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
28 #include "libguile/__scm.h"
31 #include "libguile/_scm.h"
32 #include "libguile/continuations.h"
33 #include "libguile/eq.h"
34 #include "libguile/list.h"
35 #include "libguile/macros.h"
36 #include "libguile/memoize.h"
37 #include "libguile/modules.h"
38 #include "libguile/srcprop.h"
39 #include "libguile/ports.h"
40 #include "libguile/print.h"
41 #include "libguile/strings.h"
42 #include "libguile/throw.h"
43 #include "libguile/validate.h"
50 #define CAR(x) SCM_CAR(x)
51 #define CDR(x) SCM_CDR(x)
52 #define CAAR(x) SCM_CAAR(x)
53 #define CADR(x) SCM_CADR(x)
54 #define CDAR(x) SCM_CDAR(x)
55 #define CDDR(x) SCM_CDDR(x)
56 #define CADDR(x) SCM_CADDR(x)
57 #define CDDDR(x) SCM_CDDDR(x)
58 #define CADDDR(x) SCM_CDDDR(x)
60 #define CAR(x) scm_car(x)
61 #define CDR(x) scm_cdr(x)
62 #define CAAR(x) scm_caar(x)
63 #define CADR(x) scm_cadr(x)
64 #define CDAR(x) scm_cdar(x)
65 #define CDDR(x) scm_cddr(x)
66 #define CADDR(x) scm_caddr(x)
67 #define CDDDR(x) scm_cdddr(x)
68 #define CADDDR(x) scm_cadddr(x)
72 static const char s_bad_expression
[] = "Bad expression";
73 static const char s_expression
[] = "Missing or extra expression in";
74 static const char s_missing_expression
[] = "Missing expression in";
75 static const char s_extra_expression
[] = "Extra expression in";
76 static const char s_empty_combination
[] = "Illegal empty combination";
77 static const char s_missing_body_expression
[] = "Missing body expression in";
78 static const char s_mixed_body_forms
[] = "Mixed definitions and expressions in";
79 static const char s_bad_define
[] = "Bad define placement";
80 static const char s_missing_clauses
[] = "Missing clauses";
81 static const char s_misplaced_else_clause
[] = "Misplaced else clause";
82 static const char s_bad_case_clause
[] = "Bad case clause";
83 static const char s_bad_case_labels
[] = "Bad case labels";
84 static const char s_duplicate_case_label
[] = "Duplicate case label";
85 static const char s_bad_cond_clause
[] = "Bad cond clause";
86 static const char s_missing_recipient
[] = "Missing recipient in";
87 static const char s_bad_variable
[] = "Bad variable";
88 static const char s_bad_bindings
[] = "Bad bindings";
89 static const char s_bad_binding
[] = "Bad binding";
90 static const char s_duplicate_binding
[] = "Duplicate binding";
91 static const char s_bad_exit_clause
[] = "Bad exit clause";
92 static const char s_bad_formals
[] = "Bad formals";
93 static const char s_bad_formal
[] = "Bad formal";
94 static const char s_duplicate_formal
[] = "Duplicate formal";
95 static const char s_splicing
[] = "Non-list result for unquote-splicing";
96 static const char s_bad_slot_number
[] = "Bad slot number";
99 /* Signal a syntax error. We distinguish between the form that caused the
100 * error and the enclosing expression. The error message will print out as
101 * shown in the following pattern. The file name and line number are only
102 * given when they can be determined from the erroneous form or from the
103 * enclosing expression.
105 * <filename>: In procedure memoization:
106 * <filename>: In file <name>, line <nr>: <error-message> in <expression>. */
108 SCM_SYMBOL (syntax_error_key
, "syntax-error");
110 /* The prototype is needed to indicate that the function does not return. */
112 syntax_error (const char* const, const SCM
, const SCM
) SCM_NORETURN
;
115 syntax_error (const char* const msg
, const SCM form
, const SCM expr
)
117 SCM msg_string
= scm_from_locale_string (msg
);
118 SCM filename
= SCM_BOOL_F
;
119 SCM linenr
= SCM_BOOL_F
;
123 if (scm_is_pair (form
))
125 filename
= scm_source_property (form
, scm_sym_filename
);
126 linenr
= scm_source_property (form
, scm_sym_line
);
129 if (scm_is_false (filename
) && scm_is_false (linenr
) && scm_is_pair (expr
))
131 filename
= scm_source_property (expr
, scm_sym_filename
);
132 linenr
= scm_source_property (expr
, scm_sym_line
);
135 if (!SCM_UNBNDP (expr
))
137 if (scm_is_true (filename
))
139 format
= "In file ~S, line ~S: ~A ~S in expression ~S.";
140 args
= scm_list_5 (filename
, linenr
, msg_string
, form
, expr
);
142 else if (scm_is_true (linenr
))
144 format
= "In line ~S: ~A ~S in expression ~S.";
145 args
= scm_list_4 (linenr
, msg_string
, form
, expr
);
149 format
= "~A ~S in expression ~S.";
150 args
= scm_list_3 (msg_string
, form
, expr
);
155 if (scm_is_true (filename
