1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009
2 * Free Software Foundation, Inc.
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public License
6 * as published by the Free Software Foundation; either version 3 of
7 * the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
26 #include "libguile/__scm.h"
29 #include "libguile/_scm.h"
30 #include "libguile/continuations.h"
31 #include "libguile/eq.h"
32 #include "libguile/list.h"
33 #include "libguile/macros.h"
34 #include "libguile/memoize.h"
35 #include "libguile/modules.h"
36 #include "libguile/srcprop.h"
37 #include "libguile/ports.h"
38 #include "libguile/print.h"
39 #include "libguile/strings.h"
40 #include "libguile/throw.h"
41 #include "libguile/validate.h"
48 #define CAR(x) SCM_CAR(x)
49 #define CDR(x) SCM_CDR(x)
50 #define CAAR(x) SCM_CAAR(x)
51 #define CADR(x) SCM_CADR(x)
52 #define CDAR(x) SCM_CDAR(x)
53 #define CDDR(x) SCM_CDDR(x)
54 #define CADDR(x) SCM_CADDR(x)
55 #define CDDDR(x) SCM_CDDDR(x)
56 #define CADDDR(x) SCM_CDDDR(x)
58 #define CAR(x) scm_car(x)
59 #define CDR(x) scm_cdr(x)
60 #define CAAR(x) scm_caar(x)
61 #define CADR(x) scm_cadr(x)
62 #define CDAR(x) scm_cdar(x)
63 #define CDDR(x) scm_cddr(x)
64 #define CADDR(x) scm_caddr(x)
65 #define CDDDR(x) scm_cdddr(x)
66 #define CADDDR(x) scm_cadddr(x)
70 static const char s_bad_expression
[] = "Bad expression";
71 static const char s_expression
[] = "Missing or extra expression in";
72 static const char s_missing_expression
[] = "Missing expression in";
73 static const char s_extra_expression
[] = "Extra expression in";
74 static const char s_empty_combination
[] = "Illegal empty combination";
75 static const char s_missing_body_expression
[] = "Missing body expression in";
76 static const char s_mixed_body_forms
[] = "Mixed definitions and expressions in";
77 static const char s_bad_define
[] = "Bad define placement";
78 static const char s_missing_clauses
[] = "Missing clauses";
79 static const char s_misplaced_else_clause
[] = "Misplaced else clause";
80 static const char s_bad_case_clause
[] = "Bad case clause";
81 static const char s_bad_case_labels
[] = "Bad case labels";
82 static const char s_duplicate_case_label
[] = "Duplicate case label";
83 static const char s_bad_cond_clause
[] = "Bad cond clause";
84 static const char s_missing_recipient
[] = "Missing recipient in";
85 static const char s_bad_variable
[] = "Bad variable";
86 static const char s_bad_bindings
[] = "Bad bindings";
87 static const char s_bad_binding
[] = "Bad binding";
88 static const char s_duplicate_binding
[] = "Duplicate binding";
89 static const char s_bad_exit_clause
[] = "Bad exit clause";
90 static const char s_bad_formals
[] = "Bad formals";
91 static const char s_bad_formal
[] = "Bad formal";
92 static const char s_duplicate_formal
[] = "Duplicate formal";
93 static const char s_splicing
[] = "Non-list result for unquote-splicing";
94 static const char s_bad_slot_number
[] = "Bad slot number";
97 /* Signal a syntax error. We distinguish between the form that caused the
98 * error and the enclosing expression. The error message will print out as
99 * shown in the following pattern. The file name and line number are only
100 * given when they can be determined from the erroneous form or from the
101 * enclosing expression.
103 * <filename>: In procedure memoization:
104 * <filename>: In file <name>, line <nr>: <error-message> in <expression>. */
106 SCM_SYMBOL (syntax_error_key
, "syntax-error");
108 /* The prototype is needed to indicate that the function does not return. */
110 syntax_error (const char* const, const SCM
, const SCM
) SCM_NORETURN
;
113 syntax_error (const char* const msg
, const SCM form
, const SCM expr
)
115 SCM msg_string
= scm_from_locale_string (msg
);
116 SCM filename
= SCM_BOOL_F
;
117 SCM linenr
= SCM_BOOL_F
;
121 if (scm_is_pair (form
))
123 filename
= scm_source_property (form
, scm_sym_filename
);
124 linenr
= scm_source_property (form
, scm_sym_line
);
127 if (scm_is_false (filename
) && scm_is_false (linenr
) && scm_is_pair (expr
))
129 filename
= scm_source_property (expr
, scm_sym_filename
);
130 linenr
= scm_source_property (expr
, scm_sym_line
);
133 if (!SCM_UNBNDP (expr
))
135 if (scm_is_true (filename
))
137 format
= "In file ~S, line ~S: ~A ~S in expression ~S.";
138 args
= scm_list_5 (filename
, linenr
, msg_string
, form
, expr
);
140 else if (scm_is_true (linenr
))
142 format
= "In line ~S: ~A ~S in expression ~S.";
