by commas, (as in Texinfo), or consist of the
remainder of the line, separated by whitespace.
For example:
;;@args arg1 args ...
;;@0 takes argument @1 and any number of @2
(define myfun (some-function-returning-magic))
Will result in:
@defun myfun arg1 args @dots{}
@code{myfun} takes argument @var{arg1} and any number of @var{args}
@end defun
`@args' may also be useful for indicating optional arguments by name.
If `@args' occurs inside a schmooz comment section, rather than at the
beginning, then it will generate a `@defunx' line with the arguments
supplied.
If the first at-sign in a schmooz comment is immediately followed by
whitespace, then the comment will be expanded to whatever follows that
whitespace. If the at-sign is followed by a non-whitespace character
then the at-sign will be included as the first character of the
expansion. This feature is intended to make it easy to include Texinfo
directives in schmooz comments.

File: slib.info, Node: Mathematical Packages, Next: Database Packages, Prev: Textual Conversion Packages, Up: Top
Mathematical Packages
*********************
* Menu:
* Bit-Twiddling:: 'logical
* Modular Arithmetic:: 'modular
* Prime Numbers:: 'factor
* Random Numbers:: 'random
* Fast Fourier Transform:: 'fft
* Cyclic Checksum:: 'make-crc
* Plotting:: 'charplot
* Root Finding:: 'root
* Minimizing:: 'minimize
* Commutative Rings:: 'commutative-ring
* Determinant:: 'determinant

File: slib.info, Node: Bit-Twiddling, Next: Modular Arithmetic, Prev: Mathematical Packages, Up: Mathematical Packages
Bit-Twiddling
=============
`(require 'logical)'
The bit-twiddling functions are made available through the use of the
`logical' package. `logical' is loaded by inserting `(require
'logical)' before the code that uses these functions. These functions
behave as though operating on integers in two's-complement
representation.
Bitwise Operations
------------------
- Function: logand n1 n1
Returns the integer which is the bit-wise AND of the two integer
arguments.
Example:
(number->string (logand #b1100 #b1010) 2)
=> "1000"
- Function: logior n1 n2
Returns the integer which is the bit-wise OR of the two integer
arguments.
Example:
(number->string (logior #b1100 #b1010) 2)
=> "1110"
- Function: logxor n1 n2
Returns the integer which is the bit-wise XOR of the two integer
arguments.
Example:
(number->string (logxor #b1100 #b1010) 2)
=> "110"
- Function: lognot n
Returns the integer which is the 2s-complement of the integer
argument.
Example:
(number->string (lognot #b10000000) 2)
=> "-10000001"
(number->string (lognot #b0) 2)
=> "-1"
- Function: bitwise-if mask n0 n1
Returns an integer composed of some bits from integer N0 and some
from integer N1. A bit of the result is taken from N0 if the
corresponding bit of integer MASK is 1 and from N1 if that bit of
MASK is 0.
- Function: logtest j k
(logtest j k) == (not (zero? (logand j k)))
(logtest #b0100 #b1011) => #f
(logtest #b0100 #b0111) => #t
- Function: logcount n
Returns the number of bits in integer N. If integer is positive,
the 1-bits in its binary representation are counted. If negative,
the 0-bits in its two's-complement binary representation are
counted. If 0, 0 is returned.
Example:
(logcount #b10101010)
=> 4
(logcount 0)
=> 0
(logcount -2)
=> 1
Bit Within Word
---------------
- Function: logbit? index j
(logbit? index j) == (logtest (integer-expt 2 index) j)
(logbit? 0 #b1101) => #t
(logbit? 1 #b1101) => #f
(logbit? 2 #b1101) => #t
(logbit? 3 #b1101) => #t
(logbit? 4 #b1101) => #f
- Function: copy-bit index from bit
Returns an integer the same as FROM except in the INDEXth bit,
which is 1 if BIT is `#t' and 0 if BIT is `#f'.
Example:
(number->string (copy-bit 0 0 #t) 2) => "1"
(number->string (copy-bit 2 0 #t) 2) => "100"
(number->string (copy-bit 2 #b1111 #f) 2) => "1011"
Fields of Bits
--------------
- Function: bit-field n start end
Returns the integer composed of the START (inclusive) through END
(exclusive) bits of N. The STARTth bit becomes the 0-th bit in
the result.
This function was called `bit-extract' in previous versions of
SLIB.
Example:
(number->string (bit-field #b1101101010 0 4) 2)
=> "1010"
(number->string (bit-field #b1101101010 4 9) 2)
=> "10110"
- Function: copy-bit-field to start end from
Returns an integer the same as TO except possibly in the START
(inclusive) through END (exclusive) bits, which are the same as
those of FROM. The 0-th bit of FROM becomes the STARTth bit of
the result.
Example:
(number->string (copy-bit-field #b1101101010 0 4 0) 2)
=> "1101100000"
(number->string (copy-bit-field #b1101101010 0 4 -1) 2)
=> "1101101111"
- Function: ash int count
Returns an integer equivalent to `(inexact->exact (floor (* INT
(expt 2 COUNT))))'.
Example:
(number->string (ash #b1 3) 2)
=> "1000"
(number->string (ash #b1010 -1) 2)
=> "101"
- Function: integer-length n
Returns the number of bits neccessary to represent N.
Example:
(integer-length #b10101010)
=> 8
(integer-length 0)
=> 0
(integer-length #b1111)
=> 4
- Function: integer-expt n k
Returns N raised to the non-negative integer exponent K.
Example:
(integer-expt 2 5)
=> 32
(integer-expt -3 3)
=> -27

File: slib.info, Node: Modular Arithmetic, Next: Prime Numbers, Prev: Bit-Twiddling, Up: Mathematical Packages
Modular Arithmetic
==================
`(require 'modular)'
- Function: extended-euclid n1 n2
Returns a list of 3 integers `(d x y)' such that d = gcd(N1, N2) =
N1 * x + N2 * y.
- Function: symmetric:modulus n
Returns `(quotient (+ -1 n) -2)' for positive odd integer N.
- Function: modulus->integer modulus
Returns the non-negative integer characteristic of the ring formed
when MODULUS is used with `modular:' procedures.
- Function: modular:normalize modulus n
Returns the integer `(modulo N (modulus->integer MODULUS))' in the
representation specified by MODULUS.
The rest of these functions assume normalized arguments; That is, the
arguments are constrained by the following table:
For all of these functions, if the first argument (MODULUS) is:
`positive?'
Work as before. The result is between 0 and MODULUS.
`zero?'
The arguments are treated as integers. An integer is returned.
`negative?'
The arguments and result are treated as members of the integers
modulo `(+ 1 (* -2 MODULUS))', but with "symmetric"
representation; i.e. `(<= (- MODULUS) N MODULUS)'.
If all the arguments are fixnums the computation will use only fixnums.
- Function: modular:invertable? modulus k
Returns `#t' if there exists an integer n such that K * n == 1 mod
MODULUS, and `#f' otherwise.
- Function: modular:invert modulus k2
Returns an integer n such that 1 = (n * K2) mod MODULUS. If K2
has no inverse mod MODULUS an error is signaled.
- Function: modular:negate modulus k2
Returns (-K2) mod MODULUS.
- Function: modular:+ modulus k2 k3
Returns (K2 + K3) mod MODULUS.
- Function: modular:- modulus k2 k3
Returns (K2 - K3) mod MODULUS.
- Function: modular:* modulus k2 k3
Returns (K2 * K3) mod MODULUS.
The Scheme code for `modular:*' with negative MODULUS is not
completed for fixnum-only implementations.
- Function: modular:expt modulus k2 k3
Returns (K2 ^ K3) mod MODULUS.

File: slib.info, Node: Prime Numbers, Next: Random Numbers, Prev: Modular Arithmetic, Up: Mathematical Packages
Prime Numbers
=============
`(require 'factor)'
- Variable: prime:prngs
PRIME:PRNGS is the random-state (*note Random Numbers::) used by
these procedures. If you call these procedures from more than one
thread (or from interrupt), `random' may complain about reentrant
calls.
_Note:_ The prime test and generation procedures implement (or use)
the Solovay-Strassen primality test. See
* Robert Solovay and Volker Strassen, `A Fast Monte-Carlo Test for
Primality', SIAM Journal on Computing, 1977, pp 84-85.
- Function: jacobi-symbol p q
Returns the value (+1, -1, or 0) of the Jacobi-Symbol of exact
non-negative integer P and exact positive odd integer Q.
- Variable: prime:trials
PRIME:TRIALS the maxinum number of iterations of Solovay-Strassen
that will be done to test a number for primality.
- Function: prime? n
Returns `#f' if N is composite; `#t' if N is prime. There is a
slight chance `(expt 2 (- prime:trials))' that a composite will
return `#t'.
- Function: primes< start count
Returns a list of the first COUNT prime numbers less than START.
If there are fewer than COUNT prime numbers less than START, then
the returned list will have fewer than START elements.
- Function: primes> start count
Returns a list of the first COUNT prime numbers greater than START.
- Function: factor k
Returns a list of the prime factors of K. The order of the
factors is unspecified. In order to obtain a sorted list do
`(sort! (factor K) <)'.

File: slib.info, Node: Random Numbers, Next: Fast Fourier Transform, Prev: Prime Numbers, Up: Mathematical Packages
Random Numbers
==============
`(require 'random)'
A pseudo-random number generator is only as good as the tests it
passes. George Marsaglia of Florida State University developed a
battery of tests named "DIEHARD"
(<http://stat.fsu.edu/~geo/diehard.html>). `diehard.c' has a bug which
the patch
<http://swissnet.ai.mit.edu/ftpdir/users/jaffer/diehard.c.pat> corrects.
SLIB's new PRNG generates 8 bits at a time. With the degenerate seed
`0', the numbers generated pass DIEHARD; but when bits are combined
from sequential bytes, tests fail. With the seed
`http://swissnet.ai.mit.edu/~jaffer/SLIB.html', all of those tests pass.
- Function: random n
- Function: random n state
Accepts a positive integer or real N and returns a number of the
same type between zero (inclusive) and N (exclusive). The values
returned by `random' are uniformly distributed from 0 to N.
The optional argument STATE must be of the type returned by
`(seed->random-state)' or `(make-random-state)'. It defaults to
the value of the variable `*random-state*'. This object is used
to maintain the state of the pseudo-random-number generator and is
altered as a side effect of calls to `random'.
- Variable: *random-state*
Holds a data structure that encodes the internal state of the
random-number generator that `random' uses by default. The nature
of this data structure is implementation-dependent. It may be
printed out and successfully read back in, but may or may not
function correctly as a random-number state object in another
implementation.
- Function: copy-random-state state
Returns a new copy of argument STATE.
- Function: copy-random-state
Returns a new copy of `*random-state*'.
- Function: seed->random-state seed
Returns a new object of type suitable for use as the value of the
variable `*random-state*' or as a second argument to `random'.
The number or string SEED is used to initialize the state. If
`seed->random-state' is called twice with arguments which are
`equal?', then the returned data structures will be `equal?'.
Calling `seed->random-state' with unequal arguments will nearly
always return unequal states.
- Function: make-random-state
- Function: make-random-state obj
Returns a new object of type suitable for use as the value of the
variable `*random-state*' or as a second argument to `random'. If
the optional argument OBJ is given, it should be a printable
Scheme object; the first 50 characters of its printed
representation will be used as the seed. Otherwise the value of
`*random-state*' is used as the seed.
If inexact numbers are supported by the Scheme implementation,
`randinex.scm' will be loaded as well. `randinex.scm' contains
procedures for generating inexact distributions.
- Function: random:uniform
- Function: random:uniform state
Returns an uniformly distributed inexact real random number in the
range between 0 and 1.
- Function: random:exp
- Function: random:exp state
Returns an inexact real in an exponential distribution with mean
1. For an exponential distribution with mean U use
`(* U (random:exp))'.
- Function: random:normal
- Function: random:normal state
Returns an inexact real in a normal distribution with mean 0 and
standard deviation 1. For a normal distribution with mean M and
standard deviation D use `(+ M (* D (random:normal)))'.
- Function: random:normal-vector! vect
- Function: random:normal-vector! vect state
Fills VECT with inexact real random numbers which are independent
and standard normally distributed (i.e., with mean 0 and variance
1).
- Function: random:hollow-sphere! vect
- Function: random:hollow-sphere! vect state
Fills VECT with inexact real random numbers the sum of whose
squares is equal to 1.0. Thinking of VECT as coordinates in space
of dimension n = `(vector-length VECT)', the coordinates are
uniformly distributed over the surface of the unit n-shere.
- Function: random:solid-sphere! vect
- Function: random:solid-sphere! vect state
Fills VECT with inexact real random numbers the sum of whose
squares is less than 1.0. Thinking of VECT as coordinates in
space of dimension N = `(vector-length VECT)', the coordinates are
uniformly distributed within the unit N-shere. The sum of the
squares of the numbers is returned.

File: slib.info, Node: Fast Fourier Transform, Next: Cyclic Checksum, Prev: Random Numbers, Up: Mathematical Packages
Fast Fourier Transform
======================
`(require 'fft)'
- Function: fft array
ARRAY is an array of `(expt 2 n)' numbers. `fft' returns an array
of complex numbers comprising the "Discrete Fourier Transform" of
ARRAY.
- Function: fft-1 array
`fft-1' returns an array of complex numbers comprising the inverse
Discrete Fourier Transform of ARRAY.
`(fft-1 (fft ARRAY))' will return an array of values close to ARRAY.
(fft '#(1 0+i -1 0-i 1 0+i -1 0-i)) =>
#(0.0 0.0 0.0+628.0783185208527e-18i 0.0
0.0 0.0 8.0-628.0783185208527e-18i 0.0)
(fft-1 '#(0 0 0 0 0 0 8 0)) =>
#(1.0 -61.23031769111886e-18+1.0i -1.0 61.23031769111886e-18-1.0i
1.0 -61.23031769111886e-18+1.0i -1.0 61.23031769111886e-18-1.0i)

File: slib.info, Node: Cyclic Checksum, Next: Plotting, Prev: Fast Fourier Transform, Up: Mathematical Packages
Cyclic Checksum
===============
`(require 'make-crc)'
- Function: make-port-crc
- Function: make-port-crc degree |
Returns an expression for a procedure of one argument, a port.
This procedure reads characters from the port until the end of
file and returns the integer checksum of the bytes read.
The integer DEGREE, if given, specifies the degree of the
polynomial being computed - which is also the number of bits
computed in the checksums. The default value is 32.
- Function: make-port-crc generator |
The integer GENERATOR specifies the polynomial being computed. |
The power of 2 generating each 1 bit is the exponent of a term of |
the polynomial. The value of GENERATOR must be larger than 127. |
|
- Function: make-port-crc degree generator |
The integer GENERATOR specifies the polynomial being computed.
The power of 2 generating each 1 bit is the exponent of a term of
the polynomial. The bit at position DEGREE is implicit and should
not be part of GENERATOR. This allows systems with numbers
limited to 32 bits to calculate 32 bit checksums. The default
value of GENERATOR when DEGREE is 32 (its default) is:
(make-port-crc 32 #b00000100110000010001110110110111)
Creates a procedure to calculate the P1003.2/D11.2 (POSIX.2) 32-bit
checksum from the polynomial:
32 26 23 22 16 12 11
( x + x + x + x + x + x + x +
10 8 7 5 4 2 1
x + x + x + x + x + x + x + 1 ) mod 2
(require 'make-crc)
(define crc32 (slib:eval (make-port-crc)))
(define (file-check-sum file) (call-with-input-file file crc32))
(file-check-sum (in-vicinity (library-vicinity) "ratize.scm"))
=> 157103930 |

File: slib.info, Node: Plotting, Next: Root Finding, Prev: Cyclic Checksum, Up: Mathematical Packages
Plotting on Character Devices
=============================
`(require 'charplot)'
The plotting procedure is made available through the use of the
`charplot' package. `charplot' is loaded by inserting `(require
'charplot)' before the code that uses this procedure.
- Variable: charplot:height
The number of rows to make the plot vertically.
- Variable: charplot:width
The number of columns to make the plot horizontally.
- Procedure: plot! coords x-label y-label
COORDS is a list of pairs of x and y coordinates. X-LABEL and
Y-LABEL are strings with which to label the x and y axes.
Example:
(require 'charplot)
(set! charplot:height 19)
(set! charplot:width 45)
(define (make-points n)
(if (zero? n)
'()
(cons (cons (/ n 6) (sin (/ n 6))) (make-points (1- n)))))
(plot! (make-points 37) "x" "Sin(x)")
-|
Sin(x) ______________________________________________
1.25|- |
| |
1|- **** |
| ** ** |
0.75|- * * |
| * * |
0.5|- * * |
| * |
0.25|- * |
| * * |
0|-------------------*--------------------------|
| * |
-0.25|- * * |
| * * |
-0.5|- * |
| * * |
-0.75|- * * |
| ** ** |
-1|- **** |
|____________:_____._____:_____._____:_________|
x 2 4 6
- Procedure: plot-function! func x1 x2
- Procedure: plot-function! func x1 x2 npts
Plots the function of one argument FUNC over the range X1 to X2.
If the optional integer argument NPTS is supplied, it specifies
the number of points to evaluate FUNC at.

File: slib.info, Node: Root Finding, Next: Minimizing, Prev: Plotting, Up: Mathematical Packages
Root Finding
============
`(require 'root)'
- Function: newtown:find-integer-root f df/dx x0
Given integer valued procedure F, its derivative (with respect to
its argument) DF/DX, and initial integer value X0 for which
DF/DX(X0) is non-zero, returns an integer X for which F(X) is
closer to zero than either of the integers adjacent to X; or
returns `#f' if such an integer can't be found.
To find the closest integer to a given integers square root:
(define (integer-sqrt y)
(newton:find-integer-root
(lambda (x) (- (* x x) y))
(lambda (x) (* 2 x))
(ash 1 (quotient (integer-length y) 2))))
(integer-sqrt 15) => 4
- Function: integer-sqrt y
Given a non-negative integer Y, returns the rounded square-root of
Y.
- Function: newton:find-root f df/dx x0 prec
Given real valued procedures F, DF/DX of one (real) argument,
initial real value X0 for which DF/DX(X0) is non-zero, and
positive real number PREC, returns a real X for which `abs'(F(X))
is less than PREC; or returns `#f' if such a real can't be found.
If PREC is instead a negative integer, `newton:find-root' returns
the result of -PREC iterations.
H. J. Orchard, `The Laguerre Method for Finding the Zeros of
Polynomials', IEEE Transactions on Circuits and Systems, Vol. 36, No.
11, November 1989, pp 1377-1381.
There are 2 errors in Orchard's Table II. Line k=2 for starting
value of 1000+j0 should have Z_k of 1.0475 + j4.1036 and line k=2
for starting value of 0+j1000 should have Z_k of 1.0988 + j4.0833.
- Function: laguerre:find-root f df/dz ddf/dz^2 z0 prec
Given complex valued procedure F of one (complex) argument, its
derivative (with respect to its argument) DF/DX, its second
derivative DDF/DZ^2, initial complex value Z0, and positive real
number PREC, returns a complex number Z for which
`magnitude'(F(Z)) is less than PREC; or returns `#f' if such a
number can't be found.
If PREC is instead a negative integer, `laguerre:find-root'
returns the result of -PREC iterations.
- Function: laguerre:find-polynomial-root deg f df/dz ddf/dz^2 z0 prec
Given polynomial procedure F of integer degree DEG of one
argument, its derivative (with respect to its argument) DF/DX, its
second derivative DDF/DZ^2, initial complex value Z0, and positive
real number PREC, returns a complex number Z for which
`magnitude'(F(Z)) is less than PREC; or returns `#f' if such a
number can't be found.
If PREC is instead a negative integer,
`laguerre:find-polynomial-root' returns the result of -PREC
iterations.
- Function: secant:find-root f x0 x1 prec
- Function: secant:find-bracketed-root f x0 x1 prec
Given a real valued procedure F and two real valued starting
points X0 and X1, returns a real X for which `(abs (f x))' is less
than PREC; or returns `#f' if such a real can't be found.
If X0 and X1 are chosen such that they bracket a root, that is
(or (< (f x0) 0 (f x1))
(< (f x1) 0 (f x0)))
then the root returned will be between X0 and X1, and F will not
be passed an argument outside of that interval.
`secant:find-bracketed-root' will return `#f' unless X0 and X1
bracket a root.
The secant method is used until a bracketing interval is found, at
which point a modified regula falsi method is used.
If PREC is instead a negative integer, `secant:find-root' returns
the result of -PREC iterations.
If PREC is a procedure it should accept 5 arguments: X0 F0 X1 F1
and COUNT, where F0 will be `(f x0)', F1 `(f x1)', and COUNT the
number of iterations performed so far. PREC should return
non-false if the iteration should be stopped.

File: slib.info, Node: Minimizing, Next: Commutative Rings, Prev: Root Finding, Up: Mathematical Packages
Minimizing
==========
`(require 'minimize)'
The Golden Section Search (1) algorithm finds minima of functions which
are expensive to compute or for which derivatives are not available.
Although optimum for the general case, convergence is slow, requiring
nearly 100 iterations for the example (x^3-2x-5).
If the derivative is available, Newton-Raphson is probably a better
choice. If the function is inexpensive to compute, consider
approximating the derivative.
- Function: golden-section-search f x0 x1 prec
X_0 are X_1 real numbers. The (single argument) procedure F is
unimodal over the open interval (X_0, X_1). That is, there is
exactly one point in the interval for which the derivative of F is
zero.
`golden-section-search' returns a pair (X . F(X)) where F(X) is
the minimum. The PREC parameter is the stop criterion. If PREC
is a positive number, then the iteration continues until X is
within PREC from the true value. If PREC is a negative integer,
then the procedure will iterate -PREC times or until convergence.
If PREC is a procedure of seven arguments, X0, X1, A, B, FA, FB,
and COUNT, then the iterations will stop when the procedure
returns `#t'.
Analytically, the minimum of x^3-2x-5 is 0.816497.
(define func (lambda (x) (+ (* x (+ (* x x) -2)) -5)))
(golden-section-search func 0 1 (/ 10000))
==> (816.4883855245578e-3 . -6.0886621077391165)
(golden-section-search func 0 1 -5)
==> (819.6601125010515e-3 . -6.088637561916407)
(golden-section-search func 0 1
(lambda (a b c d e f g ) (= g 500)))
==> (816.4965933140557e-3 . -6.088662107903635)
---------- Footnotes ----------
(1) David Kahaner, Cleve Moler, and Stephen Nash `Numerical Methods
and Software' Prentice-Hall, 1989, ISBN 0-13-627258-4

File: slib.info, Node: Commutative Rings, Next: Determinant, Prev: Minimizing, Up: Mathematical Packages
Commutative Rings
=================
Scheme provides a consistent and capable set of numeric functions.
Inexacts implement a field; integers a commutative ring (and Euclidean
domain). This package allows one to use basic Scheme numeric functions
with symbols and non-numeric elements of commutative rings.
`(require 'commutative-ring)'
The "commutative-ring" package makes the procedures `+', `-', `*',
`/', and `^' "careful" in the sense that any non-numeric arguments they
do not reduce appear in the expression output. In order to see what
working with this package is like, self-set all the single letter
identifiers (to their corresponding symbols).
(define a 'a)
...
(define z 'z)
Or just `(require 'self-set)'. Now try some sample expressions:
(+ (+ a b) (- a b)) => (* a 2)
(* (+ a b) (+ a b)) => (^ (+ a b) 2)
(* (+ a b) (- a b)) => (* (+ a b) (- a b))
(* (- a b) (- a b)) => (^ (- a b) 2)
(* (- a b) (+ a b)) => (* (+ a b) (- a b))
(/ (+ a b) (+ c d)) => (/ (+ a b) (+ c d))
(^ (+ a b) 3) => (^ (+ a b) 3)
(^ (+ a 2) 3) => (^ (+ 2 a) 3)
Associative rules have been applied and repeated addition and
multiplication converted to multiplication and exponentiation.
We can enable distributive rules, thus expanding to sum of products
form:
(set! *ruleset* (combined-rulesets distribute* distribute/))
(* (+ a b) (+ a b)) => (+ (* 2 a b) (^ a 2) (^ b 2))
(* (+ a b) (- a b)) => (- (^ a 2) (^ b 2))
(* (- a b) (- a b)) => (- (+ (^ a 2) (^ b 2)) (* 2 a b))
(* (- a b) (+ a b)) => (- (^ a 2) (^ b 2))
(/ (+ a b) (+ c d)) => (+ (/ a (+ c d)) (/ b (+ c d)))
(/ (+ a b) (- c d)) => (+ (/ a (- c d)) (/ b (- c d)))
(/ (- a b) (- c d)) => (- (/ a (- c d)) (/ b (- c d)))
(/ (- a b) (+ c d)) => (- (/ a (+ c d)) (/ b (+ c d)))
(^ (+ a b) 3) => (+ (* 3 a (^ b 2)) (* 3 b (^ a 2)) (^ a 3) (^ b 3))
(^ (+ a 2) 3) => (+ 8 (* a 12) (* (^ a 2) 6) (^ a 3))
Use of this package is not restricted to simple arithmetic
expressions:
(require 'determinant)
(determinant '((a b c) (d e f) (g h i))) =>
(- (+ (* a e i) (* b f g) (* c d h)) (* a f h) (* b d i) (* c e g))
Currently, only `+', `-', `*', `/', and `^' support non-numeric
elements. Expressions with `-' are converted to equivalent expressions
without `-', so behavior for `-' is not defined separately. `/'
expressions are handled similarly.
This list might be extended to include `quotient', `modulo',
`remainder', `lcm', and `gcd'; but these work only for the more
restrictive Euclidean (Unique Factorization) Domain.
Rules and Rulesets
==================
The "commutative-ring" package allows control of ring properties
through the use of "rulesets".
- Variable: *ruleset*
Contains the set of rules currently in effect. Rules defined by
`cring:define-rule' are stored within the value of *ruleset* at the
time `cring:define-rule' is called. If *RULESET* is `#f', then no
rules apply.
- Function: make-ruleset rule1 ...
- Function: make-ruleset name rule1 ...
Returns a new ruleset containing the rules formed by applying
`cring:define-rule' to each 4-element list argument RULE. If the
first argument to `make-ruleset' is a symbol, then the database
table created for the new ruleset will be named NAME. Calling
`make-ruleset' with no rule arguments creates an empty ruleset.
- Function: combined-rulesets ruleset1 ...
- Function: combined-rulesets name ruleset1 ...
Returns a new ruleset containing the rules contained in each
ruleset argument RULESET. If the first argument to
`combined-ruleset' is a symbol, then the database table created for
the new ruleset will be named NAME. Calling `combined-ruleset'
with no ruleset arguments creates an empty ruleset.
Two rulesets are defined by this package.
- Constant: distribute*
Contain the ruleset to distribute multiplication over addition and
subtraction.
- Constant: distribute/
Contain the ruleset to distribute division over addition and
subtraction.
Take care when using both DISTRIBUTE* and DISTRIBUTE/
simultaneously. It is possible to put `/' into an infinite loop.
You can specify how sum and product expressions containing non-numeric
elements simplify by specifying the rules for `+' or `*' for cases
where expressions involving objects reduce to numbers or to expressions
involving different non-numeric elements.
- Function: cring:define-rule op sub-op1 sub-op2 reduction
Defines a rule for the case when the operation represented by
symbol OP is applied to lists whose `car's are SUB-OP1 and
SUB-OP2, respectively. The argument REDUCTION is a procedure
accepting 2 arguments which will be lists whose `car's are SUB-OP1
and SUB-OP2.
- Function: cring:define-rule op sub-op1 'identity reduction
Defines a rule for the case when the operation represented by
symbol OP is applied to a list whose `car' is SUB-OP1, and some
other argument. REDUCTION will be called with the list whose
`car' is SUB-OP1 and some other argument.
If REDUCTION returns `#f', the reduction has failed and other
reductions will be tried. If REDUCTION returns a non-false value,
that value will replace the two arguments in arithmetic (`+', `-',
and `*') calculations involving non-numeric elements.
The operations `+' and `*' are assumed commutative; hence both
orders of arguments to REDUCTION will be tried if necessary.
The following rule is the definition for distributing `*' over `+'.
(cring:define-rule
'* '+ 'identity
(lambda (exp1 exp2)
(apply + (map (lambda (trm) (* trm exp2)) (cdr exp1))))))
How to Create a Commutative Ring
================================
The first step in creating your commutative ring is to write
procedures to create elements of the ring. A non-numeric element of
the ring must be represented as a list whose first element is a symbol
or string. This first element identifies the type of the object. A
convenient and clear convention is to make the type-identifying element
be the same symbol whose top-level value is the procedure to create it.
(define (n . list1)
(cond ((and (= 2 (length list1))
(eq? (car list1) (cadr list1)))
0)
((not (term< (first list1) (last1 list1)))
(apply n (reverse list1)))
(else (cons 'n list1))))
(define (s x y) (n x y))
(define (m . list1)
(cond ((neq? (first list1) (term_min list1))
(apply m (cyclicrotate list1)))
((term< (last1 list1) (cadr list1))
(apply m (reverse (cyclicrotate list1))))
(else (cons 'm list1))))
Define a procedure to multiply 2 non-numeric elements of the ring.
Other multiplicatons are handled automatically. Objects for which rules
have _not_ been defined are not changed.
(define (n*n ni nj)
(let ((list1 (cdr ni)) (list2 (cdr nj)))
(cond ((null? (intersection list1 list2)) #f)
((and (eq? (last1 list1) (first list2))
(neq? (first list1) (last1 list2)))
(apply n (splice list1 list2)))
((and (eq? (first list1) (first list2))
(neq? (last1 list1) (last1 list2)))
(apply n (splice (reverse list1) list2)))
((and (eq? (last1 list1) (last1 list2))
(neq? (first list1) (first list2)))
(apply n (splice list1 (reverse list2))))
((and (eq? (last1 list1) (first list2))
(eq? (first list1) (last1 list2)))
(apply m (cyclicsplice list1 list2)))
((and (eq? (first list1) (first list2))
(eq? (last1 list1) (last1 list2)))
(apply m (cyclicsplice (reverse list1) list2)))
(else #f))))
Test the procedures to see if they work.
;;; where cyclicrotate(list) is cyclic rotation of the list one step
;;; by putting the first element at the end
(define (cyclicrotate list1)
(append (rest list1) (list (first list1))))
;;; and where term_min(list) is the element of the list which is
;;; first in the term ordering.
(define (term_min list1)
(car (sort list1 term<)))
(define (term< sym1 sym2)
(string<? (symbol->string sym1) (symbol->string sym2)))
(define first car)
(define rest cdr)
(define (last1 list1) (car (last-pair list1)))
(define (neq? obj1 obj2) (not (eq? obj1 obj2)))
;;; where splice is the concatenation of list1 and list2 except that their
;;; common element is not repeated.
(define (splice list1 list2)
(cond ((eq? (last1 list1) (first list2))
(append list1 (cdr list2)))
(else (error 'splice list1 list2))))
;;; where cyclicsplice is the result of leaving off the last element of
;;; splice(list1,list2).
(define (cyclicsplice list1 list2)
(cond ((and (eq? (last1 list1) (first list2))
(eq? (first list1) (last1 list2)))
(butlast (splice list1 list2) 1))
(else (error 'cyclicsplice list1 list2))))
(N*N (S a b) (S a b)) => (m a b)
Then register the rule for multiplying type N objects by type N
objects.
(cring:define-rule '* 'N 'N N*N))
Now we are ready to compute!
(define (t)
(define detM
(+ (* (S g b)
(+ (* (S f d)
(- (* (S a f) (S d g)) (* (S a g) (S d f))))
(* (S f f)
(- (* (S a g) (S d d)) (* (S a d) (S d g))))
(* (S f g)
(- (* (S a d) (S d f)) (* (S a f) (S d d))))))
(* (S g d)
(+ (* (S f b)
(- (* (S a g) (S d f)) (* (S a f) (S d g))))
(* (S f f)
(- (* (S a b) (S d g)) (* (S a g) (S d b))))
(* (S f g)
(- (* (S a f) (S d b)) (* (S a b) (S d f))))))
(* (S g f)
(+ (* (S f b)
(- (* (S a d) (S d g)) (* (S a g) (S d d))))
(* (S f d)
(- (* (S a g) (S d b)) (* (S a b) (S d g))))
(* (S f g)
(- (* (S a b) (S d d)) (* (S a d) (S d b))))))
(* (S g g)
(+ (* (S f b)
(- (* (S a f) (S d d)) (* (S a d) (S d f))))
(* (S f d)
(- (* (S a b) (S d f)) (* (S a f) (S d b))))
(* (S f f)
(- (* (S a d) (S d b)) (* (S a b) (S d d))))))))
(* (S b e) (S c a) (S e c)
detM
))
(pretty-print (t))
-|
(- (+ (m a c e b d f g)
(m a c e b d g f)
(m a c e b f d g)
(m a c e b f g d)
(m a c e b g d f)
(m a c e b g f d))
(* 2 (m a b e c) (m d f g))
(* (m a c e b d) (m f g))
(* (m a c e b f) (m d g))
(* (m a c e b g) (m d f)))