))
157 format
= "In file ~S, line ~S: ~A ~S.";
158 args
= scm_list_4 (filename
, linenr
, msg_string
, form
);
160 else if (scm_is_true (linenr
))
162 format
= "In line ~S: ~A ~S.";
163 args
= scm_list_3 (linenr
, msg_string
, form
);
168 args
= scm_list_2 (msg_string
, form
);
172 scm_error (syntax_error_key
, "memoization", format
, args
, SCM_BOOL_F
);
176 /* Shortcut macros to simplify syntax error handling. */
177 #define ASSERT_SYNTAX(cond, message, form) \
178 { if (SCM_UNLIKELY (!(cond))) \
179 syntax_error (message, form, SCM_UNDEFINED); }
180 #define ASSERT_SYNTAX_2(cond, message, form, expr) \
181 { if (SCM_UNLIKELY (!(cond))) \
182 syntax_error (message, form, expr); }
187 /* {Evaluator memoized expressions}
190 scm_t_bits scm_tc16_memoized
;
192 #define MAKMEMO(n, args) (scm_cell (scm_tc16_memoized | ((n) << 16), (scm_t_bits)(args)))
194 #define MAKMEMO_BEGIN(exps) \
195 MAKMEMO (SCM_M_BEGIN, exps)
196 #define MAKMEMO_IF(test, then, else_) \
197 MAKMEMO (SCM_M_IF, scm_cons (test, scm_cons (then, else_)))
198 #define MAKMEMO_LAMBDA(nreq, rest, body) \
199 MAKMEMO (SCM_M_LAMBDA, scm_cons (SCM_I_MAKINUM (nreq), scm_cons (rest, body)))
200 #define MAKMEMO_LET(inits, body) \
201 MAKMEMO (SCM_M_LET, scm_cons (inits, body))
202 #define MAKMEMO_QUOTE(exp) \
203 MAKMEMO (SCM_M_QUOTE, exp)
204 #define MAKMEMO_DEFINE(var, val) \
205 MAKMEMO (SCM_M_DEFINE, scm_cons (var, val))
206 #define MAKMEMO_APPLY(exp) \
207 MAKMEMO (SCM_M_APPLY, exp)
208 #define MAKMEMO_CONT(proc) \
209 MAKMEMO (SCM_M_CONT, proc)
210 #define MAKMEMO_CALL_WITH_VALUES(prod, cons) \
211 MAKMEMO (SCM_M_CALL_WITH_VALUES, scm_cons (prod, cons))
212 #define MAKMEMO_CALL(proc, args) \
213 MAKMEMO (SCM_M_CALL, scm_cons (proc, args))
214 #define MAKMEMO_LEX_REF(n) \
215 MAKMEMO (SCM_M_LEXICAL_REF, SCM_I_MAKINUM (n))
216 #define MAKMEMO_LEX_SET(n, val) \
217 MAKMEMO (SCM_M_LEXICAL_SET, scm_cons (SCM_I_MAKINUM (n), val))
218 #define MAKMEMO_TOP_REF(var) \
219 MAKMEMO (SCM_M_TOPLEVEL_REF, var)
220 #define MAKMEMO_TOP_SET(var, val) \
221 MAKMEMO (SCM_M_TOPLEVEL_SET, scm_cons (var, val))
222 #define MAKMEMO_MOD_REF(mod, var, public) \
223 MAKMEMO (SCM_M_MODULE_REF, scm_cons (mod, scm_cons (var, public)))
224 #define MAKMEMO_MOD_SET(val, mod, var, public) \
225 MAKMEMO (SCM_M_MODULE_SET, scm_cons (val, scm_cons (mod, scm_cons (var, public))))
229 /* This table must agree with the list of M_ constants in memoize.h */
230 static const char *const memoized_tags
[] =
251 scm_print_memoized (SCM memoized
, SCM port
, scm_print_state
*pstate
)
253 scm_puts ("#<memoized ", port
);
254 scm_write (scm_unmemoize_expression (memoized
), port
);
255 scm_puts (">", port
);
259 static SCM
scm_m_at (SCM xorig
, SCM env
);
260 static SCM
scm_m_atat (SCM xorig
, SCM env
);
261 static SCM
scm_m_and (SCM xorig
, SCM env
);
262 static SCM
scm_m_apply (SCM xorig
, SCM env
);
263 static SCM
scm_m_begin (SCM xorig
, SCM env
);
264 static SCM
scm_m_cont (SCM xorig
, SCM env
);
265 static SCM
scm_m_at_call_with_values (SCM xorig
, SCM env
);
266 static SCM
scm_m_cond (SCM xorig
, SCM env
);
267 static SCM
scm_m_define (SCM x
, 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 typedef SCM (*t_syntax_transformer
) (SCM
, SCM
);
284 static t_syntax_transformer
285 memoize_env_ref_transformer (SCM env
, SCM x
)
288 for (; scm_is_pair (env
); env
= CDR (env
))
289 if (scm_is_eq (x
, CAR (env
)))
290 return NULL
; /* lexical */
292 var
= scm_module_variable (env
, x
);
293 if (scm_is_true (var
) && scm_is_true (scm_variable_bound_p (var
))
294 && SCM_MACROP (scm_variable_ref (var
)))
296 SCM mac
= scm_variable_ref (var
);
297 if (SCM_IMP (SCM_MACRO_CODE (mac
))
298 || (SCM_TYP7 (SCM_MACRO_CODE (mac
)) != scm_tc7_gsubr
))
299 syntax_error ("bad macro", x
, SCM_UNDEFINED
);
301 return (t_syntax_transformer
)SCM_SUBRF (SCM_MACRO_CODE (mac
)); /* global macro */
304 return NULL
; /* anything else */
308 memoize_env_var_is_free (SCM env
, SCM x
)
310 for (; scm_is_pair (env
); env
= CDR (env
))
311 if (scm_is_eq (x
, CAR (env
)))
312 return 0; /* bound */
317 memoize_env_lexical_index (SCM env
, SCM x
)
320 for (; scm_is_pair (env
); env
= CDR (env
), i
++)
321 if (scm_is_eq (x
, CAR (env
)))
322 return i
; /* bound */
323 return -1; /* free */
327 memoize_env_extend (SCM env
, SCM vars
)
329 return scm_append (scm_list_2 (vars
, env
));
333 memoize (SCM exp
, SCM env
)
