1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009,2010
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"
27 #include "libguile/_scm.h"
28 #include "libguile/continuations.h"
29 #include "libguile/eq.h"
30 #include "libguile/list.h"
31 #include "libguile/macros.h"
32 #include "libguile/memoize.h"
33 #include "libguile/modules.h"
34 #include "libguile/srcprop.h"
35 #include "libguile/ports.h"
36 #include "libguile/print.h"
37 #include "libguile/strings.h"
38 #include "libguile/throw.h"
39 #include "libguile/validate.h"
46 #define CAR(x) SCM_CAR(x)
47 #define CDR(x) SCM_CDR(x)
48 #define CAAR(x) SCM_CAAR(x)
49 #define CADR(x) SCM_CADR(x)
50 #define CDAR(x) SCM_CDAR(x)
51 #define CDDR(x) SCM_CDDR(x)
52 #define CADDR(x) SCM_CADDR(x)
53 #define CDDDR(x) SCM_CDDDR(x)
54 #define CADDDR(x) SCM_CDDDR(x)
56 #define CAR(x) scm_car(x)
57 #define CDR(x) scm_cdr(x)
58 #define CAAR(x) scm_caar(x)
59 #define CADR(x) scm_cadr(x)
60 #define CDAR(x) scm_cdar(x)
61 #define CDDR(x) scm_cddr(x)
62 #define CADDR(x) scm_caddr(x)
63 #define CDDDR(x) scm_cdddr(x)
64 #define CADDDR(x) scm_cadddr(x)
68 static const char s_bad_expression
[] = "Bad expression";
69 static const char s_expression
[] = "Missing or extra expression in";
70 static const char s_missing_expression
[] = "Missing expression in";
71 static const char s_extra_expression
[] = "Extra expression in";
72 static const char s_empty_combination
[] = "Illegal empty combination";
73 static const char s_missing_body_expression
[] = "Missing body expression in";
74 static const char s_mixed_body_forms
[] = "Mixed definitions and expressions in";
75 static const char s_bad_define
[] = "Bad define placement";
76 static const char s_missing_clauses
[] = "Missing clauses";
77 static const char s_misplaced_else_clause
[] = "Misplaced else clause";
78 static const char s_bad_case_clause
[] = "Bad case clause";
79 static const char s_bad_case_labels
[] = "Bad case labels";
80 static const char s_duplicate_case_label
[] = "Duplicate case label";
81 static const char s_bad_cond_clause
[] = "Bad cond clause";
82 static const char s_missing_recipient
[] = "Missing recipient in";
83 static const char s_bad_variable
[] = "Bad variable";
84 static const char s_bad_bindings
[] = "Bad bindings";
85 static const char s_bad_binding
[] = "Bad binding";
86 static const char s_duplicate_binding
[] = "Duplicate binding";
87 static const char s_bad_exit_clause
[] = "Bad exit clause";
88 static const char s_bad_formals
[] = "Bad formals";
89 static const char s_bad_formal
[] = "Bad formal";
90 static const char s_duplicate_formal
[] = "Duplicate formal";
91 static const char s_splicing
[] = "Non-list result for unquote-splicing";
92 static const char s_bad_slot_number
[] = "Bad slot number";
95 /* Signal a syntax error. We distinguish between the form that caused the
96 * error and the enclosing expression. The error message will print out as
97 * shown in the following pattern. The file name and line number are only
98 * given when they can be determined from the erroneous form or from the
99 * enclosing expression.
101 * <filename>: In procedure memoization:
102 * <filename>: In file <name>, line <nr>: <error-message> in <expression>. */
104 SCM_SYMBOL (syntax_error_key
, "syntax-error");
106 /* The prototype is needed to indicate that the function does not return. */
108 syntax_error (const char* const, const SCM
, const SCM
) SCM_NORETURN
;
111 syntax_error (const char* const msg
, const SCM form
, const SCM expr
)
113 SCM msg_string
= scm_from_locale_string (msg
);
114 SCM filename
= SCM_BOOL_F
;
115 SCM linenr
= SCM_BOOL_F
;
119 if (scm_is_pair (form
))
121 filename
= scm_source_property (form
, scm_sym_filename
);
122 linenr
= scm_source_property (form
, scm_sym_line
);
125 if (scm_is_false (filename
) && scm_is_false (linenr
) && scm_is_pair (expr
))
127 filename
= scm_source_property (expr
, scm_sym_filename
);
128 linenr
= scm_source_property (expr
, scm_sym_line
);
131 if (!SCM_UNBNDP (expr
))
133 if (scm_is_true (filename
))
135 format
= "In file ~S, line ~S: ~A ~S in expression ~S.";
136 args
= scm_list_5 (filename
, linenr
, msg_string
, form
, expr
);
138 else if (scm_is_true (linenr
))
140 format
= "In line ~S: ~A ~S in expression ~S.";
141 args
= scm_list_4 (linenr
, msg_string
, form
, expr
);
145 format
= "~A ~S in expression ~S.";
146 args
= scm_list_3 (msg_string
, form
, expr
);
151 if (scm_is_true (filename