143 args
= scm_list_4 (linenr
, msg_string
, form
, expr
);
147 format
= "~A ~S in expression ~S.";
148 args
= scm_list_3 (msg_string
, form
, expr
);
153 if (scm_is_true (filename
))
155 format
= "In file ~S, line ~S: ~A ~S.";
156 args
= scm_list_4 (filename
, linenr
, msg_string
, form
);
158 else if (scm_is_true (linenr
))
160 format
= "In line ~S: ~A ~S.";
161 args
= scm_list_3 (linenr
, msg_string
, form
);
166 args
= scm_list_2 (msg_string
, form
);
170 scm_error (syntax_error_key
, "memoization", format
, args
, SCM_BOOL_F
);
174 /* Shortcut macros to simplify syntax error handling. */
175 #define ASSERT_SYNTAX(cond, message, form) \
176 { if (SCM_UNLIKELY (!(cond))) \
177 syntax_error (message, form, SCM_UNDEFINED); }
178 #define ASSERT_SYNTAX_2(cond, message, form, expr) \
179 { if (SCM_UNLIKELY (!(cond))) \
180 syntax_error (message, form, expr); }
185 /* {Evaluator memoized expressions}
188 scm_t_bits scm_tc16_memoized
;
190 #define MAKMEMO(n, args) (scm_cell (scm_tc16_memoized | ((n) << 16), (scm_t_bits)(args)))
192 #define MAKMEMO_BEGIN(exps) \
193 MAKMEMO (SCM_M_BEGIN, exps)
194 #define MAKMEMO_IF(test, then, else_) \
195 MAKMEMO (SCM_M_IF, scm_cons (test, scm_cons (then, else_)))
196 #define MAKMEMO_LAMBDA(nreq, rest, body) \
197 MAKMEMO (SCM_M_LAMBDA, scm_cons (SCM_I_MAKINUM (nreq), scm_cons (rest, body)))
198 #define MAKMEMO_LET(inits, body) \
199 MAKMEMO (SCM_M_LET, scm_cons (inits, body))
200 #define MAKMEMO_QUOTE(exp) \
201 MAKMEMO (SCM_M_QUOTE, exp)
202 #define MAKMEMO_DEFINE(var, val) \
203 MAKMEMO (SCM_M_DEFINE, scm_cons (var, val))
204 #define MAKMEMO_APPLY(exp) \
205 MAKMEMO (SCM_M_APPLY, exp)
206 #define MAKMEMO_CONT(proc) \
207 MAKMEMO (SCM_M_CONT, proc)
208 #define MAKMEMO_CALL_WITH_VALUES(prod, cons) \
209 MAKMEMO (SCM_M_CALL_WITH_VALUES, scm_cons (prod, cons))
210 #define MAKMEMO_CALL(proc, args) \
211 MAKMEMO (SCM_M_CALL, scm_cons (proc, args))
212 #define MAKMEMO_LEX_REF(n) \
213 MAKMEMO (SCM_M_LEXICAL_REF, SCM_I_MAKINUM (n))
214 #define MAKMEMO_LEX_SET(n, val) \
215 MAKMEMO (SCM_M_LEXICAL_SET, scm_cons (SCM_I_MAKINUM (n), val))
216 #define MAKMEMO_TOP_REF(var) \
217 MAKMEMO (SCM_M_TOPLEVEL_REF, var)
218 #define MAKMEMO_TOP_SET(var, val) \
219 MAKMEMO (SCM_M_TOPLEVEL_SET, scm_cons (var, val))
220 #define MAKMEMO_MOD_REF(mod, var, public) \
221 MAKMEMO (SCM_M_MODULE_REF, scm_cons (mod, scm_cons (var, public)))
222 #define MAKMEMO_MOD_SET(val, mod, var, public) \
223 MAKMEMO (SCM_M_MODULE_SET, scm_cons (val, scm_cons (mod, scm_cons (var, public))))
227 /* This table must agree with the list of M_ constants in memoize.h */
228 static const char *const memoized_tags
[] =
249 scm_print_memoized (SCM memoized
, SCM port
, scm_print_state
*pstate
)
251 scm_puts ("#<memoized ", port
);
252 scm_write (scm_unmemoize_expression (memoized
), port
);
253 scm_puts (">", port
);
257 static SCM
scm_m_at (SCM xorig
, SCM env
);
258 static SCM
scm_m_atat (SCM xorig
, SCM env
);
259 static SCM
scm_m_and (SCM xorig
, SCM env
);
260 static SCM
scm_m_apply (SCM xorig
, SCM env
);
261 static SCM
scm_m_begin (SCM xorig
, SCM env
);
262 static SCM
scm_m_cont (SCM xorig
, SCM env
);
263 static SCM
scm_m_at_call_with_values (SCM xorig
, SCM env
);
264 static SCM
scm_m_cond (SCM xorig
, SCM env
);
265 static SCM
scm_m_define (SCM x
, SCM env
);
266 static SCM
scm_m_eval_when (SCM xorig
, SCM env
);
267 static SCM
scm_m_if (SCM xorig
, SCM env
);
268 static SCM
scm_m_lambda (SCM xorig
, SCM env
);
269 static SCM
scm_m_let (SCM xorig
, SCM env
);
270 static SCM
scm_m_letrec (SCM xorig
, SCM env
);
271 static SCM
scm_m_letstar (SCM xorig
, SCM env
);
272 static SCM
scm_m_or (SCM xorig
, SCM env
);
273 static SCM
scm_m_quote (SCM xorig
, SCM env
);
274 static SCM
scm_m_set_x (SCM xorig
, SCM env
);
280 typedef SCM (*t_syntax_transformer
) (SCM
, SCM
);
282 static t_syntax_transformer
283 memoize_env_ref_transformer (SCM env
, SCM x
)
286 for (; scm_is_pair (env
); env
= CDR (env
))
287 if (scm_is_eq (x
, CAR (env
)))
288 return NULL
; /* lexical */
290 var
= scm_module_variable (env
, x
);
291 if (scm_is_true (var
) && scm_is_true (scm_variable_bound_p (var
))
292 && SCM_MACROP (scm_variable_ref (var
)))
294 SCM mac
= scm_variable_ref (var
);
295 if (SCM_IMP (SCM_MACRO_CODE (mac
))
296 || (SCM_TYP7 (SCM_MACRO_CODE (mac
)) != scm_tc7_gsubr
))
297 syntax_error ("bad macro", x
, SCM_UNDEFINED
);
299 return (t_syntax_transformer
)SCM_SUBRF (SCM_MACRO_CODE (mac
