1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005
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
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but 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 02110-1301 USA
23 /* This file is read twice in order to produce debugging versions of ceval and
24 * scm_apply. These functions, deval and scm_dapply, are produced when we
25 * define the preprocessor macro DEVAL. The file is divided into sections
26 * which are treated differently with respect to DEVAL. The heads of these
27 * sections are marked with the string "SECTION:". */
29 /* SECTION: This code is compiled once.
36 #include "libguile/__scm.h"
40 /* AIX requires this to be the first thing in the file. The #pragma
41 directive is indented so pre-ANSI compilers will ignore it, rather
50 # ifndef alloca /* predefined by HP cc +Olibcalls */
58 #include "libguile/_scm.h"
59 #include "libguile/alist.h"
60 #include "libguile/async.h"
61 #include "libguile/continuations.h"
62 #include "libguile/debug.h"
63 #include "libguile/deprecation.h"
64 #include "libguile/dynwind.h"
65 #include "libguile/eq.h"
66 #include "libguile/feature.h"
67 #include "libguile/fluids.h"
68 #include "libguile/futures.h"
69 #include "libguile/goops.h"
70 #include "libguile/hash.h"
71 #include "libguile/hashtab.h"
72 #include "libguile/lang.h"
73 #include "libguile/list.h"
74 #include "libguile/macros.h"
75 #include "libguile/modules.h"
76 #include "libguile/objects.h"
77 #include "libguile/ports.h"
78 #include "libguile/print.h"
79 #include "libguile/procprop.h"
80 #include "libguile/root.h"
81 #include "libguile/smob.h"
82 #include "libguile/srcprop.h"
83 #include "libguile/stackchk.h"
84 #include "libguile/strings.h"
85 #include "libguile/threads.h"
86 #include "libguile/throw.h"
87 #include "libguile/validate.h"
88 #include "libguile/values.h"
89 #include "libguile/vectors.h"
91 #include "libguile/eval.h"
95 static SCM
unmemoize_exprs (SCM expr
, SCM env
);
96 static SCM
canonicalize_define (SCM expr
);
97 static SCM
*scm_lookupcar1 (SCM vloc
, SCM genv
, int check
);
98 static SCM
unmemoize_builtin_macro (SCM expr
, SCM env
);
99 static void eval_letrec_inits (SCM env
, SCM init_forms
, SCM
**init_values_eol
);
105 * This section defines the message strings for the syntax errors that can be
106 * detected during memoization and the functions and macros that shall be
107 * called by the memoizer code to signal syntax errors. */
110 /* Syntax errors that can be detected during memoization: */
112 /* Circular or improper lists do not form valid scheme expressions. If a
113 * circular list or an improper list is detected in a place where a scheme
114 * expression is expected, a 'Bad expression' error is signalled. */
115 static const char s_bad_expression
[] = "Bad expression";
117 /* If a form is detected that holds a different number of expressions than are
118 * required in that context, a 'Missing or extra expression' error is
120 static const char s_expression
[] = "Missing or extra expression in";
122 /* If a form is detected that holds less expressions than are required in that
123 * context, a 'Missing expression' error is signalled. */
124 static const char s_missing_expression
[] = "Missing expression in";
126 /* If a form is detected that holds more expressions than are allowed in that
127 * context, an 'Extra expression' error is signalled. */
128 static const char s_extra_expression
[] = "Extra expression in";
130 /* The empty combination '()' is not allowed as an expression in scheme. If
131 * it is detected in a place where an expression is expected, an 'Illegal
132 * empty combination' error is signalled. Note: If you encounter this error
133 * message, it is very likely that you intended to denote the empty list. To
134 * do so, you need to quote the empty list like (quote ()) or '(). */
135 static const char s_empty_combination
[] = "Illegal empty combination";
137 /* A body may hold an arbitrary number of internal defines, followed by a
138 * non-empty sequence of expressions. If a body with an empty sequence of
139 * expressions is detected, a 'Missing body expression' error is signalled.
141 static const char s_missing_body_expression
[] = "Missing body expression in";
143 /* A body may hold an arbitrary number of internal defines, followed by a
144 * non-empty sequence of expressions. Each the definitions and the
145 * expressions may be grouped arbitraryly with begin, but it is not allowed to
146 * mix definitions and expressions. If a define form in a body mixes
147 * definitions and expressions, a 'Mixed definitions and expressions' error is
149 static const char s_mixed_body_forms
[] = "Mixed definitions and expressions in";
150 /* Definitions are only allowed on the top level and at the start of a body.