))
153 format
= "In file ~S, line ~S: ~A ~S.";
154 args
= scm_list_4 (filename
, linenr
, msg_string
, form
);
156 else if (scm_is_true (linenr
))
158 format
= "In line ~S: ~A ~S.";
159 args
= scm_list_3 (linenr
, msg_string
, form
);
164 args
= scm_list_2 (msg_string
, form
);
168 scm_error (syntax_error_key
, "memoization", format
, args
, SCM_BOOL_F
);
172 /* Shortcut macros to simplify syntax error handling. */
173 #define ASSERT_SYNTAX(cond, message, form) \
174 { if (SCM_UNLIKELY (!(cond))) \
175 syntax_error (message, form, SCM_UNDEFINED); }
176 #define ASSERT_SYNTAX_2(cond, message, form, expr) \
177 { if (SCM_UNLIKELY (!(cond))) \
178 syntax_error (message, form, expr); }
183 /* {Evaluator memoized expressions}
186 scm_t_bits scm_tc16_memoized
;
188 #define MAKMEMO(n, args) (scm_cell (scm_tc16_memoized | ((n) << 16), (scm_t_bits)(args)))
190 #define MAKMEMO_BEGIN(exps) \
191 MAKMEMO (SCM_M_BEGIN, exps)
192 #define MAKMEMO_IF(test, then, else_) \
193 MAKMEMO (SCM_M_IF, scm_cons (test, scm_cons (then, else_)))
194 #define MAKMEMO_LAMBDA(nreq, rest, body) \
195 MAKMEMO (SCM_M_LAMBDA, scm_cons (SCM_I_MAKINUM (nreq), scm_cons (rest, body)))
196 #define MAKMEMO_LET(inits, body) \
197 MAKMEMO (SCM_M_LET, scm_cons (inits, body))
198 #define MAKMEMO_QUOTE(exp) \
199 MAKMEMO (SCM_M_QUOTE, exp)
200 #define MAKMEMO_DEFINE(var, val) \
201 MAKMEMO (SCM_M_DEFINE, scm_cons (var, val))
202 #define MAKMEMO_DYNWIND(in, expr, out) \
203 MAKMEMO (SCM_M_DYNWIND, scm_cons (in, scm_cons (expr, out)))
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, nargs, args) \
211 MAKMEMO (SCM_M_CALL, scm_cons (proc, scm_cons (SCM_I_MAKINUM (nargs), 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
[] =
250 scm_print_memoized (SCM memoized
, SCM port
, scm_print_state
*pstate
)
252 scm_puts ("#<memoized ", port
);
253 scm_write (scm_unmemoize_expression (memoized
), port
);
254 scm_puts (">", port
);
258 static SCM
scm_m_at (SCM xorig
, SCM env
);
259 static SCM
scm_m_atat (SCM xorig
, SCM env
);
260 static SCM
scm_m_and (SCM xorig
, SCM env
);
261 static SCM
scm_m_apply (SCM xorig
, SCM env
);
262 static SCM
scm_m_begin (SCM xorig
, SCM env
);
263 static SCM
scm_m_cont (SCM xorig
, SCM env
);
264 static SCM
scm_m_at_call_with_values (SCM xorig
, SCM env
);
265 static SCM
scm_m_cond (SCM xorig
, SCM env
);
266 static SCM
scm_m_define (SCM x
, SCM env
);
267 static SCM
scm_m_at_dynamic_wind (SCM xorig
, SCM env
);
268 static SCM
scm_m_eval_when (SCM xorig
, SCM env
);
269 static SCM
scm_m_if (SCM xorig
, SCM env
);
270 static SCM
scm_m_lambda (SCM xorig
, SCM env
);
271 static SCM
scm_m_let (SCM xorig
, SCM env
);
272 static SCM
scm_m_letrec (SCM xorig
, SCM env
);
273 static SCM
scm_m_letstar (SCM xorig
, SCM env
);
274 static SCM
scm_m_or (SCM xorig
, SCM env
);
275 static SCM
scm_m_quote (SCM xorig
, SCM env
);
276 static SCM
scm_m_set_x (SCM xorig
, SCM env
);
282 static scm_t_macro_primitive
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_is_true (scm_macro_p (scm_variable_ref (var
))))
293 return scm_i_macro_primitive (scm_variable_ref (var
));
295 return NULL
; /* anything else */
299 memoize_env_var_is_free (SCM env
, SCM x
)
301 for (; scm_is_pair (env
); env
= CDR (env
))
302 if (scm_is_eq (x
, CAR (env
)))
303 return 0; /* bound */
308 memoize_env_lexical_index (SCM env
, SCM x
)
311 for (; scm_is_pair (env
); env
= CDR (env
), i
++)
312 if (scm_is_eq (x
, CAR (env
)))
313 return i
; /* bound */
314 return -1; /* free */
318 memoize_env_extend (SCM env
, SCM vars
)
320 return scm_append (scm_list_2 (vars
, env
));
324 memoize (SCM exp
, SCM env
)
326 if (scm_is_pair (exp
))
329 scm_t_macro_primitive trans
;
332 if (scm_is_symbol (CAR
))
333 trans
= memoize_env_ref_transformer (env
, CAR
);
338 return trans (exp
, env
);
344 proc
= memoize (CAR (exp
), env
);
345 for (exp
= CDR (exp
); scm_is_pair (exp
); exp
= CDR (exp
), nargs
++)
346 args
= scm_cons (memoize (CAR (exp
), env
), args
);
347 if (scm_is_null (exp
))
348 return MAKMEMO_CALL (proc
, nargs
,
349 scm_reverse_x (args
, SCM_UNDEFINED
));
351 syntax_error ("expected a proper list", exp
, SCM_UNDEFINED
);
354 else if (scm_is_symbol (exp
))
356 int i
= memoize_env_lexical_index (env
, exp
);
358 return MAKMEMO_TOP_REF (exp
);
360 return MAKMEMO_LEX_REF (i
);
363 return MAKMEMO_QUOTE (exp
);
367 memoize_exprs (SCM forms
, const SCM env
)
371 for (; !scm_is_null (forms
); forms
= CDR (forms
))