File: slib.info, Node: Determinant, Prev: Commutative Rings, Up: Mathematical Packages
Determinant
===========
- Function: determinant square-matrix |
Returns the determinant of SQUARE-MATRIX. |
|
(require 'determinant)
(determinant '((1 2) (3 4))) => -2
(determinant '((1 2 3) (4 5 6) (7 8 9))) => 0
(determinant '((1 2 3 4) (5 6 7 8) (9 10 11 12))) => 0

File: slib.info, Node: Database Packages, Next: Other Packages, Prev: Mathematical Packages, Up: Top
Database Packages
*****************
* Menu:
* Base Table::
* Relational Database:: 'relational-database
* Weight-Balanced Trees:: 'wt-tree

File: slib.info, Node: Base Table, Next: Relational Database, Prev: Database Packages, Up: Database Packages
Base Table
==========
A base table implementation using Scheme association lists is
available as the value of the identifier `alist-table' after doing:
`(require 'alist-table)'
Association list base tables are suitable for small databases and
support all Scheme types when temporary and readable/writeable Scheme
types when saved. I hope support for other base table implementations
will be added in the future.
This rest of this section documents the interface for a base table
implementation from which the *Note Relational Database:: package
constructs a Relational system. It will be of interest primarily to
those wishing to port or write new base-table implementations.
All of these functions are accessed through a single procedure by
calling that procedure with the symbol name of the operation. A
procedure will be returned if that operation is supported and `#f'
otherwise. For example:
(require 'alist-table)
(define open-base (alist-table 'make-base))
make-base => *a procedure*
(define foo (alist-table 'foo))
foo => #f
- Function: make-base filename key-dimension column-types
Returns a new, open, low-level database (collection of tables)
associated with FILENAME. This returned database has an empty
table associated with CATALOG-ID. The positive integer
KEY-DIMENSION is the number of keys composed to make a PRIMARY-KEY
for the catalog table. The list of symbols COLUMN-TYPES describes
the types of each column for that table. If the database cannot
be created as specified, `#f' is returned.
Calling the `close-base' method on this database and possibly other
operations will cause FILENAME to be written to. If FILENAME is
`#f' a temporary, non-disk based database will be created if such
can be supported by the base table implelentation.
- Function: open-base filename mutable
Returns an open low-level database associated with FILENAME. If
MUTABLE? is `#t', this database will have methods capable of
effecting change to the database. If MUTABLE? is `#f', only
methods for inquiring the database will be available. If the
database cannot be opened as specified `#f' is returned.
Calling the `close-base' (and possibly other) method on a MUTABLE?
database will cause FILENAME to be written to.
- Function: write-base lldb filename
Causes the low-level database LLDB to be written to FILENAME. If
the write is successful, also causes LLDB to henceforth be
associated with FILENAME. Calling the `close-database' (and
possibly other) method on LLDB may cause FILENAME to be written
to. If FILENAME is `#f' this database will be changed to a
temporary, non-disk based database if such can be supported by the
underlying base table implelentation. If the operations completed
successfully, `#t' is returned. Otherwise, `#f' is returned.
- Function: sync-base lldb
Causes the file associated with the low-level database LLDB to be
updated to reflect its current state. If the associated filename
is `#f', no action is taken and `#f' is returned. If this
operation completes successfully, `#t' is returned. Otherwise,
`#f' is returned.
- Function: close-base lldb
Causes the low-level database LLDB to be written to its associated
file (if any). If the write is successful, subsequent operations
to LLDB will signal an error. If the operations complete
successfully, `#t' is returned. Otherwise, `#f' is returned.
- Function: make-table lldb key-dimension column-types
Returns the BASE-ID for a new base table, otherwise returns `#f'.
The base table can then be opened using `(open-table LLDB
BASE-ID)'. The positive integer KEY-DIMENSION is the number of
keys composed to make a PRIMARY-KEY for this table. The list of
symbols COLUMN-TYPES describes the types of each column.
- Constant: catalog-id
A constant BASE-ID suitable for passing as a parameter to
`open-table'. CATALOG-ID will be used as the base table for the
system catalog.
- Function: open-table lldb base-id key-dimension column-types
Returns a HANDLE for an existing base table in the low-level
database LLDB if that table exists and can be opened in the mode
indicated by MUTABLE?, otherwise returns `#f'.
As with `make-table', the positive integer KEY-DIMENSION is the
number of keys composed to make a PRIMARY-KEY for this table. The
list of symbols COLUMN-TYPES describes the types of each column.
- Function: kill-table lldb base-id key-dimension column-types
Returns `#t' if the base table associated with BASE-ID was removed
from the low level database LLDB, and `#f' otherwise.
- Function: make-keyifier-1 type
Returns a procedure which accepts a single argument which must be
of type TYPE. This returned procedure returns an object suitable
for being a KEY argument in the functions whose descriptions
follow.
Any 2 arguments of the supported type passed to the returned
function which are not `equal?' must result in returned values
which are not `equal?'.
- Function: make-list-keyifier key-dimension types
The list of symbols TYPES must have at least KEY-DIMENSION
elements. Returns a procedure which accepts a list of length
KEY-DIMENSION and whose types must corresopond to the types named
by TYPES. This returned procedure combines the elements of its
list argument into an object suitable for being a KEY argument in
the functions whose descriptions follow.
Any 2 lists of supported types (which must at least include
symbols and non-negative integers) passed to the returned function
which are not `equal?' must result in returned values which are not
`equal?'.
- Function: make-key-extractor key-dimension types column-number
Returns a procedure which accepts objects produced by application
of the result of `(make-list-keyifier KEY-DIMENSION TYPES)'. This
procedure returns a KEY which is `equal?' to the COLUMN-NUMBERth
element of the list which was passed to create COMBINED-KEY. The
list TYPES must have at least KEY-DIMENSION elements.
- Function: make-key->list key-dimension types
Returns a procedure which accepts objects produced by application
of the result of `(make-list-keyifier KEY-DIMENSION TYPES)'. This
procedure returns a list of KEYs which are elementwise `equal?' to
the list which was passed to create COMBINED-KEY.
In the following functions, the KEY argument can always be assumed to
be the value returned by a call to a _keyify_ routine.
In contrast, a MATCH-KEYS argument is a list of length equal to the
number of primary keys. The MATCH-KEYS restrict the actions of the
table command to those records whose primary keys all satisfy the
corresponding element of the MATCH-KEYS list. The elements and their
actions are:
`#f'
The false value matches any key in the corresponding position.
an object of type procedure
This procedure must take a single argument, the key in the
corresponding position. Any key for which the procedure
returns a non-false value is a match; Any key for which the
procedure returns a `#f' is not.
other values
Any other value matches only those keys `equal?' to it.
The KEY-DIMENSION and COLUMN-TYPES arguments are needed to decode the
combined-keys for matching with MATCH-KEYS.
- Function: for-each-key handle procedure key-dimension column-types
match-keys
Calls PROCEDURE once with each KEY in the table opened in HANDLE
which satisfy MATCH-KEYS in an unspecified order. An unspecified
value is returned.
- Function: map-key handle procedure key-dimension column-types
match-keys
Returns a list of the values returned by calling PROCEDURE once
with each KEY in the table opened in HANDLE which satisfy
MATCH-KEYS in an unspecified order.
- Function: ordered-for-each-key handle procedure key-dimension
column-types match-keys
Calls PROCEDURE once with each KEY in the table opened in HANDLE
which satisfy MATCH-KEYS in the natural order for the types of the
primary key fields of that table. An unspecified value is
returned.
- Function: delete* handle key-dimension column-types match-keys
Removes all rows which satisfy MATCH-KEYS from the table opened in
HANDLE. An unspecified value is returned.
- Function: present? handle key
Returns a non-`#f' value if there is a row associated with KEY in
the table opened in HANDLE and `#f' otherwise.
- Function: delete handle key
Removes the row associated with KEY from the table opened in
HANDLE. An unspecified value is returned.
- Function: make-getter key-dimension types
Returns a procedure which takes arguments HANDLE and KEY. This
procedure returns a list of the non-primary values of the relation
(in the base table opened in HANDLE) whose primary key is KEY if
it exists, and `#f' otherwise.
- Function: make-putter key-dimension types
Returns a procedure which takes arguments HANDLE and KEY and
VALUE-LIST. This procedure associates the primary key KEY with
the values in VALUE-LIST (in the base table opened in HANDLE) and
returns an unspecified value.
- Function: supported-type? symbol
Returns `#t' if SYMBOL names a type allowed as a column value by
the implementation, and `#f' otherwise. At a minimum, an
implementation must support the types `integer', `symbol',
`string', `boolean', and `base-id'.
- Function: supported-key-type? symbol
Returns `#t' if SYMBOL names a type allowed as a key value by the
implementation, and `#f' otherwise. At a minimum, an
implementation must support the types `integer', and `symbol'.
`integer'
Scheme exact integer.
`symbol'
Scheme symbol.
`boolean'
`#t' or `#f'.
`base-id'
Objects suitable for passing as the BASE-ID parameter to
`open-table'. The value of CATALOG-ID must be an acceptable
`base-id'.

File: slib.info, Node: Relational Database, Next: Weight-Balanced Trees, Prev: Base Table, Up: Database Packages
Relational Database
===================
`(require 'relational-database)'
This package implements a database system inspired by the Relational
Model (`E. F. Codd, A Relational Model of Data for Large Shared Data
Banks'). An SLIB relational database implementation can be created
from any *Note Base Table:: implementation.
* Menu:
* Motivations:: Database Manifesto
* Creating and Opening Relational Databases::
* Relational Database Operations::
* Table Operations::
* Catalog Representation::
* Unresolved Issues::
* Database Utilities:: 'database-utilities
* Database Reports::
* Database Browser:: 'database-browse

File: slib.info, Node: Motivations, Next: Creating and Opening Relational Databases, Prev: Relational Database, Up: Relational Database
Motivations
-----------
Most nontrivial programs contain databases: Makefiles, configure
scripts, file backup, calendars, editors, source revision control, CAD
systems, display managers, menu GUIs, games, parsers, debuggers,
profilers, and even error reporting are all rife with databases. Coding
databases is such a common activity in programming that many may not be
aware of how often they do it.
A database often starts as a dispatch in a program. The author,
perhaps because of the need to make the dispatch configurable, the need
for correlating dispatch in other routines, or because of changes or
growth, devises a data structure to contain the information, a routine
for interpreting that data structure, and perhaps routines for
augmenting and modifying the stored data. The dispatch must be
converted into this form and tested.
The programmer may need to devise an interactive program for enabling
easy examination and modification of the information contained in this
database. Often, in an attempt to foster modularity and avoid delays in
release, intermediate file formats for the database information are
devised. It often turns out that users prefer modifying these
intermediate files with a text editor to using the interactive program
in order to do operations (such as global changes) not forseen by the
program's author.
In order to address this need, the conscientious software engineer may
even provide a scripting language to allow users to make repetitive
database changes. Users will grumble that they need to read a large
manual and learn yet another programming language (even if it _almost_
has language "xyz" syntax) in order to do simple configuration.
All of these facilities need to be designed, coded, debugged,
documented, and supported; often causing what was very simple in concept
to become a major developement project.
This view of databases just outlined is somewhat the reverse of the
view of the originators of the "Relational Model" of database
abstraction. The relational model was devised to unify and allow
interoperation of large multi-user databases running on diverse
platforms. A fairly general purpose "Comprehensive Language" for
database manipulations is mandated (but not specified) as part of the
relational model for databases.
One aspect of the Relational Model of some importance is that the
"Comprehensive Language" must be expressible in some form which can be
stored in the database. This frees the programmer from having to make
programs data-driven in order to use a database.
This package includes as one of its basic supported types Scheme
"expression"s. This type allows expressions as defined by the Scheme
standards to be stored in the database. Using `slib:eval' retrieved
expressions can be evaluated (in the top-level environment). Scheme's
`lambda' facilitates closure of environments, modularity, etc. so that
procedures (which could not be stored directly most databases) can
still be effectively retrieved. Since `slib:eval' evaluates
expressions in the top-level environment, built-in and user defined
procedures can be easily accessed by name.
This package's purpose is to standardize (through a common interface)
database creation and usage in Scheme programs. The relational model's
provision for inclusion of language expressions as data as well as the
description (in tables, of course) of all of its tables assures that
relational databases are powerful enough to assume the roles currently
played by thousands of ad-hoc routines and data formats.
Such standardization to a relational-like model brings many benefits:
* Tables, fields, domains, and types can be dealt with by name in
programs.
* The underlying database implementation can be changed (for
performance or other reasons) by changing a single line of code.
* The formats of tables can be easily extended or changed without
altering code.
* Consistency checks are specified as part of the table descriptions.
Changes in checks need only occur in one place.
* All the configuration information which the developer wishes to
group together is easily grouped, without needing to change
programs aware of only some of these tables.
* Generalized report generators, interactive entry programs, and
other database utilities can be part of a shared library. The
burden of adding configurability to a program is greatly reduced.
* Scheme is the "comprehensive language" for these databases.
Scripting for configuration no longer needs to be in a separate
language with additional documentation.
* Scheme's latent types mesh well with the strict typing and logical
requirements of the relational model.
* Portable formats allow easy interchange of data. The included
table descriptions help prevent misinterpretation of format.

File: slib.info, Node: Creating and Opening Relational Databases, Next: Relational Database Operations, Prev: Motivations, Up: Relational Database
Creating and Opening Relational Databases
-----------------------------------------
- Function: make-relational-system base-table-implementation
Returns a procedure implementing a relational database using the
BASE-TABLE-IMPLEMENTATION.
All of the operations of a base table implementation are accessed
through a procedure defined by `require'ing that implementation.
Similarly, all of the operations of the relational database
implementation are accessed through the procedure returned by
`make-relational-system'. For instance, a new relational database
could be created from the procedure returned by
`make-relational-system' by:
(require 'alist-table)
(define relational-alist-system
(make-relational-system alist-table))
(define create-alist-database
(relational-alist-system 'create-database))
(define my-database
(create-alist-database "mydata.db"))
What follows are the descriptions of the methods available from
relational system returned by a call to `make-relational-system'.
- Function: create-database filename
Returns an open, nearly empty relational database associated with
FILENAME. The only tables defined are the system catalog and
domain table. Calling the `close-database' method on this database
and possibly other operations will cause FILENAME to be written
to. If FILENAME is `#f' a temporary, non-disk based database will
be created if such can be supported by the underlying base table
implelentation. If the database cannot be created as specified
`#f' is returned. For the fields and layout of descriptor tables,
*Note Catalog Representation::
- Function: open-database filename mutable?
Returns an open relational database associated with FILENAME. If
MUTABLE? is `#t', this database will have methods capable of
effecting change to the database. If MUTABLE? is `#f', only
methods for inquiring the database will be available. Calling the
`close-database' (and possibly other) method on a MUTABLE?
database will cause FILENAME to be written to. If the database
cannot be opened as specified `#f' is returned.

File: slib.info, Node: Relational Database Operations, Next: Table Operations, Prev: Creating and Opening Relational Databases, Up: Relational Database
Relational Database Operations
------------------------------
These are the descriptions of the methods available from an open
relational database. A method is retrieved from a database by calling
the database with the symbol name of the operation. For example:
(define my-database
(create-alist-database "mydata.db"))
(define telephone-table-desc
((my-database 'create-table) 'telephone-table-desc))
- Function: close-database
Causes the relational database to be written to its associated
file (if any). If the write is successful, subsequent operations
to this database will signal an error. If the operations completed
successfully, `#t' is returned. Otherwise, `#f' is returned.
- Function: write-database filename
Causes the relational database to be written to FILENAME. If the
write is successful, also causes the database to henceforth be
associated with FILENAME. Calling the `close-database' (and
possibly other) method on this database will cause FILENAME to be
written to. If FILENAME is `#f' this database will be changed to
a temporary, non-disk based database if such can be supported by
the underlying base table implelentation. If the operations
completed successfully, `#t' is returned. Otherwise, `#f' is
returned.
- Function: sync-database |
Causes any pending updates to the database file to be written out. |
If the operations completed successfully, `#t' is returned. |
Otherwise, `#f' is returned. |
|
- Function: table-exists? table-name
Returns `#t' if TABLE-NAME exists in the system catalog, otherwise
returns `#f'.
- Function: open-table table-name mutable?
Returns a "methods" procedure for an existing relational table in
this database if it exists and can be opened in the mode indicated
by MUTABLE?, otherwise returns `#f'.
These methods will be present only in databases which are MUTABLE?.
- Function: delete-table table-name
Removes and returns the TABLE-NAME row from the system catalog if
the table or view associated with TABLE-NAME gets removed from the
database, and `#f' otherwise.
- Function: create-table table-desc-name
Returns a methods procedure for a new (open) relational table for
describing the columns of a new base table in this database,
otherwise returns `#f'. For the fields and layout of descriptor
tables, *Note Catalog Representation::.
- Function: create-table table-name table-desc-name
Returns a methods procedure for a new (open) relational table with
columns as described by TABLE-DESC-NAME, otherwise returns `#f'.
- Function: create-view ??
- Function: project-table ??
- Function: restrict-table ??
- Function: cart-prod-tables ??
Not yet implemented.

File: slib.info, Node: Table Operations, Next: Catalog Representation, Prev: Relational Database Operations, Up: Relational Database
Table Operations
----------------
These are the descriptions of the methods available from an open
relational table. A method is retrieved from a table by calling the
table with the symbol name of the operation. For example:
(define telephone-table-desc
((my-database 'create-table) 'telephone-table-desc))
(require 'common-list-functions)
(define ndrp (telephone-table-desc 'row:insert))
(ndrp '(1 #t name #f string))
(ndrp '(2 #f telephone
(lambda (d)
(and (string? d) (> (string-length d) 2)
(every
(lambda (c)
(memv c '(#\0 #\1 #\2 #\3 #\4 #\5 #\6 #\7 #\8 #\9
#\+ #\( #\ #\) #\-)))
(string->list d))))
string))
Some operations described below require primary key arguments. Primary
keys arguments are denoted KEY1 KEY2 .... It is an error to call an
operation for a table which takes primary key arguments with the wrong
number of primary keys for that table.
The term "row" used below refers to a Scheme list of values (one for
each column) in the order specified in the descriptor (table) for this
table. Missing values appear as `#f'. Primary keys must not be
missing.
- Function: get column-name
Returns a procedure of arguments KEY1 KEY2 ... which returns the
value for the COLUMN-NAME column of the row associated with
primary keys KEY1, KEY2 ... if that row exists in the table, or
`#f' otherwise.
((plat 'get 'processor) 'djgpp) => i386
((plat 'get 'processor) 'be-os) => #f
- Function: get* column-name
Returns a procedure of optional arguments MATCH-KEY1 ... which
returns a list of the values for the specified column for all rows
in this table. The optional MATCH-KEY1 ... arguments restrict
actions to a subset of the table. See the match-key description
below for details.
((plat 'get* 'processor)) =>
(i386 8086 i386 8086 i386 i386 8086 m68000
m68000 m68000 m68000 m68000 powerpc)
((plat 'get* 'processor) #f) =>
(i386 8086 i386 8086 i386 i386 8086 m68000
m68000 m68000 m68000 m68000 powerpc)
(define (a-key? key)
(char=? #\a (string-ref (symbol->string key) 0)))
((plat 'get* 'processor) a-key?) =>
(m68000 m68000 m68000 m68000 m68000 powerpc)
((plat 'get* 'name) a-key?) =>
(atari-st-turbo-c atari-st-gcc amiga-sas/c-5.10
amiga-aztec amiga-dice-c aix)
- Function: row:retrieve
Returns a procedure of arguments KEY1 KEY2 ... which returns the
row associated with primary keys KEY1, KEY2 ... if it exists, or
`#f' otherwise.
((plat 'row:retrieve) 'linux) => (linux i386 linux gcc)
((plat 'row:retrieve) 'multics) => #f
- Function: row:retrieve*
Returns a procedure of optional arguments MATCH-KEY1 ... which
returns a list of all rows in this table. The optional MATCH-KEY1
... arguments restrict actions to a subset of the table. See the
match-key description below for details.
((plat 'row:retrieve*) a-key?) =>
((atari-st-turbo-c m68000 atari turbo-c)
(atari-st-gcc m68000 atari gcc)
(amiga-sas/c-5.10 m68000 amiga sas/c)
(amiga-aztec m68000 amiga aztec)
(amiga-dice-c m68000 amiga dice-c)
(aix powerpc aix -))
- Function: row:remove
Returns a procedure of arguments KEY1 KEY2 ... which removes and
returns the row associated with primary keys KEY1, KEY2 ... if it
exists, or `#f' otherwise.
- Function: row:remove*
Returns a procedure of optional arguments MATCH-KEY1 ... which
removes and returns a list of all rows in this table. The optional
MATCH-KEY1 ... arguments restrict actions to a subset of the
table. See the match-key description below for details.
- Function: row:delete
Returns a procedure of arguments KEY1 KEY2 ... which deletes the
row associated with primary keys KEY1, KEY2 ... if it exists. The
value returned is unspecified.
- Function: row:delete*
Returns a procedure of optional arguments MATCH-KEY1 ... which
Deletes all rows from this table. The optional MATCH-KEY1 ...
arguments restrict deletions to a subset of the table. See the
match-key description below for details. The value returned is
unspecified. The descriptor table and catalog entry for this
table are not affected.
- Function: row:update
Returns a procedure of one argument, ROW, which adds the row, ROW,
to this table. If a row for the primary key(s) specified by ROW
already exists in this table, it will be overwritten. The value
returned is unspecified.
- Function: row:update*
Returns a procedure of one argument, ROWS, which adds each row in
the list of rows, ROWS, to this table. If a row for the primary
key specified by an element of ROWS already exists in this table,
it will be overwritten. The value returned is unspecified.
- Function: row:insert
Adds the row ROW to this table. If a row for the primary key(s)
specified by ROW already exists in this table an error is
signaled. The value returned is unspecified.
- Function: row:insert*
Returns a procedure of one argument, ROWS, which adds each row in
the list of rows, ROWS, to this table. If a row for the primary
key specified by an element of ROWS already exists in this table,
an error is signaled. The value returned is unspecified.
- Function: for-each-row
Returns a procedure of arguments PROC MATCH-KEY1 ... which calls
PROC with each ROW in this table in the (implementation-dependent)
natural ordering for rows. The optional MATCH-KEY1 ... arguments
restrict actions to a subset of the table. See the match-key
description below for details.
_Real_ relational programmers would use some least-upper-bound join
for every row to get them in order; But we don't have joins yet.
The (optional) MATCH-KEY1 ... arguments are used to restrict actions of
a whole-table operation to a subset of that table. Those procedures
(returned by methods) which accept match-key arguments will accept any
number of match-key arguments between zero and the number of primary
keys in the table. Any unspecified MATCH-KEY arguments default to `#f'.
The MATCH-KEY1 ... restrict the actions of the table command to those
records whose primary keys each satisfy the corresponding MATCH-KEY
argument. The arguments and their actions are:
`#f'
The false value matches any key in the corresponding position.
an object of type procedure
This procedure must take a single argument, the key in the
corresponding position. Any key for which the procedure
returns a non-false value is a match; Any key for which the
procedure returns a `#f' is not.
other values
Any other value matches only those keys `equal?' to it.
- Function: close-table
Subsequent operations to this table will signal an error.
- Constant: column-names
- Constant: column-foreigns
- Constant: column-domains
- Constant: column-types
Return a list of the column names, foreign-key table names, domain
names, or type names respectively for this table. These 4 methods
are different from the others in that the list is returned, rather
than a procedure to obtain the list.
- Constant: primary-limit
Returns the number of primary keys fields in the relations in this
table.