151 * If a definition is detected anywhere else, a 'Bad define placement' error
153 static const char s_bad_define
[] = "Bad define placement";
155 /* Case or cond expressions must have at least one clause. If a case or cond
156 * expression without any clauses is detected, a 'Missing clauses' error is
158 static const char s_missing_clauses
[] = "Missing clauses";
160 /* If there is an 'else' clause in a case or a cond statement, it must be the
161 * last clause. If after the 'else' case clause further clauses are detected,
162 * a 'Misplaced else clause' error is signalled. */
163 static const char s_misplaced_else_clause
[] = "Misplaced else clause";
165 /* If a case clause is detected that is not in the format
166 * (<label(s)> <expression1> <expression2> ...)
167 * a 'Bad case clause' error is signalled. */
168 static const char s_bad_case_clause
[] = "Bad case clause";
170 /* If a case clause is detected where the <label(s)> element is neither a
171 * proper list nor (in case of the last clause) the syntactic keyword 'else',
172 * a 'Bad case labels' error is signalled. Note: If you encounter this error
173 * for an else-clause which seems to be syntactically correct, check if 'else'
174 * is really a syntactic keyword in that context. If 'else' is bound in the
175 * local or global environment, it is not considered a syntactic keyword, but
176 * will be treated as any other variable. */
177 static const char s_bad_case_labels
[] = "Bad case labels";
179 /* In a case statement all labels have to be distinct. If in a case statement
180 * a label occurs more than once, a 'Duplicate case label' error is
182 static const char s_duplicate_case_label
[] = "Duplicate case label";
184 /* If a cond clause is detected that is not in one of the formats
185 * (<test> <expression1> ...) or (else <expression1> <expression2> ...)
186 * a 'Bad cond clause' error is signalled. */
187 static const char s_bad_cond_clause
[] = "Bad cond clause";
189 /* If a cond clause is detected that uses the alternate '=>' form, but does
190 * not hold a recipient element for the test result, a 'Missing recipient'
191 * error is signalled. */
192 static const char s_missing_recipient
[] = "Missing recipient in";
194 /* If in a position where a variable name is required some other object is
195 * detected, a 'Bad variable' error is signalled. */
196 static const char s_bad_variable
[] = "Bad variable";
198 /* Bindings for forms like 'let' and 'do' have to be given in a proper,
199 * possibly empty list. If any other object is detected in a place where a
200 * list of bindings was required, a 'Bad bindings' error is signalled. */
201 static const char s_bad_bindings
[] = "Bad bindings";
203 /* Depending on the syntactic context, a binding has to be in the format
204 * (<variable> <expression>) or (<variable> <expression1> <expression2>).
205 * If anything else is detected in a place where a binding was expected, a
206 * 'Bad binding' error is signalled. */
207 static const char s_bad_binding
[] = "Bad binding";
209 /* Some syntactic forms don't allow variable names to appear more than once in
210 * a list of bindings. If such a situation is nevertheless detected, a
211 * 'Duplicate binding' error is signalled. */
212 static const char s_duplicate_binding
[] = "Duplicate binding";
214 /* If the exit form of a 'do' expression is not in the format
215 * (<test> <expression> ...)
216 * a 'Bad exit clause' error is signalled. */
217 static const char s_bad_exit_clause
[] = "Bad exit clause";
219 /* The formal function arguments of a lambda expression have to be either a
220 * single symbol or a non-cyclic list. For anything else a 'Bad formals'
221 * error is signalled. */
222 static const char s_bad_formals
[] = "Bad formals";
224 /* If in a lambda expression something else than a symbol is detected at a
225 * place where a formal function argument is required, a 'Bad formal' error is
227 static const char s_bad_formal
[] = "Bad formal";
229 /* If in the arguments list of a lambda expression an argument name occurs
230 * more than once, a 'Duplicate formal' error is signalled. */
231 static const char s_duplicate_formal
[] = "Duplicate formal";
233 /* If the evaluation of an unquote-splicing expression gives something else
234 * than a proper list, a 'Non-list result for unquote-splicing' error is
236 static const char s_splicing
[] = "Non-list result for unquote-splicing";
238 /* If something else than an exact integer is detected as the argument for
239 * @slot-ref and @slot-set!, a 'Bad slot number' error is signalled. */
240 static const char s_bad_slot_number
[] = "Bad slot number";
243 /* Signal a syntax error. We distinguish between the form that caused the
244 * error and the enclosing expression. The error message will print out as
245 * shown in the following pattern. The file name and line number are only
246 * given when they can be determined from the erroneous form or from the
247 * enclosing expression.