)); /* global macro */
302 return NULL
; /* anything else */
306 memoize_env_var_is_free (SCM env
, SCM x
)
308 for (; scm_is_pair (env
); env
= CDR (env
))
309 if (scm_is_eq (x
, CAR (env
)))
310 return 0; /* bound */
315 memoize_env_lexical_index (SCM env
, SCM x
)
318 for (; scm_is_pair (env
); env
= CDR (env
), i
++)
319 if (scm_is_eq (x
, CAR (env
)))
320 return i
; /* bound */
321 return -1; /* free */
325 memoize_env_extend (SCM env
, SCM vars
)
327 return scm_append (scm_list_2 (vars
, env
));
331 memoize (SCM exp
, SCM env
)
333 if (scm_is_pair (exp
))
336 t_syntax_transformer trans
;
339 if (scm_is_symbol (CAR
))
340 trans
= memoize_env_ref_transformer (env
, CAR
);
345 return trans (exp
, env
);
349 for (; scm_is_pair (exp
); exp
= CDR (exp
))
350 args
= scm_cons (memoize (CAR (exp
), env
), args
);
351 if (scm_is_null (exp
))
352 return MAKMEMO (SCM_M_CALL
, scm_reverse_x (args
, SCM_UNDEFINED
));
354 syntax_error ("expected a proper list", exp
, SCM_UNDEFINED
);
357 else if (scm_is_symbol (exp
))
359 int i
= memoize_env_lexical_index (env
, exp
);
361 return MAKMEMO_TOP_REF (exp
);
363 return MAKMEMO_LEX_REF (i
);
366 return MAKMEMO_QUOTE (exp
);
370 memoize_exprs (SCM forms
, const SCM env
)
374 for (; !scm_is_null (forms
); forms
= CDR (forms
))
375 ret
= scm_cons (memoize (CAR (forms
), env
), ret
);
376 return scm_reverse_x (ret
, SCM_UNDEFINED
);
380 memoize_sequence (const SCM forms
, const SCM env
)
382 ASSERT_SYNTAX (scm_ilength (forms
) >= 1, s_bad_expression
,
383 scm_cons (scm_sym_begin
, forms
));
384 return MAKMEMO_BEGIN (memoize_exprs (forms
, env
));
391 /* bimacros (built-in macros) have isym codes.
392 mmacros don't exist at runtime, they just expand out to more primitive
394 SCM_SYNTAX (s_at
, "@", scm_i_makbimacro
, scm_m_at
);
395 SCM_SYNTAX (s_atat
, "@@", scm_i_makbimacro
, scm_m_atat
);
396 SCM_SYNTAX (s_and
, "and", scm_makmmacro
, scm_m_and
);
397 SCM_SYNTAX (s_begin
, "begin", scm_i_makbimacro
, scm_m_begin
);
398 SCM_SYNTAX (s_atcall_cc
, "@call-with-current-continuation", scm_i_makbimacro
, scm_m_cont
);
399 SCM_SYNTAX (s_at_call_with_values
, "@call-with-values", scm_i_makbimacro
, scm_m_at_call_with_values
);
400 SCM_SYNTAX (s_cond
, "cond", scm_makmmacro
, scm_m_cond
);
401 SCM_SYNTAX (s_define
, "define", scm_i_makbimacro
, scm_m_define
);
402 SCM_SYNTAX (s_eval_when
, "eval-when", scm_makmmacro
, scm_m_eval_when
);
403 SCM_SYNTAX (s_if
, "if", scm_i_makbimacro
, scm_m_if
);
404 SCM_SYNTAX (s_lambda
, "lambda", scm_i_makbimacro
, scm_m_lambda
);
405 SCM_SYNTAX (s_let
, "let", scm_i_makbimacro
, scm_m_let
);
406 SCM_SYNTAX (s_letrec
, "letrec", scm_makmmacro
, scm_m_letrec
);
407 SCM_SYNTAX (s_letstar
, "let*", scm_makmmacro
, scm_m_letstar
);
408 SCM_SYNTAX (s_or
, "or", scm_makmmacro
, scm_m_or
);
409 SCM_SYNTAX (s_quote
, "quote", scm_i_makbimacro
, scm_m_quote
);
410 SCM_SYNTAX (s_set_x
, "set!", scm_i_makbimacro
, scm_m_set_x
);
411 SCM_SYNTAX (s_atapply
, "@apply", scm_i_makbimacro
, scm_m_apply
);
414 SCM_GLOBAL_SYMBOL (scm_sym_apply
, "apply");
415 SCM_GLOBAL_SYMBOL (scm_sym_arrow
, "=>");
416 SCM_GLOBAL_SYMBOL (scm_sym_at
, "@");
417 SCM_GLOBAL_SYMBOL (scm_sym_atat
, "@@");
418 SCM_GLOBAL_SYMBOL (scm_sym_at_call_with_values
, "@call-with-values");
419 SCM_GLOBAL_SYMBOL (scm_sym_atapply
, "@apply");
420 SCM_GLOBAL_SYMBOL (scm_sym_atcall_cc
, "@call-with-current-continuation");
421 SCM_GLOBAL_SYMBOL (scm_sym_begin
, "begin");
422 SCM_GLOBAL_SYMBOL (scm_sym_case
, "case");
423 SCM_GLOBAL_SYMBOL (scm_sym_cond
, "cond");
424 SCM_GLOBAL_SYMBOL (scm_sym_define
, "define");
425 SCM_GLOBAL_SYMBOL (scm_sym_else
, "else");
426 SCM_GLOBAL_SYMBOL (scm_sym_eval_when
, "eval-when");
427 SCM_GLOBAL_SYMBOL (scm_sym_if
, "if");
428 SCM_GLOBAL_SYMBOL (scm_sym_lambda
, "lambda");
429 SCM_GLOBAL_SYMBOL (scm_sym_let
, "let");
430 SCM_GLOBAL_SYMBOL (scm_sym_letrec
, "letrec");
431 SCM_GLOBAL_SYMBOL (scm_sym_letstar
, "let*");
432 SCM_GLOBAL_SYMBOL (scm_sym_or
, "or");
433 SCM_GLOBAL_SYMBOL (scm_sym_quote
, "quote");
434 SCM_GLOBAL_SYMBOL (scm_sym_set_x
, "set!");
435 SCM_SYMBOL (sym_eval
, "eval");
436 SCM_SYMBOL (sym_load
, "load");
438 SCM_GLOBAL_SYMBOL (scm_sym_unquote
, "unquote");
439 SCM_GLOBAL_SYMBOL (scm_sym_quasiquote
, "quasiquote");
440 SCM_GLOBAL_SYMBOL (scm_sym_uq_splicing
, "unquote-splicing");
444 scm_m_at (SCM expr
, SCM env SCM_UNUSED
)
446 ASSERT_SYNTAX (scm_ilength (expr
) == 3, s_bad_expression
, expr
);
447 ASSERT_SYNTAX (scm_ilength (CADR (expr