335 if (scm_is_pair (exp
))
338 t_syntax_transformer trans
;
341 if (scm_is_symbol (CAR
))
342 trans
= memoize_env_ref_transformer (env
, CAR
);
347 return trans (exp
, env
);
351 for (; scm_is_pair (exp
); exp
= CDR (exp
))
352 args
= scm_cons (memoize (CAR (exp
), env
), args
);
353 if (scm_is_null (exp
))
354 return MAKMEMO (SCM_M_CALL
, scm_reverse_x (args
, SCM_UNDEFINED
));
356 syntax_error ("expected a proper list", exp
, SCM_UNDEFINED
);
359 else if (scm_is_symbol (exp
))
361 int i
= memoize_env_lexical_index (env
, exp
);
363 return MAKMEMO_TOP_REF (exp
);
365 return MAKMEMO_LEX_REF (i
);
368 return MAKMEMO_QUOTE (exp
);
372 memoize_exprs (SCM forms
, const SCM env
)
376 for (; !scm_is_null (forms
); forms
= CDR (forms
))
377 ret
= scm_cons (memoize (CAR (forms
), env
), ret
);
378 return scm_reverse_x (ret
, SCM_UNDEFINED
);
382 memoize_sequence (const SCM forms
, const SCM env
)
384 ASSERT_SYNTAX (scm_ilength (forms
) >= 1, s_bad_expression
,
385 scm_cons (scm_sym_begin
, forms
));
386 return MAKMEMO_BEGIN (memoize_exprs (forms
, env
));
393 /* bimacros (built-in macros) have isym codes.
394 mmacros don't exist at runtime, they just expand out to more primitive
396 SCM_SYNTAX (s_at
, "@", scm_i_makbimacro
, scm_m_at
);
397 SCM_SYNTAX (s_atat
, "@@", scm_i_makbimacro
, scm_m_atat
);
398 SCM_SYNTAX (s_and
, "and", scm_makmmacro
, scm_m_and
);
399 SCM_SYNTAX (s_begin
, "begin", scm_i_makbimacro
, scm_m_begin
);
400 SCM_SYNTAX (s_atcall_cc
, "@call-with-current-continuation", scm_i_makbimacro
, scm_m_cont
);
401 SCM_SYNTAX (s_at_call_with_values
, "@call-with-values", scm_i_makbimacro
, scm_m_at_call_with_values
);
402 SCM_SYNTAX (s_cond
, "cond", scm_makmmacro
, scm_m_cond
);
403 SCM_SYNTAX (s_define
, "define", scm_i_makbimacro
, scm_m_define
);
404 SCM_SYNTAX (s_eval_when
, "eval-when", scm_makmmacro
, scm_m_eval_when
);
405 SCM_SYNTAX (s_if
, "if", scm_i_makbimacro
, scm_m_if
);
406 SCM_SYNTAX (s_lambda
, "lambda", scm_i_makbimacro
, scm_m_lambda
);
407 SCM_SYNTAX (s_let
, "let", scm_i_makbimacro
, scm_m_let
);
408 SCM_SYNTAX (s_letrec
, "letrec", scm_makmmacro
, scm_m_letrec
);
409 SCM_SYNTAX (s_letstar
, "let*", scm_makmmacro
, scm_m_letstar
);
410 SCM_SYNTAX (s_or
, "or", scm_makmmacro
, scm_m_or
);
411 SCM_SYNTAX (s_quote
, "quote", scm_i_makbimacro
, scm_m_quote
);
412 SCM_SYNTAX (s_set_x
, "set!", scm_i_makbimacro
, scm_m_set_x
);
413 SCM_SYNTAX (s_atapply
, "@apply", scm_i_makbimacro
, 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_else
, "else");
428 SCM_GLOBAL_SYMBOL (scm_sym_eval_when
, "eval-when");
429 SCM_GLOBAL_SYMBOL (scm_sym_if
, "if");
430 SCM_GLOBAL_SYMBOL (scm_sym_lambda
, "lambda");
431 SCM_GLOBAL_SYMBOL (scm_sym_let
, "let");
432 SCM_GLOBAL_SYMBOL (scm_sym_letrec
, "letrec");
433 SCM_GLOBAL_SYMBOL (scm_sym_letstar
, "let*");
434 SCM_GLOBAL_SYMBOL (scm_sym_or
, "or");
435 SCM_GLOBAL_SYMBOL (scm_sym_quote
, "quote");
436 SCM_GLOBAL_SYMBOL (scm_sym_set_x
, "set!");
437 SCM_SYMBOL (sym_eval
, "eval");
438 SCM_SYMBOL (sym_load
, "load");
440 SCM_GLOBAL_SYMBOL (scm_sym_unquote
, "unquote");
441 SCM_GLOBAL_SYMBOL (scm_sym_quasiquote
, "quasiquote");
442 SCM_GLOBAL_SYMBOL (scm_sym_uq_splicing
, "unquote-splicing");
446 scm_m_at (SCM expr
, SCM env SCM_UNUSED
)
448 ASSERT_SYNTAX (scm_ilength (expr
) == 3, s_bad_expression
, expr
);
449 ASSERT_SYNTAX (scm_ilength (CADR (expr
)) > 0, s_bad_expression
, expr
);
450 ASSERT_SYNTAX (scm_is_symbol (CADDR (expr
)), s_bad_expression
, expr
);
452 return MAKMEMO_MOD_REF (CADR (expr
), CADDR (expr
), SCM_BOOL_T
);
456 scm_m_atat (SCM expr
, SCM env SCM_UNUSED
)
458 ASSERT_SYNTAX (scm_ilength (expr
) == 3, s_bad_expression
, expr
);
459 ASSERT_SYNTAX (scm_ilength (CADR (expr
)) > 0, s_bad_expression
, expr
);
460 ASSERT_SYNTAX (scm_is_symbol (CADDR (expr
)), s_bad_expression
, expr
);
462 return MAKMEMO_MOD_REF (CADR (expr
), CADDR (expr
), SCM_BOOL_F
);
466 scm_m_and (SCM expr
, SCM env
)
468 const SCM cdr_expr
= CDR (expr
);
470 if (scm_is_null (cdr_expr
))
471 return MAKMEMO_QUOTE (SCM_BOOL_T
);
472 ASSERT_SYNTAX (scm_is_pair (cdr_expr
), s_bad_expression
, expr
);
474 if (scm_is_null (CDR (cdr_expr
)))
475 return memoize (CAR (cdr_expr
), env
);
477 return MAKMEMO_IF (memoize (CAR (cdr_expr
), env
),
478 scm_m_and (cdr_expr
, env
),
479 MAKMEMO_QUOTE (SCM_BOOL_F
));
483 scm_m_apply (SCM expr
, SCM env
)
485 const SCM cdr_expr
= CDR (expr
);