249 * <filename>: In procedure memoization:
250 * <filename>: In file <name>, line <nr>: <error-message> in <expression>. */
252 SCM_SYMBOL (syntax_error_key
, "syntax-error");
254 /* The prototype is needed to indicate that the function does not return. */
256 syntax_error (const char* const, const SCM
, const SCM
) SCM_NORETURN
;
259 syntax_error (const char* const msg
, const SCM form
, const SCM expr
)
261 SCM msg_string
= scm_from_locale_string (msg
);
262 SCM filename
= SCM_BOOL_F
;
263 SCM linenr
= SCM_BOOL_F
;
267 if (scm_is_pair (form
))
269 filename
= scm_source_property (form
, scm_sym_filename
);
270 linenr
= scm_source_property (form
, scm_sym_line
);
273 if (scm_is_false (filename
) && scm_is_false (linenr
) && scm_is_pair (expr
))
275 filename
= scm_source_property (expr
, scm_sym_filename
);
276 linenr
= scm_source_property (expr
, scm_sym_line
);
279 if (!SCM_UNBNDP (expr
))
281 if (scm_is_true (filename
))
283 format
= "In file ~S, line ~S: ~A ~S in expression ~S.";
284 args
= scm_list_5 (filename
, linenr
, msg_string
, form
, expr
);
286 else if (scm_is_true (linenr
))
288 format
= "In line ~S: ~A ~S in expression ~S.";
289 args
= scm_list_4 (linenr
, msg_string
, form
, expr
);
293 format
= "~A ~S in expression ~S.";
294 args
= scm_list_3 (msg_string
, form
, expr
);
299 if (scm_is_true (filename
))
301 format
= "In file ~S, line ~S: ~A ~S.";
302 args
= scm_list_4 (filename
, linenr
, msg_string
, form
);
304 else if (scm_is_true (linenr
))
306 format
= "In line ~S: ~A ~S.";
307 args
= scm_list_3 (linenr
, msg_string
, form
);
312 args
= scm_list_2 (msg_string
, form
);
316 scm_error (syntax_error_key
, "memoization", format
, args
, SCM_BOOL_F
);
320 /* Shortcut macros to simplify syntax error handling. */
321 #define ASSERT_SYNTAX(cond, message, form) \
322 { if (!(cond)) syntax_error (message, form, SCM_UNDEFINED); }
323 #define ASSERT_SYNTAX_2(cond, message, form, expr) \
324 { if (!(cond)) syntax_error (message, form, expr); }
330 * Ilocs are memoized references to variables in local environment frames.
331 * They are represented as three values: The relative offset of the
332 * environment frame, the number of the binding within that frame, and a
333 * boolean value indicating whether the binding is the last binding in the
336 * Frame numbers have 11 bits, relative offsets have 12 bits.
339 #define SCM_ILOC00 SCM_MAKE_ITAG8(0L, scm_tc8_iloc)
340 #define SCM_IFRINC (0x00000100L)
341 #define SCM_ICDR (0x00080000L)
342 #define SCM_IDINC (0x00100000L)
343 #define SCM_IFRAME(n) ((long)((SCM_ICDR-SCM_IFRINC)>>8) \
344 & (SCM_UNPACK (n) >> 8))
345 #define SCM_IDIST(n) (SCM_UNPACK (n) >> 20)
346 #define SCM_ICDRP(n) (SCM_ICDR & SCM_UNPACK (n))
347 #define SCM_IDSTMSK (-SCM_IDINC)
348 #define SCM_IFRAMEMAX ((1<<11)-1)
349 #define SCM_IDISTMAX ((1<<12)-1)
350 #define SCM_MAKE_ILOC(frame_nr, binding_nr, last_p) \
353 + ((binding_nr) << 20) \
354 + ((last_p) ? SCM_ICDR : 0) \
358 scm_i_print_iloc (SCM iloc
, SCM port
)
360 scm_puts ("#@", port
);
361 scm_intprint ((long) SCM_IFRAME (iloc
), 10, port
);
362 scm_putc (SCM_ICDRP (iloc
) ? '-' : '+', port
);
363 scm_intprint ((long) SCM_IDIST (iloc
), 10, port
);
366 #if (SCM_DEBUG_DEBUGGING_SUPPORT == 1)
368 SCM
scm_dbg_make_iloc (SCM frame
, SCM binding
, SCM cdrp
);
370 SCM_DEFINE (scm_dbg_make_iloc
, "dbg-make-iloc", 3, 0, 0,
371 (SCM frame
, SCM binding
, SCM cdrp
),
372 "Return a new iloc with frame offset @var{frame}, binding\n"
373 "offset @var{binding} and the cdr flag @var{cdrp}.")
374 #define FUNC_NAME s_scm_dbg_make_iloc
376 return SCM_MAKE_ILOC ((scm_t_bits
) scm_to_unsigned_integer (frame
, 0, SCM_IFRAMEMAX
),
377 (scm_t_bits
) scm_to_unsigned_integer (binding
, 0, SCM_IDISTMAX
),
382 SCM
scm_dbg_iloc_p (SCM obj
);
384 SCM_DEFINE (scm_dbg_iloc_p
, "dbg-iloc?", 1, 0, 0,
386 "Return @code{#t} if @var{obj} is an iloc.")