File: slib.info, Node: Catalog Representation, Next: Unresolved Issues, Prev: Table Operations, Up: Relational Database
Catalog Representation
----------------------
Each database (in an implementation) has a "system catalog" which
describes all the user accessible tables in that database (including
itself).
The system catalog base table has the following fields. `PRI'
indicates a primary key for that table.
PRI table-name
column-limit the highest column number
coltab-name descriptor table name
bastab-id data base table identifier
user-integrity-rule
view-procedure A scheme thunk which, when called,
produces a handle for the view. coltab
and bastab are specified if and only if
view-procedure is not.
Descriptors for base tables (not views) are tables (pointed to by
system catalog). Descriptor (base) tables have the fields:
PRI column-number sequential integers from 1
primary-key? boolean TRUE for primary key components
column-name
column-integrity-rule
domain-name
A "primary key" is any column marked as `primary-key?' in the
corresponding descriptor table. All the `primary-key?' columns must
have lower column numbers than any non-`primary-key?' columns. Every
table must have at least one primary key. Primary keys must be
sufficient to distinguish all rows from each other in the table. All of
the system defined tables have a single primary key.
This package currently supports tables having from 1 to 4 primary keys
if there are non-primary columns, and any (natural) number if _all_
columns are primary keys. If you need more than 4 primary keys, I would
like to hear what you are doing!
A "domain" is a category describing the allowable values to occur in a
column. It is described by a (base) table with the fields:
PRI domain-name
foreign-table
domain-integrity-rule
type-id
type-param
The "type-id" field value is a symbol. This symbol may be used by the
underlying base table implementation in storing that field.
If the `foreign-table' field is non-`#f' then that field names a table
from the catalog. The values for that domain must match a primary key
of the table referenced by the TYPE-PARAM (or `#f', if allowed). This
package currently does not support composite foreign-keys.
The types for which support is planned are:
atom
symbol
string [<length>]
number [<base>]
money <currency>
date-time
boolean
foreign-key <table-name>
expression
virtual <expression>

File: slib.info, Node: Unresolved Issues, Next: Database Utilities, Prev: Catalog Representation, Up: Relational Database
Unresolved Issues
-----------------
Although `rdms.scm' is not large, I found it very difficult to write
(six rewrites). I am not aware of any other examples of a generalized
relational system (although there is little new in CS). I left out
several aspects of the Relational model in order to simplify the job.
The major features lacking (which might be addressed portably) are
views, transaction boundaries, and protection.
Protection needs a model for specifying priveledges. Given how
operations are accessed from handles it should not be difficult to
restrict table accesses to those allowed for that user.
The system catalog has a field called `view-procedure'. This should
allow a purely functional implementation of views. This will work but
is unsatisfying for views resulting from a "select"ion (subset of
rows); for whole table operations it will not be possible to reduce the
number of keys scanned over when the selection is specified only by an
opaque procedure.
Transaction boundaries present the most intriguing area. Transaction
boundaries are actually a feature of the "Comprehensive Language" of the
Relational database and not of the database. Scheme would seem to
provide the opportunity for an extremely clean semantics for transaction
boundaries since the builtin procedures with side effects are small in
number and easily identified.
These side-effect builtin procedures might all be portably redefined
to versions which properly handled transactions. Compiled library
routines would need to be recompiled as well. Many system extensions
(delete-file, system, etc.) would also need to be redefined.
There are 2 scope issues that must be resolved for multiprocess
transaction boundaries:
Process scope
The actions captured by a transaction should be only for the
process which invoked the start of transaction. Although standard
Scheme does not provide process primitives as such, `dynamic-wind'
would provide a workable hook into process switching for many
implementations.
Shared utilities with state
Some shared utilities have state which should _not_ be part of a
transaction. An example would be calling a pseudo-random number
generator. If the success of a transaction depended on the
pseudo-random number and failed, the state of the generator would
be set back. Subsequent calls would keep returning the same
number and keep failing.
Pseudo-random number generators are not reentrant; thus they would
require locks in order to operate properly in a multiprocess
environment. Are all examples of utilities whose state should not
be part of transactions also non-reentrant? If so, perhaps
suspending transaction capture for the duration of locks would
solve this problem.

File: slib.info, Node: Database Utilities, Next: Database Reports, Prev: Unresolved Issues, Up: Relational Database
Database Utilities
------------------
`(require 'database-utilities)'
This enhancement wraps a utility layer on `relational-database' which
provides:
* Automatic loading of the appropriate base-table package when
opening a database.
* Automatic execution of initialization commands stored in database.
* Transparent execution of database commands stored in `*commands*'
table in database.
Also included are utilities which provide:
* Data definition from Scheme lists and
* Report generation
for any SLIB relational database.
- Function: create-database filename base-table-type
Returns an open, nearly empty enhanced (with `*commands*' table)
relational database (with base-table type BASE-TABLE-TYPE)
associated with FILENAME.
- Function: open-database filename
- Function: open-database filename base-table-type
Returns an open enchanced relational database associated with
FILENAME. The database will be opened with base-table type
BASE-TABLE-TYPE) if supplied. If BASE-TABLE-TYPE is not supplied,
`open-database' will attempt to deduce the correct
base-table-type. If the database can not be opened or if it lacks
the `*commands*' table, `#f' is returned.
- Function: open-database! filename
- Function: open-database! filename base-table-type
Returns _mutable_ open enchanced relational database ...
The table `*commands*' in an "enhanced" relational-database has the
fields (with domains):
PRI name symbol
parameters parameter-list
procedure expression
documentation string
The `parameters' field is a foreign key (domain `parameter-list') of
the `*catalog-data*' table and should have the value of a table
described by `*parameter-columns*'. This `parameter-list' table
describes the arguments suitable for passing to the associated command.
The intent of this table is to be of a form such that different
user-interfaces (for instance, pull-down menus or plain-text queries)
can operate from the same table. A `parameter-list' table has the
following fields:
PRI index uint
name symbol
arity parameter-arity
domain domain
defaulter expression
expander expression
documentation string
The `arity' field can take the values:
`single'
Requires a single parameter of the specified domain.
`optional'
A single parameter of the specified domain or zero parameters is
acceptable.
`boolean'
A single boolean parameter or zero parameters (in which case `#f'
is substituted) is acceptable.
`nary'
Any number of parameters of the specified domain are acceptable.
The argument passed to the command function is always a list of the
parameters.
`nary1'
One or more of parameters of the specified domain are acceptable.
The argument passed to the command function is always a list of the
parameters.
The `domain' field specifies the domain which a parameter or
parameters in the `index'th field must satisfy.
The `defaulter' field is an expression whose value is either `#f' or
a procedure of one argument (the parameter-list) which returns a _list_
of the default value or values as appropriate. Note that since the
`defaulter' procedure is called every time a default parameter is
needed for this column, "sticky" defaults can be implemented using
shared state with the domain-integrity-rule.
Invoking Commands
.................
When an enhanced relational-database is called with a symbol which
matches a NAME in the `*commands*' table, the associated procedure
expression is evaluated and applied to the enhanced
relational-database. A procedure should then be returned which the user
can invoke on (optional) arguments.
The command `*initialize*' is special. If present in the
`*commands*' table, `open-database' or `open-database!' will return the
value of the `*initialize*' command. Notice that arbitrary code can be
run when the `*initialize*' procedure is automatically applied to the
enhanced relational-database.
Note also that if you wish to shadow or hide from the user
relational-database methods described in *Note Relational Database
Operations::, this can be done by a dispatch in the closure returned by
the `*initialize*' expression rather than by entries in the
`*commands*' table if it is desired that the underlying methods remain
accessible to code in the `*commands*' table.
- Function: make-command-server rdb table-name
Returns a procedure of 2 arguments, a (symbol) command and a
call-back procedure. When this returned procedure is called, it
looks up COMMAND in table TABLE-NAME and calls the call-back
procedure with arguments:
COMMAND
The COMMAND
COMMAND-VALUE
The result of evaluating the expression in the PROCEDURE
field of TABLE-NAME and calling it with RDB.
PARAMETER-NAME
A list of the "official" name of each parameter. Corresponds
to the `name' field of the COMMAND's parameter-table.
POSITIONS
A list of the positive integer index of each parameter.
Corresponds to the `index' field of the COMMAND's
parameter-table.
ARITIES
A list of the arities of each parameter. Corresponds to the
`arity' field of the COMMAND's parameter-table. For a
description of `arity' see table above.
TYPES
A list of the type name of each parameter. Correspnds to the
`type-id' field of the contents of the `domain' of the
COMMAND's parameter-table.
DEFAULTERS
A list of the defaulters for each parameter. Corresponds to
the `defaulters' field of the COMMAND's parameter-table.
DOMAIN-INTEGRITY-RULES
A list of procedures (one for each parameter) which tests
whether a value for a parameter is acceptable for that
parameter. The procedure should be called with each datum in
the list for `nary' arity parameters.
ALIASES
A list of lists of `(alias parameter-name)'. There can be
more than one alias per PARAMETER-NAME.
For information about parameters, *Note Parameter lists::. Here is an
example of setting up a command with arguments and parsing those
arguments from a `getopt' style argument list (*note Getopt::).
(require 'database-utilities)
(require 'fluid-let)
(require 'parameters)
(require 'getopt)
(define my-rdb (create-database #f 'alist-table))
(define-tables my-rdb
'(foo-params
*parameter-columns*
*parameter-columns*
((1 single-string single string
(lambda (pl) '("str")) #f "single string")
(2 nary-symbols nary symbol
(lambda (pl) '()) #f "zero or more symbols")
(3 nary1-symbols nary1 symbol
(lambda (pl) '(symb)) #f "one or more symbols")
(4 optional-number optional uint
(lambda (pl) '()) #f "zero or one number")
(5 flag boolean boolean
(lambda (pl) '(#f)) #f "a boolean flag")))
'(foo-pnames
((name string))
((parameter-index uint))
(("s" 1)
("single-string" 1)
("n" 2)
("nary-symbols" 2)
("N" 3)
("nary1-symbols" 3)
("o" 4)
("optional-number" 4)
("f" 5)
("flag" 5)))
'(my-commands
((name symbol))
((parameters parameter-list)
(parameter-names parameter-name-translation)
(procedure expression)
(documentation string))
((foo
foo-params
foo-pnames
(lambda (rdb) (lambda args (print args)))
"test command arguments"))))
(define (dbutil:serve-command-line rdb command-table
command argc argv)
(set! argv (if (vector? argv) (vector->list argv) argv))
((make-command-server rdb command-table)
command
(lambda (comname comval options positions
arities types defaulters dirs aliases)
(apply comval (getopt->arglist
argc argv options positions
arities types defaulters dirs aliases)))))
(define (cmd . opts)
(fluid-let ((*optind* 1))
(printf "%-34s => "
(call-with-output-string
(lambda (pt) (write (cons 'cmd opts) pt))))
(set! opts (cons "cmd" opts))
(force-output)
(dbutil:serve-command-line
my-rdb 'my-commands 'foo (length opts) opts)))
(cmd) => ("str" () (symb) () #f)
(cmd "-f") => ("str" () (symb) () #t)
(cmd "--flag") => ("str" () (symb) () #t)
(cmd "-o177") => ("str" () (symb) (177) #f)
(cmd "-o" "177") => ("str" () (symb) (177) #f)
(cmd "--optional" "621") => ("str" () (symb) (621) #f)
(cmd "--optional=621") => ("str" () (symb) (621) #f)
(cmd "-s" "speciality") => ("speciality" () (symb) () #f)
(cmd "-sspeciality") => ("speciality" () (symb) () #f)
(cmd "--single" "serendipity") => ("serendipity" () (symb) () #f)
(cmd "--single=serendipity") => ("serendipity" () (symb) () #f)
(cmd "-n" "gravity" "piety") => ("str" () (piety gravity) () #f)
(cmd "-ngravity" "piety") => ("str" () (piety gravity) () #f)
(cmd "--nary" "chastity") => ("str" () (chastity) () #f)
(cmd "--nary=chastity" "") => ("str" () ( chastity) () #f)
(cmd "-N" "calamity") => ("str" () (calamity) () #f)
(cmd "-Ncalamity") => ("str" () (calamity) () #f)
(cmd "--nary1" "surety") => ("str" () (surety) () #f)
(cmd "--nary1=surety") => ("str" () (surety) () #f)
(cmd "-N" "levity" "fealty") => ("str" () (fealty levity) () #f)
(cmd "-Nlevity" "fealty") => ("str" () (fealty levity) () #f)
(cmd "--nary1" "surety" "brevity") => ("str" () (brevity surety) () #f)
(cmd "--nary1=surety" "brevity") => ("str" () (brevity surety) () #f)
(cmd "-?")
-|
Usage: cmd [OPTION ARGUMENT ...] ...
-f, --flag
-o, --optional[=]<number>
-n, --nary[=]<symbols> ...
-N, --nary1[=]<symbols> ...
-s, --single[=]<string>
ERROR: getopt->parameter-list "unrecognized option" "-?"
Some commands are defined in all extended relational-databases. The
are called just like *Note Relational Database Operations::.
- Function: add-domain domain-row
Adds DOMAIN-ROW to the "domains" table if there is no row in the
domains table associated with key `(car DOMAIN-ROW)' and returns
`#t'. Otherwise returns `#f'.
For the fields and layout of the domain table, *Note Catalog
Representation::. Currently, these fields are
* domain-name
* foreign-table
* domain-integrity-rule
* type-id
* type-param
The following example adds 3 domains to the `build' database.
`Optstring' is either a string or `#f'. `filename' is a string
and `build-whats' is a symbol.
(for-each (build 'add-domain)
'((optstring #f
(lambda (x) (or (not x) (string? x)))
string
#f)
(filename #f #f string #f)
(build-whats #f #f symbol #f)))
- Function: delete-domain domain-name
Removes and returns the DOMAIN-NAME row from the "domains" table.
- Function: domain-checker domain
Returns a procedure to check an argument for conformance to domain
DOMAIN.
Defining Tables
...............
- Procedure: define-tables rdb spec-0 ...
Adds tables as specified in SPEC-0 ... to the open
relational-database RDB. Each SPEC has the form:
(<name> <descriptor-name> <descriptor-name> <rows>)
or
(<name> <primary-key-fields> <other-fields> <rows>)
where <name> is the table name, <descriptor-name> is the symbol
name of a descriptor table, <primary-key-fields> and
<other-fields> describe the primary keys and other fields
respectively, and <rows> is a list of data rows to be added to the
table.
<primary-key-fields> and <other-fields> are lists of field
descriptors of the form:
(<column-name> <domain>)
or
(<column-name> <domain> <column-integrity-rule>)
where <column-name> is the column name, <domain> is the domain of
the column, and <column-integrity-rule> is an expression whose
value is a procedure of one argument (which returns `#f' to signal
an error).
If <domain> is not a defined domain name and it matches the name of
this table or an already defined (in one of SPEC-0 ...) single key
field table, a foriegn-key domain will be created for it.
The following example shows a new database with the name of `foo.db'
being created with tables describing processor families and
processor/os/compiler combinations.
The database command `define-tables' is defined to call `define-tables'
with its arguments. The database is also configured to print `Welcome'
when the database is opened. The database is then closed and reopened.
(require 'database-utilities)
(define my-rdb (create-database "foo.db" 'alist-table))
(define-tables my-rdb
'(*commands*
((name symbol))
((parameters parameter-list)
(procedure expression)
(documentation string))
((define-tables
no-parameters
no-parameter-names
(lambda (rdb) (lambda specs (apply define-tables rdb specs)))
"Create or Augment tables from list of specs")
(*initialize*
no-parameters
no-parameter-names
(lambda (rdb) (display "Welcome") (newline) rdb)
"Print Welcome"))))
((my-rdb 'define-tables)
'(processor-family
((family atom))
((also-ran processor-family))
((m68000 #f)
(m68030 m68000)
(i386 8086)
(8086 #f)
(powerpc #f)))
'(platform
((name symbol))
((processor processor-family)
(os symbol)
(compiler symbol))
((aix powerpc aix -)
(amiga-dice-c m68000 amiga dice-c)
(amiga-aztec m68000 amiga aztec)
(amiga-sas/c-5.10 m68000 amiga sas/c)
(atari-st-gcc m68000 atari gcc)
(atari-st-turbo-c m68000 atari turbo-c)
(borland-c-3.1 8086 ms-dos borland-c)
(djgpp i386 ms-dos gcc)
(linux i386 linux gcc)
(microsoft-c 8086 ms-dos microsoft-c)
(os/2-emx i386 os/2 gcc)
(turbo-c-2 8086 ms-dos turbo-c)
(watcom-9.0 i386 ms-dos watcom))))
((my-rdb 'close-database))
(set! my-rdb (open-database "foo.db" 'alist-table))
-|
Welcome
Listing Tables |
.............. |
|
- Procedure: list-table-definition rdb table-name |
If symbol TABLE-NAME exists in the open relational-database RDB, |
then returns a list of the table-name, its primary key names and |
domains, its other key names and domains, and the table's records |
(as lists). Otherwise, returns #f. |
|
The list returned by `list-table-definition', when passed as an |
argument to `define-tables', will recreate the table. |
|

File: slib.info, Node: Database Reports, Next: Database Browser, Prev: Database Utilities, Up: Relational Database
Database Reports
----------------
Code for generating database reports is in `report.scm'. After writing
it using `format', I discovered that Common-Lisp `format' is not
useable for this application because there is no mechanismm for
truncating fields. `report.scm' needs to be rewritten using `printf'.
- Procedure: create-report rdb destination report-name table
- Procedure: create-report rdb destination report-name
The symbol REPORT-NAME must be primary key in the table named
`*reports*' in the relational database RDB. DESTINATION is a
port, string, or symbol. If DESTINATION is a:
port
The table is created as ascii text and written to that port.
string
The table is created as ascii text and written to the file
named by DESTINATION.
symbol
DESTINATION is the primary key for a row in the table named
*printers*.
The report is prepared as follows:
* `Format' (*note Format::) is called with the `header' field
and the (list of) `column-names' of the table.
* `Format' is called with the `reporter' field and (on
successive calls) each record in the natural order for the
table. A count is kept of the number of newlines output by
format. When the number of newlines to be output exceeds the
number of lines per page, the set of lines will be broken if
there are more than `minimum-break' left on this page and the
number of lines for this row is larger or equal to twice
`minimum-break'.
* `Format' is called with the `footer' field and the (list of)
`column-names' of the table. The footer field should not
output a newline.
* A new page is output.
* This entire process repeats until all the rows are output.
Each row in the table *reports* has the fields:
name
The report name.
default-table
The table to report on if none is specified.
header, footer
A `format' string. At the beginning and end of each page
respectively, `format' is called with this string and the (list of)
column-names of this table.
reporter
A `format' string. For each row in the table, `format' is called
with this string and the row.
minimum-break
The minimum number of lines into which the report lines for a row
can be broken. Use `0' if a row's lines should not be broken over
page boundaries.
Each row in the table *printers* has the fields:
name
The printer name.
print-procedure
The procedure to call to actually print.

File: slib.info, Node: Database Browser, Prev: Database Reports, Up: Relational Database
Database Browser
----------------
(require 'database-browse)
- Procedure: browse database
Prints the names of all the tables in DATABASE and sets browse's
default to DATABASE.
- Procedure: browse
Prints the names of all the tables in the default database.
- Procedure: browse table-name
For each record of the table named by the symbol TABLE-NAME,
prints a line composed of all the field values.
- Procedure: browse pathname
Opens the database named by the string PATHNAME, prints the names
of all its tables, and sets browse's default to the database.
- Procedure: browse database table-name
Sets browse's default to DATABASE and prints the records of the
table named by the symbol TABLE-NAME.
- Procedure: browse pathname table-name
Opens the database named by the string PATHNAME and sets browse's
default to it; `browse' prints the records of the table named by
the symbol TABLE-NAME.

File: slib.info, Node: Weight-Balanced Trees, Prev: Relational Database, Up: Database Packages
Weight-Balanced Trees
=====================
`(require 'wt-tree)'
Balanced binary trees are a useful data structure for maintaining
large sets of ordered objects or sets of associations whose keys are
ordered. MIT Scheme has an comprehensive implementation of
weight-balanced binary trees which has several advantages over the
other data structures for large aggregates:
* In addition to the usual element-level operations like insertion,
deletion and lookup, there is a full complement of collection-level
operations, like set intersection, set union and subset test, all
of which are implemented with good orders of growth in time and
space. This makes weight balanced trees ideal for rapid
prototyping of functionally derived specifications.
* An element in a tree may be indexed by its position under the
ordering of the keys, and the ordinal position of an element may
be determined, both with reasonable efficiency.
* Operations to find and remove minimum element make weight balanced
trees simple to use for priority queues.
* The implementation is _functional_ rather than _imperative_. This
means that operations like `inserting' an association in a tree do
not destroy the old tree, in much the same way that `(+ 1 x)'
modifies neither the constant 1 nor the value bound to `x'. The
trees are referentially transparent thus the programmer need not
worry about copying the trees. Referential transparency allows
space efficiency to be achieved by sharing subtrees.
These features make weight-balanced trees suitable for a wide range of
applications, especially those that require large numbers of sets or
discrete maps. Applications that have a few global databases and/or
concentrate on element-level operations like insertion and lookup are
probably better off using hash-tables or red-black trees.
The _size_ of a tree is the number of associations that it contains.
Weight balanced binary trees are balanced to keep the sizes of the
subtrees of each node within a constant factor of each other. This
ensures logarithmic times for single-path operations (like lookup and
insertion). A weight balanced tree takes space that is proportional to
the number of associations in the tree. For the current
implementation, the constant of proportionality is six words per
association.
Weight balanced trees can be used as an implementation for either
discrete sets or discrete maps (associations). Sets are implemented by
ignoring the datum that is associated with the key. Under this scheme
if an associations exists in the tree this indicates that the key of the
association is a member of the set. Typically a value such as `()',
`#t' or `#f' is associated with the key.
Many operations can be viewed as computing a result that, depending on
whether the tree arguments are thought of as sets or maps, is known by
two different names. An example is `wt-tree/member?', which, when
regarding the tree argument as a set, computes the set membership
operation, but, when regarding the tree as a discrete map,
`wt-tree/member?' is the predicate testing if the map is defined at an
element in its domain. Most names in this package have been chosen
based on interpreting the trees as sets, hence the name
`wt-tree/member?' rather than `wt-tree/defined-at?'.
The weight balanced tree implementation is a run-time-loadable option.
To use weight balanced trees, execute
(load-option 'wt-tree)
once before calling any of the procedures defined here.
* Menu:
* Construction of Weight-Balanced Trees::
* Basic Operations on Weight-Balanced Trees::
* Advanced Operations on Weight-Balanced Trees::
* Indexing Operations on Weight-Balanced Trees::

File: slib.info, Node: Construction of Weight-Balanced Trees, Next: Basic Operations on Weight-Balanced Trees, Prev: Weight-Balanced Trees, Up: Weight-Balanced Trees
Construction of Weight-Balanced Trees
-------------------------------------
Binary trees require there to be a total order on the keys used to
arrange the elements in the tree. Weight balanced trees are organized
by _types_, where the type is an object encapsulating the ordering
relation. Creating a tree is a two-stage process. First a tree type
must be created from the predicate which gives the ordering. The tree
type is then used for making trees, either empty or singleton trees or
trees from other aggregate structures like association lists. Once
created, a tree `knows' its type and the type is used to test
compatibility between trees in operations taking two trees. Usually a
small number of tree types are created at the beginning of a program and
used many times throughout the program's execution.
- procedure+: make-wt-tree-type key<?
This procedure creates and returns a new tree type based on the
ordering predicate KEY<?. KEY<? must be a total ordering, having
the property that for all key values `a', `b' and `c':
(key<? a a) => #f
(and (key<? a b) (key<? b a)) => #f
(if (and (key<? a b) (key<? b c))
(key<? a c)
#t) => #t
Two key values are assumed to be equal if neither is less than the
other by KEY<?.
Each call to `make-wt-tree-type' returns a distinct value, and
trees are only compatible if their tree types are `eq?'. A
consequence is that trees that are intended to be used in binary
tree operations must all be created with a tree type originating
from the same call to `make-wt-tree-type'.
- variable+: number-wt-type
A standard tree type for trees with numeric keys. `Number-wt-type'
could have been defined by
(define number-wt-type (make-wt-tree-type <))
- variable+: string-wt-type
A standard tree type for trees with string keys. `String-wt-type'
could have been defined by
(define string-wt-type (make-wt-tree-type string<?))
- procedure+: make-wt-tree wt-tree-type
This procedure creates and returns a newly allocated weight
balanced tree. The tree is empty, i.e. it contains no
associations. WT-TREE-TYPE is a weight balanced tree type
obtained by calling `make-wt-tree-type'; the returned tree has
this type.
- procedure+: singleton-wt-tree wt-tree-type key datum
This procedure creates and returns a newly allocated weight
balanced tree. The tree contains a single association, that of
DATUM with KEY. WT-TREE-TYPE is a weight balanced tree type
obtained by calling `make-wt-tree-type'; the returned tree has
this type.
- procedure+: alist->wt-tree tree-type alist
Returns a newly allocated weight-balanced tree that contains the
same associations as ALIST. This procedure is equivalent to:
(lambda (type alist)
(let ((tree (make-wt-tree type)))
(for-each (lambda (association)
(wt-tree/add! tree
(car association)
(cdr association)))
alist)
tree))

File: slib.info, Node: Basic Operations on Weight-Balanced Trees, Next: Advanced Operations on Weight-Balanced Trees, Prev: Construction of Weight-Balanced Trees, Up: Weight-Balanced Trees
Basic Operations on Weight-Balanced Trees
-----------------------------------------
This section describes the basic tree operations on weight balanced
trees. These operations are the usual tree operations for insertion,
deletion and lookup, some predicates and a procedure for determining the
number of associations in a tree.
- procedure+: wt-tree? object
Returns `#t' if OBJECT is a weight-balanced tree, otherwise
returns `#f'.
- procedure+: wt-tree/empty? wt-tree
Returns `#t' if WT-TREE contains no associations, otherwise
returns `#f'.
- procedure+: wt-tree/size wt-tree
Returns the number of associations in WT-TREE, an exact
non-negative integer. This operation takes constant time.
- procedure+: wt-tree/add wt-tree key datum
Returns a new tree containing all the associations in WT-TREE and
the association of DATUM with KEY. If WT-TREE already had an
association for KEY, the new association overrides the old. The
average and worst-case times required by this operation are
proportional to the logarithm of the number of associations in
WT-TREE.
- procedure+: wt-tree/add! wt-tree key datum
Associates DATUM with KEY in WT-TREE and returns an unspecified
value. If WT-TREE already has an association for KEY, that
association is replaced. The average and worst-case times
required by this operation are proportional to the logarithm of
the number of associations in WT-TREE.
- procedure+: wt-tree/member? key wt-tree
Returns `#t' if WT-TREE contains an association for KEY, otherwise
returns `#f'. The average and worst-case times required by this
operation are proportional to the logarithm of the number of
associations in WT-TREE.
- procedure+: wt-tree/lookup wt-tree key default
Returns the datum associated with KEY in WT-TREE. If WT-TREE
doesn't contain an association for KEY, DEFAULT is returned. The
average and worst-case times required by this operation are
proportional to the logarithm of the number of associations in
WT-TREE.
- procedure+: wt-tree/delete wt-tree key
Returns a new tree containing all the associations in WT-TREE,
except that if WT-TREE contains an association for KEY, it is
removed from the result. The average and worst-case times required
by this operation are proportional to the logarithm of the number
of associations in WT-TREE.
- procedure+: wt-tree/delete! wt-tree key
If WT-TREE contains an association for KEY the association is
removed. Returns an unspecified value. The average and worst-case
times required by this operation are proportional to the logarithm
of the number of associations in WT-TREE.