372 ret
= scm_cons (memoize (CAR (forms
), env
), ret
);
373 return scm_reverse_x (ret
, SCM_UNDEFINED
);
377 memoize_sequence (const SCM forms
, const SCM env
)
379 ASSERT_SYNTAX (scm_ilength (forms
) >= 1, s_bad_expression
,
380 scm_cons (scm_sym_begin
, forms
));
381 if (scm_is_null (CDR (forms
)))
382 return memoize (CAR (forms
), env
);
384 return MAKMEMO_BEGIN (memoize_exprs (forms
, env
));
391 #define SCM_SYNTAX(RANAME, STR, CFN) \
392 SCM_SNARF_HERE(static const char RANAME[]=STR)\
393 SCM_SNARF_INIT(scm_c_define (RANAME, scm_i_make_primitive_macro (RANAME, CFN)))
395 SCM_SYNTAX (s_at
, "@", scm_m_at
);
396 SCM_SYNTAX (s_atat
, "@@", scm_m_atat
);
397 SCM_SYNTAX (s_and
, "and", scm_m_and
);
398 SCM_SYNTAX (s_begin
, "begin", scm_m_begin
);
399 SCM_SYNTAX (s_atcall_cc
, "@call-with-current-continuation", scm_m_cont
);
400 SCM_SYNTAX (s_at_call_with_values
, "@call-with-values", scm_m_at_call_with_values
);
401 SCM_SYNTAX (s_cond
, "cond", scm_m_cond
);
402 SCM_SYNTAX (s_define
, "define", scm_m_define
);
403 SCM_SYNTAX (s_at_dynamic_wind
, "@dynamic-wind", scm_m_at_dynamic_wind
);
404 SCM_SYNTAX (s_eval_when
, "eval-when", scm_m_eval_when
);
405 SCM_SYNTAX (s_if
, "if", scm_m_if
);
406 SCM_SYNTAX (s_lambda
, "lambda", scm_m_lambda
);
407 SCM_SYNTAX (s_let
, "let", scm_m_let
);
408 SCM_SYNTAX (s_letrec
, "letrec", scm_m_letrec
);
409 SCM_SYNTAX (s_letstar
, "let*", scm_m_letstar
);
410 SCM_SYNTAX (s_or
, "or", scm_m_or
);
411 SCM_SYNTAX (s_quote
, "quote", scm_m_quote
);
412 SCM_SYNTAX (s_set_x
, "set!", scm_m_set_x
);
413 SCM_SYNTAX (s_atapply
, "@apply", scm_m_apply
);
416 SCM_GLOBAL_SYMBOL (scm_sym_apply
, "apply");
417 SCM_GLOBAL_SYMBOL (scm_sym_arrow
, "=>");
418 SCM_GLOBAL_SYMBOL (scm_sym_at
, "@");
419 SCM_GLOBAL_SYMBOL (scm_sym_atat
, "@@");
420 SCM_GLOBAL_SYMBOL (scm_sym_at_call_with_values
, "@call-with-values");
421 SCM_GLOBAL_SYMBOL (scm_sym_atapply
, "@apply");
422 SCM_GLOBAL_SYMBOL (scm_sym_atcall_cc
, "@call-with-current-continuation");
423 SCM_GLOBAL_SYMBOL (scm_sym_begin
, "begin");
424 SCM_GLOBAL_SYMBOL (scm_sym_case
, "case");
425 SCM_GLOBAL_SYMBOL (scm_sym_cond
, "cond");
426 SCM_GLOBAL_SYMBOL (scm_sym_define
, "define");
427 SCM_GLOBAL_SYMBOL (scm_sym_at_dynamic_wind
, "@dynamic-wind");
428 SCM_GLOBAL_SYMBOL (scm_sym_else
, "else");
429 SCM_GLOBAL_SYMBOL (scm_sym_eval_when
, "eval-when");
430 SCM_GLOBAL_SYMBOL (scm_sym_if
, "if");
431 SCM_GLOBAL_SYMBOL (scm_sym_lambda
, "lambda");
432 SCM_GLOBAL_SYMBOL (scm_sym_let
, "let");
433 SCM_GLOBAL_SYMBOL (scm_sym_letrec
, "letrec");
434 SCM_GLOBAL_SYMBOL (scm_sym_letstar
, "let*");
435 SCM_GLOBAL_SYMBOL (scm_sym_or
, "or");
436 SCM_GLOBAL_SYMBOL (scm_sym_quote
, "quote");
437 SCM_GLOBAL_SYMBOL (scm_sym_set_x
, "set!");
438 SCM_SYMBOL (sym_eval
, "eval");
439 SCM_SYMBOL (sym_load
, "load");
441 SCM_GLOBAL_SYMBOL (scm_sym_unquote
, "unquote");
442 SCM_GLOBAL_SYMBOL (scm_sym_quasiquote
, "quasiquote");
443 SCM_GLOBAL_SYMBOL (scm_sym_uq_splicing
, "unquote-splicing");
447 scm_m_at (SCM expr
, SCM env SCM_UNUSED
)
449 ASSERT_SYNTAX (scm_ilength (expr
) == 3, s_bad_expression
, expr
);
450 ASSERT_SYNTAX (scm_ilength (CADR (expr
)) > 0, s_bad_expression
, expr
);
451 ASSERT_SYNTAX (scm_is_symbol (CADDR (expr
)), s_bad_expression
, expr
);
453 return MAKMEMO_MOD_REF (CADR (expr
), CADDR (expr
), SCM_BOOL_T
);
457 scm_m_atat (SCM expr
, SCM env SCM_UNUSED
)
459 ASSERT_SYNTAX (scm_ilength (expr
) == 3, s_bad_expression
, expr
);
460 ASSERT_SYNTAX (scm_ilength (CADR (expr
)) > 0, s_bad_expression
, expr
);
461 ASSERT_SYNTAX (scm_is_symbol (CADDR (expr
)), s_bad_expression
, expr
);
463 return MAKMEMO_MOD_REF (CADR (expr
), CADDR (expr
), SCM_BOOL_F
);
467 scm_m_and (SCM expr
, SCM env
)
469 const SCM cdr_expr
= CDR (expr
);
471 if (scm_is_null (cdr_expr
))
472 return MAKMEMO_QUOTE (SCM_BOOL_T
);
473 ASSERT_SYNTAX (scm_is_pair (cdr_expr
), s_bad_expression
, expr
);
475 if (scm_is_null (CDR (cdr_expr
)))
476 return memoize (CAR (cdr_expr
), env
);
478 return MAKMEMO_IF (memoize (CAR (cdr_expr
), env
),
479 scm_m_and (cdr_expr
, env
),
480 MAKMEMO_QUOTE (SCM_BOOL_F
));
484 scm_m_apply (SCM expr
, SCM env
)
486 const SCM cdr_expr
= CDR (expr
);
487 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
488 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_missing_expression
, expr
);
490 return MAKMEMO_APPLY (memoize_exprs (cdr_expr
, env
));
494 scm_m_begin (SCM expr
, SCM env
)