387 #define FUNC_NAME s_scm_dbg_iloc_p
389 return scm_from_bool (SCM_ILOCP (obj
));
397 /* {Evaluator byte codes (isyms)}
400 #define ISYMNUM(n) (SCM_ITAG8_DATA (n))
402 /* This table must agree with the list of SCM_IM_ constants in tags.h */
403 static const char *const isymnames
[] =
420 "#@call-with-current-continuation",
426 "#@call-with-values",
434 scm_i_print_isym (SCM isym
, SCM port
)
436 const size_t isymnum
= ISYMNUM (isym
);
437 if (isymnum
< (sizeof isymnames
/ sizeof (char *)))
438 scm_puts (isymnames
[isymnum
], port
);
440 scm_ipruk ("isym", isym
, port
);
445 /* The function lookup_symbol is used during memoization: Lookup the symbol in
446 * the environment. If there is no binding for the symbol, SCM_UNDEFINED is
447 * returned. If the symbol is a global variable, the variable object to which
448 * the symbol is bound is returned. Finally, if the symbol is a local
449 * variable the corresponding iloc object is returned. */
451 /* A helper function for lookup_symbol: Try to find the symbol in the top
452 * level environment frame. The function returns SCM_UNDEFINED if the symbol
453 * is unbound and it returns a variable object if the symbol is a global
456 lookup_global_symbol (const SCM symbol
, const SCM top_level
)
458 const SCM variable
= scm_sym2var (symbol
, top_level
, SCM_BOOL_F
);
459 if (scm_is_false (variable
))
460 return SCM_UNDEFINED
;
466 lookup_symbol (const SCM symbol
, const SCM env
)
469 unsigned int frame_nr
;
471 for (frame_idx
= env
, frame_nr
= 0;
472 !scm_is_null (frame_idx
);
473 frame_idx
= SCM_CDR (frame_idx
), ++frame_nr
)
475 const SCM frame
= SCM_CAR (frame_idx
);
476 if (scm_is_pair (frame
))
478 /* frame holds a local environment frame */
480 unsigned int symbol_nr
;
482 for (symbol_idx
= SCM_CAR (frame
), symbol_nr
= 0;
483 scm_is_pair (symbol_idx
);
484 symbol_idx
= SCM_CDR (symbol_idx
), ++symbol_nr
)
486 if (scm_is_eq (SCM_CAR (symbol_idx
), symbol
))
487 /* found the symbol, therefore return the iloc */
488 return SCM_MAKE_ILOC (frame_nr
, symbol_nr
, 0);
490 if (scm_is_eq (symbol_idx
, symbol
))
491 /* found the symbol as the last element of the current frame */
492 return SCM_MAKE_ILOC (frame_nr
, symbol_nr
, 1);
496 /* no more local environment frames */
497 return lookup_global_symbol (symbol
, frame
);
501 return lookup_global_symbol (symbol
, SCM_BOOL_F
);
505 /* Return true if the symbol is - from the point of view of a macro
506 * transformer - a literal in the sense specified in chapter "pattern
507 * language" of R5RS. In the code below, however, we don't match the
508 * definition of R5RS exactly: It returns true if the identifier has no
509 * binding or if it is a syntactic keyword. */
511 literal_p (const SCM symbol
, const SCM env
)
513 const SCM variable
= lookup_symbol (symbol
, env
);
514 if (SCM_UNBNDP (variable
))
516 if (SCM_VARIABLEP (variable
) && SCM_MACROP (SCM_VARIABLE_REF (variable
)))
523 /* Return true if the expression is self-quoting in the memoized code. Thus,
524 * some other objects (like e. g. vectors) are reported as self-quoting, which
525 * according to R5RS would need to be quoted. */
527 is_self_quoting_p (const SCM expr
)
529 if (scm_is_pair (expr
))
531 else if (scm_is_symbol (expr
))
533 else if (scm_is_null (expr
))
539 SCM_SYMBOL (sym_three_question_marks
, "???");
542 unmemoize_expression (const SCM expr
, const SCM env
)
544 if (SCM_ILOCP (expr
))
547 unsigned long int frame_nr
;
549 unsigned long int symbol_nr
;
551 for (frame_idx
= env
, frame_nr
= SCM_IFRAME (expr
);
553 frame_idx
= SCM_CDR (frame_idx
), --frame_nr
)
555 for (symbol_idx
= SCM_CAAR (frame_idx
), symbol_nr
= SCM_IDIST (expr
);
557 symbol_idx
= SCM_CDR (symbol_idx
), --symbol_nr
)
559 return SCM_ICDRP (expr
) ? symbol_idx
: SCM_CAR (symbol_idx
);
561 else if (SCM_VARIABLEP (expr
))
563 const SCM sym
= scm_module_reverse_lookup (scm_env_module (env
), expr
);
564 return scm_is_true (sym
) ? sym
: sym_three_question_marks
;
566 else if (scm_is_simple_vector (expr
))
568 return scm_list_2 (scm_sym_quote
, expr
);
570 else if (!scm_is_pair (expr
))