486 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
487 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_missing_expression
, expr
);
489 return MAKMEMO_APPLY (memoize_exprs (cdr_expr
, env
));
493 scm_m_begin (SCM expr
, SCM env
)
495 const SCM cdr_expr
= CDR (expr
);
496 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 1, s_bad_expression
, expr
);
497 return MAKMEMO_BEGIN (memoize_exprs (cdr_expr
, env
));
501 scm_m_cont (SCM expr
, SCM env
)
503 const SCM cdr_expr
= CDR (expr
);
504 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
505 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
507 return MAKMEMO_CONT (memoize (CADR (expr
), env
));
511 scm_m_at_call_with_values (SCM expr
, SCM env
)
513 const SCM cdr_expr
= CDR (expr
);
514 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
515 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
517 return MAKMEMO_CALL_WITH_VALUES (memoize (CADR (expr
), env
),
518 memoize (CADDR (expr
), env
));
522 scm_m_cond (SCM expr
, SCM env
)
524 /* Check, whether 'else or '=> is a literal, i. e. not bound to a value. */
525 const int else_literal_p
= memoize_env_var_is_free (env
, scm_sym_else
);
526 const int arrow_literal_p
= memoize_env_var_is_free (env
, scm_sym_arrow
);
528 const SCM clauses
= CDR (expr
);
532 ASSERT_SYNTAX (scm_ilength (clauses
) >= 0, s_bad_expression
, expr
);
533 ASSERT_SYNTAX (scm_ilength (clauses
) >= 1, s_missing_clauses
, expr
);
535 ret
= scm_cons (SCM_UNDEFINED
, MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
538 for (clause_idx
= clauses
;
539 !scm_is_null (clause_idx
);
540 clause_idx
= CDR (clause_idx
))
544 const SCM clause
= CAR (clause_idx
);
545 const long length
= scm_ilength (clause
);
546 ASSERT_SYNTAX_2 (length
>= 1, s_bad_cond_clause
, clause
, expr
);
549 if (scm_is_eq (test
, scm_sym_else
) && else_literal_p
)
551 const int last_clause_p
= scm_is_null (CDR (clause_idx
));
552 ASSERT_SYNTAX_2 (length
>= 2,
553 s_bad_cond_clause
, clause
, expr
);
554 ASSERT_SYNTAX_2 (last_clause_p
,
555 s_misplaced_else_clause
, clause
, expr
);
557 memoize (scm_cons (scm_sym_begin
, CDR (clause
)), env
));
560 && scm_is_eq (CADR (clause
), scm_sym_arrow
)
563 SCM tmp
= scm_gensym (scm_from_locale_string ("cond "));
565 SCM new_env
= scm_cons (tmp
, env
);
566 ASSERT_SYNTAX_2 (length
> 2, s_missing_recipient
, clause
, expr
);
567 ASSERT_SYNTAX_2 (length
== 3, s_extra_expression
, clause
, expr
);
568 i
= MAKMEMO_IF (MAKMEMO_LEX_REF (0),
569 MAKMEMO_CALL (memoize (CADDR (clause
),
570 scm_cons (tmp
, new_env
)),
571 scm_list_1 (MAKMEMO_LEX_REF (0))),
572 MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
574 MAKMEMO_LET (scm_list_1 (memoize (CAR (clause
), env
)),
577 loc
= scm_last_pair (SCM_MEMOIZED_ARGS (i
));
579 /* FIXME length == 1 case */
582 SCM i
= MAKMEMO_IF (memoize (CAR (clause
), env
),
583 memoize (scm_cons (scm_sym_begin
, CDR (clause
)), env
),
584 MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
586 loc
= scm_last_pair (SCM_MEMOIZED_ARGS (i
));
593 /* According to Section 5.2.1 of R5RS we first have to make sure that the
594 variable is bound, and then perform the `(set! variable expression)'
595 operation. However, EXPRESSION _can_ be evaluated before VARIABLE is
596 bound. This means that EXPRESSION won't necessarily be able to assign
597 values to VARIABLE as in `(define foo (begin (set! foo 1) (+ foo 1)))'. */
599 scm_m_define (SCM expr
, SCM env
)
601 const SCM cdr_expr
= CDR (expr
);
605 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
606 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
607 ASSERT_SYNTAX (!scm_is_pair (env
), s_bad_define
, expr
);
609 body
= CDR (cdr_expr
);
610 variable
= CAR (cdr_expr
);
612 if (scm_is_pair (variable
))
614 ASSERT_SYNTAX_2 (scm_is_symbol (CAR (variable
)), s_bad_variable
, variable
, expr
);
615 return MAKMEMO_DEFINE (CAR (variable
),
616 memoize (scm_cons (scm_sym_lambda
,
617 scm_cons (CDR (variable
), body
)),
620 ASSERT_SYNTAX_2 (scm_is_symbol (variable
), s_bad_variable
, variable
, expr
);
621 ASSERT_SYNTAX (scm_ilength (body
) == 1, s_expression
, expr
);
622 return MAKMEMO_DEFINE (variable
, memoize (CAR (body
), env
));
626 scm_m_eval_when (SCM expr
, SCM env
)
628 ASSERT_SYNTAX (scm_ilength (expr
) >= 3, s_bad_expression
, expr
);
629 ASSERT_SYNTAX (scm_ilength (CADR (expr
)) > 0, s_bad_expression
, expr
);
631 if (scm_is_true (scm_memq (sym_eval