)) > 0, s_bad_expression
, expr
);
448 ASSERT_SYNTAX (scm_is_symbol (CADDR (expr
)), s_bad_expression
, expr
);
450 return MAKMEMO_MOD_REF (CADR (expr
), CADDR (expr
), SCM_BOOL_T
);
454 scm_m_atat (SCM expr
, SCM env SCM_UNUSED
)
456 ASSERT_SYNTAX (scm_ilength (expr
) == 3, s_bad_expression
, expr
);
457 ASSERT_SYNTAX (scm_ilength (CADR (expr
)) > 0, s_bad_expression
, expr
);
458 ASSERT_SYNTAX (scm_is_symbol (CADDR (expr
)), s_bad_expression
, expr
);
460 return MAKMEMO_MOD_REF (CADR (expr
), CADDR (expr
), SCM_BOOL_F
);
464 scm_m_and (SCM expr
, SCM env
)
466 const SCM cdr_expr
= CDR (expr
);
468 if (scm_is_null (cdr_expr
))
469 return MAKMEMO_QUOTE (SCM_BOOL_T
);
470 ASSERT_SYNTAX (scm_is_pair (cdr_expr
), s_bad_expression
, expr
);
472 if (scm_is_null (CDR (cdr_expr
)))
473 return memoize (CAR (cdr_expr
), env
);
475 return MAKMEMO_IF (memoize (CAR (cdr_expr
), env
),
476 scm_m_and (cdr_expr
, env
),
477 MAKMEMO_QUOTE (SCM_BOOL_F
));
481 scm_m_apply (SCM expr
, SCM env
)
483 const SCM cdr_expr
= CDR (expr
);
484 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
485 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_missing_expression
, expr
);
487 return MAKMEMO_APPLY (memoize_exprs (cdr_expr
, env
));
491 scm_m_begin (SCM expr
, SCM env
)
493 const SCM cdr_expr
= CDR (expr
);
494 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 1, s_bad_expression
, expr
);
495 return MAKMEMO_BEGIN (memoize_exprs (cdr_expr
, env
));
499 scm_m_cont (SCM expr
, SCM env
)
501 const SCM cdr_expr
= CDR (expr
);
502 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
503 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
505 return MAKMEMO_CONT (memoize (CADR (expr
), env
));
509 scm_m_at_call_with_values (SCM expr
, SCM env
)
511 const SCM cdr_expr
= CDR (expr
);
512 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
513 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
515 return MAKMEMO_CALL_WITH_VALUES (memoize (CADR (expr
), env
),
516 memoize (CADDR (expr
), env
));
520 scm_m_cond (SCM expr
, SCM env
)
522 /* Check, whether 'else or '=> is a literal, i. e. not bound to a value. */
523 const int else_literal_p
= memoize_env_var_is_free (env
, scm_sym_else
);
524 const int arrow_literal_p
= memoize_env_var_is_free (env
, scm_sym_arrow
);
526 const SCM clauses
= CDR (expr
);
530 ASSERT_SYNTAX (scm_ilength (clauses
) >= 0, s_bad_expression
, expr
);
531 ASSERT_SYNTAX (scm_ilength (clauses
) >= 1, s_missing_clauses
, expr
);
533 ret
= scm_cons (SCM_UNDEFINED
, MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
536 for (clause_idx
= clauses
;
537 !scm_is_null (clause_idx
);
538 clause_idx
= CDR (clause_idx
))
542 const SCM clause
= CAR (clause_idx
);
543 const long length
= scm_ilength (clause
);
544 ASSERT_SYNTAX_2 (length
>= 1, s_bad_cond_clause
, clause
, expr
);
547 if (scm_is_eq (test
, scm_sym_else
) && else_literal_p
)
549 const int last_clause_p
= scm_is_null (CDR (clause_idx
));
550 ASSERT_SYNTAX_2 (length
>= 2,
551 s_bad_cond_clause
, clause
, expr
);
552 ASSERT_SYNTAX_2 (last_clause_p
,
553 s_misplaced_else_clause
, clause
, expr
);
555 memoize (scm_cons (scm_sym_begin
, CDR (clause
)), env
));
558 && scm_is_eq (CADR (clause
), scm_sym_arrow
)
561 SCM tmp
= scm_gensym (scm_from_locale_string ("cond "));
563 SCM new_env
= scm_cons (tmp
, env
);
564 ASSERT_SYNTAX_2 (length
> 2, s_missing_recipient
, clause
, expr
);
565 ASSERT_SYNTAX_2 (length
== 3, s_extra_expression
, clause
, expr
);
566 i
= MAKMEMO_IF (MAKMEMO_LEX_REF (0),
567 MAKMEMO_CALL (memoize (CADDR (clause
),
568 scm_cons (tmp
, new_env
)),
569 scm_list_1 (MAKMEMO_LEX_REF (0))),
570 MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
572 MAKMEMO_LET (scm_list_1 (memoize (CAR (clause
), env
)),
575 loc
= scm_last_pair (SCM_MEMOIZED_ARGS (i
));
577 /* FIXME length == 1 case */
580 SCM i
= MAKMEMO_IF (memoize (CAR (clause
), env
),
581 memoize (scm_cons (scm_sym_begin
, CDR (clause
)), env
),
582 MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
584 loc
= scm_last_pair (SCM_MEMOIZED_ARGS (i
));
591 /* According to Section 5.2.1 of R5RS we first have to make sure that the
592 variable is bound, and then perform the `(set! variable expression)'
593 operation. However, EXPRESSION _can_ be evaluated before VARIABLE is
594 bound. This means that EXPRESSION won't necessarily be able to assign
595 values to VARIABLE as in `(define foo (begin (set! foo 1) (+ foo 1)))'. */