File: slib.info, Node: Advanced Operations on Weight-Balanced Trees, Next: Indexing Operations on Weight-Balanced Trees, Prev: Basic Operations on Weight-Balanced Trees, Up: Weight-Balanced Trees
Advanced Operations on Weight-Balanced Trees
--------------------------------------------
In the following the _size_ of a tree is the number of associations
that the tree contains, and a _smaller_ tree contains fewer
associations.
- procedure+: wt-tree/split< wt-tree bound
Returns a new tree containing all and only the associations in
WT-TREE which have a key that is less than BOUND in the ordering
relation of the tree type of WT-TREE. The average and worst-case
times required by this operation are proportional to the logarithm
of the size of WT-TREE.
- procedure+: wt-tree/split> wt-tree bound
Returns a new tree containing all and only the associations in
WT-TREE which have a key that is greater than BOUND in the
ordering relation of the tree type of WT-TREE. The average and
worst-case times required by this operation are proportional to the
logarithm of size of WT-TREE.
- procedure+: wt-tree/union wt-tree-1 wt-tree-2
Returns a new tree containing all the associations from both trees.
This operation is asymmetric: when both trees have an association
for the same key, the returned tree associates the datum from
WT-TREE-2 with the key. Thus if the trees are viewed as discrete
maps then `wt-tree/union' computes the map override of WT-TREE-1 by
WT-TREE-2. If the trees are viewed as sets the result is the set
union of the arguments. The worst-case time required by this
operation is proportional to the sum of the sizes of both trees.
If the minimum key of one tree is greater than the maximum key of
the other tree then the time required is at worst proportional to
the logarithm of the size of the larger tree.
- procedure+: wt-tree/intersection wt-tree-1 wt-tree-2
Returns a new tree containing all and only those associations from
WT-TREE-1 which have keys appearing as the key of an association
in WT-TREE-2. Thus the associated data in the result are those
from WT-TREE-1. If the trees are being used as sets the result is
the set intersection of the arguments. As a discrete map
operation, `wt-tree/intersection' computes the domain restriction
of WT-TREE-1 to (the domain of) WT-TREE-2. The time required by
this operation is never worse that proportional to the sum of the
sizes of the trees.
- procedure+: wt-tree/difference wt-tree-1 wt-tree-2
Returns a new tree containing all and only those associations from
WT-TREE-1 which have keys that _do not_ appear as the key of an
association in WT-TREE-2. If the trees are viewed as sets the
result is the asymmetric set difference of the arguments. As a
discrete map operation, it computes the domain restriction of
WT-TREE-1 to the complement of (the domain of) WT-TREE-2. The
time required by this operation is never worse that proportional to
the sum of the sizes of the trees.
- procedure+: wt-tree/subset? wt-tree-1 wt-tree-2
Returns `#t' iff the key of each association in WT-TREE-1 is the
key of some association in WT-TREE-2, otherwise returns `#f'.
Viewed as a set operation, `wt-tree/subset?' is the improper subset
predicate. A proper subset predicate can be constructed:
(define (proper-subset? s1 s2)
(and (wt-tree/subset? s1 s2)
(< (wt-tree/size s1) (wt-tree/size s2))))
As a discrete map operation, `wt-tree/subset?' is the subset test
on the domain(s) of the map(s). In the worst-case the time
required by this operation is proportional to the size of
WT-TREE-1.
- procedure+: wt-tree/set-equal? wt-tree-1 wt-tree-2
Returns `#t' iff for every association in WT-TREE-1 there is an
association in WT-TREE-2 that has the same key, and _vice versa_.
Viewing the arguments as sets `wt-tree/set-equal?' is the set
equality predicate. As a map operation it determines if two maps
are defined on the same domain.
This procedure is equivalent to
(lambda (wt-tree-1 wt-tree-2)
(and (wt-tree/subset? wt-tree-1 wt-tree-2
(wt-tree/subset? wt-tree-2 wt-tree-1)))
In the worst-case the time required by this operation is
proportional to the size of the smaller tree.
- procedure+: wt-tree/fold combiner initial wt-tree
This procedure reduces WT-TREE by combining all the associations,
using an reverse in-order traversal, so the associations are
visited in reverse order. COMBINER is a procedure of three
arguments: a key, a datum and the accumulated result so far.
Provided COMBINER takes time bounded by a constant, `wt-tree/fold'
takes time proportional to the size of WT-TREE.
A sorted association list can be derived simply:
(wt-tree/fold (lambda (key datum list)
(cons (cons key datum) list))
'()
WT-TREE))
The data in the associations can be summed like this:
(wt-tree/fold (lambda (key datum sum) (+ sum datum))
0
WT-TREE)
- procedure+: wt-tree/for-each action wt-tree
This procedure traverses the tree in-order, applying ACTION to
each association. The associations are processed in increasing
order of their keys. ACTION is a procedure of two arguments which
take the key and datum respectively of the association. Provided
ACTION takes time bounded by a constant, `wt-tree/for-each' takes
time proportional to in the size of WT-TREE. The example prints
the tree:
(wt-tree/for-each (lambda (key value)
(display (list key value)))
WT-TREE))

File: slib.info, Node: Indexing Operations on Weight-Balanced Trees, Prev: Advanced Operations on Weight-Balanced Trees, Up: Weight-Balanced Trees
Indexing Operations on Weight-Balanced Trees
--------------------------------------------
Weight balanced trees support operations that view the tree as sorted
sequence of associations. Elements of the sequence can be accessed by
position, and the position of an element in the sequence can be
determined, both in logarthmic time.
- procedure+: wt-tree/index wt-tree index
- procedure+: wt-tree/index-datum wt-tree index
- procedure+: wt-tree/index-pair wt-tree index
Returns the 0-based INDEXth association of WT-TREE in the sorted
sequence under the tree's ordering relation on the keys.
`wt-tree/index' returns the INDEXth key, `wt-tree/index-datum'
returns the datum associated with the INDEXth key and
`wt-tree/index-pair' returns a new pair `(KEY . DATUM)' which is
the `cons' of the INDEXth key and its datum. The average and
worst-case times required by this operation are proportional to
the logarithm of the number of associations in the tree.
These operations signal an error if the tree is empty, if
INDEX`<0', or if INDEX is greater than or equal to the number of
associations in the tree.
Indexing can be used to find the median and maximum keys in the
tree as follows:
median: (wt-tree/index WT-TREE
(quotient (wt-tree/size WT-TREE) 2))
maximum: (wt-tree/index WT-TREE
(-1+ (wt-tree/size WT-TREE)))
- procedure+: wt-tree/rank wt-tree key
Determines the 0-based position of KEY in the sorted sequence of
the keys under the tree's ordering relation, or `#f' if the tree
has no association with for KEY. This procedure returns either an
exact non-negative integer or `#f'. The average and worst-case
times required by this operation are proportional to the logarithm
of the number of associations in the tree.
- procedure+: wt-tree/min wt-tree
- procedure+: wt-tree/min-datum wt-tree
- procedure+: wt-tree/min-pair wt-tree
Returns the association of WT-TREE that has the least key under
the tree's ordering relation. `wt-tree/min' returns the least key,
`wt-tree/min-datum' returns the datum associated with the least key
and `wt-tree/min-pair' returns a new pair `(key . datum)' which is
the `cons' of the minimum key and its datum. The average and
worst-case times required by this operation are proportional to the
logarithm of the number of associations in the tree.
These operations signal an error if the tree is empty. They could
be written
(define (wt-tree/min tree) (wt-tree/index tree 0))
(define (wt-tree/min-datum tree) (wt-tree/index-datum tree 0))
(define (wt-tree/min-pair tree) (wt-tree/index-pair tree 0))
- procedure+: wt-tree/delete-min wt-tree
Returns a new tree containing all of the associations in WT-TREE
except the association with the least key under the WT-TREE's
ordering relation. An error is signalled if the tree is empty.
The average and worst-case times required by this operation are
proportional to the logarithm of the number of associations in the
tree. This operation is equivalent to
(wt-tree/delete WT-TREE (wt-tree/min WT-TREE))
- procedure+: wt-tree/delete-min! wt-tree
Removes the association with the least key under the WT-TREE's
ordering relation. An error is signalled if the tree is empty.
The average and worst-case times required by this operation are
proportional to the logarithm of the number of associations in the
tree. This operation is equivalent to
(wt-tree/delete! WT-TREE (wt-tree/min WT-TREE))

File: slib.info, Node: Other Packages, Next: About SLIB, Prev: Database Packages, Up: Top
Other Packages
**************
* Menu:
* Data Structures:: Various data structures.
* Procedures:: Miscellaneous utility procedures.
* Standards Support:: Support for Scheme Standards.
* Session Support:: REPL and Debugging.
* Extra-SLIB Packages::

File: slib.info, Node: Data Structures, Next: Procedures, Prev: Other Packages, Up: Other Packages
Data Structures
===============
* Menu:
* Arrays:: 'array
* Array Mapping:: 'array-for-each
* Association Lists:: 'alist
* Byte:: 'byte
* Portable Image Files:: 'pnm
* Collections:: 'collect
* Dynamic Data Type:: 'dynamic
* Hash Tables:: 'hash-table
* Hashing:: 'hash, 'sierpinski, 'soundex
* Object:: 'object
* Priority Queues:: 'priority-queue
* Queues:: 'queue
* Records:: 'record
* Structures:: 'struct, 'structure

File: slib.info, Node: Arrays, Next: Array Mapping, Prev: Data Structures, Up: Data Structures
Arrays
------
`(require 'array)'
- Function: array? obj
Returns `#t' if the OBJ is an array, and `#f' if not.
- Function: make-array initial-value bound1 bound2 ...
Creates and returns an array that has as many dimensins as there
are BOUNDs and fills it with INITIAL-VALUE.
When constructing an array, BOUND is either an inclusive range of
indices expressed as a two element list, or an upper bound expressed as
a single integer. So
(make-array 'foo 3 3) == (make-array 'foo '(0 2) '(0 2))
- Function: make-shared-array array mapper bound1 bound2 ...
`make-shared-array' can be used to create shared subarrays of other
arrays. The MAPPER is a function that translates coordinates in
the new array into coordinates in the old array. A MAPPER must be
linear, and its range must stay within the bounds of the old
array, but it can be otherwise arbitrary. A simple example:
(define fred (make-array #f 8 8))
(define freds-diagonal
(make-shared-array fred (lambda (i) (list i i)) 8))
(array-set! freds-diagonal 'foo 3)
(array-ref fred 3 3)
=> FOO
(define freds-center
(make-shared-array fred (lambda (i j) (list (+ 3 i) (+ 3 j)))
2 2))
(array-ref freds-center 0 0)
=> FOO
- Function: array-rank obj
Returns the number of dimensions of OBJ. If OBJ is not an array,
0 is returned.
- Function: array-shape array
`array-shape' returns a list of inclusive bounds. So:
(array-shape (make-array 'foo 3 5))
=> ((0 2) (0 4))
- Function: array-dimensions array
`array-dimensions' is similar to `array-shape' but replaces
elements with a 0 minimum with one greater than the maximum. So:
(array-dimensions (make-array 'foo 3 5))
=> (3 5)
- Procedure: array-in-bounds? array index1 index2 ...
Returns `#t' if its arguments would be acceptable to `array-ref'.
- Function: array-ref array index1 index2 ...
Returns the element at the `(INDEX1, INDEX2)' element in ARRAY.
- Procedure: array-set! array new-value index1 index2 ...
- Function: array-1d-ref array index
- Function: array-2d-ref array index1 index2
- Function: array-3d-ref array index1 index2 index3
- Procedure: array-1d-set! array new-value index
- Procedure: array-2d-set! array new-value index1 index2
- Procedure: array-3d-set! array new-value index1 index2 index3
The functions are just fast versions of `array-ref' and `array-set!'
that take a fixed number of arguments, and perform no bounds checking.
If you comment out the bounds checking code, this is about as
efficient as you could ask for without help from the compiler.
An exercise left to the reader: implement the rest of APL.

File: slib.info, Node: Array Mapping, Next: Association Lists, Prev: Arrays, Up: Data Structures
Array Mapping
-------------
`(require 'array-for-each)'
- Function: array-map! array0 proc array1 ...
ARRAY1, ... must have the same number of dimensions as ARRAY0 and
have a range for each index which includes the range for the
corresponding index in ARRAY0. PROC is applied to each tuple of
elements of ARRAY1 ... and the result is stored as the
corresponding element in ARRAY0. The value returned is
unspecified. The order of application is unspecified.
- Function: array-for-each PROC ARRAY0 ...
PROC is applied to each tuple of elements of ARRAY0 ... in
row-major order. The value returned is unspecified.
- Function: array-indexes ARRAY
Returns an array of lists of indexes for ARRAY such that, if LI is
a list of indexes for which ARRAY is defined, (equal? LI (apply
array-ref (array-indexes ARRAY) LI)).
- Function: array-index-map! array proc
applies PROC to the indices of each element of ARRAY in turn,
storing the result in the corresponding element. The value
returned and the order of application are unspecified.
One can implement ARRAY-INDEXES as
(define (array-indexes array)
(let ((ra (apply make-array #f (array-shape array))))
(array-index-map! ra (lambda x x))
ra))
Another example:
(define (apl:index-generator n)
(let ((v (make-uniform-vector n 1)))
(array-index-map! v (lambda (i) i))
v))
- Function: array-copy! source destination
Copies every element from vector or array SOURCE to the
corresponding element of DESTINATION. DESTINATION must have the
same rank as SOURCE, and be at least as large in each dimension.
The order of copying is unspecified.

File: slib.info, Node: Association Lists, Next: Byte, Prev: Array Mapping, Up: Data Structures
Association Lists
-----------------
`(require 'alist)'
Alist functions provide utilities for treating a list of key-value
pairs as an associative database. These functions take an equality
predicate, PRED, as an argument. This predicate should be repeatable,
symmetric, and transitive.
Alist functions can be used with a secondary index method such as hash
tables for improved performance.
- Function: predicate->asso pred
Returns an "association function" (like `assq', `assv', or
`assoc') corresponding to PRED. The returned function returns a
key-value pair whose key is `pred'-equal to its first argument or
`#f' if no key in the alist is PRED-equal to the first argument.
- Function: alist-inquirer pred
Returns a procedure of 2 arguments, ALIST and KEY, which returns
the value associated with KEY in ALIST or `#f' if KEY does not
appear in ALIST.
- Function: alist-associator pred
Returns a procedure of 3 arguments, ALIST, KEY, and VALUE, which
returns an alist with KEY and VALUE associated. Any previous
value associated with KEY will be lost. This returned procedure
may or may not have side effects on its ALIST argument. An
example of correct usage is:
(define put (alist-associator string-ci=?))
(define alist '())
(set! alist (put alist "Foo" 9))
- Function: alist-remover pred
Returns a procedure of 2 arguments, ALIST and KEY, which returns
an alist with an association whose KEY is key removed. This
returned procedure may or may not have side effects on its ALIST
argument. An example of correct usage is:
(define rem (alist-remover string-ci=?))
(set! alist (rem alist "foo"))
- Function: alist-map proc alist
Returns a new association list formed by mapping PROC over the
keys and values of ALIST. PROC must be a function of 2 arguments
which returns the new value part.
- Function: alist-for-each proc alist
Applies PROC to each pair of keys and values of ALIST. PROC must
be a function of 2 arguments. The returned value is unspecified.

File: slib.info, Node: Byte, Next: Portable Image Files, Prev: Association Lists, Up: Data Structures
Byte
----
`(require 'byte)'
Some algorithms are expressed in terms of arrays of small integers.
Using Scheme strings to implement these arrays is not portable vis-a-vis
the correspondence between integers and characters and non-ascii
character sets. These functions abstract the notion of a "byte".
- Function: byte-ref bytes k
K must be a valid index of BYTES. `byte-ref' returns byte K of
BYTES using zero-origin indexing.
- Procedure: byte-set! bytes k byte
K must be a valid index of BYTES%, and BYTE must be a small
integer. `Byte-set!' stores BYTE in element K of BYTES and
returns an unspecified value.
- Function: make-bytes k
- Function: make-bytes k byte
`Make-bytes' returns a newly allocated byte-array of length K. If
BYTE is given, then all elements of the byte-array are initialized
to BYTE, otherwise the contents of the byte-array are unspecified.
- Function: bytes-length bytes
`bytes-length' returns length of byte-array BYTES.
- Function: write-byte byte
- Function: write-byte byte port
Writes the byte BYTE (not an external representation of the byte)
to the given PORT and returns an unspecified value. The PORT
argument may be omitted, in which case it defaults to the value
returned by `current-output-port'.
- Function: read-byte
- Function: read-byte port
Returns the next byte available from the input PORT, updating the
PORT to point to the following byte. If no more bytes are
available, an end of file object is returned. PORT may be
omitted, in which case it defaults to the value returned by
`current-input-port'.
- Function: bytes byte ...
Returns a newly allocated byte-array composed of the arguments.
- Function: bytes->list bytes
- Function: list->bytes bytes
`Bytes->list' returns a newly allocated list of the bytes that
make up the given byte-array. `List->bytes' returns a newly
allocated byte-array formed from the small integers in the list
BYTES. `Bytes->list' and `list->bytes' are inverses so far as
`equal?' is concerned.

File: slib.info, Node: Portable Image Files, Next: Collections, Prev: Byte, Up: Data Structures
Portable Image Files
--------------------
`(require 'pnm)'
- Function: pnm:type-dimensions path
The string PATH must name a "portable bitmap graphics" file.
`pnm:type-dimensions' returns a list of 4 items:
1. A symbol describing the type of the file named by PATH.
2. The image width in pixels.
3. The image height in pixels.
4. The maximum value of pixels assume in the file.
The current set of file-type symbols is:
pbm
pbm-raw
Black-and-White image; pixel values are 0 or 1.
pgm
pgm-raw
Gray (monochrome) image; pixel values are from 0 to MAXVAL
specified in file header.
ppm
ppm-raw
RGB (full color) image; red, green, and blue interleaved
pixel values are from 0 to MAXVAL
- Function: pnm:image-file->array path array
Reads the "portable bitmap graphics" file named by PATH into
ARRAY. ARRAY must be the correct size and type for PATH. ARRAY
is returned.
- Function: pnm:image-file->array path
`pnm:image-file->array' creates and returns an array with the
"portable bitmap graphics" file named by PATH read into it.
- Procedure: pnm:array-write type array maxval path
Writes the contents of ARRAY to a TYPE image file named PATH. The
file will have pixel values between 0 and MAXVAL, which must be
compatible with TYPE. For `pbm' files, MAXVAL must be `1'.

File: slib.info, Node: Collections, Next: Dynamic Data Type, Prev: Portable Image Files, Up: Data Structures
Collections
-----------
`(require 'collect)'
Routines for managing collections. Collections are aggregate data
structures supporting iteration over their elements, similar to the
Dylan(TM) language, but with a different interface. They have
"elements" indexed by corresponding "keys", although the keys may be
implicit (as with lists).
New types of collections may be defined as YASOS objects (*note
Yasos::). They must support the following operations:
* `(collection? SELF)' (always returns `#t');
* `(size SELF)' returns the number of elements in the collection;
* `(print SELF PORT)' is a specialized print operation for the
collection which prints a suitable representation on the given
PORT or returns it as a string if PORT is `#t';
* `(gen-elts SELF)' returns a thunk which on successive invocations
yields elements of SELF in order or gives an error if it is
invoked more than `(size SELF)' times;
* `(gen-keys SELF)' is like `gen-elts', but yields the collection's
keys in order.
They might support specialized `for-each-key' and `for-each-elt'
operations.
- Function: collection? obj
A predicate, true initially of lists, vectors and strings. New
sorts of collections must answer `#t' to `collection?'.
- Procedure: map-elts proc . collections
- Procedure: do-elts proc . collections
PROC is a procedure taking as many arguments as there are
COLLECTIONS (at least one). The COLLECTIONS are iterated over in
their natural order and PROC is applied to the elements yielded by
each iteration in turn. The order in which the arguments are
supplied corresponds to te order in which the COLLECTIONS appear.
`do-elts' is used when only side-effects of PROC are of interest
and its return value is unspecified. `map-elts' returns a
collection (actually a vector) of the results of the applications
of PROC.
Example:
(map-elts + (list 1 2 3) (vector 1 2 3))
=> #(2 4 6)
- Procedure: map-keys proc . collections
- Procedure: do-keys proc . collections
These are analogous to `map-elts' and `do-elts', but each
iteration is over the COLLECTIONS' _keys_ rather than their
elements.
Example:
(map-keys + (list 1 2 3) (vector 1 2 3))
=> #(0 2 4)
- Procedure: for-each-key collection proc
- Procedure: for-each-elt collection proc
These are like `do-keys' and `do-elts' but only for a single
collection; they are potentially more efficient.
- Function: reduce proc seed . collections
A generalization of the list-based `comlist:reduce-init' (*note
Lists as sequences::) to collections which will shadow the
list-based version if `(require 'collect)' follows `(require
'common-list-functions)' (*note Common List Functions::).
Examples:
(reduce + 0 (vector 1 2 3))
=> 6
(reduce union '() '((a b c) (b c d) (d a)))
=> (c b d a).
- Function: any? pred . collections
A generalization of the list-based `some' (*note Lists as
sequences::) to collections.
Example:
(any? odd? (list 2 3 4 5))
=> #t
- Function: every? pred . collections
A generalization of the list-based `every' (*note Lists as
sequences::) to collections.
Example:
(every? collection? '((1 2) #(1 2)))
=> #t
- Function: empty? collection
Returns `#t' iff there are no elements in COLLECTION.
`(empty? COLLECTION) == (zero? (size COLLECTION))'
- Function: size collection
Returns the number of elements in COLLECTION.
- Function: Setter list-ref
See *Note Setters:: for a definition of "setter". N.B. `(setter
list-ref)' doesn't work properly for element 0 of a list.
Here is a sample collection: `simple-table' which is also a `table'.
(define-predicate TABLE?)
(define-operation (LOOKUP table key failure-object))
(define-operation (ASSOCIATE! table key value)) ;; returns key
(define-operation (REMOVE! table key)) ;; returns value
(define (MAKE-SIMPLE-TABLE)
(let ( (table (list)) )
(object
;; table behaviors
((TABLE? self) #t)
((SIZE self) (size table))
((PRINT self port) (format port "#<SIMPLE-TABLE>"))
((LOOKUP self key failure-object)
(cond
((assq key table) => cdr)
(else failure-object)
))
((ASSOCIATE! self key value)
(cond
((assq key table)
=> (lambda (bucket) (set-cdr! bucket value) key))
(else
(set! table (cons (cons key value) table))
key)
))
((REMOVE! self key);; returns old value
(cond
((null? table) (slib:error "TABLE:REMOVE! Key not found: " key))
((eq? key (caar table))
(let ( (value (cdar table)) )
(set! table (cdr table))
value)
)
(else
(let loop ( (last table) (this (cdr table)) )
(cond
((null? this)
(slib:error "TABLE:REMOVE! Key not found: " key))
((eq? key (caar this))
(let ( (value (cdar this)) )
(set-cdr! last (cdr this))
value)
)
(else
(loop (cdr last) (cdr this)))
) ) )
))
;; collection behaviors
((COLLECTION? self) #t)
((GEN-KEYS self) (collect:list-gen-elts (map car table)))
((GEN-ELTS self) (collect:list-gen-elts (map cdr table)))
((FOR-EACH-KEY self proc)
(for-each (lambda (bucket) (proc (car bucket))) table)
)
((FOR-EACH-ELT self proc)
(for-each (lambda (bucket) (proc (cdr bucket))) table)
)
) ) )

File: slib.info, Node: Dynamic Data Type, Next: Hash Tables, Prev: Collections, Up: Data Structures
Dynamic Data Type
-----------------
`(require 'dynamic)'
- Function: make-dynamic obj
Create and returns a new "dynamic" whose global value is OBJ.
- Function: dynamic? obj
Returns true if and only if OBJ is a dynamic. No object
satisfying `dynamic?' satisfies any of the other standard type
predicates.
- Function: dynamic-ref dyn
Return the value of the given dynamic in the current dynamic
environment.
- Procedure: dynamic-set! dyn obj
Change the value of the given dynamic to OBJ in the current
dynamic environment. The returned value is unspecified.
- Function: call-with-dynamic-binding dyn obj thunk
Invoke and return the value of the given thunk in a new, nested
dynamic environment in which the given dynamic has been bound to a
new location whose initial contents are the value OBJ. This
dynamic environment has precisely the same extent as the
invocation of the thunk and is thus captured by continuations
created within that invocation and re-established by those
continuations when they are invoked.
The `dynamic-bind' macro is not implemented.

File: slib.info, Node: Hash Tables, Next: Hashing, Prev: Dynamic Data Type, Up: Data Structures
Hash Tables
-----------
`(require 'hash-table)'
- Function: predicate->hash pred
Returns a hash function (like `hashq', `hashv', or `hash')
corresponding to the equality predicate PRED. PRED should be
`eq?', `eqv?', `equal?', `=', `char=?', `char-ci=?', `string=?', or
`string-ci=?'.
A hash table is a vector of association lists.
- Function: make-hash-table k
Returns a vector of K empty (association) lists.
Hash table functions provide utilities for an associative database.
These functions take an equality predicate, PRED, as an argument. PRED
should be `eq?', `eqv?', `equal?', `=', `char=?', `char-ci=?',
`string=?', or `string-ci=?'.
- Function: predicate->hash-asso pred
Returns a hash association function of 2 arguments, KEY and
HASHTAB, corresponding to PRED. The returned function returns a
key-value pair whose key is PRED-equal to its first argument or
`#f' if no key in HASHTAB is PRED-equal to the first argument.
- Function: hash-inquirer pred
Returns a procedure of 3 arguments, `hashtab' and `key', which
returns the value associated with `key' in `hashtab' or `#f' if
key does not appear in `hashtab'.
- Function: hash-associator pred
Returns a procedure of 3 arguments, HASHTAB, KEY, and VALUE, which
modifies HASHTAB so that KEY and VALUE associated. Any previous
value associated with KEY will be lost.
- Function: hash-remover pred
Returns a procedure of 2 arguments, HASHTAB and KEY, which
modifies HASHTAB so that the association whose key is KEY is
removed.
- Function: hash-map proc hash-table
Returns a new hash table formed by mapping PROC over the keys and
values of HASH-TABLE. PROC must be a function of 2 arguments
which returns the new value part.
- Function: hash-for-each proc hash-table
Applies PROC to each pair of keys and values of HASH-TABLE. PROC
must be a function of 2 arguments. The returned value is
unspecified.

File: slib.info, Node: Hashing, Next: Object, Prev: Hash Tables, Up: Data Structures
Hashing
-------
`(require 'hash)'
These hashing functions are for use in quickly classifying objects.
Hash tables use these functions.
- Function: hashq obj k
- Function: hashv obj k
- Function: hash obj k
Returns an exact non-negative integer less than K. For each
non-negative integer less than K there are arguments OBJ for which
the hashing functions applied to OBJ and K returns that integer.
For `hashq', `(eq? obj1 obj2)' implies `(= (hashq obj1 k) (hashq
obj2))'.
For `hashv', `(eqv? obj1 obj2)' implies `(= (hashv obj1 k) (hashv
obj2))'.
For `hash', `(equal? obj1 obj2)' implies `(= (hash obj1 k) (hash
obj2))'.
`hash', `hashv', and `hashq' return in time bounded by a constant.
Notice that items having the same `hash' implies the items have
the same `hashv' implies the items have the same `hashq'.
`(require 'sierpinski)'
- Function: make-sierpinski-indexer max-coordinate
Returns a procedure (eg hash-function) of 2 numeric arguments which
preserves _nearness_ in its mapping from NxN to N.
MAX-COORDINATE is the maximum coordinate (a positive integer) of a
population of points. The returned procedures is a function that
takes the x and y coordinates of a point, (non-negative integers)
and returns an integer corresponding to the relative position of
that point along a Sierpinski curve. (You can think of this as
computing a (pseudo-) inverse of the Sierpinski spacefilling
curve.)
Example use: Make an indexer (hash-function) for integer points
lying in square of integer grid points [0,99]x[0,99]:
(define space-key (make-sierpinski-indexer 100))
Now let's compute the index of some points:
(space-key 24 78) => 9206
(space-key 23 80) => 9172
Note that locations (24, 78) and (23, 80) are near in index and
therefore, because the Sierpinski spacefilling curve is
continuous, we know they must also be near in the plane. Nearness
in the plane does not, however, necessarily correspond to nearness
in index, although it _tends_ to be so.
Example applications:
* Sort points by Sierpinski index to get heuristic solution to
_travelling salesman problem_. For details of performance,
see L. Platzman and J. Bartholdi, "Spacefilling curves and the
Euclidean travelling salesman problem", JACM 36(4):719-737
(October 1989) and references therein.
* Use Sierpinski index as key by which to store 2-dimensional
data in a 1-dimensional data structure (such as a table).
Then locations that are near each other in 2-d space will
tend to be near each other in 1-d data structure; and
locations that are near in 1-d data structure will be near in
2-d space. This can significantly speed retrieval from
secondary storage because contiguous regions in the plane
will tend to correspond to contiguous regions in secondary
storage. (This is a standard technique for managing CAD/CAM
or geographic data.)
`(require 'soundex)'
- Function: soundex name
Computes the _soundex_ hash of NAME. Returns a string of an
initial letter and up to three digits between 0 and 6. Soundex
supposedly has the property that names that sound similar in normal
English pronunciation tend to map to the same key.
Soundex was a classic algorithm used for manual filing of personal
records before the advent of computers. It performs adequately for
English names but has trouble with other languages. |
See Knuth, Vol. 3 `Sorting and searching', pp 391-2
To manage unusual inputs, `soundex' omits all non-alphabetic
characters. Consequently, in this implementation:
(soundex <string of blanks>) => ""
(soundex "") => ""
Examples from Knuth:
(map soundex '("Euler" "Gauss" "Hilbert" "Knuth"
"Lloyd" "Lukasiewicz"))
=> ("E460" "G200" "H416" "K530" "L300" "L222")
(map soundex '("Ellery" "Ghosh" "Heilbronn" "Kant"
"Ladd" "Lissajous"))
=> ("E460" "G200" "H416" "K530" "L300" "L222")
Some cases in which the algorithm fails (Knuth):
(map soundex '("Rogers" "Rodgers")) => ("R262" "R326")
(map soundex '("Sinclair" "St. Clair")) => ("S524" "S324")
(map soundex '("Tchebysheff" "Chebyshev")) => ("T212" "C121")