, CADR (expr
)))
632 || scm_is_true (scm_memq (sym_load
, CADR (expr
))))
633 return MAKMEMO_BEGIN (memoize_exprs (CDDR (expr
), env
));
635 return MAKMEMO_QUOTE (SCM_UNSPECIFIED
);
639 scm_m_if (SCM expr
, SCM env SCM_UNUSED
)
641 const SCM cdr_expr
= CDR (expr
);
642 const long length
= scm_ilength (cdr_expr
);
643 ASSERT_SYNTAX (length
== 2 || length
== 3, s_expression
, expr
);
644 return MAKMEMO_IF (memoize (CADR (expr
), env
),
645 memoize (CADDR (expr
), env
),
647 ? memoize (CADDDR (expr
), env
)
648 : MAKMEMO_QUOTE (SCM_UNSPECIFIED
)));
651 /* A helper function for memoize_lambda to support checking for duplicate
652 * formal arguments: Return true if OBJ is `eq?' to one of the elements of
653 * LIST or to the CDR of the last cons. Therefore, LIST may have any of the
654 * forms that a formal argument can have:
655 * <rest>, (<arg1> ...), (<arg1> ... . <rest>) */
657 c_improper_memq (SCM obj
, SCM list
)
659 for (; scm_is_pair (list
); list
= CDR (list
))
661 if (scm_is_eq (CAR (list
), obj
))
664 return scm_is_eq (list
, obj
);
668 scm_m_lambda (SCM expr
, SCM env SCM_UNUSED
)
672 SCM formal_vars
= SCM_EOL
;
675 const SCM cdr_expr
= CDR (expr
);
676 const long length
= scm_ilength (cdr_expr
);
677 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
678 ASSERT_SYNTAX (length
>= 2, s_missing_expression
, expr
);
680 /* Before iterating the list of formal arguments, make sure the formals
681 * actually are given as either a symbol or a non-cyclic list. */
682 formals
= CAR (cdr_expr
);
683 if (scm_is_pair (formals
))
685 /* Dirk:FIXME:: We should check for a cyclic list of formals, and if
686 * detected, report a 'Bad formals' error. */
690 ASSERT_SYNTAX_2 (scm_is_symbol (formals
) || scm_is_null (formals
),
691 s_bad_formals
, formals
, expr
);
694 /* Now iterate the list of formal arguments to check if all formals are
695 * symbols, and that there are no duplicates. */
696 formals_idx
= formals
;
697 while (scm_is_pair (formals_idx
))
699 const SCM formal
= CAR (formals_idx
);
700 const SCM next_idx
= CDR (formals_idx
);
701 ASSERT_SYNTAX_2 (scm_is_symbol (formal
), s_bad_formal
, formal
, expr
);
702 ASSERT_SYNTAX_2 (!c_improper_memq (formal
, next_idx
),
703 s_duplicate_formal
, formal
, expr
);
705 formal_vars
= scm_cons (formal
, formal_vars
);
706 formals_idx
= next_idx
;
708 ASSERT_SYNTAX_2 (scm_is_null (formals_idx
) || scm_is_symbol (formals_idx
),
709 s_bad_formal
, formals_idx
, expr
);
710 if (scm_is_symbol (formals_idx
))
711 formal_vars
= scm_cons (formals_idx
, formal_vars
);
712 return MAKMEMO_LAMBDA (nreq
, scm_symbol_p (formals_idx
),
713 memoize_sequence (CDDR (expr
),
714 memoize_env_extend (env
, formal_vars
)));
717 /* Check if the format of the bindings is ((<symbol> <init-form>) ...). */
719 check_bindings (const SCM bindings
, const SCM expr
)
723 ASSERT_SYNTAX_2 (scm_ilength (bindings
) >= 0,
724 s_bad_bindings
, bindings
, expr
);
726 binding_idx
= bindings
;
727 for (; !scm_is_null (binding_idx
); binding_idx
= CDR (binding_idx
))
729 SCM name
; /* const */
731 const SCM binding
= CAR (binding_idx
);
732 ASSERT_SYNTAX_2 (scm_ilength (binding
) == 2,
733 s_bad_binding
, binding
, expr
);
735 name
= CAR (binding
);
736 ASSERT_SYNTAX_2 (scm_is_symbol (name
), s_bad_variable
, name
, expr
);
740 /* The bindings, which must have the format ((v1 i1) (v2 i2) ... (vn in)), are
741 * transformed to the lists (vn .. v2 v1) and (i1 i2 ... in). If a duplicate
742 * variable name is detected, an error is signalled. */
744 transform_bindings (const SCM bindings
, const SCM expr
,
745 SCM
*const rvarptr
, SCM
*const initptr
)
747 SCM rvariables
= SCM_EOL
;
748 SCM rinits
= SCM_EOL
;
749 SCM binding_idx
= bindings
;
751 for (; !scm_is_null (binding_idx
); binding_idx
= CDR (binding_idx
))
753 const SCM binding
= CAR (binding_idx
);
754 const SCM CDR_binding
= CDR (binding
);
755 const SCM name
= CAR (binding
);
756 ASSERT_SYNTAX_2 (scm_is_false (scm_c_memq (name
, rvariables
)),
757 s_duplicate_binding
, name
, expr
);
758 rvariables
= scm_cons (name
, rvariables
);
759 rinits
= scm_cons (CAR (CDR_binding
), rinits
);
762 *rvarptr
= rvariables
;
763 *initptr
= scm_reverse_x (rinits
, SCM_UNDEFINED
);
767 /* This function is a helper function for memoize_let. It transforms
768 * (let name ((var init) ...) body ...) into
769 * ((letrec ((name (lambda (var ...) body ...))) name) init ...)
