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more NEWS updates

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* NEWS: Update some more.
This commit is contained in:
Andy Wingo 2009-12-13 20:18:50 +01:00
parent 9331f91cc4
commit 61521ea034
1 changed files with 83 additions and 74 deletions
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157
NEWS
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@ -22,17 +22,18 @@ to execute on the same stack, unifying multiple-value return semantics,
providing for proper tail recursion between interpreted and compiled
code, and simplifying debugging.
goes along with a new c evaluator -- memoization completely before
evaluation -- threadsafe, not debug-happy
As part of this change, the evaluator no longer mutates the internal
representation of the code being evaluated in a thread-unsafe manner.
loadsa c interface changes, see changelog
There are two negative aspects of this change, however. First, Guile
takes a lot longer to compile now. Also, there is less debugging
information available for debugging interpreted code. We hope to improve
both of these situations.
remove local-eval
** GOOPS dispatch in scheme
not much user-level change, but neat to note; possibility for method
combinations &c
There are many changes to the internal C evalator interface, but all
public interfaces should be the same. See the ChangeLog for details. If
we have inadvertantly changed an interface that you were using, please
contact bug-guile@gnu.org.
** Elisp compiler
@ -44,7 +45,7 @@ bug-guile@gnu.org.
** Faster SRFI-9 record access
SRFI-9 records are now implemented directly on top of Guile's structs,
and their accessors are defined in such a way that normal callsites
and their accessors are defined in such a way that normal call-sites
inline to special VM opcodes, while still allowing for the general case
(e.g. passing a record accessor to `apply').
@ -94,6 +95,28 @@ patch, and Kent Dybvig for the code.
`scm_c_make_struct' and `scm_c_make_structv' are new varargs and array
constructors, respectively, for structs. You might find them useful.
** Applicable struct support
One may now make structs from Scheme that may be applied as procedures.
To do so, make a struct whose vtable is `<applicable-struct-vtable>'.
That struct will be the vtable of your applicable structs; instances of
that new struct are assumed to have the procedure in their first slot.
`<applicable-struct-vtable>' is like Common Lisp's
`funcallable-standard-class'. Likewise there is
`<applicable-struct-with-setter-vtable>', which looks for the setter in
the second slot. This needs to be better documented.
** GOOPS dispatch in scheme
As an implementation detail, GOOPS dispatch is no longer implemented by
special evaluator bytecodes, but rather directly via a Scheme function
associated with an applicable struct. There is some VM support for the
underlying primitives, like `class-of'.
This change will in the future allow users to customize generic function
dispatch without incurring a performance penalty, and allow us to
implement method combinations.
** Procedures-with-setters are now implemented using applicable structs
From a user's perspective this doesn't mean very much. But if, for some
@ -101,13 +124,20 @@ odd reason, you used the SCM_PROCEDURE_WITH_SETTER_P, SCM_PROCEDURE, or
SCM_SETTER macros, know that they're deprecated now. Also, scm_tc7_pws
is gone.
** No more `local-eval'
`local-eval' used to exist so that one could evaluate code in the
lexical context of a function. Since there is no way to get the lexical
environment any more, as that concept has no meaning for the compiler,
and a different meaning for the interpreter, we have removed the
function.
If you think you need `local-eval', you should probably implement your
own metacircular evaluator. It will probably be as fast as Guile's
anyway.
** Bit twiddlings
*** smob to tc7
Fluids, dynamic states, and hash tables used to be SMOB objects, but now
they have statically allocated typecodes.
*** Remove old evaluator closures
There used to be ranges of typecodes allocated to interpreted data
@ -118,40 +148,17 @@ details.
*** Simplify representation of primitive procedures
Remove scm_tc7_cxr, scm_tc7_rpsubr, scm_tc7_asubr, scm_tc7_dsubr.
Remove scm_tc7_subr_* and scm_tc7_lsubr_*
It used to be that there were something like 12 different typecodes
allocated to primitive procedures, each with its own calling convention.