File: slib.info, Node: Object, Next: Priority Queues, Prev: Hashing, Up: Data Structures
Macroless Object System
-----------------------
`(require 'object)'
This is the Macroless Object System written by Wade Humeniuk
(whumeniu@datap.ca). Conceptual Tributes: *Note Yasos::, MacScheme's
%object, CLOS, Lack of R4RS macros.
Concepts
--------
OBJECT
An object is an ordered association-list (by `eq?') of methods
(procedures). Methods can be added (`make-method!'), deleted
(`unmake-method!') and retrieved (`get-method'). Objects may
inherit methods from other objects. The object binds to the
environment it was created in, allowing closures to be used to
hide private procedures and data.
GENERIC-METHOD
A generic-method associates (in terms of `eq?') object's method.
This allows scheme function style to be used for objects. The
calling scheme for using a generic method is `(generic-method
object param1 param2 ...)'.
METHOD
A method is a procedure that exists in the object. To use a method
get-method must be called to look-up the method. Generic methods
implement the get-method functionality. Methods may be added to an
object associated with any scheme obj in terms of eq?
GENERIC-PREDICATE
A generic method that returns a boolean value for any scheme obj.
PREDICATE
A object's method asscociated with a generic-predicate. Returns
`#t'.
Procedures
----------
- Function: make-object ancestor ...
Returns an object. Current object implementation is a tagged
vector. ANCESTORs are optional and must be objects in terms of
object?. ANCESTORs methods are included in the object. Multiple
ANCESTORs might associate the same generic-method with a method.
In this case the method of the ANCESTOR first appearing in the
list is the one returned by `get-method'.
- Function: object? obj
Returns boolean value whether OBJ was created by make-object.
- Function: make-generic-method exception-procedure
Returns a procedure which be associated with an object's methods.
If EXCEPTION-PROCEDURE is specified then it is used to process
non-objects.
- Function: make-generic-predicate
Returns a boolean procedure for any scheme object.
- Function: make-method! object generic-method method
Associates METHOD to the GENERIC-METHOD in the object. The METHOD
overrides any previous association with the GENERIC-METHOD within
the object. Using `unmake-method!' will restore the object's
previous association with the GENERIC-METHOD. METHOD must be a
procedure.
- Function: make-predicate! object generic-preciate
Makes a predicate method associated with the GENERIC-PREDICATE.
- Function: unmake-method! object generic-method
Removes an object's association with a GENERIC-METHOD .
- Function: get-method object generic-method
Returns the object's method associated (if any) with the
GENERIC-METHOD. If no associated method exists an error is
flagged.
Examples
--------
(require 'object)
(define instantiate (make-generic-method))
(define (make-instance-object . ancestors)
(define self (apply make-object
(map (lambda (obj) (instantiate obj)) ancestors)))
(make-method! self instantiate (lambda (self) self))
self)
(define who (make-generic-method))
(define imigrate! (make-generic-method))
(define emigrate! (make-generic-method))
(define describe (make-generic-method))
(define name (make-generic-method))
(define address (make-generic-method))
(define members (make-generic-method))
(define society
(let ()
(define self (make-instance-object))
(define population '())
(make-method! self imigrate!
(lambda (new-person)
(if (not (eq? new-person self))
(set! population (cons new-person population)))))
(make-method! self emigrate!
(lambda (person)
(if (not (eq? person self))
(set! population
(comlist:remove-if (lambda (member)
(eq? member person))
population)))))
(make-method! self describe
(lambda (self)
(map (lambda (person) (describe person)) population)))
(make-method! self who
(lambda (self) (map (lambda (person) (name person))
population)))
(make-method! self members (lambda (self) population))
self))
(define (make-person %name %address)
(define self (make-instance-object society))
(make-method! self name (lambda (self) %name))
(make-method! self address (lambda (self) %address))
(make-method! self who (lambda (self) (name self)))
(make-method! self instantiate
(lambda (self)
(make-person (string-append (name self) "-son-of")
%address)))
(make-method! self describe
(lambda (self) (list (name self) (address self))))
(imigrate! self)
self)
Inverter Documentation
......................
Inheritance:
<inverter>::(<number> <description>)
Generic-methods
<inverter>::value => <number>::value
<inverter>::set-value! => <number>::set-value!
<inverter>::describe => <description>::describe
<inverter>::help
<inverter>::invert
<inverter>::inverter?
Number Documention
..................
Inheritance
<number>::()
Slots
<number>::<x>
Generic Methods
<number>::value
<number>::set-value!
Inverter code
.............
(require 'object)
(define value (make-generic-method (lambda (val) val)))
(define set-value! (make-generic-method))
(define invert (make-generic-method
(lambda (val)
(if (number? val)
(/ 1 val)
(error "Method not supported:" val)))))
(define noop (make-generic-method))
(define inverter? (make-generic-predicate))
(define describe (make-generic-method))
(define help (make-generic-method))
(define (make-number x)
(define self (make-object))
(make-method! self value (lambda (this) x))
(make-method! self set-value!
(lambda (this new-value) (set! x new-value)))
self)
(define (make-description str)
(define self (make-object))
(make-method! self describe (lambda (this) str))
(make-method! self help (lambda (this) "Help not available"))
self)
(define (make-inverter)
(let* ((self (make-object
(make-number 1)
(make-description "A number which can be inverted")))
(<value> (get-method self value)))
(make-method! self invert (lambda (self) (/ 1 (<value> self))))
(make-predicate! self inverter?)
(unmake-method! self help)
(make-method! self help
(lambda (self)
(display "Inverter Methods:") (newline)
(display " (value inverter) ==> n") (newline)))
self))
;;;; Try it out
(define invert! (make-generic-method))
(define x (make-inverter))
(make-method! x invert! (lambda (x) (set-value! x (/ 1 (value x)))))
(value x) => 1
(set-value! x 33) => undefined
(invert! x) => undefined
(value x) => 1/33
(unmake-method! x invert!) => undefined
(invert! x) error--> ERROR: Method not supported: x

File: slib.info, Node: Priority Queues, Next: Queues, Prev: Object, Up: Data Structures
Priority Queues
---------------
`(require 'priority-queue)'
- Function: make-heap pred<?
Returns a binary heap suitable which can be used for priority queue
operations.
- Function: heap-length heap
Returns the number of elements in HEAP.
- Procedure: heap-insert! heap item
Inserts ITEM into HEAP. ITEM can be inserted multiple times. The
value returned is unspecified.
- Function: heap-extract-max! heap
Returns the item which is larger than all others according to the
PRED<? argument to `make-heap'. If there are no items in HEAP, an
error is signaled.
The algorithm for priority queues was taken from `Introduction to
Algorithms' by T. Cormen, C. Leiserson, R. Rivest. 1989 MIT Press.

File: slib.info, Node: Queues, Next: Records, Prev: Priority Queues, Up: Data Structures
Queues
------
`(require 'queue)'
A "queue" is a list where elements can be added to both the front and
rear, and removed from the front (i.e., they are what are often called
"dequeues"). A queue may also be used like a stack.
- Function: make-queue
Returns a new, empty queue.
- Function: queue? obj
Returns `#t' if OBJ is a queue.
- Function: queue-empty? q
Returns `#t' if the queue Q is empty.
- Procedure: queue-push! q datum
Adds DATUM to the front of queue Q.
- Procedure: enquque! q datum
Adds DATUM to the rear of queue Q.
All of the following functions raise an error if the queue Q is empty.
- Function: queue-front q
Returns the datum at the front of the queue Q.
- Function: queue-rear q
Returns the datum at the rear of the queue Q.
- Prcoedure: queue-pop! q
- Procedure: dequeue! q
Both of these procedures remove and return the datum at the front
of the queue. `queue-pop!' is used to suggest that the queue is
being used like a stack.

File: slib.info, Node: Records, Next: Structures, Prev: Queues, Up: Data Structures
Records
-------
`(require 'record)'
The Record package provides a facility for user to define their own
record data types.
- Function: make-record-type type-name field-names
Returns a "record-type descriptor", a value representing a new data
type disjoint from all others. The TYPE-NAME argument must be a
string, but is only used for debugging purposes (such as the
printed representation of a record of the new type). The
FIELD-NAMES argument is a list of symbols naming the "fields" of a
record of the new type. It is an error if the list contains any
duplicates. It is unspecified how record-type descriptors are
represented.
- Function: record-constructor rtd [field-names]
Returns a procedure for constructing new members of the type
represented by RTD. The returned procedure accepts exactly as
many arguments as there are symbols in the given list,
FIELD-NAMES; these are used, in order, as the initial values of
those fields in a new record, which is returned by the constructor
procedure. The values of any fields not named in that list are
unspecified. The FIELD-NAMES argument defaults to the list of
field names in the call to `make-record-type' that created the
type represented by RTD; if the FIELD-NAMES argument is provided,
it is an error if it contains any duplicates or any symbols not in
the default list.
- Function: record-predicate rtd
Returns a procedure for testing membership in the type represented
by RTD. The returned procedure accepts exactly one argument and
returns a true value if the argument is a member of the indicated
record type; it returns a false value otherwise.
- Function: record-accessor rtd field-name
Returns a procedure for reading the value of a particular field of
a member of the type represented by RTD. The returned procedure
accepts exactly one argument which must be a record of the
appropriate type; it returns the current value of the field named
by the symbol FIELD-NAME in that record. The symbol FIELD-NAME
must be a member of the list of field-names in the call to
`make-record-type' that created the type represented by RTD.
- Function: record-modifier rtd field-name
Returns a procedure for writing the value of a particular field of
a member of the type represented by RTD. The returned procedure
accepts exactly two arguments: first, a record of the appropriate
type, and second, an arbitrary Scheme value; it modifies the field
named by the symbol FIELD-NAME in that record to contain the given
value. The returned value of the modifier procedure is
unspecified. The symbol FIELD-NAME must be a member of the list
of field-names in the call to `make-record-type' that created the
type represented by RTD.
In May of 1996, as a product of discussion on the `rrrs-authors'
mailing list, I rewrote `record.scm' to portably implement type
disjointness for record data types.
As long as an implementation's procedures are opaque and the `record'
code is loaded before other programs, this will give disjoint record
types which are unforgeable and incorruptible by R4RS procedures.
As a consequence, the procedures `record?', `record-type-descriptor',
`record-type-name'.and `record-type-field-names' are no longer
supported.

File: slib.info, Node: Structures, Prev: Records, Up: Data Structures
Structures
----------
`(require 'struct)' (uses defmacros)
`defmacro's which implement "records" from the book `Essentials of
Programming Languages' by Daniel P. Friedman, M. Wand and C.T. Haynes.
Copyright 1992 Jeff Alexander, Shinnder Lee, and Lewis Patterson
Matthew McDonald <mafm@cs.uwa.edu.au> added field setters.
- Macro: define-record tag (var1 var2 ...)
Defines several functions pertaining to record-name TAG:
- Function: make-TAG var1 var2 ...
- Function: TAG? obj
- Function: TAG->var1 obj
- Function: TAG->var2 obj
...
- Function: set-TAG-var1! obj val
- Function: set-TAG-var2! obj val
...
Here is an example of its use.
(define-record term (operator left right))
=> #<unspecified>
(define foo (make-term 'plus 1 2))
=> foo
(term->left foo)
=> 1
(set-term-left! foo 2345)
=> #<unspecified>
(term->left foo)
=> 2345
- Macro: variant-case exp (tag (var1 var2 ...) body) ...
executes the following for the matching clause:
((lambda (VAR1 VAR ...) BODY)
(TAG->VAR1 EXP)
(TAG->VAR2 EXP) ...)

File: slib.info, Node: Procedures, Next: Standards Support, Prev: Data Structures, Up: Other Packages
Procedures
==========
Anything that doesn't fall neatly into any of the other categories
winds up here.
* Menu:
* Common List Functions:: 'common-list-functions
* Tree Operations:: 'tree
* Type Coercion:: 'coerce |
* Chapter Ordering:: 'chapter-order
* Sorting:: 'sort
* Topological Sort:: Keep your socks on.
* String-Case:: 'string-case
* String Ports:: 'string-port
* String Search:: Also Search from a Port.
* Line I/O:: 'line-i/o
* Multi-Processing:: 'process
* Metric Units:: Portable manifest types for numeric values. |

File: slib.info, Node: Common List Functions, Next: Tree Operations, Prev: Procedures, Up: Procedures
Common List Functions
---------------------
`(require 'common-list-functions)'
The procedures below follow the Common LISP equivalents apart from
optional arguments in some cases.
* Menu:
* List construction::
* Lists as sets::
* Lists as sequences::
* Destructive list operations::
* Non-List functions::

File: slib.info, Node: List construction, Next: Lists as sets, Prev: Common List Functions, Up: Common List Functions
List construction
.................
- Function: make-list k . init
`make-list' creates and returns a list of K elements. If INIT is
included, all elements in the list are initialized to INIT.
Example:
(make-list 3)
=> (#<unspecified> #<unspecified> #<unspecified>)
(make-list 5 'foo)
=> (foo foo foo foo foo)
- Function: list* x . y
Works like `list' except that the cdr of the last pair is the last
argument unless there is only one argument, when the result is
just that argument. Sometimes called `cons*'. E.g.:
(list* 1)
=> 1
(list* 1 2 3)
=> (1 2 . 3)
(list* 1 2 '(3 4))
=> (1 2 3 4)
(list* ARGS '())
== (list ARGS)
- Function: copy-list lst
`copy-list' makes a copy of LST using new pairs and returns it.
Only the top level of the list is copied, i.e., pairs forming
elements of the copied list remain `eq?' to the corresponding
elements of the original; the copy is, however, not `eq?' to the
original, but is `equal?' to it.
Example:
(copy-list '(foo foo foo))
=> (foo foo foo)
(define q '(foo bar baz bang))
(define p q)
(eq? p q)
=> #t
(define r (copy-list q))
(eq? q r)
=> #f
(equal? q r)
=> #t
(define bar '(bar))
(eq? bar (car (copy-list (list bar 'foo))))
=> #t

File: slib.info, Node: Lists as sets, Next: Lists as sequences, Prev: List construction, Up: Common List Functions
Lists as sets
.............
`eqv?' is used to test for membership by procedures which treat lists
as sets.
- Function: adjoin e l
`adjoin' returns the adjoint of the element E and the list L.
That is, if E is in L, `adjoin' returns L, otherwise, it returns
`(cons E L)'.
Example:
(adjoin 'baz '(bar baz bang))
=> (bar baz bang)
(adjoin 'foo '(bar baz bang))
=> (foo bar baz bang)
- Function: union l1 l2
`union' returns the combination of L1 and L2. Duplicates between
L1 and L2 are culled. Duplicates within L1 or within L2 may or
may not be removed.
Example:
(union '(1 2 3 4) '(5 6 7 8))
=> (4 3 2 1 5 6 7 8)
(union '(1 2 3 4) '(3 4 5 6))
=> (2 1 3 4 5 6)
- Function: intersection l1 l2
`intersection' returns all elements that are in both L1 and L2.
Example:
(intersection '(1 2 3 4) '(3 4 5 6))
=> (4 3) |
(intersection '(1 2 3 4) '(5 6 7 8))
=> ()
- Function: set-difference l1 l2
`set-difference' returns all elements that are in L1 but not in L2.
Example:
(set-difference '(1 2 3 4) '(3 4 5 6))
=> (2 1) |
(set-difference '(1 2 3 4) '(1 2 3 4 5 6))
=> ()
- Function: member-if pred lst
`member-if' returns LST if `(PRED ELEMENT)' is `#t' for any
ELEMENT in LST. Returns `#f' if PRED does not apply to any
ELEMENT in LST.
Example:
(member-if vector? '(1 2 3 4))
=> #f
(member-if number? '(1 2 3 4))
=> (1 2 3 4)
- Function: some pred lst . more-lsts
PRED is a boolean function of as many arguments as there are list
arguments to `some' i.e., LST plus any optional arguments. PRED
is applied to successive elements of the list arguments in order.
`some' returns `#t' as soon as one of these applications returns
`#t', and is `#f' if none returns `#t'. All the lists should have
the same length.
Example:
(some odd? '(1 2 3 4))
=> #t
(some odd? '(2 4 6 8))
=> #f
(some > '(2 3) '(1 4))
=> #f
- Function: every pred lst . more-lsts
`every' is analogous to `some' except it returns `#t' if every
application of PRED is `#t' and `#f' otherwise.
Example:
(every even? '(1 2 3 4))
=> #f
(every even? '(2 4 6 8))
=> #t
(every > '(2 3) '(1 4))
=> #f
- Function: notany pred . lst
`notany' is analogous to `some' but returns `#t' if no application
of PRED returns `#t' or `#f' as soon as any one does.
- Function: notevery pred . lst
`notevery' is analogous to `some' but returns `#t' as soon as an
application of PRED returns `#f', and `#f' otherwise.
Example:
(notevery even? '(1 2 3 4))
=> #t
(notevery even? '(2 4 6 8))
=> #f
- Function: list-of?? predicate |
Returns a predicate which returns true if its argument is a list |
every element of which satisfies PREDICATE. |
|
- Function: list-of?? predicate low-bound high-bound |
LOW-BOUND and HIGH-BOUND are non-negative integers. `list-of??' |
returns a predicate which returns true if its argument is a list |
of length between LOW-BOUND and HIGH-BOUND (inclusive); every |
element of which satisfies PREDICATE. |
|
- Function: list-of?? predicate bound |
BOUND is an integer. If BOUND is negative, `list-of??' returns a |
predicate which returns true if its argument is a list of length |
greater than `(- BOUND)'; every element of which satisfies |
PREDICATE. Otherwise, `list-of??' returns a predicate which |
returns true if its argument is a list of length less than or |
equal to BOUND; every element of which satisfies PREDICATE. |
|
- Function: find-if pred lst
`find-if' searches for the first ELEMENT in LST such that `(PRED
ELEMENT)' returns `#t'. If it finds any such ELEMENT in LST,
ELEMENT is returned. Otherwise, `#f' is returned.
Example:
(find-if number? '(foo 1 bar 2))
=> 1
(find-if number? '(foo bar baz bang))
=> #f
(find-if symbol? '(1 2 foo bar))
=> foo
- Function: remove elt lst
`remove' removes all occurrences of ELT from LST using `eqv?' to
test for equality and returns everything that's left. N.B.: other
implementations (Chez, Scheme->C and T, at least) use `equal?' as
the equality test.
Example:
(remove 1 '(1 2 1 3 1 4 1 5))
=> (5 4 3 2) |
(remove 'foo '(bar baz bang))
=> (bang baz bar) |
- Function: remove-if pred lst
`remove-if' removes all ELEMENTs from LST where `(PRED ELEMENT)'
is `#t' and returns everything that's left.
Example:
(remove-if number? '(1 2 3 4))
=> ()
(remove-if even? '(1 2 3 4 5 6 7 8))
=> (7 5 3 1) |
- Function: remove-if-not pred lst
`remove-if-not' removes all ELEMENTs from LST for which `(PRED
ELEMENT)' is `#f' and returns everything that's left.
Example:
(remove-if-not number? '(foo bar baz))
=> ()
(remove-if-not odd? '(1 2 3 4 5 6 7 8))
=> (7 5 3 1) |
- Function: has-duplicates? lst
returns `#t' if 2 members of LST are `equal?', `#f' otherwise.
Example:
(has-duplicates? '(1 2 3 4))
=> #f
(has-duplicates? '(2 4 3 4))
=> #t
The procedure `remove-duplicates' uses `member' (rather than `memv').
- Function: remove-duplicates lst
returns a copy of LST with its duplicate members removed.
Elements are considered duplicate if they are `equal?'.
Example:
(remove-duplicates '(1 2 3 4))
=> (4 3 2 1)
(remove-duplicates '(2 4 3 4))
=> (3 4 2)

File: slib.info, Node: Lists as sequences, Next: Destructive list operations, Prev: Lists as sets, Up: Common List Functions
Lists as sequences
..................
- Function: position obj lst
`position' returns the 0-based position of OBJ in LST, or `#f' if
OBJ does not occur in LST.
Example:
(position 'foo '(foo bar baz bang))
=> 0
(position 'baz '(foo bar baz bang))
=> 2
(position 'oops '(foo bar baz bang))
=> #f
- Function: reduce p lst
`reduce' combines all the elements of a sequence using a binary
operation (the combination is left-associative). For example,
using `+', one can add up all the elements. `reduce' allows you to
apply a function which accepts only two arguments to more than 2
objects. Functional programmers usually refer to this as "foldl".
`collect:reduce' (*note Collections::) provides a version of
`collect' generalized to collections.
Example:
(reduce + '(1 2 3 4))
=> 10
(define (bad-sum . l) (reduce + l))
(bad-sum 1 2 3 4)
== (reduce + (1 2 3 4))
== (+ (+ (+ 1 2) 3) 4)
=> 10
(bad-sum)
== (reduce + ())
=> ()
(reduce string-append '("hello" "cruel" "world"))
== (string-append (string-append "hello" "cruel") "world")
=> "hellocruelworld"
(reduce anything '())
=> ()
(reduce anything '(x))
=> x
What follows is a rather non-standard implementation of `reverse'
in terms of `reduce' and a combinator elsewhere called "C".
;;; Contributed by Jussi Piitulainen (jpiitula@ling.helsinki.fi)
(define commute
(lambda (f)
(lambda (x y)
(f y x))))
(define reverse
(lambda (args)
(reduce-init (commute cons) '() args)))
- Function: reduce-init p init lst
`reduce-init' is the same as reduce, except that it implicitly
inserts INIT at the start of the list. `reduce-init' is preferred
if you want to handle the null list, the one-element, and lists
with two or more elements consistently. It is common to use the
operator's idempotent as the initializer. Functional programmers
usually call this "foldl".
Example:
(define (sum . l) (reduce-init + 0 l))
(sum 1 2 3 4)
== (reduce-init + 0 (1 2 3 4))
== (+ (+ (+ (+ 0 1) 2) 3) 4)
=> 10
(sum)
== (reduce-init + 0 '())
=> 0
(reduce-init string-append "@" '("hello" "cruel" "world"))
==
(string-append (string-append (string-append "@" "hello")
"cruel")
"world")
=> "@hellocruelworld"
Given a differentiation of 2 arguments, `diff', the following will
differentiate by any number of variables.
(define (diff* exp . vars)
(reduce-init diff exp vars))
Example:
;;; Real-world example: Insertion sort using reduce-init.
(define (insert l item)
(if (null? l)
(list item)
(if (< (car l) item)
(cons (car l) (insert (cdr l) item))
(cons item l))))
(define (insertion-sort l) (reduce-init insert '() l))
(insertion-sort '(3 1 4 1 5)
== (reduce-init insert () (3 1 4 1 5))
== (insert (insert (insert (insert (insert () 3) 1) 4) 1) 5)
== (insert (insert (insert (insert (3)) 1) 4) 1) 5)
== (insert (insert (insert (1 3) 4) 1) 5)
== (insert (insert (1 3 4) 1) 5)
== (insert (1 1 3 4) 5)
=> (1 1 3 4 5)
- Function: last lst n
`last' returns the last N elements of LST. N must be a
non-negative integer.
Example:
(last '(foo bar baz bang) 2)
=> (baz bang)
(last '(1 2 3) 0)
=> 0
- Function: butlast lst n
`butlast' returns all but the last N elements of LST.
Example:
(butlast '(a b c d) 3)
=> (a)
(butlast '(a b c d) 4)
=> ()
`last' and `butlast' split a list into two parts when given identical
arugments.
(last '(a b c d e) 2)
=> (d e)
(butlast '(a b c d e) 2)
=> (a b c)
- Function: nthcdr n lst
`nthcdr' takes N `cdr's of LST and returns the result. Thus
`(nthcdr 3 LST)' == `(cdddr LST)'
Example:
(nthcdr 2 '(a b c d))
=> (c d)
(nthcdr 0 '(a b c d))
=> (a b c d)
- Function: butnthcdr n lst
`butnthcdr' returns all but the nthcdr N elements of LST.
Example:
(butnthcdr 3 '(a b c d))
=> (a b c)
(butnthcdr 4 '(a b c d))
=> (a b c d) |
`nthcdr' and `butnthcdr' split a list into two parts when given
identical arugments.
(nthcdr 2 '(a b c d e))
=> (c d e)
(butnthcdr 2 '(a b c d e))
=> (a b)

File: slib.info, Node: Destructive list operations, Next: Non-List functions, Prev: Lists as sequences, Up: Common List Functions
Destructive list operations
...........................
These procedures may mutate the list they operate on, but any such
mutation is undefined.
- Procedure: nconc args
`nconc' destructively concatenates its arguments. (Compare this
with `append', which copies arguments rather than destroying them.)
Sometimes called `append!' (*note Rev2 Procedures::).
Example: You want to find the subsets of a set. Here's the
obvious way:
(define (subsets set)
(if (null? set)
'(())
(append (mapcar (lambda (sub) (cons (car set) sub))
(subsets (cdr set)))
(subsets (cdr set)))))
But that does way more consing than you need. Instead, you could
replace the `append' with `nconc', since you don't have any need
for all the intermediate results.
Example:
(define x '(a b c))
(define y '(d e f))
(nconc x y)
=> (a b c d e f)
x
=> (a b c d e f)
`nconc' is the same as `append!' in `sc2.scm'.
- Procedure: nreverse lst
`nreverse' reverses the order of elements in LST by mutating
`cdr's of the list. Sometimes called `reverse!'.
Example:
(define foo '(a b c))
(nreverse foo)
=> (c b a)
foo
=> (a)
Some people have been confused about how to use `nreverse',
thinking that it doesn't return a value. It needs to be pointed
out that
(set! lst (nreverse lst))
is the proper usage, not
(nreverse lst)
The example should suffice to show why this is the case.
- Procedure: delete elt lst
- Procedure: delete-if pred lst
- Procedure: delete-if-not pred lst
Destructive versions of `remove' `remove-if', and `remove-if-not'.
Example:
(define lst '(foo bar baz bang))
(delete 'foo lst)
=> (bar baz bang)
lst
=> (foo bar baz bang)
(define lst '(1 2 3 4 5 6 7 8 9))
(delete-if odd? lst)
=> (2 4 6 8)
lst
=> (1 2 4 6 8)
Some people have been confused about how to use `delete',
`delete-if', and `delete-if', thinking that they dont' return a
value. It needs to be pointed out that
(set! lst (delete el lst))
is the proper usage, not
(delete el lst)
The examples should suffice to show why this is the case.