597 scm_m_define (SCM expr
, SCM env
)
599 const SCM cdr_expr
= CDR (expr
);
603 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
604 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
605 ASSERT_SYNTAX (!scm_is_pair (env
), s_bad_define
, expr
);
607 body
= CDR (cdr_expr
);
608 variable
= CAR (cdr_expr
);
610 if (scm_is_pair (variable
))
612 ASSERT_SYNTAX_2 (scm_is_symbol (CAR (variable
)), s_bad_variable
, variable
, expr
);
613 return MAKMEMO_DEFINE (CAR (variable
),
614 memoize (scm_cons (scm_sym_lambda
,
615 scm_cons (CDR (variable
), body
)),
618 ASSERT_SYNTAX_2 (scm_is_symbol (variable
), s_bad_variable
, variable
, expr
);
619 ASSERT_SYNTAX (scm_ilength (body
) == 1, s_expression
, expr
);
620 return MAKMEMO_DEFINE (variable
, memoize (CAR (body
), env
));
624 scm_m_eval_when (SCM expr
, SCM env
)
626 ASSERT_SYNTAX (scm_ilength (expr
) >= 3, s_bad_expression
, expr
);
627 ASSERT_SYNTAX (scm_ilength (CADR (expr
)) > 0, s_bad_expression
, expr
);
629 if (scm_is_true (scm_memq (sym_eval
, CADR (expr
)))
630 || scm_is_true (scm_memq (sym_load
, CADR (expr
))))
631 return MAKMEMO_BEGIN (memoize_exprs (CDDR (expr
), env
));
633 return MAKMEMO_QUOTE (SCM_UNSPECIFIED
);
637 scm_m_if (SCM expr
, SCM env SCM_UNUSED
)
639 const SCM cdr_expr
= CDR (expr
);
640 const long length
= scm_ilength (cdr_expr
);
641 ASSERT_SYNTAX (length
== 2 || length
== 3, s_expression
, expr
);
642 return MAKMEMO_IF (memoize (CADR (expr
), env
),
643 memoize (CADDR (expr
), env
),
645 ? memoize (CADDDR (expr
), env
)
646 : MAKMEMO_QUOTE (SCM_UNSPECIFIED
)));
649 /* A helper function for memoize_lambda to support checking for duplicate
650 * formal arguments: Return true if OBJ is `eq?' to one of the elements of
651 * LIST or to the CDR of the last cons. Therefore, LIST may have any of the
652 * forms that a formal argument can have:
653 * <rest>, (<arg1> ...), (<arg1> ... . <rest>) */
655 c_improper_memq (SCM obj
, SCM list
)
657 for (; scm_is_pair (list
); list
= CDR (list
))
659 if (scm_is_eq (CAR (list
), obj
))
662 return scm_is_eq (list
, obj
);
666 scm_m_lambda (SCM expr
, SCM env SCM_UNUSED
)
670 SCM formal_vars
= SCM_EOL
;
673 const SCM cdr_expr
= CDR (expr
);
674 const long length
= scm_ilength (cdr_expr
);
675 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
676 ASSERT_SYNTAX (length
>= 2, s_missing_expression
, expr
);
678 /* Before iterating the list of formal arguments, make sure the formals
679 * actually are given as either a symbol or a non-cyclic list. */
680 formals
= CAR (cdr_expr
);
681 if (scm_is_pair (formals
))
683 /* Dirk:FIXME:: We should check for a cyclic list of formals, and if
684 * detected, report a 'Bad formals' error. */
688 ASSERT_SYNTAX_2 (scm_is_symbol (formals
) || scm_is_null (formals
),
689 s_bad_formals
, formals
, expr
);
692 /* Now iterate the list of formal arguments to check if all formals are
693 * symbols, and that there are no duplicates. */
694 formals_idx
= formals
;
695 while (scm_is_pair (formals_idx
))
697 const SCM formal
= CAR (formals_idx
);
698 const SCM next_idx
= CDR (formals_idx
);
699 ASSERT_SYNTAX_2 (scm_is_symbol (formal
), s_bad_formal
, formal
, expr
);
700 ASSERT_SYNTAX_2 (!c_improper_memq (formal
, next_idx
),
701 s_duplicate_formal
, formal
, expr
);
703 formal_vars
= scm_cons (formal
, formal_vars
);
704 formals_idx
= next_idx
;
706 ASSERT_SYNTAX_2 (scm_is_null (formals_idx
) || scm_is_symbol (formals_idx
),
707 s_bad_formal
, formals_idx
, expr
);
708 if (scm_is_symbol (formals_idx
))
709 formal_vars
= scm_cons (formals_idx
, formal_vars
);
710 return MAKMEMO_LAMBDA (nreq
, scm_symbol_p (formals_idx
),
711 memoize_sequence (CDDR (expr
),
712 memoize_env_extend (env
, formal_vars
)));
715 /* Check if the format of the bindings is ((<symbol> <init-form>) ...). */
717 check_bindings (const SCM bindings
, const SCM expr
)
721 ASSERT_SYNTAX_2 (scm_ilength (bindings
) >= 0,
722 s_bad_bindings
, bindings
, expr
);
724 binding_idx
= bindings
;
725 for (; !scm_is_null (binding_idx
); binding_idx
= CDR (binding_idx
))
727 SCM name
; /* const */
729 const SCM binding
= CAR (binding_idx
);
730 ASSERT_SYNTAX_2 (scm_ilength (binding
) == 2,
731 s_bad_binding
, binding
, expr
);
733 name
= CAR (binding
);
734 ASSERT_SYNTAX_2 (scm_is_symbol (name
), s_bad_variable
, name
, expr
);
738 /* The bindings, which must have the format ((v1 i1) (v2 i2) ... (vn in)), are
739 * transformed to the lists (vn .. v2 v1) and (i1 i2 ... in). If a duplicate