574 else if (SCM_ISYMP (SCM_CAR (expr
)))
576 return unmemoize_builtin_macro (expr
, env
);
580 return unmemoize_exprs (expr
, env
);
586 unmemoize_exprs (const SCM exprs
, const SCM env
)
588 SCM r_result
= SCM_EOL
;
589 SCM expr_idx
= exprs
;
592 /* Note that due to the current lazy memoizer we may find partially memoized
593 * code during execution. In such code we have to expect improper lists of
594 * expressions: On the one hand, for such code syntax checks have not yet
595 * fully been performed, on the other hand, there may be even legal code
596 * like '(a . b) appear as an improper list of expressions as long as the
597 * quote expression is still in its unmemoized form. For this reason, the
598 * following code handles improper lists of expressions until memoization
599 * and execution have been completely separated. */
600 for (; scm_is_pair (expr_idx
); expr_idx
= SCM_CDR (expr_idx
))
602 const SCM expr
= SCM_CAR (expr_idx
);
604 /* In partially memoized code, lists of expressions that stem from a
605 * body form may start with an ISYM if the body itself has not yet been
606 * memoized. This isym is just an internal marker to indicate that the
607 * body still needs to be memoized. An isym may occur at the very
608 * beginning of the body or after one or more comment strings. It is
609 * dropped during unmemoization. */
610 if (!SCM_ISYMP (expr
))
612 um_expr
= unmemoize_expression (expr
, env
);
613 r_result
= scm_cons (um_expr
, r_result
);
616 um_expr
= unmemoize_expression (expr_idx
, env
);
617 if (!scm_is_null (r_result
))
619 const SCM result
= scm_reverse_x (r_result
, SCM_UNDEFINED
);
620 SCM_SETCDR (r_result
, um_expr
);
630 /* Rewrite the body (which is given as the list of expressions forming the
631 * body) into its internal form. The internal form of a body (<expr> ...) is
632 * just the body itself, but prefixed with an ISYM that denotes to what kind
633 * of outer construct this body belongs: (<ISYM> <expr> ...). A lambda body
634 * starts with SCM_IM_LAMBDA, for example, a body of a let starts with
637 * It is assumed that the calling expression has already made sure that the
638 * body is a proper list. */
640 m_body (SCM op
, SCM exprs
)
642 /* Don't add another ISYM if one is present already. */
643 if (SCM_ISYMP (SCM_CAR (exprs
)))
646 return scm_cons (op
, exprs
);
650 /* The function m_expand_body memoizes a proper list of expressions forming a
651 * body. This function takes care of dealing with internal defines and
652 * transforming them into an equivalent letrec expression. The list of
653 * expressions is rewritten in place. */
655 /* This is a helper function for m_expand_body. If the argument expression is
656 * a symbol that denotes a syntactic keyword, the corresponding macro object
657 * is returned, in all other cases the function returns SCM_UNDEFINED. */
659 try_macro_lookup (const SCM expr
, const SCM env
)
661 if (scm_is_symbol (expr
))
663 const SCM variable
= lookup_symbol (expr
, env
);
664 if (SCM_VARIABLEP (variable
))
666 const SCM value
= SCM_VARIABLE_REF (variable
);
667 if (SCM_MACROP (value
))
672 return SCM_UNDEFINED
;
675 /* This is a helper function for m_expand_body. It expands user macros,
676 * because for the correct translation of a body we need to know whether they
677 * expand to a definition. */
679 expand_user_macros (SCM expr
, const SCM env
)
681 while (scm_is_pair (expr
))
683 const SCM car_expr
= SCM_CAR (expr
);
684 const SCM new_car
= expand_user_macros (car_expr
, env
);
685 const SCM value
= try_macro_lookup (new_car
, env
);
687 if (SCM_MACROP (value
) && SCM_MACRO_TYPE (value
) == 2)
689 /* User macros transform code into code. */
690 expr
= scm_call_2 (SCM_MACRO_CODE (value
), expr
, env
);
691 /* We need to reiterate on the transformed code. */
695 /* No user macro: return. */
696 SCM_SETCAR (expr
, new_car
);
704 /* This is a helper function for m_expand_body. It determines if a given form
705 * represents an application of a given built-in macro. The built-in macro to
706 * check for is identified by its syntactic keyword. The form is an