File: slib.info, Node: Non-List functions, Prev: Destructive list operations, Up: Common List Functions
Non-List functions
..................
- Function: and? . args
`and?' checks to see if all its arguments are true. If they are,
`and?' returns `#t', otherwise, `#f'. (In contrast to `and', this
is a function, so all arguments are always evaluated and in an
unspecified order.)
Example:
(and? 1 2 3)
=> #t
(and #f 1 2)
=> #f
- Function: or? . args
`or?' checks to see if any of its arguments are true. If any is
true, `or?' returns `#t', and `#f' otherwise. (To `or' as `and?'
is to `and'.)
Example:
(or? 1 2 #f)
=> #t
(or? #f #f #f)
=> #f
- Function: atom? object
Returns `#t' if OBJECT is not a pair and `#f' if it is pair.
(Called `atom' in Common LISP.)
(atom? 1)
=> #t
(atom? '(1 2))
=> #f
(atom? #(1 2)) ; dubious!
=> #t
|

File: slib.info, Node: Tree Operations, Next: Type Coercion, Prev: Common List Functions, Up: Procedures
|
Tree operations
---------------
`(require 'tree)'
These are operations that treat lists a representations of trees.
- Function: subst new old tree
- Function: substq new old tree
- Function: substv new old tree
`subst' makes a copy of TREE, substituting NEW for every subtree
or leaf of TREE which is `equal?' to OLD and returns a modified
tree. The original TREE is unchanged, but may share parts with
the result.
`substq' and `substv' are similar, but test against OLD using
`eq?' and `eqv?' respectively.
Examples:
(substq 'tempest 'hurricane '(shakespeare wrote (the hurricane)))
=> (shakespeare wrote (the tempest))
(substq 'foo '() '(shakespeare wrote (twelfth night)))
=> (shakespeare wrote (twelfth night . foo) . foo)
(subst '(a . cons) '(old . pair)
'((old . spice) ((old . shoes) old . pair) (old . pair)))
=> ((old . spice) ((old . shoes) a . cons) (a . cons))
- Function: copy-tree tree
Makes a copy of the nested list structure TREE using new pairs and
returns it. All levels are copied, so that none of the pairs in
the tree are `eq?' to the original ones - only the leaves are.
Example:
(define bar '(bar))
(copy-tree (list bar 'foo))
=> ((bar) foo)
(eq? bar (car (copy-tree (list bar 'foo))))
=> #f

File: slib.info, Node: Type Coercion, Next: Chapter Ordering, Prev: Tree Operations, Up: Procedures
|
Type Coercion |
------------- |
|
`(require 'coerce)' |
|
- Function: type-of obj |
Returns a symbol name for the type of OBJ. |
|
- Function: coerce obj result-type |
Converts and returns OBJ of type `char', `number', `string', |
`symbol', `list', or `vector' to RESULT-TYPE (which must be one of |
these symbols). |
|

File: slib.info, Node: Chapter Ordering, Next: Sorting, Prev: Type Coercion, Up: Procedures
|
Chapter Ordering
----------------
`(require 'chapter-order)'
The `chap:' functions deal with strings which are ordered like
chapter numbers (or letters) in a book. Each section of the string
consists of consecutive numeric or consecutive aphabetic characters of
like case.
- Function: chap:string<? string1 string2
Returns #t if the first non-matching run of alphabetic upper-case
or the first non-matching run of alphabetic lower-case or the first
non-matching run of numeric characters of STRING1 is `string<?'
than the corresponding non-matching run of characters of STRING2.
(chap:string<? "a.9" "a.10") => #t
(chap:string<? "4c" "4aa") => #t
(chap:string<? "Revised^{3.99}" "Revised^{4}") => #t
- Function: chap:string>? string1 string2
- Function: chap:string<=? string1 string2
- Function: chap:string>=? string1 string2
Implement the corresponding chapter-order predicates.
- Function: chap:next-string string
Returns the next string in the _chapter order_. If STRING has no
alphabetic or numeric characters, `(string-append STRING "0")' is
returnd. The argument to chap:next-string will always be
`chap:string<?' than the result.
(chap:next-string "a.9") => "a.10"
(chap:next-string "4c") => "4d"
(chap:next-string "4z") => "4aa"
(chap:next-string "Revised^{4}") => "Revised^{5}"

File: slib.info, Node: Sorting, Next: Topological Sort, Prev: Chapter Ordering, Up: Procedures
Sorting
-------
`(require 'sort)'
Many Scheme systems provide some kind of sorting functions. They do
not, however, always provide the _same_ sorting functions, and those
that I have had the opportunity to test provided inefficient ones (a
common blunder is to use quicksort which does not perform well).
Because `sort' and `sort!' are not in the standard, there is very
little agreement about what these functions look like. For example,
Dybvig says that Chez Scheme provides
(merge predicate list1 list2)
(merge! predicate list1 list2)
(sort predicate list)
(sort! predicate list)
while MIT Scheme 7.1, following Common LISP, offers unstable
(sort list predicate)
TI PC Scheme offers
(sort! list/vector predicate?)
and Elk offers
(sort list/vector predicate?)
(sort! list/vector predicate?)
Here is a comprehensive catalogue of the variations I have found.
1. Both `sort' and `sort!' may be provided.
2. `sort' may be provided without `sort!'.
3. `sort!' may be provided without `sort'.
4. Neither may be provided.
5. The sequence argument may be either a list or a vector.
6. The sequence argument may only be a list.
7. The sequence argument may only be a vector.
8. The comparison function may be expected to behave like `<'.
9. The comparison function may be expected to behave like `<='.
10. The interface may be `(sort predicate? sequence)'.
11. The interface may be `(sort sequence predicate?)'.
12. The interface may be `(sort sequence &optional (predicate? <))'.
13. The sort may be stable.
14. The sort may be unstable.
All of this variation really does not help anybody. A nice simple
merge sort is both stable and fast (quite a lot faster than _quick_
sort).
I am providing this source code with no restrictions at all on its use
(but please retain D.H.D.Warren's credit for the original idea). You
may have to rename some of these functions in order to use them in a
system which already provides incompatible or inferior sorts. For each
of the functions, only the top-level define needs to be edited to do
that.
I could have given these functions names which would not clash with
any Scheme that I know of, but I would like to encourage implementors to
converge on a single interface, and this may serve as a hint. The
argument order for all functions has been chosen to be as close to
Common LISP as made sense, in order to avoid NIH-itis.
Each of the five functions has a required _last_ parameter which is a
comparison function. A comparison function `f' is a function of 2
arguments which acts like `<'. For example,
(not (f x x))
(and (f x y) (f y z)) == (f x z)
The standard functions `<', `>', `char<?', `char>?', `char-ci<?',
`char-ci>?', `string<?', `string>?', `string-ci<?', and `string-ci>?'
are suitable for use as comparison functions. Think of `(less? x y)'
as saying when `x' must _not_ precede `y'.
- Function: sorted? sequence less?
Returns `#t' when the sequence argument is in non-decreasing order
according to LESS? (that is, there is no adjacent pair `... x y
...' for which `(less? y x)').
Returns `#f' when the sequence contains at least one out-of-order
pair. It is an error if the sequence is neither a list nor a
vector.
- Function: merge list1 list2 less?
This merges two lists, producing a completely new list as result.
I gave serious consideration to producing a Common-LISP-compatible
version. However, Common LISP's `sort' is our `sort!' (well, in
fact Common LISP's `stable-sort' is our `sort!', merge sort is
_fast_ as well as stable!) so adapting CL code to Scheme takes a
bit of work anyway. I did, however, appeal to CL to determine the
_order_ of the arguments.
- Procedure: merge! list1 list2 less?
Merges two lists, re-using the pairs of LIST1 and LIST2 to build
the result. If the code is compiled, and LESS? constructs no new
pairs, no pairs at all will be allocated. The first pair of the
result will be either the first pair of LIST1 or the first pair of
LIST2, but you can't predict which.
The code of `merge' and `merge!' could have been quite a bit
simpler, but they have been coded to reduce the amount of work
done per iteration. (For example, we only have one `null?' test
per iteration.)
- Function: sort sequence less?
Accepts either a list or a vector, and returns a new sequence
which is sorted. The new sequence is the same type as the input.
Always `(sorted? (sort sequence less?) less?)'. The original
sequence is not altered in any way. The new sequence shares its
_elements_ with the old one; no elements are copied.
- Procedure: sort! sequence less?
Returns its sorted result in the original boxes. If the original
sequence is a list, no new storage is allocated at all. If the
original sequence is a vector, the sorted elements are put back in
the same vector.
Some people have been confused about how to use `sort!', thinking
that it doesn't return a value. It needs to be pointed out that
(set! slist (sort! slist <))
is the proper usage, not
(sort! slist <)
Note that these functions do _not_ accept a CL-style `:key' argument.
A simple device for obtaining the same expressiveness is to define
(define (keyed less? key)
(lambda (x y) (less? (key x) (key y))))
and then, when you would have written
(sort a-sequence #'my-less :key #'my-key)
in Common LISP, just write
(sort! a-sequence (keyed my-less? my-key))
in Scheme.

File: slib.info, Node: Topological Sort, Next: String-Case, Prev: Sorting, Up: Procedures
Topological Sort
----------------
`(require 'topological-sort)' or `(require 'tsort)'
The algorithm is inspired by Cormen, Leiserson and Rivest (1990)
`Introduction to Algorithms', chapter 23.
- Function: tsort dag pred
- Function: topological-sort dag pred
where
DAG
is a list of sublists. The car of each sublist is a vertex.
The cdr is the adjacency list of that vertex, i.e. a list of
all vertices to which there exists an edge from the car
vertex.
PRED
is one of `eq?', `eqv?', `equal?', `=', `char=?',
`char-ci=?', `string=?', or `string-ci=?'.
Sort the directed acyclic graph DAG so that for every edge from
vertex U to V, U will come before V in the resulting list of
vertices.
Time complexity: O (|V| + |E|)
Example (from Cormen):
Prof. Bumstead topologically sorts his clothing when getting
dressed. The first argument to `tsort' describes which
garments he needs to put on before others. (For example,
Prof Bumstead needs to put on his shirt before he puts on his
tie or his belt.) `tsort' gives the correct order of
dressing:
(require 'tsort)
(tsort '((shirt tie belt)
(tie jacket)
(belt jacket)
(watch)
(pants shoes belt)
(undershorts pants shoes)
(socks shoes))
eq?)
=>
(socks undershorts pants shoes watch shirt belt tie jacket)

File: slib.info, Node: String-Case, Next: String Ports, Prev: Topological Sort, Up: Procedures
String-Case
-----------
`(require 'string-case)'
- Procedure: string-upcase str
- Procedure: string-downcase str
- Procedure: string-capitalize str
The obvious string conversion routines. These are non-destructive.
- Function: string-upcase! str
- Function: string-downcase! str
- Function: string-captialize! str
The destructive versions of the functions above.
- Function: string-ci->symbol str
Converts string STR to a symbol having the same case as if the
symbol had been `read'.
- Function: symbol-append obj1 ... |
Converts OBJ1 ... to strings, appends them, and converts to a |
symbol which is returned. Strings and numbers are converted to |
read's symbol case; the case of symbol characters is not changed. |
#f is converted to the empty string (symbol). |
|

File: slib.info, Node: String Ports, Next: String Search, Prev: String-Case, Up: Procedures
String Ports
------------
`(require 'string-port)'
- Procedure: call-with-output-string proc
PROC must be a procedure of one argument. This procedure calls
PROC with one argument: a (newly created) output port. When the
function returns, the string composed of the characters written
into the port is returned.
- Procedure: call-with-input-string string proc
PROC must be a procedure of one argument. This procedure calls
PROC with one argument: an (newly created) input port from which
STRING's contents may be read. When PROC returns, the port is
closed and the value yielded by the procedure PROC is returned.

File: slib.info, Node: String Search, Next: Line I/O, Prev: String Ports, Up: Procedures
String Search
-------------
`(require 'string-search)'
- Procedure: string-index string char
- Procedure: string-index-ci string char
Returns the index of the first occurence of CHAR within STRING, or
`#f' if the STRING does not contain a character CHAR.
- Procedure: string-reverse-index string char
- Procedure: string-reverse-index-ci string char
Returns the index of the last occurence of CHAR within STRING, or
`#f' if the STRING does not contain a character CHAR.
- procedure: substring? pattern string
- procedure: substring-ci? pattern string
Searches STRING to see if some substring of STRING is equal to
PATTERN. `substring?' returns the index of the first character of
the first substring of STRING that is equal to PATTERN; or `#f' if
STRING does not contain PATTERN.
(substring? "rat" "pirate") => 2
(substring? "rat" "outrage") => #f
(substring? "" any-string) => 0
- Procedure: find-string-from-port? str in-port max-no-chars
Looks for a string STR within the first MAX-NO-CHARS chars of the
input port IN-PORT.
- Procedure: find-string-from-port? str in-port
When called with two arguments, the search span is limited by the
end of the input stream.
- Procedure: find-string-from-port? str in-port char
Searches up to the first occurrence of character CHAR in STR.
- Procedure: find-string-from-port? str in-port proc
Searches up to the first occurrence of the procedure PROC
returning non-false when called with a character (from IN-PORT)
argument.
When the STR is found, `find-string-from-port?' returns the number
of characters it has read from the port, and the port is set to
read the first char after that (that is, after the STR) The
function returns `#f' when the STR isn't found.
`find-string-from-port?' reads the port _strictly_ sequentially,
and does not perform any buffering. So `find-string-from-port?'
can be used even if the IN-PORT is open to a pipe or other
communication channel.
- Function: string-subst txt old1 new1 ...
Returns a copy of string TXT with all occurrences of string OLD1
in TXT replaced with NEW1, OLD2 replaced with NEW2 ....

File: slib.info, Node: Line I/O, Next: Multi-Processing, Prev: String Search, Up: Procedures
Line I/O
--------
`(require 'line-i/o)'
- Function: read-line
- Function: read-line port
Returns a string of the characters up to, but not including a
newline or end of file, updating PORT to point to the character
following the newline. If no characters are available, an end of
file object is returned. The PORT argument may be omitted, in
which case it defaults to the value returned by
`current-input-port'.
- Function: read-line! string
- Function: read-line! string port
Fills STRING with characters up to, but not including a newline or
end of file, updating the PORT to point to the last character read
or following the newline if it was read. If no characters are
available, an end of file object is returned. If a newline or end
of file was found, the number of characters read is returned.
Otherwise, `#f' is returned. The PORT argument may be omitted, in
which case it defaults to the value returned by
`current-input-port'.
- Function: write-line string
- Function: write-line string port
Writes STRING followed by a newline to the given PORT and returns
an unspecified value. The PORT argument may be omitted, in which
case it defaults to the value returned by `current-input-port'.
- Function: display-file path
- Function: display-file path port
Displays the contents of the file named by PATH to PORT. The PORT
argument may be ommited, in which case it defaults to the value
returned by `current-output-port'.

File: slib.info, Node: Multi-Processing, Next: Metric Units, Prev: Line I/O, Up: Procedures
|
Multi-Processing
----------------
`(require 'process)'
This module implements asynchronous (non-polled) time-sliced
multi-processing in the SCM Scheme implementation using procedures
`alarm' and `alarm-interrupt'. Until this is ported to another
implementation, consider it an example of writing schedulers in Scheme.
- Procedure: add-process! proc
Adds proc, which must be a procedure (or continuation) capable of
accepting accepting one argument, to the `process:queue'. The
value returned is unspecified. The argument to PROC should be
ignored. If PROC returns, the process is killed.
- Procedure: process:schedule!
Saves the current process on `process:queue' and runs the next
process from `process:queue'. The value returned is unspecified.
- Procedure: kill-process!
Kills the current process and runs the next process from
`process:queue'. If there are no more processes on
`process:queue', `(slib:exit)' is called (*note System::).

File: slib.info, Node: Metric Units, Prev: Multi-Processing, Up: Procedures
|
Metric Units |
------------ |
|
`(require 'metric-units)' |
|
<http://swissnet.ai.mit.edu/~jaffer/MIXF.html> |
|
"Metric Interchange Format" is a character string encoding for |
numerical values and units which: |
|
* is unambiguous in all locales; |
|
* uses only [TOG] "Portable Character Set" characters matching "Basic |
Latin" characters in Plane 0 of the Universal Character Set [UCS]; |
|
* is transparent to [UTF-7] and [UTF-8] UCS transformation formats; |
|
* is human readable and writable; |
|
* is machine readable and writable; |
|
* incorporates SI prefixes and units; |
|
* incorporates [ISO 6093] numbers; and |
|
* incorporates [IEC 60027-2] binary prefixes. |
|
In the expression for the value of a quantity, the unit symbol is |
placed after the numerical value. A dot (PERIOD, `.') is placed between |
the numerical value and the unit symbol. |
|
Within a compound unit, each of the base and derived symbols can |
optionally have an attached SI prefix. |
|
Unit symbols formed from other unit symbols by multiplication are |
indicated by means of a dot (PERIOD, `.') placed between them. |
|
Unit symbols formed from other unit symbols by division are indicated |
by means of a SOLIDUS (`/') or negative exponents. The SOLIDUS must |
not be repeated in the same compound unit unless contained within a |
parenthesized subexpression. |
|
The grouping formed by a prefix symbol attached to a unit symbol |
constitutes a new inseparable symbol (forming a multiple or submultiple |
of the unit concerned) which can be raised to a positive or negative |
power and which can be combined with other unit symbols to form compound |
unit symbols. |
|
The grouping formed by surrounding compound unit symbols with |
parentheses (`(' and `)') constitutes a new inseparable symbol which |
can be raised to a positive or negative power and which can be combined |
with other unit symbols to form compound unit symbols. |
|
Compound prefix symbols, that is, prefix symbols formed by the |
juxtaposition of two or more prefix symbols, are not permitted. |
|
Prefix symbols are not used with the time-related unit symbols min |
(minute), h (hour), d (day). No prefix symbol may be used with dB |
(decibel). Only submultiple prefix symbols may be used with the unit |
symbols L (liter), Np (neper), o (degree), oC (degree Celsius), rad |
(radian), and sr (steradian). Submultiple prefix symbols may not be |
used with the unit symbols t (metric ton), r (revolution), or Bd (baud). |
|
A unit exponent follows the unit, separated by a CIRCUMFLEX (`^'). |
Exponents may be positive or negative. Fractional exponents must be |
parenthesized. |
|
SI Prefixes |
........... |
|
Factor Name Symbol | Factor Name Symbol |
====== ==== ====== | ====== ==== ====== |
1e24 yotta Y | 1e-1 deci d |
1e21 zetta Z | 1e-2 centi c |
1e18 exa E | 1e-3 milli m |
1e15 peta P | 1e-6 micro u |
1e12 tera T | 1e-9 nano n |
1e9 giga G | 1e-12 pico p |
1e6 mega M | 1e-15 femto f |
1e3 kilo k | 1e-18 atto a |
1e2 hecto h | 1e-21 zepto z |
1e1 deka da | 1e-24 yocto y |
|
Binary Prefixes |
............... |
|
These binary prefixes are valid only with the units B (byte) and bit. |
However, decimal prefixes can also be used with bit; and decimal |
multiple (not submultiple) prefixes can also be used with B (byte). |
|
Factor (power-of-2) Name Symbol |
====== ============ ==== ====== |
1.152921504606846976e18 (2^60) exbi Ei |
1.125899906842624e15 (2^50) pebi Pi |
1.099511627776e12 (2^40) tebi Ti |
1.073741824e9 (2^30) gibi Gi |
1.048576e6 (2^20) mebi Mi |
1.024e3 (2^10) kibi Ki |
|
Unit Symbols |
............ |
|
Type of Quantity Name Symbol Equivalent |
================ ==== ====== ========== |
time second s |
time minute min = 60.s |
time hour h = 60.min |
time day d = 24.h |
frequency hertz Hz s^-1 |
signaling rate baud Bd s^-1 |
length meter m |
volume liter L dm^3 |
plane angle radian rad |
solid angle steradian sr rad^2 |
plane angle revolution * r = 6.283185307179586.rad |
plane angle degree * o = 2.777777777777778e-3.r |
information capacity bit bit |
information capacity byte, octet B = 8.bit |
mass gram g |
mass ton t Mg |
mass unified atomic mass unit u = 1.66053873e-27.kg |
amount of substance mole mol |
catalytic activity katal kat mol/s |
thermodynamic temperature kelvin K |
centigrade temperature degree Celsius oC |
luminous intensity candela cd |
luminous flux lumen lm cd.sr |
illuminance lux lx lm/m^2 |
force newton N m.kg.s^-2 |
pressure, stress pascal Pa N/m^2 |
energy, work, heat joule J N.m |
energy electronvolt eV = 1.602176462e-19.J |
power, radiant flux watt W J/s |
logarithm of power ratio neper Np |
logarithm of power ratio decibel * dB = 0.1151293.Np |
electric current ampere A |
electric charge coulomb C s.A |
electric potential, EMF volt V W/A |
capacitance farad F C/V |
electric resistance ohm Ohm V/A |
electric conductance siemens S A/V |
magnetic flux weber Wb V.s |
magnetic flux density tesla T Wb/m^2 |
inductance henry H Wb/A |
radionuclide activity becquerel Bq s^-1 |
absorbed dose energy gray Gy m^2.s^-2 |
dose equivalent sievert Sv m^2.s^-2 |
|
* The formulas are: |
|
* r/rad = 8 * atan(1) |
|
* o/r = 1 / 360 |
|
* db/Np = ln(10) / 20 |
|
- Function: si:conversion-factor to-unit from-unit |
If the strings FROM-UNIT and TO-UNIT express valid unit |
expressions for quantities of the same unit-dimensions, then the |
value returned by `si:conversion-factor' will be such that |
multiplying a numerical value expressed in FROM-UNITs by the |
returned conversion factor yields the numerical value expressed in |
TO-UNITs. |
|
Otherwise, `si:conversion-factor' returns: |
|
-3 |
if neither FROM-UNIT nor TO-UNIT is a syntactically valid |
unit. |
|
-2 |
if FROM-UNIT is not a syntactically valid unit. |
|
-1 |
if TO-UNIT is not a syntactically valid unit. |
|
0 |
if linear conversion (by a factor) is not possible. |
|
|
(si:conversion-factor "km/s" "m/s" ) => 0.001 |
(si:conversion-factor "N" "m/s" ) => 0 |
(si:conversion-factor "moC" "oC" ) => 1000 |
(si:conversion-factor "mK" "oC" ) => 0 |
(si:conversion-factor "rad" "o" ) => 0.0174533 |
(si:conversion-factor "K" "o" ) => 0 |
(si:conversion-factor "K" "K" ) => 1 |
(si:conversion-factor "oK" "oK" ) => -3 |
(si:conversion-factor "" "s/s" ) => 1 |
(si:conversion-factor "km/h" "mph" ) => -2 |
|

File: slib.info, Node: Standards Support, Next: Session Support, Prev: Procedures, Up: Other Packages
|
Standards Support
=================
* Menu:
* With-File:: 'with-file
* Transcripts:: 'transcript
* Rev2 Procedures:: 'rev2-procedures
* Rev4 Optional Procedures:: 'rev4-optional-procedures
* Multi-argument / and -:: 'multiarg/and-
* Multi-argument Apply:: 'multiarg-apply
* Rationalize:: 'rationalize
* Promises:: 'promise
* Dynamic-Wind:: 'dynamic-wind
* Eval:: 'eval
* Values:: 'values

File: slib.info, Node: With-File, Next: Transcripts, Prev: Standards Support, Up: Standards Support
With-File
---------
`(require 'with-file)'
- Function: with-input-from-file file thunk
- Function: with-output-to-file file thunk
Description found in R4RS.

File: slib.info, Node: Transcripts, Next: Rev2 Procedures, Prev: With-File, Up: Standards Support
Transcripts
-----------
`(require 'transcript)'
- Function: transcript-on filename
- Function: transcript-off filename
Redefines `read-char', `read', `write-char', `write', `display',
and `newline'.

File: slib.info, Node: Rev2 Procedures, Next: Rev4 Optional Procedures, Prev: Transcripts, Up: Standards Support
Rev2 Procedures
---------------
`(require 'rev2-procedures)'
The procedures below were specified in the `Revised^2 Report on
Scheme'. *N.B.*: The symbols `1+' and `-1+' are not `R4RS' syntax.
Scheme->C, for instance, barfs on this module.
- Procedure: substring-move-left! string1 start1 end1 string2 start2
- Procedure: substring-move-right! string1 start1 end1 string2 start2
STRING1 and STRING2 must be a strings, and START1, START2 and END1
must be exact integers satisfying
0 <= START1 <= END1 <= (string-length STRING1)
0 <= START2 <= END1 - START1 + START2 <= (string-length STRING2)
`substring-move-left!' and `substring-move-right!' store
characters of STRING1 beginning with index START1 (inclusive) and
ending with index END1 (exclusive) into STRING2 beginning with
index START2 (inclusive).
`substring-move-left!' stores characters in time order of
increasing indices. `substring-move-right!' stores characters in
time order of increasing indeces.
- Procedure: substring-fill! string start end char
Fills the elements START-END of STRING with the character CHAR.
- Function: string-null? str
== `(= 0 (string-length STR))'
- Procedure: append! . pairs
Destructively appends its arguments. Equivalent to `nconc'.
- Function: 1+ n
Adds 1 to N.
- Function: -1+ n
Subtracts 1 from N.
- Function: <?
- Function: <=?
- Function: =?
- Function: >?
- Function: >=?
These are equivalent to the procedures of the same name but
without the trailing `?'.

File: slib.info, Node: Rev4 Optional Procedures, Next: Multi-argument / and -, Prev: Rev2 Procedures, Up: Standards Support
Rev4 Optional Procedures
------------------------
`(require 'rev4-optional-procedures)'
For the specification of these optional procedures, *Note Standard
procedures: (r4rs)Standard procedures.
- Function: list-tail l p
- Function: string->list s
- Function: list->string l
- Function: string-copy
- Procedure: string-fill! s obj
- Function: list->vector l
- Function: vector->list s
- Procedure: vector-fill! s obj

File: slib.info, Node: Multi-argument / and -, Next: Multi-argument Apply, Prev: Rev4 Optional Procedures, Up: Standards Support
Multi-argument / and -
----------------------
`(require 'mutliarg/and-)'
For the specification of these optional forms, *Note Numerical
operations: (r4rs)Numerical operations. The `two-arg:'* forms are only
defined if the implementation does not support the many-argument forms.
- Function: two-arg:/ n1 n2
The original two-argument version of `/'.
- Function: / divident . divisors
- Function: two-arg:- n1 n2
The original two-argument version of `-'.
- Function: - minuend . subtrahends

File: slib.info, Node: Multi-argument Apply, Next: Rationalize, Prev: Multi-argument / and -, Up: Standards Support
Multi-argument Apply
--------------------
`(require 'multiarg-apply)'
For the specification of this optional form, *Note Control features:
(r4rs)Control features.
- Function: two-arg:apply proc l
The implementation's native `apply'. Only defined for
implementations which don't support the many-argument version.
- Function: apply proc . args

File: slib.info, Node: Rationalize, Next: Promises, Prev: Multi-argument Apply, Up: Standards Support
Rationalize
-----------
`(require 'rationalize)'
The procedure "rationalize" is interesting because most programming
languages do not provide anything analogous to it. Thanks to Alan
Bawden for contributing this algorithm.
- Function: rationalize x y
Computes the correct result for exact arguments (provided the
implementation supports exact rational numbers of unlimited
precision); and produces a reasonable answer for inexact arguments
when inexact arithmetic is implemented using floating-point.
`Rationalize' has limited use in implementations lacking exact
(non-integer) rational numbers. The following procedures return a list
of the numerator and denominator.
- Function: find-ratio x y
`find-ratio' returns the list of the _simplest_ numerator and
denominator whose quotient differs from X by no more than Y.
(find-ratio 3/97 .0001) => (3 97) |
(find-ratio 3/97 .001) => (1 32) |
- Function: find-ratio-between x y
`find-ratio-between' returns the list of the _simplest_ numerator
and denominator between X and Y.
(find-ratio-between 2/7 3/5) => (1 2) |
(find-ratio-between -3/5 -2/7) => (-1 2) |

File: slib.info, Node: Promises, Next: Dynamic-Wind, Prev: Rationalize, Up: Standards Support
Promises
--------
`(require 'promise)'
- Function: make-promise proc
Change occurrences of `(delay EXPRESSION)' to `(make-promise (lambda
() EXPRESSION))' and `(define force promise:force)' to implement
promises if your implementation doesn't support them (*note Control
features: (r4rs)Control features.).

File: slib.info, Node: Dynamic-Wind, Next: Eval, Prev: Promises, Up: Standards Support
Dynamic-Wind
------------
`(require 'dynamic-wind)'
This facility is a generalization of Common LISP `unwind-protect',
designed to take into account the fact that continuations produced by
`call-with-current-continuation' may be reentered.
- Procedure: dynamic-wind thunk1 thunk2 thunk3
The arguments THUNK1, THUNK2, and THUNK3 must all be procedures of
no arguments (thunks).
`dynamic-wind' calls THUNK1, THUNK2, and then THUNK3. The value
returned by THUNK2 is returned as the result of `dynamic-wind'.
THUNK3 is also called just before control leaves the dynamic
context of THUNK2 by calling a continuation created outside that
context. Furthermore, THUNK1 is called before reentering the
dynamic context of THUNK2 by calling a continuation created inside
that context. (Control is inside the context of THUNK2 if THUNK2
is on the current return stack).
*Warning:* There is no provision for dealing with errors or
interrupts. If an error or interrupt occurs while using
`dynamic-wind', the dynamic environment will be that in effect at
the time of the error or interrupt.

File: slib.info, Node: Eval, Next: Values, Prev: Dynamic-Wind, Up: Standards Support
Eval
----
`(require 'eval)'
- Function: eval expression environment-specifier
Evaluates EXPRESSION in the specified environment and returns its
value. EXPRESSION must be a valid Scheme expression represented
as data, and ENVIRONMENT-SPECIFIER must be a value returned by one
of the three procedures described below. Implementations may
extend `eval' to allow non-expression programs (definitions) as
the first argument and to allow other values as environments, with
the restriction that `eval' is not allowed to create new bindings
in the environments associated with `null-environment' or
`scheme-report-environment'.
(eval '(* 7 3) (scheme-report-environment 5))
=> 21
(let ((f (eval '(lambda (f x) (f x x))
(null-environment))))
(f + 10))
=> 20
- Function: scheme-report-environment version
- Function: null-environment version
- Function: null-environment
VERSION must be an exact non-negative integer N corresponding to a
version of one of the Revised^N Reports on Scheme.
`Scheme-report-environment' returns a specifier for an environment
that contains the set of bindings specified in the corresponding
report that the implementation supports. `Null-environment'
returns a specifier for an environment that contains only the
(syntactic) bindings for all the syntactic keywords defined in the
given version of the report.
Not all versions may be available in all implementations at all
times. However, an implementation that conforms to version N of
the Revised^N Reports on Scheme must accept version N. An error
is signalled if the specified version is not available.
The effect of assigning (through the use of `eval') a variable
bound in a `scheme-report-environment' (for example `car') is
unspecified. Thus the environments specified by
`scheme-report-environment' may be immutable.
- Function: interaction-environment
This optional procedure returns a specifier for the environment
that contains implementation-defined bindings, typically a
superset of those listed in the report. The intent is that this
procedure will return the environment in which the implementation
would evaluate expressions dynamically typed by the user.
Here are some more `eval' examples:
(require 'eval)
=> #<unspecified>
(define car 'volvo)
=> #<unspecified>
car
=> volvo
(eval 'car (interaction-environment))
=> volvo
(eval 'car (scheme-report-environment 5))
=> #<primitive-procedure car>
(eval '(eval 'car (interaction-environment))
(scheme-report-environment 5))
=> volvo
(eval '(eval '(set! car 'buick) (interaction-environment))
(scheme-report-environment 5))
=> #<unspecified>
car
=> buick
(eval 'car (scheme-report-environment 5))
=> #<primitive-procedure car>
(eval '(eval 'car (interaction-environment))
(scheme-report-environment 5))
=> buick

File: slib.info, Node: Values, Prev: Eval, Up: Standards Support
Values
------
`(require 'values)'
- Function: values obj ...
`values' takes any number of arguments, and passes (returns) them
to its continuation.
- Function: call-with-values thunk proc
THUNK must be a procedure of no arguments, and PROC must be a
procedure. `call-with-values' calls THUNK with a continuation
that, when passed some values, calls PROC with those values as
arguments.
Except for continuations created by the `call-with-values'
procedure, all continuations take exactly one value, as now; the
effect of passing no value or more than one value to continuations
that were not created by the `call-with-values' procedure is
unspecified.