740 * variable name is detected, an error is signalled. */
742 transform_bindings (const SCM bindings
, const SCM expr
,
743 SCM
*const rvarptr
, SCM
*const initptr
)
745 SCM rvariables
= SCM_EOL
;
746 SCM rinits
= SCM_EOL
;
747 SCM binding_idx
= bindings
;
749 for (; !scm_is_null (binding_idx
); binding_idx
= CDR (binding_idx
))
751 const SCM binding
= CAR (binding_idx
);
752 const SCM CDR_binding
= CDR (binding
);
753 const SCM name
= CAR (binding
);
754 ASSERT_SYNTAX_2 (scm_is_false (scm_c_memq (name
, rvariables
)),
755 s_duplicate_binding
, name
, expr
);
756 rvariables
= scm_cons (name
, rvariables
);
757 rinits
= scm_cons (CAR (CDR_binding
), rinits
);
760 *rvarptr
= rvariables
;
761 *initptr
= scm_reverse_x (rinits
, SCM_UNDEFINED
);
765 /* This function is a helper function for memoize_let. It transforms
766 * (let name ((var init) ...) body ...) into
767 * ((letrec ((name (lambda (var ...) body ...))) name) init ...)
768 * and memoizes the expression. It is assumed that the caller has checked
769 * that name is a symbol and that there are bindings and a body. */
771 memoize_named_let (const SCM expr
, SCM env
)
777 const SCM cdr_expr
= CDR (expr
);
778 const SCM name
= CAR (cdr_expr
);
779 const SCM cddr_expr
= CDR (cdr_expr
);
780 const SCM bindings
= CAR (cddr_expr
);
781 check_bindings (bindings
, expr
);
783 nreq
= transform_bindings (bindings
, expr
, &rvariables
, &inits
);
785 env
= scm_cons (name
, env
);
787 (scm_list_1 (MAKMEMO_QUOTE (SCM_UNDEFINED
)),
789 (scm_list_2 (MAKMEMO_LEX_SET
793 memoize_sequence (CDDDR (expr
),
794 memoize_env_extend (env
, rvariables
)))),
795 MAKMEMO_CALL (MAKMEMO_LEX_REF (0),
796 memoize_exprs (inits
, env
)))));
799 /* (let ((v1 i1) (v2 i2) ...) body) with variables v1 .. vn and initializers
800 * i1 .. in is transformed to (#@let (vn ... v2 v1) (i1 i2 ...) body). */
802 scm_m_let (SCM expr
, SCM env
)
806 const SCM cdr_expr
= CDR (expr
);
807 const long length
= scm_ilength (cdr_expr
);
808 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
809 ASSERT_SYNTAX (length
>= 2, s_missing_expression
, expr
);
811 bindings
= CAR (cdr_expr
);
812 if (scm_is_symbol (bindings
))
814 ASSERT_SYNTAX (length
>= 3, s_missing_expression
, expr
);
815 return memoize_named_let (expr
, env
);
818 check_bindings (bindings
, expr
);
819 if (scm_is_null (bindings
))
820 return memoize_sequence (CDDR (expr
), env
);
825 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
826 return MAKMEMO_LET (memoize_exprs (inits
, env
),
827 memoize_sequence (CDDR (expr
),
828 memoize_env_extend (env
, rvariables
)));
833 scm_m_letrec (SCM expr
, SCM env
)
837 const SCM cdr_expr
= CDR (expr
);
838 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
839 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
841 bindings
= CAR (cdr_expr
);
842 if (scm_is_null (bindings
))
843 return memoize_sequence (CDDR (expr
), env
);
849 SCM undefs
= SCM_EOL
;
854 int n
= transform_bindings (bindings
, expr
, &rvariables
, &inits
);
856 new_env
= memoize_env_extend (env
, rvariables
);
857 for (v
= scm_reverse (rvariables
), i
= inits
; scm_is_pair (v
);
858 v
= CDR (v
), i
= CDR (i
), n
--)
860 undefs
= scm_cons (MAKMEMO_QUOTE (SCM_UNDEFINED
), undefs
);
861 vals
= scm_cons (memoize (CAR (i
), new_env
), vals
);
862 sets
= scm_cons (MAKMEMO_LEX_SET ((n
-1) + offset
,
863 MAKMEMO_LEX_REF (n
-1)),
868 MAKMEMO_BEGIN (scm_list_2 (MAKMEMO_LET (scm_reverse (vals
),
869 MAKMEMO_BEGIN (sets
)),
870 memoize_sequence (CDDR (expr
),
876 scm_m_letstar (SCM expr
, SCM env SCM_UNUSED
)
880 const SCM cdr_expr
= CDR (expr
);
881 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
882 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
884 bindings
= CAR (cdr_expr
);
885 if (scm_is_null (bindings
))
886 return memoize_sequence (CDDR (expr
), env
);
893 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
894 variables
= scm_reverse (rvariables
);
895 ret
= scm_cons (SCM_UNDEFINED
, SCM_UNSPECIFIED
);
897 for (; scm_is_pair (variables
);
898 variables
= CDR (variables
), inits
= CDR (inits
))
899 { SCM x
= MAKMEMO_LET (scm_list_1 (memoize (CAR (inits
), env
)),
900 MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
902 loc
= scm_last_pair (SCM_MEMOIZED_ARGS (x
));
903 env
= scm_cons (CAR (variables
), env
);
905 SCM_SETCDR (loc
, memoize_sequence (CDDR (expr
), env
));
911 scm_m_or (SCM expr
, SCM env SCM_UNUSED
)
913 SCM tail
= CDR (expr
);
915 const long length
= scm_ilength (tail