770 * and memoizes the expression. It is assumed that the caller has checked
771 * that name is a symbol and that there are bindings and a body. */
773 memoize_named_let (const SCM expr
, SCM env
)
779 const SCM cdr_expr
= CDR (expr
);
780 const SCM name
= CAR (cdr_expr
);
781 const SCM cddr_expr
= CDR (cdr_expr
);
782 const SCM bindings
= CAR (cddr_expr
);
783 check_bindings (bindings
, expr
);
785 nreq
= transform_bindings (bindings
, expr
, &rvariables
, &inits
);
787 env
= scm_cons (name
, env
);
789 (scm_list_1 (MAKMEMO_QUOTE (SCM_UNDEFINED
)),
791 (scm_list_2 (MAKMEMO_LEX_SET
795 memoize_sequence (CDDDR (expr
),
796 memoize_env_extend (env
, rvariables
)))),
797 MAKMEMO_CALL (MAKMEMO_LEX_REF (0),
798 memoize_exprs (inits
, env
)))));
801 /* (let ((v1 i1) (v2 i2) ...) body) with variables v1 .. vn and initializers
802 * i1 .. in is transformed to (#@let (vn ... v2 v1) (i1 i2 ...) body). */
804 scm_m_let (SCM expr
, SCM env
)
808 const SCM cdr_expr
= CDR (expr
);
809 const long length
= scm_ilength (cdr_expr
);
810 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
811 ASSERT_SYNTAX (length
>= 2, s_missing_expression
, expr
);
813 bindings
= CAR (cdr_expr
);
814 if (scm_is_symbol (bindings
))
816 ASSERT_SYNTAX (length
>= 3, s_missing_expression
, expr
);
817 return memoize_named_let (expr
, env
);
820 check_bindings (bindings
, expr
);
821 if (scm_is_null (bindings
))
822 return memoize_sequence (CDDR (expr
), env
);
827 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
828 return MAKMEMO_LET (memoize_exprs (inits
, env
),
829 memoize_sequence (CDDR (expr
),
830 memoize_env_extend (env
, rvariables
)));
835 scm_m_letrec (SCM expr
, SCM env
)
839 const SCM cdr_expr
= CDR (expr
);
840 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
841 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
843 bindings
= CAR (cdr_expr
);
844 if (scm_is_null (bindings
))
845 return memoize_sequence (CDDR (expr
), env
);
851 SCM undefs
= SCM_EOL
;
856 int n
= transform_bindings (bindings
, expr
, &rvariables
, &inits
);
858 new_env
= memoize_env_extend (env
, rvariables
);
859 for (v
= scm_reverse (rvariables
), i
= inits
; scm_is_pair (v
);
860 v
= CDR (v
), i
= CDR (i
), n
--)
862 undefs
= scm_cons (MAKMEMO_QUOTE (SCM_UNDEFINED
), undefs
);
863 vals
= scm_cons (memoize (CAR (i
), new_env
), vals
);
864 sets
= scm_cons (MAKMEMO_LEX_SET ((n
-1) + offset
,
865 MAKMEMO_LEX_REF (n
-1)),
870 MAKMEMO_BEGIN (scm_list_2 (MAKMEMO_LET (scm_reverse (vals
),
871 MAKMEMO_BEGIN (sets
)),
872 memoize_sequence (CDDR (expr
),
878 scm_m_letstar (SCM expr
, SCM env SCM_UNUSED
)
882 const SCM cdr_expr
= CDR (expr
);
883 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
884 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
886 bindings
= CAR (cdr_expr
);
887 if (scm_is_null (bindings
))
888 return memoize_sequence (CDDR (expr
), env
);
895 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
896 variables
= scm_reverse (rvariables
);
897 ret
= scm_cons (SCM_UNDEFINED
, SCM_UNSPECIFIED
);
899 for (; scm_is_pair (variables
);
900 variables
= CDR (variables
), inits
= CDR (inits
))
901 { SCM x
= MAKMEMO_LET (scm_list_1 (memoize (CAR (inits
), env
)),
902 MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
904 loc
= scm_last_pair (SCM_MEMOIZED_ARGS (x
));
905 env
= scm_cons (CAR (variables
), env
);
907 SCM_SETCDR (loc
, memoize_sequence (CDDR (expr
), env
));
913 scm_m_or (SCM expr
, SCM env SCM_UNUSED
)
915 SCM tail
= CDR (expr
);
917 const long length
= scm_ilength (tail
);
919 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
921 ret
= scm_cons (SCM_UNDEFINED
, SCM_UNSPECIFIED
);
923 for (; scm_is_pair (tail
); tail
= CDR (tail
))
925 SCM tmp
= scm_gensym (scm_from_locale_string ("cond "));
926 SCM x
= MAKMEMO_IF (MAKMEMO_LEX_REF (0),
928 MAKMEMO_QUOTE (SCM_UNSPECIFIED
));
929 SCM new_env
= scm_cons (tmp
, env
);
930 SCM_SETCDR (loc
, MAKMEMO_LET (scm_list_1 (memoize (CAR (tail
),
934 loc
= scm_last_pair (SCM_MEMOIZED_ARGS (x