File: slib.info, Node: Session Support, Next: Extra-SLIB Packages, Prev: Standards Support, Up: Other Packages
Session Support
===============
* Menu:
* Repl:: Macros at top-level
* Quick Print:: Loop-safe Output
* Debug:: To err is human ...
* Breakpoints:: Pause execution
* Trace:: 'trace
* System Interface:: 'system, 'getenv, and 'net-clients

File: slib.info, Node: Repl, Next: Quick Print, Prev: Session Support, Up: Session Support
Repl
----
`(require 'repl)'
Here is a read-eval-print-loop which, given an eval, evaluates forms.
- Procedure: repl:top-level repl:eval
`read's, `repl:eval's and `write's expressions from
`(current-input-port)' to `(current-output-port)' until an
end-of-file is encountered. `load', `slib:eval', `slib:error',
and `repl:quit' dynamically bound during `repl:top-level'.
- Procedure: repl:quit
Exits from the invocation of `repl:top-level'.
The `repl:' procedures establish, as much as is possible to do
portably, a top level environment supporting macros. `repl:top-level'
uses `dynamic-wind' to catch error conditions and interrupts. If your
implementation supports this you are all set.
Otherwise, if there is some way your implementation can catch error
conditions and interrupts, then have them call `slib:error'. It will
display its arguments and reenter `repl:top-level'. `slib:error'
dynamically bound by `repl:top-level'.
To have your top level loop always use macros, add any interrupt
catching lines and the following lines to your Scheme init file:
(require 'macro)
(require 'repl)
(repl:top-level macro:eval)

File: slib.info, Node: Quick Print, Next: Debug, Prev: Repl, Up: Session Support
Quick Print
-----------
`(require 'qp)'
When displaying error messages and warnings, it is paramount that the
output generated for circular lists and large data structures be
limited. This section supplies a procedure to do this. It could be
much improved.
Notice that the neccessity for truncating output eliminates
Common-Lisp's *Note Format:: from consideration; even when
variables `*print-level*' and `*print-level*' are set, huge
strings and bit-vectors are _not_ limited.
- Procedure: qp arg1 ...
- Procedure: qpn arg1 ...
- Procedure: qpr arg1 ...
`qp' writes its arguments, separated by spaces, to
`(current-output-port)'. `qp' compresses printing by substituting
`...' for substructure it does not have sufficient room to print.
`qpn' is like `qp' but outputs a newline before returning. `qpr'
is like `qpn' except that it returns its last argument.
- Variable: *qp-width*
`*qp-width*' is the largest number of characters that `qp' should
use.

File: slib.info, Node: Debug, Next: Breakpoints, Prev: Quick Print, Up: Session Support
Debug
-----
`(require 'debug)'
Requiring `debug' automatically requires `trace' and `break'.
An application with its own datatypes may want to substitute its own
printer for `qp'. This example shows how to do this:
(define qpn (lambda args) ...)
(provide 'qp)
(require 'debug)
- Procedure: trace-all file ...
Traces (*note Trace::) all procedures `define'd at top-level in
`file' ....
- Procedure: track-all file ...
Tracks (*note Trace::) all procedures `define'd at top-level in
`file' ....
- Procedure: stack-all file ...
Stacks (*note Trace::) all procedures `define'd at top-level in
`file' ....
- Procedure: break-all file ...
Breakpoints (*note Breakpoints::) all procedures `define'd at
top-level in `file' ....

File: slib.info, Node: Breakpoints, Next: Trace, Prev: Debug, Up: Session Support
Breakpoints
-----------
`(require 'break)'
- Function: init-debug
If your Scheme implementation does not support `break' or `abort',
a message will appear when you `(require 'break)' or `(require
'debug)' telling you to type `(init-debug)'. This is in order to
establish a top-level continuation. Typing `(init-debug)' at top
level sets up a continuation for `break'.
- Function: breakpoint arg1 ...
Returns from the top level continuation and pushes the
continuation from which it was called on a continuation stack.
- Function: continue
Pops the topmost continuation off of the continuation stack and
returns an unspecified value to it.
- Function: continue arg1 ...
Pops the topmost continuation off of the continuation stack and
returns ARG1 ... to it.
- Macro: break proc1 ...
Redefines the top-level named procedures given as arguments so that
`breakpoint' is called before calling PROC1 ....
- Macro: break
With no arguments, makes sure that all the currently broken
identifiers are broken (even if those identifiers have been
redefined) and returns a list of the broken identifiers.
- Macro: unbreak proc1 ...
Turns breakpoints off for its arguments.
- Macro: unbreak
With no arguments, unbreaks all currently broken identifiers and
returns a list of these formerly broken identifiers.
These are _procedures_ for breaking. If defmacros are not natively
supported by your implementation, these might be more convenient to use.
- Function: breakf proc
- Function: breakf proc name
To break, type
(set! SYMBOL (breakf SYMBOL))
or
(set! SYMBOL (breakf SYMBOL 'SYMBOL))
or
(define SYMBOL (breakf FUNCTION))
or
(define SYMBOL (breakf FUNCTION 'SYMBOL))
- Function: unbreakf proc
To unbreak, type
(set! SYMBOL (unbreakf SYMBOL))

File: slib.info, Node: Trace, Next: System Interface, Prev: Breakpoints, Up: Session Support
Tracing
-------
`(require 'trace)'
This feature provides three ways to monitor procedure invocations:
stack
Pushes the procedure-name when the procedure is called; pops when
it returns.
track
Pushes the procedure-name and arguments when the procedure is
called; pops when it returns.
trace
Pushes the procedure-name and prints `CALL PROCEDURE-NAME ARG1
...' when the procdure is called; pops and prints `RETN
PROCEDURE-NAME VALUE' when the procedure returns.
- Variable: debug:max-count
If a traced procedure calls itself or untraced procedures which
call it, stack, track, and trace will limit the number of stack
pushes to DEBUG:MAX-COUNT.
- Function: print-call-stack
- Function: print-call-stack port
Prints the call-stack to PORT or the current-error-port.
- Macro: trace proc1 ...
Traces the top-level named procedures given as arguments.
- Macro: trace
With no arguments, makes sure that all the currently traced
identifiers are traced (even if those identifiers have been
redefined) and returns a list of the traced identifiers.
- Macro: track proc1 ...
Traces the top-level named procedures given as arguments.
- Macro: track
With no arguments, makes sure that all the currently tracked
identifiers are tracked (even if those identifiers have been
redefined) and returns a list of the tracked identifiers.
- Macro: stack proc1 ...
Traces the top-level named procedures given as arguments.
- Macro: stack
With no arguments, makes sure that all the currently stacked
identifiers are stacked (even if those identifiers have been
redefined) and returns a list of the stacked identifiers.
- Macro: untrace proc1 ...
Turns tracing, tracking, and off for its arguments.
- Macro: untrace
With no arguments, untraces all currently traced identifiers and
returns a list of these formerly traced identifiers.
- Macro: untrack proc1 ...
Turns tracing, tracking, and off for its arguments.
- Macro: untrack
With no arguments, untracks all currently tracked identifiers and
returns a list of these formerly tracked identifiers.
- Macro: unstack proc1 ...
Turns tracing, stacking, and off for its arguments.
- Macro: unstack
With no arguments, unstacks all currently stacked identifiers and
returns a list of these formerly stacked identifiers.
These are _procedures_ for tracing. If defmacros are not natively
supported by your implementation, these might be more convenient to use.
- Function: tracef proc
- Function: tracef proc name
To trace, type
(set! SYMBOL (tracef SYMBOL))
or
(set! SYMBOL (tracef SYMBOL 'SYMBOL))
or
(define SYMBOL (tracef FUNCTION))
or
(define SYMBOL (tracef FUNCTION 'SYMBOL))
- Function: untracef proc
Removes tracing, tracking, or stacking for PROC. To untrace, type
(set! SYMBOL (untracef SYMBOL))

File: slib.info, Node: System Interface, Prev: Trace, Up: Session Support
System Interface
----------------
If `(provided? 'getenv)':
- Function: getenv name
Looks up NAME, a string, in the program environment. If NAME is
found a string of its value is returned. Otherwise, `#f' is
returned.
If `(provided? 'system)':
- Function: system command-string
Executes the COMMAND-STRING on the computer and returns the
integer status code.
If `system' is provided by the Scheme implementation, the "net-clients"
package provides interfaces to common network client programs like FTP,
mail, and Netscape.
`(require 'net-clients)'
- Function: call-with-tmpnam proc
- Function: call-with-tmpnam proc k
Calls PROC with K arguments, strings returned by successive calls
to `tmpnam'. If PROC returns, then any files named by the
arguments to PROC are deleted automatically and the value(s)
yielded by the PROC is(are) returned. K may be ommited, in which
case it defaults to `1'.
- Function: user-email-address
`user-email-address' returns a string of the form
`username@hostname'. If this e-mail address cannot be obtained,
#f is returned.
- Function: current-directory
`current-directory' returns a string containing the absolute file
name representing the current working directory. If this string
cannot be obtained, #f is returned.
If `current-directory' cannot be supported by the platform, the
value of `current-directory' is #f.
- Function: make-directory name
Creates a sub-directory NAME of the current-directory. If
successful, `make-directory' returns #t; otherwise #f.
- Function: null-directory? file-name
Returns #t if changing directory to FILE-NAME makes the current
working directory the same as it is before changing directory;
otherwise returns #f.
- Function: absolute-path? file-name
Returns #t if FILE-NAME is a fully specified pathname (does not
depend on the current working directory); otherwise returns #f.
- Function: glob-pattern? str
Returns #t if the string STR contains characters used for
specifying glob patterns, namely `*', `?', or `['.
- Function: parse-ftp-address uri |
Returns a list of the decoded FTP URI; or #f if indecipherable. |
FTP "Uniform Resource Locator", "ange-ftp", and "getit" formats
are handled. The returned list has four elements which are
strings or #f:
0. username
1. password
2. remote-site
3. remote-directory
- Function: ftp-upload paths user password remote-site remote-dir
PASSWORD must be a non-empty string or #f. PATHS must be a
non-empty list of pathnames or Glob patterns (*note Filenames::)
matching files to transfer.
`ftp-upload' puts the files specified by PATHS into the REMOTE-DIR
directory of FTP REMOTE-SITE using name USER with (optional)
PASSWORD.
If PASSWORD is #f and USER is not `ftp' or `anonymous', then USER
is ignored; FTP takes the username and password from the `.netrc'
or equivalent file.
- Function: path->uri path |
Returns a URI-string for PATH on the local host. |
- Function: browse-url-netscape url
If a `netscape' browser is running, `browse-url-netscape' causes
the browser to display the page specified by string URL and
returns #t.
If the browser is not running, `browse-url-netscape' runs
`netscape' with the argument URL. If the browser starts as a
background job, `browse-url-netscape' returns #t immediately; if
the browser starts as a foreground job, then `browse-url-netscape'
returns #t when the browser exits; otherwise it returns #f.

File: slib.info, Node: Extra-SLIB Packages, Prev: Session Support, Up: Other Packages
Extra-SLIB Packages
===================
Several Scheme packages have been written using SLIB. There are
several reasons why a package might not be included in the SLIB
distribution:
* Because it requires special hardware or software which is not
universal.
* Because it is large and of limited interest to most Scheme users.
* Because it has copying terms different enough from the other SLIB
packages that its inclusion would cause confusion.
* Because it is an application program, rather than a library module.
* Because I have been too busy to integrate it.
Once an optional package is installed (and an entry added to
`*catalog*', the `require' mechanism allows it to be called up and used
as easily as any other SLIB package. Some optional packages (for which
`*catalog*' already has entries) available from SLIB sites are:
SLIB-PSD
is a portable debugger for Scheme (requires emacs editor).
http://swissnet.ai.mit.edu/ftpdir/scm/slib-psd1-3.tar.gz
swissnet.ai.mit.edu:/pub/scm/slib-psd1-3.tar.gz
ftp.maths.tcd.ie:pub/bosullvn/jacal/slib-psd1-3.tar.gz
ftp.cs.indiana.edu:/pub/scheme-repository/utl/slib-psd1-3.tar.gz
With PSD, you can run a Scheme program in an Emacs buffer, set
breakpoints, single step evaluation and access and modify the
program's variables. It works by instrumenting the original source
code, so it should run with any R4RS compliant Scheme. It has been
tested with SCM, Elk 1.5, and the sci interpreter in the Scheme->C
system, but should work with other Schemes with a minimal amount
of porting, if at all. Includes documentation and user's manual.
Written by Pertti Kellom\"aki, pk@cs.tut.fi. The Lisp Pointers
article describing PSD (Lisp Pointers VI(1):15-23, January-March
1993) is available as
http://www.cs.tut.fi/staff/pk/scheme/psd/article/article.html
SCHELOG
is an embedding of Prolog in Scheme.
http://www.cs.rice.edu/CS/PLT/packages/schelog/
JFILTER
is a Scheme program which converts text among the JIS, EUC, and
Shift-JIS Japanese character sets.
http://www.sci.toyama-u.ac.jp/~iwao/Scheme/Jfilter/index.html

File: slib.info, Node: About SLIB, Next: Index, Prev: Other Packages, Up: Top
About SLIB
**********
More people than I can name have contributed to SLIB. Thanks to all of
you!
SLIB 2d1, released March 2001. |
Aubrey Jaffer <jaffer @ ai.mit.edu>
Hyperactive Software - The Maniac Inside!
<http://swissnet.ai.mit.edu/~jaffer/SLIB.html>
* Menu:
* Installation:: How to install SLIB on your system.
* Porting:: SLIB to new platforms.
* Coding Guidelines:: How to write modules for SLIB.
* Copyrights:: Intellectual propery issues.

File: slib.info, Node: Installation, Next: Porting, Prev: About SLIB, Up: About SLIB
Installation
============
Check the manifest in `README' to find a configuration file for your
Scheme implementation. Initialization files for most IEEE P1178
compliant Scheme Implementations are included with this distribution.
If the Scheme implementation supports `getenv', then the value of the
shell environment variable SCHEME_LIBRARY_PATH will be used for
`(library-vicinity)' if it is defined. Currently, Chez, Elk,
MITScheme, scheme->c, VSCM, and SCM support `getenv'. Scheme48
supports `getenv' but does not use it for determining
`library-vicinity'. (That is done from the Makefile.)
You should check the definitions of `software-type',
`scheme-implementation-version', `implementation-vicinity', and
`library-vicinity' in the initialization file. There are comments in
the file for how to configure it.
Once this is done you can modify the startup file for your Scheme
implementation to `load' this initialization file. SLIB is then
installed.
Multiple implementations of Scheme can all use the same SLIB
directory. Simply configure each implementation's initialization file
as outlined above.
- Implementation: SCM
The SCM implementation does not require any initialization file as
SLIB support is already built into SCM. See the documentation
with SCM for installation instructions.
- Implementation: VSCM
From: Matthias Blume <blume@cs.Princeton.EDU>
Date: Tue, 1 Mar 1994 11:42:31 -0500
Disclaimer: The code below is only a quick hack. If I find some
time to spare I might get around to make some more things work.
You have to provide `vscm.init' as an explicit command line
argument. Since this is not very nice I would recommend the
following installation procedure:
1. run scheme
2. `(load "vscm.init")'
3. `(slib:dump "dumpfile")'
4. mv dumpfile place-where-vscm-standard-bootfile-resides e.g.
mv dumpfile /usr/local/vscm/lib/scheme-boot (In this case
vscm should have been compiled with flag
-DDEFAULT_BOOTFILE='"/usr/local/vscm/lib/scheme-boot"'. See
Makefile (definition of DDP) for details.)
- Implementation: Scheme48
To make a Scheme48 image for an installation under `<prefix>',
1. `cd' to the SLIB directory
2. type `make prefix=<prefix> slib48'.
3. To install the image, type `make prefix=<prefix> install48'.
This will also create a shell script with the name `slib48'
which will invoke the saved image.
- Implementation: PLT Scheme
- Implementation: DrScheme
- Implementation: MzScheme
Date: Mon, 2 Oct 2000 21:29:48 -0400 (EDT)
From: Shriram Krishnamurthi <sk@cs.brown.edu>
We distribute an SLIB init file for our system. If you have PLT
Scheme (our preferred name for the entire suite, which includes
DrScheme, MzScheme and other implementations) installed, you ought
to be able to run "help-desk", or run `drscheme' and choose Help
Desk from the Help menu; in Help Desk, type `slib'. This will give
instructions for how to load the SLIB init file.

File: slib.info, Node: Porting, Next: Coding Guidelines, Prev: Installation, Up: About SLIB
Porting
=======
If there is no initialization file for your Scheme implementation, you
will have to create one. Your Scheme implementation must be largely
compliant with `IEEE Std 1178-1990', `Revised^4 Report on the
Algorithmic Language Scheme', or `Revised^5 Report on the Algorithmic
Language Scheme' in order to support SLIB. (1)
`Template.scm' is an example configuration file. The comments inside
will direct you on how to customize it to reflect your system. Give
your new initialization file the implementation's name with `.init'
appended. For instance, if you were porting `foo-scheme' then the
initialization file might be called `foo.init'.
Your customized version should then be loaded as part of your scheme
implementation's initialization. It will load `require.scm' from the
library; this will allow the use of `provide', `provided?', and
`require' along with the "vicinity" functions (these functions are
documented in the section *Note Require::). The rest of the library
will then be accessible in a system independent fashion.
Please mail new working configuration files to `jaffer @ ai.mit.edu'
so that they can be included in the SLIB distribution.
---------- Footnotes ----------
(1) If you are porting a `Revised^3 Report on the Algorithmic
Language Scheme' implementation, then you will need to finish writing
`sc4sc3.scm' and `load' it from your initialization file.

File: slib.info, Node: Coding Guidelines, Next: Copyrights, Prev: Porting, Up: About SLIB
Coding Guidelines
=================
All library packages are written in IEEE P1178 Scheme and assume that
a configuration file and `require.scm' package have already been
loaded. Other versions of Scheme can be supported in library packages
as well by using, for example, `(provided? 'rev3-report)' or `(require
'rev3-report)' (*note Require::).
The module name and `:' should prefix each symbol defined in the
package. Definitions for external use should then be exported by having
`(define foo module-name:foo)'.
Code submitted for inclusion in SLIB should not duplicate routines
already in SLIB files. Use `require' to force those library routines
to be used by your package. Care should be taken that there are no
circularities in the `require's and `load's between the library
packages.
Documentation should be provided in Emacs Texinfo format if possible,
But documentation must be provided.
Your package will be released sooner with SLIB if you send me a file
which tests your code. Please run this test _before_ you send me the
code!
Modifications
-------------
Please document your changes. A line or two for `ChangeLog' is
sufficient for simple fixes or extensions. Look at the format of
`ChangeLog' to see what information is desired. Please send me `diff'
files from the latest SLIB distribution (remember to send `diff's of
`slib.texi' and `ChangeLog'). This makes for less email traffic and
makes it easier for me to integrate when more than one person is
changing a file (this happens a lot with `slib.texi' and `*.init'
files).
If someone else wrote a package you want to significantly modify,
please try to contact the author, who may be working on a new version.
This will insure against wasting effort on obsolete versions.
Please _do not_ reformat the source code with your favorite
beautifier, make 10 fixes, and send me the resulting source code. I do
not have the time to fish through 10000 diffs to find your 10 real
fixes.

File: slib.info, Node: Copyrights, Prev: Coding Guidelines, Up: About SLIB
Copyrights
==========
This section has instructions for SLIB authors regarding copyrights.
Each package in SLIB must either be in the public domain, or come
with a statement of terms permitting users to copy, redistribute and
modify it. The comments at the beginning of `require.scm' and
`macwork.scm' illustrate copyright and appropriate terms.
If your code or changes amount to less than about 10 lines, you do not
need to add your copyright or send a disclaimer.
Putting code into the Public Domain
-----------------------------------
In order to put code in the public domain you should sign a copyright
disclaimer and send it to the SLIB maintainer. Contact jaffer @
ai.mit.edu for the address to mail the disclaimer to.
I, NAME, hereby affirm that I have placed the software package
NAME in the public domain.
I affirm that I am the sole author and sole copyright holder for
the software package, that I have the right to place this software
package in the public domain, and that I will do nothing to
undermine this status in the future.
SIGNATURE AND DATE
This wording assumes that you are the sole author. If you are not the
sole author, the wording needs to be different. If you don't want to be
bothered with sending a letter every time you release or modify a
module, make your letter say that it also applies to your future
revisions of that module.
Make sure no employer has any claim to the copyright on the work you
are submitting. If there is any doubt, create a copyright disclaimer
and have your employer sign it. Mail the signed disclaimer to the SLIB
maintainer. Contact jaffer @ ai.mit.edu for the address to mail the
disclaimer to. An example disclaimer follows.
Explicit copying terms
----------------------
If you submit more than about 10 lines of code which you are not placing
into the Public Domain (by sending me a disclaimer) you need to:
* Arrange that your name appears in a copyright line for the
appropriate year. Multiple copyright lines are acceptable.
* With your copyright line, specify any terms you require to be
different from those already in the file.
* Make sure no employer has any claim to the copyright on the work
you are submitting. If there is any doubt, create a copyright
disclaimer and have your employer sign it. Mail the signed
disclaim to the SLIB maintainer. Contact jaffer @ ai.mit.edu for
the address to mail the disclaimer to.
Example: Company Copyright Disclaimer
-------------------------------------
This disclaimer should be signed by a vice president or general
manager of the company. If you can't get at them, anyone else
authorized to license out software produced there will do. Here is a
sample wording:
EMPLOYER Corporation hereby disclaims all copyright interest in
the program PROGRAM written by NAME.
EMPLOYER Corporation affirms that it has no other intellectual
property interest that would undermine this release, and will do
nothing to undermine it in the future.
SIGNATURE AND DATE,
NAME, TITLE, EMPLOYER Corporation