Now there is only one, the gsubr. This may affect user code if you were
defining a procedure using scm_c_make_subr rather scm_c_make_gsubr. The
solution is to switch to use scm_c_make_gsubr. This solution works well
both with the old 1.8 and and with the current 1.9 branch.
| | implement transcendental sin, cos etc in c; deprecate $sin, $cos, etc
| |
| | * libguile/deprecated.h:
| | * libguile/deprecated.c (scm_asinh, scm_acosh, scm_atanh): Deprecate
| | these stand-ins for the C99 asinh, acosh, and atanh functions. Guile
| | is not gnulib.
| | (scm_sys_atan2): Deprecate as well, in favor of scm_atan.
| |
| | * libguile/numbers.h:
| | * libguile/numbers.c (scm_sin, scm_cos, scm_tan)
| | (scm_sinh, scm_cosh, scm_tanh)
| | (scm_asin, scm_acos, scm_atan)
| | (scm_sys_asinh, scm_sys_acosh, scm_sys_atanh): New functions,
| | replacing the combination of dsubrs and boot-9 wrappers with C subrs
| | that handle complex values. The latter three have _sys_ in their names
| | due to the name conflict with the deprecated scm_asinh et al.
...
| | Remove the $abs, $sin etc "dsubrs".
| |
| | expt implemented in C, handles complex numbers
| |
| | * libguile/numbers.h:
| | * libguile/numbers.c (scm_expt): Rename from scm_sys_expt, and handle
| | the complex cases as well.
| |
| | * libguile/deprecated.h:
| | * libguile/deprecated.c (scm_sys_expt): Add a deprecated shim.
| |
| | * module/ice-9/boot-9.scm (expt): Remove definition, scm_expt does all
| | we need.
| |
*** Some SMOB types changed to have static typecodes
Fluids, dynamic states, and hash tables used to be SMOB objects, but now
they have statically allocated tc7 typecodes.
*** Preparations for changing SMOB representation
@ -169,43 +176,45 @@ VM stack. Now Guile's procedures only run on the VM stack, simplifying
much of the C API. See the ChangeLog for details. The Scheme API has not
been changed significantly.
** define!
** New procedure, `define!'
a procedure to do a toplevel define
`define!' is a procedure that takes two arguments, a symbol and a value,
and binds the value to the symbol in the current module. It's useful to
programmatically make definitions in the current module, and is slightly
less verbose than `module-define!'.
** applicable struct support
** eqv? not a generic
** eqv not a generic
One used to be able to extend `eqv?' as a primitive-generic, but no
more. Because `eqv?' is in the expansion of `case' (via `memv'), which
should be able to compile to static dispatch tables, it doesn't make
sense to allow extensions that would subvert this optimization.
** deprecate trampolines
** Deprecate trampolines
| | (scm_the_root_module): Undeprecate, it's actually a useful function,
| | that other parts of the code use.
There used to be C functions `scm_trampoline_0', `scm_trampoline_1', and
so on. The point was to do some precomputation on the type of the
procedure, then return a specialized "call" procedure. However this
optimization wasn't actually an optimization, so it is now deprecated.
Just use `scm_call_0', etc instead.
** deval/ceval distinction removed
** Undeprecate `scm_the_root_module ()'
** --disable-discouraged builds cleanly.
It's useful to be able to get the root module from C without doing a
full module lookup.
** new metatables: scm_standard_vtable_vtable,
scm_applicable_struct_vtable_vtable, scm_applicable_struct_with_setter_vtable_vtable
** New struct slot allocation: "hidden"
| | (scm_init_struct): Define <applicable-struct-vtable>, a magical vtable
| | like CL's funcallable-standard-class. Also define
| | <applicable-struct-with-setter-vtable>.
** hidden slots
** better (?) intptr support
| | * libguile/__scm.h (SCM_T_UINTPTR_MAX, SCM_T_INTPTR_MIN,
| | SCM_T_INTPTR_MAX): New macros.
| | * libguile/_scm.h (SIZEOF_SCM_T_BITS): New macro.
| | * libguile/gen-scmconfig.c (main): Produce typedefs for `scm_t_intptr'
| | and `scm_t_uintptr'.
| | * libguile/gen-scmconfig.h.in (SCM_I_GSC_T_INTPTR, SCM_I_GSC_T_UINPTR):
| | New macros.
A hidden slot is readable and writable, but will not be initialized by a
call to make-struct. For example in your layout you would say "ph"
instead of "pw". Hidden slots are useful for adding new slots to a
vtable without breaking existing invocations to make-struct.
** New type definitions for `scm_t_intptr' and friends.
`SCM_T_UINTPTR_MAX', `SCM_T_INTPTR_MIN', `SCM_T_INTPTR_MAX',
`SIZEOF_SCM_T_BITS', `scm_t_intptr' and `scm_t_uintptr' are now
available to C. Have fun!
** And of course, the usual collection of bugfixes