);
917 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
919 ret
= scm_cons (SCM_UNDEFINED
, SCM_UNSPECIFIED
);
921 for (; scm_is_pair (tail
); tail
= CDR (tail
))
923 SCM tmp
= scm_gensym (scm_from_locale_string ("cond "));
924 SCM x
= MAKMEMO_IF (MAKMEMO_LEX_REF (0),
926 MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
927 SCM new_env
= scm_cons (tmp
, env
);
928 SCM_SETCDR (loc
, MAKMEMO_LET (scm_list_1 (memoize (CAR (tail
),
932 loc
= scm_last_pair (SCM_MEMOIZED_ARGS (x
));
934 SCM_SETCDR (loc
, MAKMEMO_QUOTE (SCM_BOOL_F
));
939 scm_m_quote (SCM expr
, SCM env SCM_UNUSED
)
943 const SCM cdr_expr
= CDR (expr
);
944 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
945 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
946 quotee
= CAR (cdr_expr
);
947 return MAKMEMO_QUOTE (quotee
);
951 scm_m_set_x (SCM expr
, SCM env
)
956 const SCM cdr_expr
= CDR (expr
);
957 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
958 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
959 variable
= CAR (cdr_expr
);
960 vmem
= memoize (variable
, env
);
962 switch (SCM_MEMOIZED_TAG (vmem
))
964 case SCM_M_LEXICAL_REF
:
965 return MAKMEMO_LEX_SET (SCM_I_INUM (SCM_MEMOIZED_ARGS (vmem
)),
966 memoize (CADDR (expr
), env
));
967 case SCM_M_TOPLEVEL_REF
:
968 return MAKMEMO_TOP_SET (variable
,
969 memoize (CADDR (expr
), env
));
970 case SCM_M_MODULE_REF
:
971 return MAKMEMO_MOD_SET (memoize (CADDR (expr
), env
),
972 CAR (SCM_MEMOIZED_ARGS (vmem
)),
973 CADR (SCM_MEMOIZED_ARGS (vmem
)),
974 CDDR (SCM_MEMOIZED_ARGS (vmem
)));
976 syntax_error (s_bad_variable
, variable
, expr
);
983 SCM_DEFINE (scm_memoize_expression
, "memoize-expression", 1, 0, 0,
985 "Memoize the expression @var{exp}.")
986 #define FUNC_NAME s_scm_memoize_expression
988 return memoize (exp
, scm_current_module ());
995 SCM_SYMBOL (sym_placeholder
, "_");
997 static SCM
unmemoize (SCM expr
);
1000 unmemoize_exprs (SCM exprs
)
1003 if (scm_is_null (exprs
))
1005 ret
= scm_list_1 (unmemoize (CAR (exprs
)));
1007 for (exprs
= CDR (exprs
); !scm_is_null (exprs
); exprs
= CDR (exprs
))
1009 SCM_SETCDR (tail
, scm_list_1 (unmemoize (CAR (exprs
))));
1016 unmemoize_bindings (SCM inits
)
1019 if (scm_is_null (inits
))
1021 ret
= scm_list_1 (scm_list_2 (sym_placeholder
, unmemoize (CAR (inits
))));
1023 for (inits
= CDR (inits
); !scm_is_null (inits
); inits
= CDR (inits
))
1025 SCM_SETCDR (tail
, scm_list_1 (scm_list_2 (sym_placeholder
,
1026 unmemoize (CAR (inits
)))));
1033 unmemoize_lexical (SCM n
)
1037 snprintf (buf
, 15, "<%u>", scm_to_uint32 (n
));
1038 return scm_from_locale_symbol (buf
);
1042 unmemoize (const SCM expr
)
1046 if (!SCM_MEMOIZED_P (expr
))
1049 args
= SCM_MEMOIZED_ARGS (expr
);
1050 switch (SCM_MEMOIZED_TAG (expr
))
1053 return scm_cons (scm_sym_atapply
, unmemoize_exprs (args
));
1055 return scm_cons (scm_sym_begin
, unmemoize_exprs (args
));
1057 return unmemoize_exprs (args
);
1059 return scm_list_2 (scm_sym_atcall_cc
, unmemoize (args
));
1060 case SCM_M_CALL_WITH_VALUES
:
1061 return scm_list_3 (scm_sym_at_call_with_values
,
1062 unmemoize (CAR (args
)), unmemoize (CDR (args
)));
1064 return scm_list_3 (scm_sym_define
, CAR (args
), unmemoize (CDR (args
)));
1066 return scm_list_4 (scm_sym_if
, unmemoize (scm_car (args
)),
1067 unmemoize (scm_cadr (args
)), unmemoize (scm_cddr (args
)));
1069 return scm_list_3 (scm_sym_lambda
,
1070 scm_make_list (CAR (args
), sym_placeholder
),
1071 unmemoize (CDDR (args
)));
1073 return scm_list_3 (scm_sym_let
,
1074 unmemoize_bindings (CAR (args
)),
1075 unmemoize (CDR (args
)));
1077 return scm_list_2 (scm_sym_quote
, args
);
1078 case SCM_M_LEXICAL_REF
:
1079 return unmemoize_lexical (args
);
1080 case SCM_M_LEXICAL_SET
:
1081 return scm_list_3 (scm_sym_set_x
, unmemoize_lexical (CAR (args
)),
1082 unmemoize (CDR (args
)));
1083 case SCM_M_TOPLEVEL_REF
:
1085 case SCM_M_TOPLEVEL_SET
:
1086 return scm_list_3 (scm_sym_set_x
, CAR (args
), unmemoize (CDR (args
)));
1087 case SCM_M_MODULE_REF
:
1088 return scm_list_3 (scm_is_true (CDDR (args
)) ? scm_sym_at
: scm_sym_atat
,
1089 scm_i_finite_list_copy (CAR (args
)),
1091 case SCM_M_MODULE_SET
:
1092 return scm_list_3 (scm_sym_set_x
,
1093 scm_list_3 (scm_is_true (CDDDR (args
))
1094 ? scm_sym_at
: scm_sym_atat
,
1095 scm_i_finite_list_copy (CADR (args
)),
1097 unmemoize (CAR (args
)));
1103 SCM_DEFINE (scm_memoized_p
, "memoized?", 1, 0, 0,
1105 "Return @code{#t} if @var{obj} is memoized.")