496 const SCM cdr_expr
= CDR (expr
);
497 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 1, s_bad_expression
, expr
);
498 return MAKMEMO_BEGIN (memoize_exprs (cdr_expr
, env
));
502 scm_m_cont (SCM expr
, SCM env
)
504 const SCM cdr_expr
= CDR (expr
);
505 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
506 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
508 return MAKMEMO_CONT (memoize (CADR (expr
), env
));
512 scm_m_at_call_with_values (SCM expr
, SCM env
)
514 const SCM cdr_expr
= CDR (expr
);
515 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
516 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
518 return MAKMEMO_CALL_WITH_VALUES (memoize (CADR (expr
), env
),
519 memoize (CADDR (expr
), env
));
523 scm_m_cond (SCM expr
, SCM env
)
525 /* Check, whether 'else or '=> is a literal, i. e. not bound to a value. */
526 const int else_literal_p
= memoize_env_var_is_free (env
, scm_sym_else
);
527 const int arrow_literal_p
= memoize_env_var_is_free (env
, scm_sym_arrow
);
529 const SCM clauses
= CDR (expr
);
533 ASSERT_SYNTAX (scm_ilength (clauses
) >= 0, s_bad_expression
, expr
);
534 ASSERT_SYNTAX (scm_ilength (clauses
) >= 1, s_missing_clauses
, expr
);
536 ret
= scm_cons (SCM_UNDEFINED
, MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
539 for (clause_idx
= clauses
;
540 !scm_is_null (clause_idx
);
541 clause_idx
= CDR (clause_idx
))
545 const SCM clause
= CAR (clause_idx
);
546 const long length
= scm_ilength (clause
);
547 ASSERT_SYNTAX_2 (length
>= 1, s_bad_cond_clause
, clause
, expr
);
550 if (scm_is_eq (test
, scm_sym_else
) && else_literal_p
)
552 const int last_clause_p
= scm_is_null (CDR (clause_idx
));
553 ASSERT_SYNTAX_2 (length
>= 2,
554 s_bad_cond_clause
, clause
, expr
);
555 ASSERT_SYNTAX_2 (last_clause_p
,
556 s_misplaced_else_clause
, clause
, expr
);
558 memoize (scm_cons (scm_sym_begin
, CDR (clause
)), env
));
561 && scm_is_eq (CADR (clause
), scm_sym_arrow
)
564 SCM tmp
= scm_gensym (scm_from_locale_string ("cond "));
566 SCM new_env
= scm_cons (tmp
, env
);
567 ASSERT_SYNTAX_2 (length
> 2, s_missing_recipient
, clause
, expr
);
568 ASSERT_SYNTAX_2 (length
== 3, s_extra_expression
, clause
, expr
);
569 i
= MAKMEMO_IF (MAKMEMO_LEX_REF (0),
570 MAKMEMO_CALL (memoize (CADDR (clause
),
571 scm_cons (tmp
, new_env
)),
573 scm_list_1 (MAKMEMO_LEX_REF (0))),
574 MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
576 MAKMEMO_LET (scm_list_1 (memoize (CAR (clause
), env
)),
579 loc
= scm_last_pair (SCM_MEMOIZED_ARGS (i
));
581 /* FIXME length == 1 case */
584 SCM i
= MAKMEMO_IF (memoize (CAR (clause
), env
),
585 memoize (scm_cons (scm_sym_begin
, CDR (clause
)), env
),
586 MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
588 loc
= scm_last_pair (SCM_MEMOIZED_ARGS (i
));
595 /* According to Section 5.2.1 of R5RS we first have to make sure that the
596 variable is bound, and then perform the `(set! variable expression)'
597 operation. However, EXPRESSION _can_ be evaluated before VARIABLE is
598 bound. This means that EXPRESSION won't necessarily be able to assign
599 values to VARIABLE as in `(define foo (begin (set! foo 1) (+ foo 1)))'. */
601 scm_m_define (SCM expr
, SCM env
)
603 const SCM cdr_expr
= CDR (expr
);
607 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
608 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
609 ASSERT_SYNTAX (!scm_is_pair (env
), s_bad_define
, expr
);
611 body
= CDR (cdr_expr
);
612 variable
= CAR (cdr_expr
);
614 if (scm_is_pair (variable
))
616 ASSERT_SYNTAX_2 (scm_is_symbol (CAR (variable
)), s_bad_variable
, variable
, expr
);
617 return MAKMEMO_DEFINE (CAR (variable
),
618 memoize (scm_cons (scm_sym_lambda
,
619 scm_cons (CDR (variable
), body
)),
622 ASSERT_SYNTAX_2 (scm_is_symbol (variable
), s_bad_variable
, variable
, expr
);
623 ASSERT_SYNTAX (scm_ilength (body
) == 1, s_expression
, expr
);
624 return MAKMEMO_DEFINE (variable
, memoize (CAR (body
), env
));
628 scm_m_at_dynamic_wind (SCM expr
, SCM env
)
630 const SCM cdr_expr
= CDR (expr
);
631 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 3, s_bad_expression
, expr
);
633 return MAKMEMO_DYNWIND (memoize (CADR (expr
), env
),
634 memoize (CADDR (expr
), env
),
635 memoize (CADDDR (expr
), env
));
639 scm_m_eval_when (SCM expr
, SCM env
)
641 ASSERT_SYNTAX (scm_ilength (expr
) >= 3, s_bad_expression
, expr
);
642 ASSERT_SYNTAX (scm_ilength (CADR (expr
)) > 0, s_bad_expression
, expr
);
