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guile/libguile/macros.c
2002-03-14 03:47:43 +00:00

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/* Copyright (C) 1995,1996,1997,1998,2000,2001 Free Software Foundation, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*
* As a special exception, the Free Software Foundation gives permission
* for additional uses of the text contained in its release of GUILE.
*
* The exception is that, if you link the GUILE library with other files
* to produce an executable, this does not by itself cause the
* resulting executable to be covered by the GNU General Public License.
* Your use of that executable is in no way restricted on account of
* linking the GUILE library code into it.
*
* This exception does not however invalidate any other reasons why
* the executable file might be covered by the GNU General Public License.
*
* This exception applies only to the code released by the
* Free Software Foundation under the name GUILE. If you copy
* code from other Free Software Foundation releases into a copy of
* GUILE, as the General Public License permits, the exception does
* not apply to the code that you add in this way. To avoid misleading
* anyone as to the status of such modified files, you must delete
* this exception notice from them.
*
* If you write modifications of your own for GUILE, it is your choice
* whether to permit this exception to apply to your modifications.
* If you do not wish that, delete this exception notice. */
#include "libguile/_scm.h"
#include "libguile/alist.h" /* for SCM_EXTEND_ENV (well...) */
#include "libguile/eval.h"
#include "libguile/ports.h"
#include "libguile/print.h"
#include "libguile/root.h"
#include "libguile/smob.h"
#include "libguile/validate.h"
#include "libguile/macros.h"
scm_t_bits scm_tc16_macro;
static int
macro_print (SCM macro, SCM port, scm_print_state *pstate)
{
SCM code = SCM_MACRO_CODE (macro);
if (!SCM_CLOSUREP (code)
|| SCM_FALSEP (scm_procedure_p (SCM_PRINT_CLOSURE))
|| SCM_FALSEP (scm_printer_apply (SCM_PRINT_CLOSURE,
macro, port, pstate)))
{
if (!SCM_CLOSUREP (code))
scm_puts ("#<primitive-", port);
else
scm_puts ("#<", port);
if (SCM_MACRO_TYPE (macro) == 0)
scm_puts ("syntax", port);
else if (SCM_MACRO_TYPE (macro) == 1)
scm_puts ("macro", port);
if (SCM_MACRO_TYPE (macro) == 2)
scm_puts ("macro!", port);
scm_putc (' ', port);
scm_iprin1 (scm_macro_name (macro), port, pstate);
if (SCM_CLOSUREP (code) && SCM_PRINT_SOURCE_P)
{
SCM formals = SCM_CLOSURE_FORMALS (code);
SCM env = SCM_ENV (code);
SCM xenv = SCM_EXTEND_ENV (formals, SCM_EOL, env);
SCM src = scm_unmemocopy (SCM_CODE (code), xenv);
scm_putc (' ', port);
scm_iprin1 (src, port, pstate);
}
scm_putc ('>', port);
}
return 1;
}
SCM_DEFINE (scm_makacro, "procedure->syntax", 1, 0, 0,
(SCM code),
"Return a @dfn{macro} which, when a symbol defined to this value\n"
"appears as the first symbol in an expression, returns the\n"
"result of applying @var{code} to the expression and the\n"
"environment.")