));
936 SCM_SETCDR (loc
, MAKMEMO_QUOTE (SCM_BOOL_F
));
941 scm_m_quote (SCM expr
, SCM env SCM_UNUSED
)
945 const SCM cdr_expr
= CDR (expr
);
946 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
947 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
948 quotee
= CAR (cdr_expr
);
949 return MAKMEMO_QUOTE (quotee
);
953 scm_m_set_x (SCM expr
, SCM env
)
958 const SCM cdr_expr
= CDR (expr
);
959 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
960 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
961 variable
= CAR (cdr_expr
);
962 vmem
= memoize (variable
, env
);
964 switch (SCM_MEMOIZED_TAG (vmem
))
966 case SCM_M_LEXICAL_REF
:
967 return MAKMEMO_LEX_SET (SCM_I_INUM (SCM_MEMOIZED_ARGS (vmem
)),
968 memoize (CADDR (expr
), env
));
969 case SCM_M_TOPLEVEL_REF
:
970 return MAKMEMO_TOP_SET (variable
,
971 memoize (CADDR (expr
), env
));
972 case SCM_M_MODULE_REF
:
973 return MAKMEMO_MOD_SET (memoize (CADDR (expr
), env
),
974 CAR (SCM_MEMOIZED_ARGS (vmem
)),
975 CADR (SCM_MEMOIZED_ARGS (vmem
)),
976 CDDR (SCM_MEMOIZED_ARGS (vmem
)));
978 syntax_error (s_bad_variable
, variable
, expr
);
985 SCM_DEFINE (scm_memoize_expression
, "memoize-expression", 1, 0, 0,
987 "Memoize the expression @var{exp}.")
988 #define FUNC_NAME s_scm_memoize_expression
990 return memoize (exp
, scm_current_module ());
997 SCM_SYMBOL (sym_placeholder
, "_");
999 static SCM
unmemoize (SCM expr
);
1002 unmemoize_exprs (SCM exprs
)
1005 if (scm_is_null (exprs
))
1007 ret
= scm_list_1 (unmemoize (CAR (exprs
)));
1009 for (exprs
= CDR (exprs
); !scm_is_null (exprs
); exprs
= CDR (exprs
))
1011 SCM_SETCDR (tail
, scm_list_1 (unmemoize (CAR (exprs
))));
1018 unmemoize_bindings (SCM inits
)
1021 if (scm_is_null (inits
))
1023 ret
= scm_list_1 (scm_list_2 (sym_placeholder
, unmemoize (CAR (inits
))));
1025 for (inits
= CDR (inits
); !scm_is_null (inits
); inits
= CDR (inits
))
1027 SCM_SETCDR (tail
, scm_list_1 (scm_list_2 (sym_placeholder
,
1028 unmemoize (CAR (inits
)))));
1035 unmemoize_lexical (SCM n
)
1039 snprintf (buf
, 15, "<%u>", scm_to_uint32 (n
));
1040 return scm_from_locale_symbol (buf
);
1044 unmemoize (const SCM expr
)
1048 if (!SCM_MEMOIZED_P (expr
))
1051 args
= SCM_MEMOIZED_ARGS (expr
);
1052 switch (SCM_MEMOIZED_TAG (expr
))
1055 return scm_cons (scm_sym_atapply
, unmemoize_exprs (args
));
1057 return scm_cons (scm_sym_begin
, unmemoize_exprs (args
));
1059 return unmemoize_exprs (args
);
1061 return scm_list_2 (scm_sym_atcall_cc
, unmemoize (args
));
1062 case SCM_M_CALL_WITH_VALUES
:
1063 return scm_list_3 (scm_sym_at_call_with_values
,
1064 unmemoize (CAR (args
)), unmemoize (CDR (args
)));
1066 return scm_list_3 (scm_sym_define
, CAR (args
), unmemoize (CDR (args
)));
1068 return scm_list_4 (scm_sym_if
, unmemoize (scm_car (args
)),
1069 unmemoize (scm_cadr (args
)), unmemoize (scm_cddr (args
)));
1071 return scm_list_3 (scm_sym_lambda
,
1072 scm_make_list (CAR (args
), sym_placeholder
),
1073 unmemoize (CDDR (args
)));
1075 return scm_list_3 (scm_sym_let
,
1076 unmemoize_bindings (CAR (args
)),
1077 unmemoize (CDR (args
)));
1079 return scm_list_2 (scm_sym_quote
, args
);
1080 case SCM_M_LEXICAL_REF
:
1081 return unmemoize_lexical (args
);
1082 case SCM_M_LEXICAL_SET
:
1083 return scm_list_3 (scm_sym_set_x
, unmemoize_lexical (CAR (args
)),
1084 unmemoize (CDR (args
)));
1085 case SCM_M_TOPLEVEL_REF
:
1087 case SCM_M_TOPLEVEL_SET
:
1088 return scm_list_3 (scm_sym_set_x
, CAR (args
), unmemoize (CDR (args
)));
1089 case SCM_M_MODULE_REF
:
1090 return scm_list_3 (scm_is_true (CDDR (args
)) ? scm_sym_at
: scm_sym_atat
,
1091 scm_i_finite_list_copy (CAR (args
)),
1093 case SCM_M_MODULE_SET
:
1094 return scm_list_3 (scm_sym_set_x
,
1095 scm_list_3 (scm_is_true (CDDDR (args
))
1096 ? scm_sym_at
: scm_sym_atat
,
1097 scm_i_finite_list_copy (CADR (args
)),
1099 unmemoize (CAR (args
)));
1105 SCM_DEFINE (scm_memoized_p
, "memoized?", 1, 0, 0,
1107 "Return @code{#t} if @var{obj} is memoized.")