1106 #define FUNC_NAME s_scm_memoized_p
1108 return scm_from_bool (SCM_MEMOIZED_P (obj
));
1112 SCM_DEFINE (scm_unmemoize_expression
, "unmemoize-expression", 1, 0, 0,
1114 "Unmemoize the memoized expression @var{m}.")
1115 #define FUNC_NAME s_scm_unmemoize_expression
1117 SCM_VALIDATE_MEMOIZED (1, m
);
1118 return unmemoize (m
);
1122 SCM_DEFINE (scm_memoized_expression_typecode
, "memoized-expression-typecode", 1, 0, 0,
1124 "Return the typecode from the memoized expression @var{m}.")
1125 #define FUNC_NAME s_scm_memoized_expression_typecode
1127 SCM_VALIDATE_MEMOIZED (1, m
);
1128 return scm_from_uint16 (SCM_MEMOIZED_TAG (m
));
1132 SCM_DEFINE (scm_memoized_expression_data
, "memoized-expression-data", 1, 0, 0,
1134 "Return the data from the memoized expression @var{m}.")
1135 #define FUNC_NAME s_scm_memoized_expression_data
1137 SCM_VALIDATE_MEMOIZED (1, m
);
1138 return SCM_MEMOIZED_ARGS (m
);
1142 SCM_DEFINE (scm_memoized_typecode
, "memoized-typecode", 1, 0, 0,
1144 "Return the memoized typecode corresponding to the symbol @var{sym}.")
1145 #define FUNC_NAME s_scm_memoized_typecode
1149 SCM_VALIDATE_SYMBOL (1, sym
);
1151 for (i
= 0; i
< sizeof(memoized_tags
)/sizeof(const char*); i
++)
1152 if (strcmp (scm_i_symbol_chars (sym
), memoized_tags
[i
]) == 0)
1153 return scm_from_int32 (i
);
1159 SCM_SYMBOL (scm_unbound_variable_key
, "unbound-variable");
1160 static void error_unbound_variable (SCM symbol
) SCM_NORETURN
;
1161 static void error_unbound_variable (SCM symbol
)
1163 scm_error (scm_unbound_variable_key
, NULL
, "Unbound variable: ~S",
1164 scm_list_1 (symbol
), SCM_BOOL_F
);
1167 SCM_DEFINE (scm_memoize_variable_access_x
, "memoize-variable-access!", 2, 0, 0,
1169 "Look up and cache the variable that @var{m} will access, returning the variable.")
1170 #define FUNC_NAME s_scm_memoize_variable_access_x
1173 SCM_VALIDATE_MEMOIZED (1, m
);
1174 mx
= SCM_MEMOIZED_ARGS (m
);
1175 switch (SCM_MEMOIZED_TAG (m
))
1177 case SCM_M_TOPLEVEL_REF
:
1178 if (SCM_VARIABLEP (mx
))
1182 SCM var
= scm_module_variable (mod
, mx
);
1183 if (scm_is_false (var
) || scm_is_false (scm_variable_bound_p (var
)))
1184 error_unbound_variable (mx
);
1185 SCM_SET_SMOB_OBJECT (m
, var
);
1189 case SCM_M_TOPLEVEL_SET
:
1192 if (SCM_VARIABLEP (var
))
1196 var
= scm_module_variable (mod
, var
);
1197 if (scm_is_false (var
))
1198 error_unbound_variable (CAR (mx
));
1199 SCM_SETCAR (mx
, var
);
1204 case SCM_M_MODULE_REF
:
1205 if (SCM_VARIABLEP (mx
))
1210 mod
= scm_resolve_module (CAR (mx
));
1211 if (scm_is_true (CDDR (mx
)))
1212 mod
= scm_module_public_interface (mod
);
1213 var
= scm_module_lookup (mod
, CADR (mx
));
1214 if (scm_is_false (scm_variable_bound_p (var
)))
1215 error_unbound_variable (CADR (mx
));
1216 SCM_SET_SMOB_OBJECT (m
, var
);
1220 case SCM_M_MODULE_SET
:
1221 /* FIXME: not quite threadsafe */
1222 if (SCM_VARIABLEP (CDR (mx
)))
1227 mod
= scm_resolve_module (CADR (mx
));
1228 if (scm_is_true (CDDDR (mx
)))
1229 mod
= scm_module_public_interface (mod
);
1230 var
= scm_module_lookup (mod
, CADDR (mx
));
1231 SCM_SETCDR (mx
, var
);
1236 scm_wrong_type_arg (FUNC_NAME
, 1, m
);
1248 scm_tc16_memoized
= scm_make_smob_type ("%memoized", 0);
1249 scm_set_smob_mark (scm_tc16_memoized
, scm_markcdr
);
1250 scm_set_smob_print (scm_tc16_memoized
, scm_print_memoized
);
1252 #include "libguile/memoize.x"