644 if (scm_is_true (scm_memq (sym_eval
, CADR (expr
)))
645 || scm_is_true (scm_memq (sym_load
, CADR (expr
))))
646 return MAKMEMO_BEGIN (memoize_exprs (CDDR (expr
), env
));
648 return MAKMEMO_QUOTE (SCM_UNSPECIFIED
);
652 scm_m_if (SCM expr
, SCM env SCM_UNUSED
)
654 const SCM cdr_expr
= CDR (expr
);
655 const long length
= scm_ilength (cdr_expr
);
656 ASSERT_SYNTAX (length
== 2 || length
== 3, s_expression
, expr
);
657 return MAKMEMO_IF (memoize (CADR (expr
), env
),
658 memoize (CADDR (expr
), env
),
660 ? memoize (CADDDR (expr
), env
)
661 : MAKMEMO_QUOTE (SCM_UNSPECIFIED
)));
664 /* A helper function for memoize_lambda to support checking for duplicate
665 * formal arguments: Return true if OBJ is `eq?' to one of the elements of
666 * LIST or to the CDR of the last cons. Therefore, LIST may have any of the
667 * forms that a formal argument can have:
668 * <rest>, (<arg1> ...), (<arg1> ... . <rest>) */
670 c_improper_memq (SCM obj
, SCM list
)
672 for (; scm_is_pair (list
); list
= CDR (list
))
674 if (scm_is_eq (CAR (list
), obj
))
677 return scm_is_eq (list
, obj
);
681 scm_m_lambda (SCM expr
, SCM env SCM_UNUSED
)
685 SCM formal_vars
= SCM_EOL
;
688 const SCM cdr_expr
= CDR (expr
);
689 const long length
= scm_ilength (cdr_expr
);
690 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
691 ASSERT_SYNTAX (length
>= 2, s_missing_expression
, expr
);
693 /* Before iterating the list of formal arguments, make sure the formals
694 * actually are given as either a symbol or a non-cyclic list. */
695 formals
= CAR (cdr_expr
);
696 if (scm_is_pair (formals
))
698 /* Dirk:FIXME:: We should check for a cyclic list of formals, and if
699 * detected, report a 'Bad formals' error. */
703 ASSERT_SYNTAX_2 (scm_is_symbol (formals
) || scm_is_null (formals
),
704 s_bad_formals
, formals
, expr
);
707 /* Now iterate the list of formal arguments to check if all formals are
708 * symbols, and that there are no duplicates. */
709 formals_idx
= formals
;
710 while (scm_is_pair (formals_idx
))
712 const SCM formal
= CAR (formals_idx
);
713 const SCM next_idx
= CDR (formals_idx
);
714 ASSERT_SYNTAX_2 (scm_is_symbol (formal
), s_bad_formal
, formal
, expr
);
715 ASSERT_SYNTAX_2 (!c_improper_memq (formal
, next_idx
),
716 s_duplicate_formal
, formal
, expr
);
718 formal_vars
= scm_cons (formal
, formal_vars
);
719 formals_idx
= next_idx
;
721 ASSERT_SYNTAX_2 (scm_is_null (formals_idx
) || scm_is_symbol (formals_idx
),
722 s_bad_formal
, formals_idx
, expr
);
723 if (scm_is_symbol (formals_idx
))
724 formal_vars
= scm_cons (formals_idx
, formal_vars
);
725 return MAKMEMO_LAMBDA (nreq
, scm_symbol_p (formals_idx
),
726 memoize_sequence (CDDR (expr
),
727 memoize_env_extend (env
, formal_vars
)));
730 /* Check if the format of the bindings is ((<symbol> <init-form>) ...). */
732 check_bindings (const SCM bindings
, const SCM expr
)
736 ASSERT_SYNTAX_2 (scm_ilength (bindings
) >= 0,
737 s_bad_bindings
, bindings
, expr
);
739 binding_idx
= bindings
;
740 for (; !scm_is_null (binding_idx
); binding_idx
= CDR (binding_idx
))
742 SCM name
; /* const */
744 const SCM binding
= CAR (binding_idx
);
745 ASSERT_SYNTAX_2 (scm_ilength (binding
) == 2,
746 s_bad_binding
, binding
, expr
);
748 name
= CAR (binding
);
749 ASSERT_SYNTAX_2 (scm_is_symbol (name
), s_bad_variable
, name
, expr
);
753 /* The bindings, which must have the format ((v1 i1) (v2 i2) ... (vn in)), are
754 * transformed to the lists (vn .. v2 v1) and (i1 i2 ... in). If a duplicate
755 * variable name is detected, an error is signalled. */
757 transform_bindings (const SCM bindings
, const SCM expr
,
758 SCM
*const rvarptr
, SCM
*const initptr
)
760 SCM rvariables
= SCM_EOL
;
761 SCM rinits
= SCM_EOL
;
762 SCM binding_idx
= bindings
;
764 for (; !scm_is_null (binding_idx
); binding_idx
= CDR (binding_idx
))
766 const SCM binding
= CAR (binding_idx
);
767 const SCM CDR_binding
= CDR (binding
);
768 const SCM name
= CAR (binding
);
769 ASSERT_SYNTAX_2 (scm_is_false (scm_c_memq (name
, rvariables
)),
770 s_duplicate_binding
, name
, expr
);
771 rvariables
= scm_cons (name
, rvariables
);
772 rinits
= scm_cons (CAR (CDR_binding
), rinits
);
775 *rvarptr
= rvariables
;
776 *initptr
= scm_reverse_x (rinits
, SCM_UNDEFINED
);
780 /* This function is a helper function for memoize_let. It transforms
781 * (let name ((var init) ...) body ...) into
782 * ((letrec ((name (lambda (var ...) body ...))) name) init ...)