707 * application of the given macro if looking up the car of the form in the
708 * given environment actually returns the built-in macro. */
710 is_system_macro_p (const SCM syntactic_keyword
, const SCM form
, const SCM env
)
712 if (scm_is_pair (form
))
714 const SCM car_form
= SCM_CAR (form
);
715 const SCM value
= try_macro_lookup (car_form
, env
);
716 if (SCM_BUILTIN_MACRO_P (value
))
718 const SCM macro_name
= scm_macro_name (value
);
719 return scm_is_eq (macro_name
, syntactic_keyword
);
727 m_expand_body (const SCM forms
, const SCM env
)
729 /* The first body form can be skipped since it is known to be the ISYM that
730 * was prepended to the body by m_body. */
731 SCM cdr_forms
= SCM_CDR (forms
);
732 SCM form_idx
= cdr_forms
;
733 SCM definitions
= SCM_EOL
;
734 SCM sequence
= SCM_EOL
;
736 /* According to R5RS, the list of body forms consists of two parts: a number
737 * (maybe zero) of definitions, followed by a non-empty sequence of
738 * expressions. Each the definitions and the expressions may be grouped
739 * arbitrarily with begin, but it is not allowed to mix definitions and
740 * expressions. The task of the following loop therefore is to split the
741 * list of body forms into the list of definitions and the sequence of
743 while (!scm_is_null (form_idx
))
745 const SCM form
= SCM_CAR (form_idx
);
746 const SCM new_form
= expand_user_macros (form
, env
);
747 if (is_system_macro_p (scm_sym_define
, new_form
, env
))
749 definitions
= scm_cons (new_form
, definitions
);
750 form_idx
= SCM_CDR (form_idx
);
752 else if (is_system_macro_p (scm_sym_begin
, new_form
, env
))
754 /* We have encountered a group of forms. This has to be either a
755 * (possibly empty) group of (possibly further grouped) definitions,
756 * or a non-empty group of (possibly further grouped)
758 const SCM grouped_forms
= SCM_CDR (new_form
);
759 unsigned int found_definition
= 0;
760 unsigned int found_expression
= 0;
761 SCM grouped_form_idx
= grouped_forms
;
762 while (!found_expression
&& !scm_is_null (grouped_form_idx
))
764 const SCM inner_form
= SCM_CAR (grouped_form_idx
);
765 const SCM new_inner_form
= expand_user_macros (inner_form
, env
);
766 if (is_system_macro_p (scm_sym_define
, new_inner_form
, env
))
768 found_definition
= 1;
769 definitions
= scm_cons (new_inner_form
, definitions
);
770 grouped_form_idx
= SCM_CDR (grouped_form_idx
);
772 else if (is_system_macro_p (scm_sym_begin
, new_inner_form
, env
))
774 const SCM inner_group
= SCM_CDR (new_inner_form
);
776 = scm_append (scm_list_2 (inner_group
,
777 SCM_CDR (grouped_form_idx
)));
781 /* The group marks the start of the expressions of the body.
782 * We have to make sure that within the same group we have
783 * not encountered a definition before. */
784 ASSERT_SYNTAX (!found_definition
, s_mixed_body_forms
, form
);
785 found_expression
= 1;
786 grouped_form_idx
= SCM_EOL
;
790 /* We have finished processing the group. If we have not yet
791 * encountered an expression we continue processing the forms of the
792 * body to collect further definition forms. Otherwise, the group
793 * marks the start of the sequence of expressions of the body. */
794 if (!found_expression
)
796 form_idx
= SCM_CDR (form_idx
);
806 /* We have detected a form which is no definition. This marks the
807 * start of the sequence of expressions of the body. */
813 /* FIXME: forms does not hold information about the file location. */
814 ASSERT_SYNTAX (scm_is_pair (sequence
), s_missing_body_expression
, cdr_forms
);
816 if (!scm_is_null (definitions
))
820 SCM letrec_expression
;
821 SCM new_letrec_expression
;
823 SCM bindings
= SCM_EOL
;
824 for (definition_idx
= definitions
;
825 !scm_is_null (definition_idx
);
826 definition_idx
= SCM_CDR (definition_idx
))
828 const SCM definition
= SCM_CAR (definition_idx
);
829 const SCM canonical_definition
= canonicalize_define (definition
);
830 const SCM binding
= SCM_CDR (canonical_definition
);
831 bindings
= scm_cons (binding
, bindings
);
834 letrec_tail
= scm_cons (bindings
, sequence
);
835 /* FIXME: forms does not hold information about the file location. */