1108 #define FUNC_NAME s_scm_memoized_p
1110 return scm_from_bool (SCM_MEMOIZED_P (obj
));
1114 SCM_DEFINE (scm_unmemoize_expression
, "unmemoize-expression", 1, 0, 0,
1116 "Unmemoize the memoized expression @var{m}.")
1117 #define FUNC_NAME s_scm_unmemoize_expression
1119 SCM_VALIDATE_MEMOIZED (1, m
);
1120 return unmemoize (m
);
1124 SCM_DEFINE (scm_memoized_expression_typecode
, "memoized-expression-typecode", 1, 0, 0,
1126 "Return the typecode from the memoized expression @var{m}.")
1127 #define FUNC_NAME s_scm_memoized_expression_typecode
1129 SCM_VALIDATE_MEMOIZED (1, m
);
1130 return scm_from_uint16 (SCM_MEMOIZED_TAG (m
));
1134 SCM_DEFINE (scm_memoized_expression_data
, "memoized-expression-data", 1, 0, 0,
1136 "Return the data from the memoized expression @var{m}.")
1137 #define FUNC_NAME s_scm_memoized_expression_data
1139 SCM_VALIDATE_MEMOIZED (1, m
);
1140 return SCM_MEMOIZED_ARGS (m
);
1144 SCM_DEFINE (scm_memoized_typecode
, "memoized-typecode", 1, 0, 0,
1146 "Return the memoized typecode corresponding to the symbol @var{sym}.")
1147 #define FUNC_NAME s_scm_memoized_typecode
1151 SCM_VALIDATE_SYMBOL (1, sym
);
1153 for (i
= 0; i
< sizeof(memoized_tags
)/sizeof(const char*); i
++)
1154 if (strcmp (scm_i_symbol_chars (sym
), memoized_tags
[i
]) == 0)
1155 return scm_from_int32 (i
);
1161 SCM_SYMBOL (scm_unbound_variable_key
, "unbound-variable");
1162 static void error_unbound_variable (SCM symbol
) SCM_NORETURN
;
1163 static void error_unbound_variable (SCM symbol
)
1165 scm_error (scm_unbound_variable_key
, NULL
, "Unbound variable: ~S",
1166 scm_list_1 (symbol
), SCM_BOOL_F
);
1169 SCM_DEFINE (scm_memoize_variable_access_x
, "memoize-variable-access!", 2, 0, 0,
1171 "Look up and cache the variable that @var{m} will access, returning the variable.")
1172 #define FUNC_NAME s_scm_memoized_expression_data
1175 SCM_VALIDATE_MEMOIZED (1, m
);
1176 mx
= SCM_MEMOIZED_ARGS (m
);
1177 switch (SCM_MEMOIZED_TAG (m
))
1179 case SCM_M_TOPLEVEL_REF
:
1180 if (SCM_VARIABLEP (mx
))
1184 SCM var
= scm_module_variable (mod
, mx
);
1185 if (scm_is_false (var
) || scm_is_false (scm_variable_bound_p (var
)))
1186 error_unbound_variable (mx
);
1187 SCM_SET_SMOB_OBJECT (m
, var
);
1191 case SCM_M_TOPLEVEL_SET
:
1194 if (SCM_VARIABLEP (var
))
1198 var
= scm_module_variable (mod
, var
);
1199 if (scm_is_false (var
))
1200 error_unbound_variable (CAR (mx
));
1201 SCM_SETCAR (mx
, var
);
1206 case SCM_M_MODULE_REF
:
1207 if (SCM_VARIABLEP (mx
))
1212 mod
= scm_resolve_module (CAR (mx
));
1213 if (scm_is_true (CDDR (mx
)))
1214 mod
= scm_module_public_interface (mod
);
1215 var
= scm_module_lookup (mod
, CADR (mx
));
1216 if (scm_is_false (scm_variable_bound_p (var
)))
1217 error_unbound_variable (CADR (mx
));
1218 SCM_SET_SMOB_OBJECT (m
, var
);
1222 case SCM_M_MODULE_SET
:
1223 /* FIXME: not quite threadsafe */
1224 if (SCM_VARIABLEP (CDR (mx
)))
1229 mod
= scm_resolve_module (CADR (mx
));
1230 if (scm_is_true (CDDDR (mx
)))
1231 mod
= scm_module_public_interface (mod
);
1232 var
= scm_module_lookup (mod
, CADDR (mx
));
1233 SCM_SETCDR (mx
, var
);
1238 scm_wrong_type_arg (FUNC_NAME
, 1, m
);
1250 scm_tc16_memoized
= scm_make_smob_type ("%memoized", 0);
1251 scm_set_smob_mark (scm_tc16_memoized
, scm_markcdr
);
1252 scm_set_smob_print (scm_tc16_memoized
, scm_print_memoized
);
1254 #include "libguile/memoize.x"