783 * and memoizes the expression. It is assumed that the caller has checked
784 * that name is a symbol and that there are bindings and a body. */
786 memoize_named_let (const SCM expr
, SCM env
)
792 const SCM cdr_expr
= CDR (expr
);
793 const SCM name
= CAR (cdr_expr
);
794 const SCM cddr_expr
= CDR (cdr_expr
);
795 const SCM bindings
= CAR (cddr_expr
);
796 check_bindings (bindings
, expr
);
798 nreq
= transform_bindings (bindings
, expr
, &rvariables
, &inits
);
800 env
= scm_cons (name
, env
);
802 (scm_list_1 (MAKMEMO_QUOTE (SCM_UNDEFINED
)),
804 (scm_list_2 (MAKMEMO_LEX_SET
808 memoize_sequence (CDDDR (expr
),
809 memoize_env_extend (env
, rvariables
)))),
810 MAKMEMO_CALL (MAKMEMO_LEX_REF (0),
812 memoize_exprs (inits
, env
)))));
815 /* (let ((v1 i1) (v2 i2) ...) body) with variables v1 .. vn and initializers
816 * i1 .. in is transformed to (#@let (vn ... v2 v1) (i1 i2 ...) body). */
818 scm_m_let (SCM expr
, SCM env
)
822 const SCM cdr_expr
= CDR (expr
);
823 const long length
= scm_ilength (cdr_expr
);
824 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
825 ASSERT_SYNTAX (length
>= 2, s_missing_expression
, expr
);
827 bindings
= CAR (cdr_expr
);
828 if (scm_is_symbol (bindings
))
830 ASSERT_SYNTAX (length
>= 3, s_missing_expression
, expr
);
831 return memoize_named_let (expr
, env
);
834 check_bindings (bindings
, expr
);
835 if (scm_is_null (bindings
))
836 return memoize_sequence (CDDR (expr
), env
);
841 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
842 return MAKMEMO_LET (memoize_exprs (inits
, env
),
843 memoize_sequence (CDDR (expr
),
844 memoize_env_extend (env
, rvariables
)));
849 scm_m_letrec (SCM expr
, SCM env
)
853 const SCM cdr_expr
= CDR (expr
);
854 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
855 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
857 bindings
= CAR (cdr_expr
);
858 if (scm_is_null (bindings
))
859 return memoize_sequence (CDDR (expr
), env
);
865 SCM undefs
= SCM_EOL
;
870 int n
= transform_bindings (bindings
, expr
, &rvariables
, &inits
);
872 new_env
= memoize_env_extend (env
, rvariables
);
873 for (v
= scm_reverse (rvariables
), i
= inits
; scm_is_pair (v
);
874 v
= CDR (v
), i
= CDR (i
), n
--)
876 undefs
= scm_cons (MAKMEMO_QUOTE (SCM_UNDEFINED
), undefs
);
877 vals
= scm_cons (memoize (CAR (i
), new_env
), vals
);
878 sets
= scm_cons (MAKMEMO_LEX_SET ((n
-1) + offset
,
879 MAKMEMO_LEX_REF (n
-1)),
884 MAKMEMO_BEGIN (scm_list_2 (MAKMEMO_LET (scm_reverse (vals
),
885 MAKMEMO_BEGIN (sets
)),
886 memoize_sequence (CDDR (expr
),
892 scm_m_letstar (SCM expr
, SCM env SCM_UNUSED
)
896 const SCM cdr_expr
= CDR (expr
);
897 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
898 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
900 bindings
= CAR (cdr_expr
);
901 if (scm_is_null (bindings
))
902 return memoize_sequence (CDDR (expr
), env
);
909 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
910 variables
= scm_reverse (rvariables
);
911 ret
= scm_cons (SCM_UNDEFINED
, SCM_UNSPECIFIED
);
913 for (; scm_is_pair (variables
);
914 variables
= CDR (variables
), inits
= CDR (inits
))
915 { SCM x
= MAKMEMO_LET (scm_list_1 (memoize (CAR (inits
), env
)),
916 MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
918 loc
= scm_last_pair (SCM_MEMOIZED_ARGS (x
));
919 env
= scm_cons (CAR (variables
), env
);
921 SCM_SETCDR (loc
, memoize_sequence (CDDR (expr
), env
));
927 scm_m_or (SCM expr
, SCM env SCM_UNUSED
)
929 SCM tail
= CDR (expr
);
931 const long length
= scm_ilength (tail
);
933 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
935 ret
= scm_cons (SCM_UNDEFINED
, SCM_UNSPECIFIED
);
937 for (; scm_is_pair (tail
); tail
= CDR (tail
))
939 SCM tmp
= scm_gensym (scm_from_locale_string ("cond "));
940 SCM x
= MAKMEMO_IF (MAKMEMO_LEX_REF (0),
942 MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
943 SCM new_env
= scm_cons (tmp
, env
);
944 SCM_SETCDR (loc
, MAKMEMO_LET (scm_list_1 (memoize (CAR (tail
),
948 loc
= scm_last_pair (SCM_MEMOIZED_ARGS (x
));
950 SCM_SETCDR (loc
, MAKMEMO_QUOTE (SCM_BOOL_F
));
955 scm_m_quote (SCM expr
, SCM env SCM_UNUSED
)