836 letrec_expression
= scm_cons_source (forms
, scm_sym_letrec
, letrec_tail
);
837 new_letrec_expression
= scm_m_letrec (letrec_expression
, env
);
838 SCM_SETCAR (forms
, new_letrec_expression
);
839 SCM_SETCDR (forms
, SCM_EOL
);
843 SCM_SETCAR (forms
, SCM_CAR (sequence
));
844 SCM_SETCDR (forms
, SCM_CDR (sequence
));
849 macroexp (SCM x
, SCM env
)
851 SCM res
, proc
, orig_sym
;
853 /* Don't bother to produce error messages here. We get them when we
854 eventually execute the code for real. */
857 orig_sym
= SCM_CAR (x
);
858 if (!scm_is_symbol (orig_sym
))
862 SCM
*proc_ptr
= scm_lookupcar1 (x
, env
, 0);
863 if (proc_ptr
== NULL
)
865 /* We have lost the race. */
871 /* Only handle memoizing macros. `Acros' and `macros' are really
872 special forms and should not be evaluated here. */
874 if (!SCM_MACROP (proc
)
875 || (SCM_MACRO_TYPE (proc
) != 2 && !SCM_BUILTIN_MACRO_P (proc
)))
878 SCM_SETCAR (x
, orig_sym
); /* Undo memoizing effect of lookupcar */
879 res
= scm_call_2 (SCM_MACRO_CODE (proc
), x
, env
);
881 if (scm_ilength (res
) <= 0)
882 res
= scm_list_2 (SCM_IM_BEGIN
, res
);
884 /* njrev: Several queries here: (1) I don't see how it can be
885 correct that the SCM_SETCAR 2 lines below this comment needs
886 protection, but the SCM_SETCAR 6 lines above does not, so
887 something here is probably wrong. (2) macroexp() is now only
888 used in one place - scm_m_generalized_set_x - whereas all other
889 macro expansion happens through expand_user_macros. Therefore
890 (2.1) perhaps macroexp() could be eliminated completely now?
891 (2.2) Does expand_user_macros need any critical section
894 SCM_CRITICAL_SECTION_START
;
895 SCM_SETCAR (x
, SCM_CAR (res
));
896 SCM_SETCDR (x
, SCM_CDR (res
));
897 SCM_CRITICAL_SECTION_END
;
902 /* Start of the memoizers for the standard R5RS builtin macros. */
905 SCM_SYNTAX (s_and
, "and", scm_i_makbimacro
, scm_m_and
);
906 SCM_GLOBAL_SYMBOL (scm_sym_and
, s_and
);
909 scm_m_and (SCM expr
, SCM env SCM_UNUSED
)
911 const SCM cdr_expr
= SCM_CDR (expr
);
912 const long length
= scm_ilength (cdr_expr
);
914 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
918 /* Special case: (and) is replaced by #t. */
923 SCM_SETCAR (expr
, SCM_IM_AND
);
929 unmemoize_and (const SCM expr
, const SCM env
)
931 return scm_cons (scm_sym_and
, unmemoize_exprs (SCM_CDR (expr
), env
));
935 SCM_SYNTAX (s_begin
, "begin", scm_i_makbimacro
, scm_m_begin
);
936 SCM_GLOBAL_SYMBOL (scm_sym_begin
, s_begin
);
939 scm_m_begin (SCM expr
, SCM env SCM_UNUSED
)
941 const SCM cdr_expr
= SCM_CDR (expr
);
942 /* Dirk:FIXME:: An empty begin clause is not generally allowed by R5RS.
943 * That means, there should be a distinction between uses of begin where an
944 * empty clause is OK and where it is not. */
945 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
947 SCM_SETCAR (expr
, SCM_IM_BEGIN
);
952 unmemoize_begin (const SCM expr
, const SCM env
)
954 return scm_cons (scm_sym_begin
, unmemoize_exprs (SCM_CDR (expr
), env
));
958 SCM_SYNTAX (s_case
, "case", scm_i_makbimacro
, scm_m_case
);
959 SCM_GLOBAL_SYMBOL (scm_sym_case
, s_case
);
960 SCM_GLOBAL_SYMBOL (scm_sym_else
, "else");
963 scm_m_case (SCM expr
, SCM env
)
966 SCM all_labels
= SCM_EOL
;
968 /* Check, whether 'else is a literal, i. e. not bound to a value. */
969 const int else_literal_p
= literal_p (scm_sym_else
, env
);
971 const SCM cdr_expr
= SCM_CDR (expr
);
972 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
973 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_clauses
, expr
);
975 clauses
= SCM_CDR (cdr_expr
);
976 while (!scm_is_null (clauses
))
980 const SCM clause
= SCM_CAR (clauses
);
981 ASSERT_SYNTAX_2 (scm_ilength (clause
) >= 2,
982 s_bad_case_clause
, clause
, expr
);
984 labels
= SCM_CAR (clause
);
985 if (scm_is_pair (labels
))
987 ASSERT_SYNTAX_2 (scm_ilength (labels
) >= 0,
988 s_bad_case_labels
, labels
, expr
);
989 all_labels
= scm_append (scm_list_2 (labels
, all_labels
));
991 else if (scm_is_null (labels
))
993 /* The list of labels is empty. According to R5RS this is allowed.
