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* data-rep.texi (Immediates vs. Non-immediates): Update

Browse source 
out-of-date documentation.  (Thanks to Dirk Herrmann for the
report!)
(Immediates vs Non-immediates): Renamed without the dot, since the
dot causes `info' not to be able to display this node!

* Makefile.am (guile_TEXINFOS): Add in a few more source files
that had got left out.
This commit is contained in:
Neil Jerram 2001-04-02 21:53:20 +00:00
parent f5e645584a
commit abaec75d1d
3 changed files with 25 additions and 24 deletions
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11
doc/ChangeLog
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@ -1,3 +1,14 @@
2001-04-02 Neil Jerram <neil@ossau.uklinux.net>
* data-rep.texi (Immediates vs. Non-immediates): Update
out-of-date documentation. (Thanks to Dirk Herrmann for the
report!)
(Immediates vs Non-immediates): Renamed without the dot, since the
dot causes `info' not to be able to display this node!
* Makefile.am (guile_TEXINFOS): Add in a few more source files
that had got left out.
2001-03-30 Neil Jerram <neil@ossau.uklinux.net>
* scheme-reading.texi (Further Reading): Add bullets to further

3
doc/Makefile.am
View file

@ -31,7 +31,8 @@ guile_TEXINFOS = preface.texi intro.texi scheme-intro.texi \
scheme-translation.texi scheme-debug.texi deprecated.texi \
scheme-reading.texi scheme-indices.texi slib.texi posix.texi \
expect.texi scsh.texi tcltk.texi scripts.texi gh.texi scm.texi \
appendices.texi indices.texi script-getopt.texi
appendices.texi indices.texi script-getopt.texi data-rep.texi \
extend.texi
goops_TEXINFOS = goops-tutorial.texi hierarchy.eps hierarchy.txt

35
doc/data-rep.texi
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@ -46,7 +46,7 @@
@c essay @sp 10
@c essay @comment The title is printed in a large font.
@c essay @title Data Representation in Guile
@c essay @subtitle $Id: data-rep.texi,v 1.17 2001-03-09 08:21:59 ossau Exp $
@c essay @subtitle $Id: data-rep.texi,v 1.18 2001-04-02 21:53:20 ossau Exp $
@c essay @subtitle For use with Guile @value{VERSION}
@c essay @author Jim Blandy
@c essay @author Free Software Foundation
@ -433,7 +433,7 @@ everything one need know to use Guile's data.
@menu
* General Rules::
* Conservative GC::
* Immediates vs. Non-immediates::
* Immediates vs Non-immediates::
* Immediate Datatypes::
* Non-immediate Datatypes::
* Signalling Type Errors::
@ -554,8 +554,8 @@ many pieces of code, it is enough for the collector to find the cell,
and then use the cell's type to find more pointers to trace.
@node Immediates vs. Non-immediates
@subsection Immediates vs. Non-immediates
@node Immediates vs Non-immediates
@subsection Immediates vs Non-immediates
Guile classifies Scheme objects into two kinds: those that fit entirely
within an @code{SCM}, and those that require heap storage.
@ -575,25 +575,14 @@ Return non-zero iff @var{x} is an immediate object.
@deftypefn Macro int SCM_NIMP (SCM @var{x})
Return non-zero iff @var{x} is a non-immediate object. This is the
exact complement of @code{SCM_IMP}, above.
You must use this macro before calling a finer-grained predicate to
determine @var{x}'s type. For example, to see if @var{x} is a pair, you
must write:
@example
SCM_NIMP (@var{x}) && SCM_CONSP (@var{x})
@end example
This is because Guile stores typing information for non-immediate values
in their cells, rather than in the @code{SCM} value itself; thus, you
must determine whether @var{x} refers to a cell before looking inside
it.
This is somewhat of a pity, because it means that the programmer needs
to know which types Guile implements as immediates vs. non-immediates.
There are (possibly better) representations in which @code{SCM_CONSP}
can be self-sufficient. The immediate type predicates do not suffer
from this weakness.
@end deftypefn
Note that, as of Guile 1.4, it is no longer necessary to use the
@code{SCM_NIMP} macro before calling a finer-grained predicate to
determine @var{x}'s type, such as @code{SCM_CONSP} or
@code{SCM_VECTORP}. The definitions of all Guile type predicates
now include a call to @code{SCM_NIMP} where necessary.
@node Immediate Datatypes
@subsection Immediate Datatypes
@ -601,7 +590,7 @@ from this weakness.
The following datatypes are immediate values; that is, they fit entirely
within an @code{SCM} value. The @code{SCM_IMP} and @code{SCM_NIMP}
macros will distinguish these from non-immediates; see @ref{Immediates
vs. Non-immediates} for an explanation of the distinction.
vs Non-immediates} for an explanation of the distinction.
Note that the type predicates for immediate values work correctly on any
@code{SCM} value; you do not need to call @code{SCM_IMP} first, to
@ -748,7 +737,7 @@ specific storage location (in the nomenclature of the Revised^4 Report
on Scheme).
The @code{SCM_IMP} and @code{SCM_NIMP} macros will distinguish these
from immediates; see @ref{Immediates vs. Non-immediates}.
from immediates; see @ref{Immediates vs Non-immediates}.
Given a cell, Guile distinguishes between pairs and other non-immediate
types by storing special @dfn{tag} values in a non-pair cell's car, that