959 const SCM cdr_expr
= CDR (expr
);
960 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
961 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
962 quotee
= CAR (cdr_expr
);
963 return MAKMEMO_QUOTE (quotee
);
967 scm_m_set_x (SCM expr
, SCM env
)
972 const SCM cdr_expr
= CDR (expr
);
973 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
974 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
975 variable
= CAR (cdr_expr
);
976 vmem
= memoize (variable
, env
);
978 switch (SCM_MEMOIZED_TAG (vmem
))
980 case SCM_M_LEXICAL_REF
:
981 return MAKMEMO_LEX_SET (SCM_I_INUM (SCM_MEMOIZED_ARGS (vmem
)),
982 memoize (CADDR (expr
), env
));
983 case SCM_M_TOPLEVEL_REF
:
984 return MAKMEMO_TOP_SET (variable
,
985 memoize (CADDR (expr
), env
));
986 case SCM_M_MODULE_REF
:
987 return MAKMEMO_MOD_SET (memoize (CADDR (expr
), env
),
988 CAR (SCM_MEMOIZED_ARGS (vmem
)),
989 CADR (SCM_MEMOIZED_ARGS (vmem
)),
990 CDDR (SCM_MEMOIZED_ARGS (vmem
)));
992 syntax_error (s_bad_variable
, variable
, expr
);
999 SCM_DEFINE (scm_memoize_expression
, "memoize-expression", 1, 0, 0,
1001 "Memoize the expression @var{exp}.")
1002 #define FUNC_NAME s_scm_memoize_expression
1004 return memoize (exp
, scm_current_module ());
1011 SCM_SYMBOL (sym_placeholder
, "_");
1013 static SCM
unmemoize (SCM expr
);
1016 unmemoize_exprs (SCM exprs
)
1019 if (scm_is_null (exprs
))
1021 ret
= scm_list_1 (unmemoize (CAR (exprs
)));
1023 for (exprs
= CDR (exprs
); !scm_is_null (exprs
); exprs
= CDR (exprs
))
1025 SCM_SETCDR (tail
, scm_list_1 (unmemoize (CAR (exprs
))));
1032 unmemoize_bindings (SCM inits
)
1035 if (scm_is_null (inits
))
1037 ret
= scm_list_1 (scm_list_2 (sym_placeholder
, unmemoize (CAR (inits
))));
1039 for (inits
= CDR (inits
); !scm_is_null (inits
); inits
= CDR (inits
))
1041 SCM_SETCDR (tail
, scm_list_1 (scm_list_2 (sym_placeholder
,
1042 unmemoize (CAR (inits
)))));
1049 unmemoize_lexical (SCM n
)
1053 snprintf (buf
, 15, "<%u>", scm_to_uint32 (n
));
1054 return scm_from_locale_symbol (buf
);
1058 unmemoize (const SCM expr
)
1062 if (!SCM_MEMOIZED_P (expr
))
1065 args
= SCM_MEMOIZED_ARGS (expr
);
1066 switch (SCM_MEMOIZED_TAG (expr
))
1069 return scm_cons (scm_sym_atapply
, unmemoize_exprs (args
));
1071 return scm_cons (scm_sym_begin
, unmemoize_exprs (args
));
1073 return scm_cons (unmemoize (CAR (args
)), unmemoize_exprs (CDDR (args
)));
1075 return scm_list_2 (scm_sym_atcall_cc
, unmemoize (args
));
1076 case SCM_M_CALL_WITH_VALUES
:
1077 return scm_list_3 (scm_sym_at_call_with_values
,
1078 unmemoize (CAR (args
)), unmemoize (CDR (args
)));
1080 return scm_list_3 (scm_sym_define
, CAR (args
), unmemoize (CDR (args
)));
1082 return scm_list_4 (scm_sym_at_dynamic_wind
,
1083 unmemoize (CAR (args
)),
1084 unmemoize (CADR (args
)),
1085 unmemoize (CDDR (args
)));
1087 return scm_list_4 (scm_sym_if
, unmemoize (scm_car (args
)),
1088 unmemoize (scm_cadr (args
)), unmemoize (scm_cddr (args
)));
1090 return scm_list_3 (scm_sym_lambda
,
1091 scm_make_list (CAR (args
), sym_placeholder
),
1092 unmemoize (CDDR (args
)));
1094 return scm_list_3 (scm_sym_let
,
1095 unmemoize_bindings (CAR (args
)),
1096 unmemoize (CDR (args
)));
1098 return scm_list_2 (scm_sym_quote
, args
);
1099 case SCM_M_LEXICAL_REF
:
1100 return unmemoize_lexical (args
);
1101 case SCM_M_LEXICAL_SET
:
1102 return scm_list_3 (scm_sym_set_x
, unmemoize_lexical (CAR (args
)),
1103 unmemoize (CDR (args
)));
1104 case SCM_M_TOPLEVEL_REF
:
1106 case SCM_M_TOPLEVEL_SET
:
1107 return scm_list_3 (scm_sym_set_x
, CAR (args
), unmemoize (CDR (args
)));
1108 case SCM_M_MODULE_REF
:
1109 return SCM_VARIABLEP (args
) ? args
1110 : scm_list_3 (scm_is_true (CDDR (args
)) ? scm_sym_at
: scm_sym_atat
,
1111 scm_i_finite_list_copy (CAR (args
)),
1113 case SCM_M_MODULE_SET
:
1114 return scm_list_3 (scm_sym_set_x
,
1115 SCM_VARIABLEP (CDR (args
)) ? CDR (args
)
1116 : scm_list_3 (scm_is_true (CDDDR (args
))
1117 ? scm_sym_at
: scm_sym_atat
,
1118 scm_i_finite_list_copy (CADR (args
)),
1120 unmemoize (CAR (args
)));
1126 SCM_DEFINE (scm_memoized_p
, "memoized?", 1, 0, 0,
1128 "Return @code{#t} if @var{obj} is memoized.")