File: slib.info, Node: Index, Prev: About SLIB, Up: Top
Procedure and Macro Index
*************************
This is an alphabetical list of all the procedures and macros in SLIB.
* Menu:
* -: Multi-argument / and -.
* -1+: Rev2 Procedures.
* /: Multi-argument / and -.
* 1+: Rev2 Procedures.
* <=?: Rev2 Procedures.
* <?: Rev2 Procedures.
* =?: Rev2 Procedures.
* >=?: Rev2 Procedures.
* >?: Rev2 Procedures.
* absolute-path?: System Interface.
* add-domain: Database Utilities.
* add-process!: Multi-Processing.
* add-setter: Setters.
* adjoin: Lists as sets.
* adjoin-parameters!: Parameter lists.
* alarm: Multi-Processing.
* alarm-interrupt: Multi-Processing.
* alist->wt-tree: Construction of Weight-Balanced Trees.
* alist-associator: Association Lists.
* alist-for-each: Association Lists.
* alist-inquirer: Association Lists.
* alist-map: Association Lists.
* alist-remover: Association Lists.
* and?: Non-List functions.
* any?: Collections.
* append!: Rev2 Procedures.
* apply: Multi-argument Apply.
* array-1d-ref: Arrays.
* array-1d-set!: Arrays.
* array-2d-ref: Arrays.
* array-2d-set!: Arrays.
* array-3d-ref: Arrays.
* array-3d-set!: Arrays.
* array-copy!: Array Mapping.
* array-dimensions: Arrays.
* array-for-each: Array Mapping.
* array-in-bounds?: Arrays.
* array-index-map!: Array Mapping.
* array-indexes: Array Mapping.
* array-map!: Array Mapping.
* array-rank: Arrays.
* array-ref: Arrays.
* array-set!: Arrays.
* array-shape: Arrays.
* array?: Arrays.
* asctime: Posix Time.
* ash: Bit-Twiddling.
* atom?: Non-List functions.
* batch:call-with-output-script: Batch.
* batch:command: Batch.
* batch:comment: Batch.
* batch:delete-file: Batch.
* batch:initialize!: Batch.
* batch:lines->file: Batch.
* batch:rename-file: Batch.
* batch:run-script: Batch.
* batch:try-chopped-command: Batch.
* batch:try-command: Batch.
* bit-extract: Bit-Twiddling.
* bit-field: Bit-Twiddling.
* bitwise-if: Bit-Twiddling.
* break: Breakpoints.
* break-all: Debug.
* breakf: Breakpoints.
* breakpoint: Breakpoints.
* browse: Database Browser.
* browse-url-netscape: System Interface.
* butlast: Lists as sequences.
* butnthcdr: Lists as sequences.
* byte-ref: Byte.
* byte-set!: Byte.
* bytes: Byte.
* bytes->list: Byte.
* bytes-length: Byte.
* call-with-dynamic-binding: Dynamic Data Type.
* call-with-input-string: String Ports.
* call-with-output-string: String Ports.
* call-with-tmpnam: System Interface.
* call-with-values: Values.
* capture-syntactic-environment: Syntactic Closures.
* cart-prod-tables: Relational Database Operations.
* catalog->html: HTML Tables. |
* cgi:serve-query: HTTP and CGI.
* chap:next-string: Chapter Ordering.
* chap:string<=?: Chapter Ordering.
* chap:string<?: Chapter Ordering.
* chap:string>=?: Chapter Ordering.
* chap:string>?: Chapter Ordering.
* check-parameters: Parameter lists.
* close-base: Base Table.
* close-database: Relational Database Operations.
* close-table: Table Operations.
* coerce: Type Coercion. |
* collection?: Collections.
* combined-rulesets: Commutative Rings.
* command->p-specs: HTML. |
* command:make-editable-table: HTML Tables. |
* command:modify-table: HTML Tables. |
* continue: Breakpoints.
* copy-bit: Bit-Twiddling.
* copy-bit-field: Bit-Twiddling.
* copy-list: List construction.
* copy-random-state: Random Numbers.
* copy-tree: Tree Operations.
* create-database <1>: Database Utilities.
* create-database: Creating and Opening Relational Databases.
* create-report: Database Reports.
* create-table: Relational Database Operations.
* create-view: Relational Database Operations.
* cring:define-rule: Commutative Rings.
* ctime: Posix Time.
* current-directory: System Interface.
* current-error-port: Input/Output.
* current-input-port <1>: Byte.
* current-input-port: Ruleset Definition and Use.
* current-output-port: Byte.
* current-time: Time and Date.
* db->html-directory: HTML Tables. |
* db->html-files: HTML Tables. |
* db->netscape: HTML Tables.
* decode-universal-time: Common-Lisp Time.
* define-access-operation: Setters.
* define-operation: Yasos interface.
* define-predicate: Yasos interface.
* define-record: Structures.
* define-syntax: Macro by Example.
* define-tables: Database Utilities.
* defmacro: Defmacro.
* defmacro:eval: Defmacro.
* defmacro:expand*: Defmacro.
* defmacro:load: Defmacro.
* defmacro?: Defmacro.
* delete <1>: Destructive list operations.
* delete: Base Table.
* delete*: Base Table.
* delete-domain: Database Utilities.
* delete-file: Input/Output.
* delete-if: Destructive list operations.
* delete-if-not: Destructive list operations.
* delete-table: Relational Database Operations.
* dequeue!: Queues.
* determinant: Determinant. |
* difftime: Time and Date.
* display-file: Line I/O.
* do-elts: Collections.
* do-keys: Collections.
* domain-checker: Database Utilities.
* dynamic-ref: Dynamic Data Type.
* dynamic-set!: Dynamic Data Type.
* dynamic-wind: Dynamic-Wind.
* dynamic?: Dynamic Data Type.
* empty?: Collections.
* encode-universal-time: Common-Lisp Time.
* enquque!: Queues.
* equal?: Byte.
* eval: Eval.
* every: Lists as sets.
* every?: Collections.
* extended-euclid: Modular Arithmetic.
* factor: Prime Numbers.
* fft: Fast Fourier Transform.
* fft-1: Fast Fourier Transform.
* file-exists?: Input/Output.
* filename:match-ci??: Filenames.
* filename:match??: Filenames.
* filename:substitute-ci??: Filenames.
* filename:substitute??: Filenames.
* fill-empty-parameters: Parameter lists.
* find-if: Lists as sets.
* find-ratio: Rationalize.
* find-ratio-between: Rationalize.
* find-string-from-port?: String Search.
* fluid-let: Fluid-Let.
* for-each-elt: Collections.
* for-each-key <1>: Collections.
* for-each-key: Base Table.
* for-each-row: Table Operations.
* force-output: Input/Output.
* form:delimited: HTML. |
* form:element: HTML. |
* form:image: HTML. |
* form:reset: HTML. |
* form:submit: HTML. |
* format: Format Interface.
* fprintf: Standard Formatted Output.
* fscanf: Standard Formatted Input.
* ftp-upload: System Interface.
* generic-write: Generic-Write.
* gentemp: Defmacro.
* get: Table Operations.
* get*: Table Operations.
* get-decoded-time: Common-Lisp Time.
* get-method: Object.
* get-universal-time: Common-Lisp Time.
* getenv: System Interface.
* getopt: Getopt.
* getopt--: Getopt.
* getopt->arglist: Getopt Parameter lists.
* getopt->parameter-list: Getopt Parameter lists.
* glob-pattern?: System Interface.
* gmktime: Posix Time.
* gmtime: Posix Time.
* golden-section-search: Minimizing.
* gtime: Posix Time.
* has-duplicates?: Lists as sets.
* hash: Hashing.
* hash-associator: Hash Tables.
* hash-for-each: Hash Tables.
* hash-inquirer: Hash Tables.
* hash-map: Hash Tables.
* hash-remover: Hash Tables.
* hashq: Hashing.
* hashv: Hashing.
* heap-extract-max!: Priority Queues.
* heap-insert!: Priority Queues.
* heap-length: Priority Queues.
* home-vicinity: Vicinity.
* html:anchor: URI. |
* html:atval: HTML.
* html:base: URI. |
* html:body: HTML.
* html:buttons: HTML. |
* html:caption: HTML Tables. |
* html:checkbox: HTML. |
* html:comment: HTML.
* html:editable-row-converter: HTML Tables. |
* html:form: HTML.
* html:head: HTML.
* html:heading: HTML Tables.
* html:hidden: HTML. |
* html:href-heading: HTML Tables.
* html:http-equiv: HTML. |
* html:isindex: URI. |
* html:link: URI. |
* html:linked-row-converter: HTML Tables. |
* html:meta: HTML. |
* html:meta-refresh: HTML. |
* html:plain: HTML.
* html:pre: HTML.
* html:select: HTML. |
* html:table: HTML Tables.
* html:text: HTML. |
* html:text-area: HTML. |
* http:content: HTTP and CGI.
* http:error-page: HTTP and CGI.
* http:forwarding-page: HTTP and CGI. |
* http:header: HTTP and CGI.
* http:serve-query: HTTP and CGI.
* identifier=?: Syntactic Closures.
* identifier?: Syntactic Closures.
* identity: Legacy.
* implementation-vicinity: Vicinity.
* in-vicinity: Vicinity.
* init-debug: Breakpoints.
* integer-expt: Bit-Twiddling.
* integer-length: Bit-Twiddling.
* integer-sqrt: Root Finding.
* interaction-environment: Eval.
* intersection: Lists as sets.
* jacobi-symbol: Prime Numbers.
* kill-process!: Multi-Processing.
* kill-table: Base Table.
* laguerre:find-polynomial-root: Root Finding.
* laguerre:find-root: Root Finding.
* last: Lists as sequences.
* last-pair: Legacy.
* library-vicinity: Vicinity.
* list*: List construction.
* list->bytes: Byte.
* list->string: Rev4 Optional Procedures.
* list->vector: Rev4 Optional Procedures.
* list-of??: Lists as sets. |
* list-table-definition: Database Utilities. |
* list-tail: Rev4 Optional Procedures.
* load-option: Weight-Balanced Trees.
* localtime: Posix Time.
* logand: Bit-Twiddling.
* logbit?: Bit-Twiddling.
* logcount: Bit-Twiddling.
* logior: Bit-Twiddling.
* lognot: Bit-Twiddling.
* logtest: Bit-Twiddling.
* logxor: Bit-Twiddling.
* macro:eval <1>: Syntax-Case Macros.
* macro:eval <2>: Syntactic Closures.
* macro:eval <3>: Macros That Work.
* macro:eval: R4RS Macros.
* macro:expand <1>: Syntax-Case Macros.
* macro:expand <2>: Syntactic Closures.
* macro:expand <3>: Macros That Work.
* macro:expand: R4RS Macros.
* macro:load <1>: Syntax-Case Macros.
* macro:load <2>: Syntactic Closures.
* macro:load <3>: Macros That Work.
* macro:load: R4RS Macros.
* macroexpand: Defmacro.
* macroexpand-1: Defmacro.
* macwork:eval: Macros That Work.
* macwork:expand: Macros That Work.
* macwork:load: Macros That Work.
* make-: Structures.
* make-array: Arrays.
* make-base: Base Table.
* make-bytes: Byte.
* make-command-server: Database Utilities.
* make-directory: System Interface.
* make-dynamic: Dynamic Data Type.
* make-generic-method: Object.
* make-generic-predicate: Object.
* make-getter: Base Table.
* make-hash-table: Hash Tables.
* make-heap: Priority Queues.
* make-key->list: Base Table.
* make-key-extractor: Base Table.
* make-keyifier-1: Base Table.
* make-list: List construction.
* make-list-keyifier: Base Table.
* make-method!: Object.
* make-object: Object.
* make-parameter-list: Parameter lists.
* make-port-crc: Cyclic Checksum.
* make-predicate!: Object.
* make-promise: Promises.
* make-putter: Base Table.
* make-query-alist-command-server: HTTP and CGI. |
* make-queue: Queues.
* make-random-state: Random Numbers.
* make-record-type: Records.
* make-relational-system: Creating and Opening Relational Databases.
* make-ruleset: Commutative Rings.
* make-shared-array: Arrays.
* make-sierpinski-indexer: Hashing.
* make-syntactic-closure: Syntactic Closures.
* make-table: Base Table.
* make-uri: URI. |
* make-vicinity: Vicinity.
* make-wt-tree: Construction of Weight-Balanced Trees.
* make-wt-tree-type: Construction of Weight-Balanced Trees.
* map-elts: Collections.
* map-key: Base Table.
* map-keys: Collections.
* member-if: Lists as sets.
* merge: Sorting.
* merge!: Sorting.
* mktime: Posix Time.
* modular:: Modular Arithmetic.
* modular:*: Modular Arithmetic.
* modular:+: Modular Arithmetic.
* modular:expt: Modular Arithmetic.
* modular:invert: Modular Arithmetic.
* modular:invertable?: Modular Arithmetic.
* modular:negate: Modular Arithmetic.
* modular:normalize: Modular Arithmetic.
* modulus->integer: Modular Arithmetic.
* must-be-first: Batch.
* must-be-last: Batch.
* nconc: Destructive list operations.
* newton:find-root: Root Finding.
* newtown:find-integer-root: Root Finding.
* notany: Lists as sets.
* notevery: Lists as sets.
* nreverse: Destructive list operations.
* nthcdr: Lists as sequences.
* null-directory?: System Interface.
* null-environment: Eval.
* object: Yasos interface.
* object->limited-string: Object-To-String.
* object->string: Object-To-String.
* object-with-ancestors: Yasos interface.
* object?: Object.
* offset-time: Time and Date.
* open-base: Base Table.
* open-database <1>: Database Utilities.
* open-database: Creating and Opening Relational Databases.
* open-database!: Database Utilities.
* open-table <1>: Relational Database Operations.
* open-table: Base Table.
* operate-as: Yasos interface.
* or?: Non-List functions.
* ordered-for-each-key: Base Table.
* os->batch-dialect: Batch.
* output-port-height: Input/Output.
* output-port-width: Input/Output.
* parameter-list->arglist: Parameter lists.
* parameter-list-expand: Parameter lists.
* parameter-list-ref: Parameter lists.
* parse-ftp-address: System Interface.
* path->uri: System Interface. |
* plot!: Plotting.
* plot-function!: Plotting.
* pnm:array-write: Portable Image Files.
* pnm:image-file->array: Portable Image Files.
* pnm:type-dimensions: Portable Image Files.
* position: Lists as sequences.
* pprint-file: Pretty-Print.
* pprint-filter-file: Pretty-Print.
* prec:commentfix: Grammar Rule Definition.
* prec:define-grammar: Ruleset Definition and Use.
* prec:delim: Grammar Rule Definition.
* prec:infix: Grammar Rule Definition.
* prec:inmatchfix: Grammar Rule Definition.
* prec:make-led: Nud and Led Definition.
* prec:make-nud: Nud and Led Definition.
* prec:matchfix: Grammar Rule Definition.
* prec:nary: Grammar Rule Definition.
* prec:nofix: Grammar Rule Definition.
* prec:parse: Ruleset Definition and Use.
* prec:postfix: Grammar Rule Definition.
* prec:prefix: Grammar Rule Definition.
* prec:prestfix: Grammar Rule Definition.
* predicate->asso: Association Lists.
* predicate->hash: Hash Tables.
* predicate->hash-asso: Hash Tables.
* present?: Base Table.
* pretty-print: Pretty-Print.
* pretty-print->string: Pretty-Print. |
* prime?: Prime Numbers.
* primes<: Prime Numbers.
* primes>: Prime Numbers.
* print: Yasos interface.
* print-call-stack: Trace.
* printf: Standard Formatted Output.
* process:schedule!: Multi-Processing.
* program-vicinity: Vicinity.
* project-table: Relational Database Operations.
* provide <1>: Require.
* provide: Feature.
* provided? <1>: Require.
* provided?: Feature.
* qp: Quick Print.
* qpn: Quick Print.
* qpr: Quick Print.
* queue-empty?: Queues.
* queue-front: Queues.
* queue-pop!: Queues.
* queue-push!: Queues.
* queue-rear: Queues.
* queue?: Queues.
* random: Random Numbers.
* random:exp: Random Numbers.
* random:hollow-sphere!: Random Numbers.
* random:normal: Random Numbers.
* random:normal-vector!: Random Numbers.
* random:solid-sphere!: Random Numbers.
* random:uniform: Random Numbers.
* rationalize: Rationalize.
* read-byte: Byte.
* read-command: Command Line.
* read-line: Line I/O.
* read-line!: Line I/O.
* read-options-file: Command Line.
* record-accessor: Records.
* record-constructor: Records.
* record-modifier: Records.
* record-predicate: Records.
* reduce <1>: Lists as sequences.
* reduce: Collections.
* reduce-init: Lists as sequences.
* remove: Lists as sets.
* remove-duplicates: Lists as sets.
* remove-if: Lists as sets.
* remove-if-not: Lists as sets.
* remove-parameter: Parameter lists.
* remove-setter-for: Setters.
* repl:quit: Repl.
* repl:top-level: Repl.
* replace-suffix: Filenames.
* require <1>: Require.
* require <2>: Catalog Compilation.
* require: Requesting Features.
* require:feature->path <1>: Require.
* require:feature->path: Requesting Features.
* restrict-table: Relational Database Operations.
* row:delete: Table Operations.
* row:delete*: Table Operations.
* row:insert: Table Operations.
* row:insert*: Table Operations.
* row:remove: Table Operations.
* row:remove*: Table Operations.
* row:retrieve: Table Operations.
* row:retrieve*: Table Operations.
* row:update: Table Operations.
* row:update*: Table Operations.
* scanf: Standard Formatted Input.
* scanf-read-list: Standard Formatted Input.
* scheme-report-environment: Eval.
* schmooz: Schmooz.
* secant:find-bracketed-root: Root Finding.
* secant:find-root: Root Finding.
* seed->random-state: Random Numbers.
* set: Setters.
* set-: Structures.
* set-difference: Lists as sets.
* Setter: Collections.
* setter: Setters.
* si:conversion-factor: Metric Units. |
* singleton-wt-tree: Construction of Weight-Balanced Trees.
* size <1>: Collections.
* size: Yasos interface.
* slib:error: System.
* slib:eval: System.
* slib:eval-load: System.
* slib:exit: System.
* slib:load: System.
* slib:load-compiled: System.
* slib:load-source: System.
* slib:report: Configuration.
* slib:report-version: Configuration.
* slib:warn: System.
* software-type: Configuration.
* some: Lists as sets.
* sort: Sorting.
* sort!: Sorting.
* sorted?: Sorting.
* soundex: Hashing.
* sprintf: Standard Formatted Output.
* sscanf: Standard Formatted Input.
* stack: Trace.
* stack-all: Debug.
* string->list: Rev4 Optional Procedures.
* string-capitalize: String-Case.
* string-captialize!: String-Case.
* string-ci->symbol: String-Case.
* string-copy: Rev4 Optional Procedures.
* string-downcase: String-Case.
* string-downcase!: String-Case.
* string-fill!: Rev4 Optional Procedures.
* string-index: String Search.
* string-index-ci: String Search.
* string-join: Batch.
* string-null?: Rev2 Procedures.
* string-reverse-index: String Search.
* string-reverse-index-ci: String Search.
* string-subst: String Search.
* string-upcase: String-Case.
* string-upcase!: String-Case.
* sub-vicinity: Vicinity.
* subst: Tree Operations.
* substq: Tree Operations.
* substring-ci?: String Search.
* substring-fill!: Rev2 Procedures.
* substring-move-left!: Rev2 Procedures.
* substring-move-right!: Rev2 Procedures.
* substring?: String Search.
* substv: Tree Operations.
* supported-key-type?: Base Table.
* supported-type?: Base Table.
* symbol-append: String-Case. |
* symmetric:modulus: Modular Arithmetic.
* sync-base: Base Table.
* sync-database: Relational Database Operations. |
* syncase:eval: Syntax-Case Macros.
* syncase:expand: Syntax-Case Macros.
* syncase:load: Syntax-Case Macros.
* synclo:eval: Syntactic Closures.
* synclo:expand: Syntactic Closures.
* synclo:load: Syntactic Closures.
* syntax-rules: Macro by Example.
* system: System Interface.
* table->linked-html: HTML Tables. |
* table->linked-page: HTML Tables. |
* table-exists?: Relational Database Operations.
* table-name->filename: HTML Tables.
* TAG: Structures.
* tek40:draw: Tektronix Graphics Support.
* tek40:graphics: Tektronix Graphics Support.
* tek40:init: Tektronix Graphics Support.
* tek40:linetype: Tektronix Graphics Support.
* tek40:move: Tektronix Graphics Support.
* tek40:put-text: Tektronix Graphics Support.
* tek40:reset: Tektronix Graphics Support.
* tek40:text: Tektronix Graphics Support.
* tek41:draw: Tektronix Graphics Support.
* tek41:encode-int: Tektronix Graphics Support.
* tek41:encode-x-y: Tektronix Graphics Support.
* tek41:graphics: Tektronix Graphics Support.
* tek41:init: Tektronix Graphics Support.
* tek41:move: Tektronix Graphics Support.
* tek41:point: Tektronix Graphics Support.
* tek41:reset: Tektronix Graphics Support.
* time-zone: Time Zone.
* tmpnam: Input/Output.
* tok:char-group: Token definition.
* topological-sort: Topological Sort.
* trace: Trace.
* trace-all: Debug.
* tracef: Trace.
* track: Trace.
* track-all: Debug.
* transcript-off: Transcripts.
* transcript-on: Transcripts.
* transformer: Syntactic Closures.
* truncate-up-to: Batch.
* tsort: Topological Sort.
* two-arg:-: Multi-argument / and -.
* two-arg:/: Multi-argument / and -.
* two-arg:apply: Multi-argument Apply.
* type-of: Type Coercion. |
* tz:params: Time Zone.
* tzset: Time Zone.
* unbreak: Breakpoints.
* unbreakf: Breakpoints.
* union: Lists as sets.
* unmake-method!: Object.
* unstack: Trace.
* untrace: Trace.
* untracef: Trace.
* untrack: Trace.
* uri->tree: URI. |
* uric:decode: URI. |
* uric:encode: URI. |
* user-email-address: System Interface.
* user-vicinity: Vicinity.
* values: Values.
* variant-case: Structures.
* vector->list: Rev4 Optional Procedures.
* vector-fill!: Rev4 Optional Procedures.
* with-input-from-file: With-File.
* with-output-to-file: With-File.
* write-base: Base Table.
* write-byte: Byte.
* write-database: Relational Database Operations.
* write-line: Line I/O.
* wt-tree/add: Basic Operations on Weight-Balanced Trees.
* wt-tree/add!: Basic Operations on Weight-Balanced Trees.
* wt-tree/delete: Basic Operations on Weight-Balanced Trees.
* wt-tree/delete!: Basic Operations on Weight-Balanced Trees.
* wt-tree/delete-min: Indexing Operations on Weight-Balanced Trees.
* wt-tree/delete-min!: Indexing Operations on Weight-Balanced Trees.
* wt-tree/difference: Advanced Operations on Weight-Balanced Trees.
* wt-tree/empty?: Basic Operations on Weight-Balanced Trees.
* wt-tree/fold: Advanced Operations on Weight-Balanced Trees.
* wt-tree/for-each: Advanced Operations on Weight-Balanced Trees.
* wt-tree/index: Indexing Operations on Weight-Balanced Trees.
* wt-tree/index-datum: Indexing Operations on Weight-Balanced Trees.
* wt-tree/index-pair: Indexing Operations on Weight-Balanced Trees.
* wt-tree/intersection: Advanced Operations on Weight-Balanced Trees.
* wt-tree/lookup: Basic Operations on Weight-Balanced Trees.
* wt-tree/member?: Basic Operations on Weight-Balanced Trees.
* wt-tree/min: Indexing Operations on Weight-Balanced Trees.
* wt-tree/min-datum: Indexing Operations on Weight-Balanced Trees.
* wt-tree/min-pair: Indexing Operations on Weight-Balanced Trees.
* wt-tree/rank: Indexing Operations on Weight-Balanced Trees.
* wt-tree/set-equal?: Advanced Operations on Weight-Balanced Trees.
* wt-tree/size: Basic Operations on Weight-Balanced Trees.
* wt-tree/split<: Advanced Operations on Weight-Balanced Trees.
* wt-tree/split>: Advanced Operations on Weight-Balanced Trees.
* wt-tree/subset?: Advanced Operations on Weight-Balanced Trees.
* wt-tree/union: Advanced Operations on Weight-Balanced Trees.
* wt-tree?: Basic Operations on Weight-Balanced Trees.
Variable Index
**************
This is an alphabetical list of all the global variables in SLIB.
* Menu:
* *catalog*: Require.
* *features*: Require.
* *http:byline*: HTTP and CGI.
* *modules*: Require.
* *optarg*: Getopt.
* *optind*: Getopt.
* *qp-width*: Quick Print.
* *random-state*: Random Numbers.
* *ruleset*: Commutative Rings.
* *syn-defs*: Ruleset Definition and Use.
* *syn-ignore-whitespace*: Ruleset Definition and Use.
* *timezone*: Time Zone.
* batch:platform: Batch.
* catalog-id: Base Table.
* char-code-limit: Configuration.
* charplot:height: Plotting.
* charplot:width: Plotting.
* column-domains: Table Operations.
* column-foreigns: Table Operations.
* column-names: Table Operations.
* column-types: Table Operations.
* daylight?: Time Zone.
* debug:max-count: Trace.
* distribute*: Commutative Rings.
* distribute/: Commutative Rings.
* most-positive-fixnum: Configuration.
* nil: Legacy.
* number-wt-type: Construction of Weight-Balanced Trees.
* primary-limit: Table Operations.
* prime:prngs: Prime Numbers.
* prime:trials: Prime Numbers.
* slib:form-feed: Configuration.
* slib:tab: Configuration.
* stderr: Standard Formatted I/O.
* stdin: Standard Formatted I/O.
* stdout: Standard Formatted I/O.
* string-wt-type: Construction of Weight-Balanced Trees.
* t: Legacy.
* tok:decimal-digits: Token definition.
* tok:lower-case: Token definition.
* tok:upper-case: Token definition.
* tok:whitespaces: Token definition.
* tzname: Time Zone.
Concept and Feature Index
*************************
* Menu:
* alist: Association Lists.
* alist-table <1>: Creating and Opening Relational Databases.
* alist-table: Base Table.
* ange-ftp: System Interface.
* array: Arrays.
* array-for-each: Array Mapping.
* attribute-value: HTML.
* balanced binary trees: Weight-Balanced Trees.
* base: URI. |
* batch: Batch.
* binary trees: Weight-Balanced Trees.
* binary trees, as discrete maps: Weight-Balanced Trees.
* binary trees, as sets: Weight-Balanced Trees.
* break: Breakpoints.
* byte: Byte.
* calendar time <1>: Posix Time.
* calendar time: Time and Date.
* Calendar-Time: Posix Time.
* caltime: Posix Time.
* careful: Commutative Rings.
* catalog: Requesting Features.
* Catalog File: Library Catalogs.
* chapter-order: Chapter Ordering.
* charplot: Plotting.
* coerce: Type Coercion. |
* collect: Collections.
* command line: Command Line.
* commentfix: Precedence Parsing Overview.
* common-list-functions <1>: Common List Functions.
* common-list-functions: Collections.
* commutative-ring: Commutative Rings.
* Coordinated Universal Time: Posix Time.
* database-utilities <1>: Database Utilities.
* database-utilities: Batch.
* debug <1>: Breakpoints.
* debug: Debug.
* defmacroexpand <1>: Pretty-Print.
* defmacroexpand: Defmacro.
* delim: Precedence Parsing Overview.
* discrete maps, using binary trees: Weight-Balanced Trees.
* DrScheme: Installation.
* dynamic: Dynamic Data Type.
* dynamic-wind: Dynamic-Wind.
* escaped: URI. |
* Euclidean Domain: Commutative Rings.
* factor: Prime Numbers.
* feature <1>: About this manual.
* feature <2>: Requesting Features.
* feature: Feature.
* fft: Fast Fourier Transform.
* fluid-let <1>: Database Utilities.
* fluid-let: Fluid-Let.
* form: HTML.
* format: Format.
* generic-write: Generic-Write.
* getit: System Interface.
* getopt <1>: Database Utilities.
* getopt: Getopt.
* glob <1>: Batch.
* glob: Filenames.
* hash: Hashing.
* hash-table: Hash Tables.
* HOME <1>: Vicinity.
* HOME: Library Catalogs.
* homecat: Catalog Compilation.
* implcat: Catalog Compilation.
* infix: Precedence Parsing Overview.
* inmatchfix: Precedence Parsing Overview.
* Left Denotation, led: Nud and Led Definition.
* line-i: Line I/O.
* logical: Bit-Twiddling.
* macro <1>: Repl.
* macro: R4RS Macros.
* macro-by-example: Macro by Example.
* macros-that-work: Macros That Work.
* make-crc: Cyclic Checksum.
* match: Base Table.
* match-keys <1>: Table Operations.
* match-keys: Base Table.
* matchfix: Precedence Parsing Overview.
* metric-units: Metric Units. |
* minimize: Minimizing.
* minimum field width (printf): Standard Formatted Output.
* mkimpcat.scm: Catalog Compilation.
* mklibcat.scm: Catalog Compilation.
* modular: Modular Arithmetic.
* multiarg-apply: Multi-argument Apply.
* mutliarg: Multi-argument / and -.
* MzScheme: Installation.
* nary: Precedence Parsing Overview.
* net-clients: System Interface.
* new-catalog: Catalog Compilation. |
* nofix: Precedence Parsing Overview.
* null: HTML Tables. |
* Null Denotation, nud: Nud and Led Definition.
* object: Object.
* object->string: Object-To-String.
* oop: Yasos.
* option, run-time-loadable: Weight-Balanced Trees.
* options file: Command Line.
* parameters <1>: Database Utilities.
* parameters <2>: Batch.
* parameters: Parameter lists.
* parse: Precedence Parsing.
* plain-text: HTML.
* PLT Scheme: Installation.
* posix-time: Posix Time.
* postfix: Precedence Parsing Overview.
* pprint-file: Pretty-Print.
* PRE: HTML.
* precedence: Precedence Parsing.
* precision (printf): Standard Formatted Output.
* prefix: Precedence Parsing Overview.
* prestfix: Precedence Parsing Overview.
* pretty-print: Pretty-Print.
* primes: Prime Numbers.
* printf: Standard Formatted Output.
* priority-queue: Priority Queues.
* PRNG: Random Numbers.
* process: Multi-Processing.
* promise: Promises.
* qp <1>: Quick Print.
* qp: Getopt.
* query-string: HTTP and CGI.
* queue: Queues.
* random: Random Numbers.
* rationalize: Rationalize.
* read-command: Command Line.
* record: Records.
* relational-database: Relational Database.
* repl <1>: Repl.
* repl: Syntax-Case Macros.
* reset: HTML.
* rev2-procedures: Rev2 Procedures.
* rev3-report: Coding Guidelines.
* rev4-optional-procedures: Rev4 Optional Procedures.
* ring, commutative: Commutative Rings.
* RNG: Random Numbers.
* root: Root Finding.
* run-time-loadable option: Weight-Balanced Trees.
* scanf: Standard Formatted Input.
* Scheme48: Installation.
* schmooz: Schmooz.
* SCM: Installation.
* Server-based Naming Authority: URI. |
* session: Feature.
* sets, using binary trees: Weight-Balanced Trees.
* sierpinski: Hashing.
* sitecat: Catalog Compilation.
* slibcat: Catalog Compilation.
* sort: Sorting.
* soundex: Hashing.
* stdio: Standard Formatted I/O.
* string-case: String-Case.
* string-port: String Ports.
* string-search: String Search.
* struct: Structures.
* syntactic-closures: Syntactic Closures.
* syntax-case: Syntax-Case Macros.
* time: Time and Date.
* time-zone: Time Zone.
* topological-sort: Topological Sort.
* trace: Trace.
* transcript: Transcripts.
* tree: Tree Operations.
* trees, balanced binary: Weight-Balanced Trees.
* tsort: Topological Sort.
* TZ-string: Time Zone.
* Uniform Resource Identifiers: URI. |
* Uniform Resource Locator: System Interface.
* Unique Factorization: Commutative Rings.
* unsafe: URI. |
* URI: HTTP and CGI.
* usercat: Catalog Compilation.
* UTC: Posix Time.
* values: Values.
* VSCM: Installation.
* weight-balanced binary trees: Weight-Balanced Trees.
* wild-card: Base Table.
* with-file: With-File.
* wt-tree: Weight-Balanced Trees.
* yasos: Yasos.

Tag Table:
Node: Top1026
Node: The Library System1740
Node: Feature2054
Node: Requesting Features3004
Node: Library Catalogs4363
Node: Catalog Compilation6815
Node: Built-in Support9624
Node: Require10255
Node: Vicinity12747
Node: Configuration15714
Node: Input/Output18655
Node: Legacy20254
Node: System21096
Node: About this manual23588
Node: Scheme Syntax Extension Packages24145
Node: Defmacro24830
Node: R4RS Macros26781
Node: Macro by Example28036
Node: Macros That Work30913
Node: Syntactic Closures36971
Node: Syntax-Case Macros54405
Node: Fluid-Let58531
Node: Yasos59472
Node: Yasos terms60265
Node: Yasos interface61289
Node: Setters63364
Node: Yasos examples66005
Node: Textual Conversion Packages68999
Node: Precedence Parsing69697
Node: Precedence Parsing Overview70360
Ref: Precedence Parsing Overview-Footnote-172358
Node: Ruleset Definition and Use72561
Node: Token definition74942
Node: Nud and Led Definition77211
Node: Grammar Rule Definition79660
Node: Format87234
Node: Format Interface87482
Node: Format Specification89219
Node: Standard Formatted I/O99349
Node: Standard Formatted Output99915
Node: Standard Formatted Input109182
Node: Programs and Arguments115842
Node: Getopt116342
Node: Command Line122184
Node: Parameter lists125373
Node: Getopt Parameter lists129358
Node: Filenames133527
Node: Batch136757
Node: HTML144550
Node: HTML Tables155838
Node: HTTP and CGI166135
Node: URI171452
Node: Printing Scheme177162
Node: Generic-Write177550
Node: Object-To-String178953
Node: Pretty-Print179357
Node: Time and Date184343
Node: Time Zone185370
Node: Posix Time189931
Node: Common-Lisp Time192067
Node: Vector Graphics193646
Node: Tektronix Graphics Support193835
Node: Schmooz195209
Node: Mathematical Packages199435
Node: Bit-Twiddling200069
Node: Modular Arithmetic204660
Node: Prime Numbers206794
Node: Random Numbers208477
Node: Fast Fourier Transform213113
Node: Cyclic Checksum214031
Node: Plotting216292
Node: Root Finding219151
Node: Minimizing223138
Ref: Minimizing-Footnote-1208597
Node: Commutative Rings225178
Node: Determinant236562
Node: Database Packages237120
Node: Base Table237384
Node: Relational Database247798
Node: Motivations248582
Node: Creating and Opening Relational Databases253629
Node: Relational Database Operations256061
Node: Table Operations259258
Node: Catalog Representation267136
Node: Unresolved Issues270034
Node: Database Utilities272985
Node: Database Reports289598
Node: Database Browser292352
Node: Weight-Balanced Trees293413
Node: Construction of Weight-Balanced Trees297284
Node: Basic Operations on Weight-Balanced Trees300734
Node: Advanced Operations on Weight-Balanced Trees303699
Node: Indexing Operations on Weight-Balanced Trees309721
Node: Other Packages313635
Node: Data Structures314034
Node: Arrays314790
Node: Array Mapping317744
Node: Association Lists319661
Node: Byte321912
Node: Portable Image Files324152
Node: Collections325699
Node: Dynamic Data Type331817
Node: Hash Tables333078
Node: Hashing335195
Node: Object339989
Node: Priority Queues348225
Node: Queues349068
Node: Records350194
Node: Structures353705
Node: Procedures355005
Node: Common List Functions355852
Node: List construction356276
Node: Lists as sets357939
Node: Lists as sequences365060
Node: Destructive list operations370366
Node: Non-List functions373029
Node: Tree Operations374174
Node: Type Coercion375796
Node: Chapter Ordering377022
Node: Sorting378719
Node: Topological Sort384496
Node: String-Case386183
Node: String Ports387284
Node: String Search388048
Node: Line I/O390415
Node: Multi-Processing392065
Node: Metric Units393248
Node: Standards Support408689
Node: With-File409423
Node: Transcripts409699
Node: Rev2 Procedures410020
Node: Rev4 Optional Procedures411727
Node: Multi-argument / and -412297
Node: Multi-argument Apply412948
Node: Rationalize413434
Node: Promises414876
Node: Dynamic-Wind415293
Node: Eval416547
Node: Values419884
Node: Session Support420671
Node: Repl421139
Node: Quick Print422422
Node: Debug423535
Node: Breakpoints424421
Node: Trace426444
Node: System Interface429555
Node: Extra-SLIB Packages433443
Node: About SLIB435743
Node: Installation436407
Node: Porting439635
Ref: Porting-Footnote-1413781
Node: Coding Guidelines441153
Node: Copyrights443234
Node: Index446519

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