#define FUNC_NAME s_scm_makacro
{
SCM_VALIDATE_PROC (1,code);
SCM_RETURN_NEWSMOB (scm_tc16_macro, SCM_UNPACK (code));
}
#undef FUNC_NAME
SCM_DEFINE (scm_makmacro, "procedure->macro", 1, 0, 0,
(SCM code),
"Return a @dfn{macro} which, when a symbol defined to this value\n"
"appears as the first symbol in an expression, evaluates the\n"
"result of applying @var{code} to the expression and the\n"
"environment. The value returned from @var{code} which has been\n"
"passed to @code{procedure->memoizing-macro} replaces the form\n"
"passed to @var{code}. For example:\n"
"\n"
"@lisp\n"
"(define trace\n"
" (procedure->macro\n"
" (lambda (x env) `(set! ,(cadr x) (tracef ,(cadr x) ',(cadr x))))))\n\n"
"(trace @i{foo}) @equiv{} (set! @i{foo} (tracef @i{foo} '@i{foo})).\n"
"@end lisp")
#define FUNC_NAME s_scm_makmacro
{
SCM_VALIDATE_PROC (1,code);
SCM_RETURN_NEWSMOB (scm_tc16_macro | (1L << 16), SCM_UNPACK (code));
}
#undef FUNC_NAME
SCM_DEFINE (scm_makmmacro, "procedure->memoizing-macro", 1, 0, 0,
(SCM code),
"Return a @dfn{macro} which, when a symbol defined to this value\n"
"appears as the first symbol in an expression, evaluates the\n"
"result of applying @var{proc} to the expression and the\n"
"environment. The value returned from @var{proc} which has been\n"
"passed to @code{procedure->memoizing-macro} replaces the form\n"
"passed to @var{proc}. For example:\n"
"\n"
"@lisp\n"
"(define trace\n"
" (procedure->macro\n"
" (lambda (x env) `(set! ,(cadr x) (tracef ,(cadr x) ',(cadr x))))))\n\n"
"(trace @i{foo}) @equiv{} (set! @i{foo} (tracef @i{foo} '@i{foo})).\n"
"@end lisp")
#define FUNC_NAME s_scm_makmmacro
{
SCM_VALIDATE_PROC (1,code);
SCM_RETURN_NEWSMOB (scm_tc16_macro | (2L << 16), SCM_UNPACK (code));
}
#undef FUNC_NAME
SCM_DEFINE (scm_macro_p, "macro?", 1, 0, 0,
(SCM obj),
"Return @code{#t} if @var{obj} is a regular macro, a memoizing macro or a\n"
"syntax transformer.")
#define FUNC_NAME s_scm_macro_p
{
return SCM_BOOL (SCM_TYP16_PREDICATE (scm_tc16_macro, obj));
}
#undef FUNC_NAME
SCM_SYMBOL (scm_sym_syntax, "syntax");
SCM_SYMBOL (scm_sym_macro, "macro");
SCM_SYMBOL (scm_sym_mmacro, "macro!");
SCM_DEFINE (scm_macro_type, "macro-type", 1, 0, 0,
(SCM m),
"Return one of the symbols @code{syntax}, @code{macro} or\n"
"@code{macro!}, depending on whether @var{m} is a syntax\n"
"transformer, a regular macro, or a memoizing macro,\n"
"respectively. If @var{m} is not a macro, @code{#f} is\n"
"returned.")
#define FUNC_NAME s_scm_macro_type
{
if (!SCM_TYP16_PREDICATE (scm_tc16_macro, m))
return SCM_BOOL_F;
switch (SCM_MACRO_TYPE (m))
{
case 0: return scm_sym_syntax;
case 1: return scm_sym_macro;
case 2: return scm_sym_mmacro;
default: scm_wrong_type_arg (FUNC_NAME, 1, m);
}
}
#undef FUNC_NAME
SCM_DEFINE (scm_macro_name, "macro-name", 1, 0, 0,
(SCM m),
"Return the name of the macro @var{m}.")
#define FUNC_NAME s_scm_macro_name
{
SCM_VALIDATE_SMOB (1,m,macro);
return scm_procedure_name (SCM_PACK (SCM_SMOB_DATA (m)));
}
#undef FUNC_NAME
SCM_DEFINE (scm_macro_transformer, "macro-transformer", 1, 0, 0,
(SCM m),
"Return the transformer of the macro @var{m}.")
#define FUNC_NAME s_scm_macro_transformer
{
SCM_VALIDATE_SMOB (1,m,macro);
return ((SCM_CLOSUREP (SCM_PACK (SCM_SMOB_DATA (m)))) ?
SCM_PACK(SCM_SMOB_DATA (m)) : SCM_BOOL_F);
}
#undef FUNC_NAME
SCM
scm_make_synt (const char *name, SCM (*macroizer) (), SCM (*fcn)() )
{
SCM var = scm_c_define (name, SCM_UNDEFINED);
SCM transformer = scm_c_make_subr (name, scm_tc7_subr_2, fcn);
SCM_VARIABLE_SET (var, macroizer (transformer));
return SCM_UNSPECIFIED;
}
void
scm_init_macros ()
{
scm_tc16_macro = scm_make_smob_type ("macro", 0);
scm_set_smob_mark (scm_tc16_macro, scm_markcdr);
scm_set_smob_print (scm_tc16_macro, macro_print);
#include "libguile/macros.x"
}
/*
Local Variables:
c-file-style: "gnu"
End:
*/