1129 #define FUNC_NAME s_scm_memoized_p
1131 return scm_from_bool (SCM_MEMOIZED_P (obj
));
1135 SCM_DEFINE (scm_unmemoize_expression
, "unmemoize-expression", 1, 0, 0,
1137 "Unmemoize the memoized expression @var{m}.")
1138 #define FUNC_NAME s_scm_unmemoize_expression
1140 SCM_VALIDATE_MEMOIZED (1, m
);
1141 return unmemoize (m
);
1145 SCM_DEFINE (scm_memoized_expression_typecode
, "memoized-expression-typecode", 1, 0, 0,
1147 "Return the typecode from the memoized expression @var{m}.")
1148 #define FUNC_NAME s_scm_memoized_expression_typecode
1150 SCM_VALIDATE_MEMOIZED (1, m
);
1151 return scm_from_uint16 (SCM_MEMOIZED_TAG (m
));
1155 SCM_DEFINE (scm_memoized_expression_data
, "memoized-expression-data", 1, 0, 0,
1157 "Return the data from the memoized expression @var{m}.")
1158 #define FUNC_NAME s_scm_memoized_expression_data
1160 SCM_VALIDATE_MEMOIZED (1, m
);
1161 return SCM_MEMOIZED_ARGS (m
);
1165 SCM_DEFINE (scm_memoized_typecode
, "memoized-typecode", 1, 0, 0,
1167 "Return the memoized typecode corresponding to the symbol @var{sym}.")
1168 #define FUNC_NAME s_scm_memoized_typecode
1172 SCM_VALIDATE_SYMBOL (1, sym
);
1174 for (i
= 0; i
< sizeof(memoized_tags
)/sizeof(const char*); i
++)
1175 if (strcmp (scm_i_symbol_chars (sym
), memoized_tags
[i
]) == 0)
1176 return scm_from_int32 (i
);
1182 SCM_SYMBOL (scm_unbound_variable_key
, "unbound-variable");
1183 static void error_unbound_variable (SCM symbol
) SCM_NORETURN
;
1184 static void error_unbound_variable (SCM symbol
)
1186 scm_error (scm_unbound_variable_key
, NULL
, "Unbound variable: ~S",
1187 scm_list_1 (symbol
), SCM_BOOL_F
);
1190 SCM_DEFINE (scm_memoize_variable_access_x
, "memoize-variable-access!", 2, 0, 0,
1192 "Look up and cache the variable that @var{m} will access, returning the variable.")
1193 #define FUNC_NAME s_scm_memoize_variable_access_x
1196 SCM_VALIDATE_MEMOIZED (1, m
);
1197 mx
= SCM_MEMOIZED_ARGS (m
);
1198 switch (SCM_MEMOIZED_TAG (m
))
1200 case SCM_M_TOPLEVEL_REF
:
1201 if (SCM_VARIABLEP (mx
))
1205 SCM var
= scm_module_variable (mod
, mx
);
1206 if (scm_is_false (var
) || scm_is_false (scm_variable_bound_p (var
)))
1207 error_unbound_variable (mx
);
1208 SCM_SET_SMOB_OBJECT (m
, var
);
1212 case SCM_M_TOPLEVEL_SET
:
1215 if (SCM_VARIABLEP (var
))
1219 var
= scm_module_variable (mod
, var
);
1220 if (scm_is_false (var
))
1221 error_unbound_variable (CAR (mx
));
1222 SCM_SETCAR (mx
, var
);
1227 case SCM_M_MODULE_REF
:
1228 if (SCM_VARIABLEP (mx
))
1233 mod
= scm_resolve_module (CAR (mx
));
1234 if (scm_is_true (CDDR (mx
)))
1235 mod
= scm_module_public_interface (mod
);
1236 var
= scm_module_lookup (mod
, CADR (mx
));
1237 if (scm_is_false (scm_variable_bound_p (var
)))
1238 error_unbound_variable (CADR (mx
));
1239 SCM_SET_SMOB_OBJECT (m
, var
);
1243 case SCM_M_MODULE_SET
:
1244 /* FIXME: not quite threadsafe */
1245 if (SCM_VARIABLEP (CDR (mx
)))
1250 mod
= scm_resolve_module (CADR (mx
));
1251 if (scm_is_true (CDDDR (mx
)))
1252 mod
= scm_module_public_interface (mod
);
1253 var
= scm_module_lookup (mod
, CADDR (mx
));
1254 SCM_SETCDR (mx
, var
);
1259 scm_wrong_type_arg (FUNC_NAME
, 1, m
);
1271 scm_tc16_memoized
= scm_make_smob_type ("%memoized", 0);
1272 scm_set_smob_mark (scm_tc16_memoized
, scm_markcdr
);
1273 scm_set_smob_print (scm_tc16_memoized
, scm_print_memoized
);
1275 #include "libguile/memoize.x"