994 * It means that the sequence of expressions will never be executed.
995 * Therefore, as an optimization, we could remove the whole
1000 ASSERT_SYNTAX_2 (scm_is_eq (labels
, scm_sym_else
) && else_literal_p
,
1001 s_bad_case_labels
, labels
, expr
);
1002 ASSERT_SYNTAX_2 (scm_is_null (SCM_CDR (clauses
)),
1003 s_misplaced_else_clause
, clause
, expr
);
1006 /* build the new clause */
1007 if (scm_is_eq (labels
, scm_sym_else
))
1008 SCM_SETCAR (clause
, SCM_IM_ELSE
);
1010 clauses
= SCM_CDR (clauses
);
1013 /* Check whether all case labels are distinct. */
1014 for (; !scm_is_null (all_labels
); all_labels
= SCM_CDR (all_labels
))
1016 const SCM label
= SCM_CAR (all_labels
);
1017 ASSERT_SYNTAX_2 (scm_is_false (scm_c_memq (label
, SCM_CDR (all_labels
))),
1018 s_duplicate_case_label
, label
, expr
);
1021 SCM_SETCAR (expr
, SCM_IM_CASE
);
1026 unmemoize_case (const SCM expr
, const SCM env
)
1028 const SCM um_key_expr
= unmemoize_expression (SCM_CADR (expr
), env
);
1029 SCM um_clauses
= SCM_EOL
;
1032 for (clause_idx
= SCM_CDDR (expr
);
1033 !scm_is_null (clause_idx
);
1034 clause_idx
= SCM_CDR (clause_idx
))
1036 const SCM clause
= SCM_CAR (clause_idx
);
1037 const SCM labels
= SCM_CAR (clause
);
1038 const SCM exprs
= SCM_CDR (clause
);
1040 const SCM um_exprs
= unmemoize_exprs (exprs
, env
);
1041 const SCM um_labels
= (scm_is_eq (labels
, SCM_IM_ELSE
))
1043 : scm_i_finite_list_copy (labels
);
1044 const SCM um_clause
= scm_cons (um_labels
, um_exprs
);
1046 um_clauses
= scm_cons (um_clause
, um_clauses
);
1048 um_clauses
= scm_reverse_x (um_clauses
, SCM_UNDEFINED
);
1050 return scm_cons2 (scm_sym_case
, um_key_expr
, um_clauses
);
1054 SCM_SYNTAX (s_cond
, "cond", scm_i_makbimacro
, scm_m_cond
);
1055 SCM_GLOBAL_SYMBOL (scm_sym_cond
, s_cond
);
1056 SCM_GLOBAL_SYMBOL (scm_sym_arrow
, "=>");
1059 scm_m_cond (SCM expr
, SCM env
)
1061 /* Check, whether 'else or '=> is a literal, i. e. not bound to a value. */
1062 const int else_literal_p
= literal_p (scm_sym_else
, env
);
1063 const int arrow_literal_p
= literal_p (scm_sym_arrow
, env
);
1065 const SCM clauses
= SCM_CDR (expr
);
1068 ASSERT_SYNTAX (scm_ilength (clauses
) >= 0, s_bad_expression
, expr
);
1069 ASSERT_SYNTAX (scm_ilength (clauses
) >= 1, s_missing_clauses
, expr
);
1071 for (clause_idx
= clauses
;
1072 !scm_is_null (clause_idx
);
1073 clause_idx
= SCM_CDR (clause_idx
))
1077 const SCM clause
= SCM_CAR (clause_idx
);
1078 const long length
= scm_ilength (clause
);
1079 ASSERT_SYNTAX_2 (length
>= 1, s_bad_cond_clause
, clause
, expr
);
1081 test
= SCM_CAR (clause
);
1082 if (scm_is_eq (test
, scm_sym_else
) && else_literal_p
)
1084 const int last_clause_p
= scm_is_null (SCM_CDR (clause_idx
));
1085 ASSERT_SYNTAX_2 (length
>= 2,
1086 s_bad_cond_clause
, clause
, expr
);
1087 ASSERT_SYNTAX_2 (last_clause_p
,
1088 s_misplaced_else_clause
, clause
, expr
);
1089 SCM_SETCAR (clause
, SCM_IM_ELSE
);
1091 else if (length
>= 2
1092 && scm_is_eq (SCM_CADR (clause
), scm_sym_arrow
)
1095 ASSERT_SYNTAX_2 (length
> 2, s_missing_recipient
, clause
, expr
);
1096 ASSERT_SYNTAX_2 (length
== 3, s_extra_expression
, clause
, expr
);
1097 SCM_SETCAR (SCM_CDR (clause
), SCM_IM_ARROW
);
1099 /* SRFI 61 extended cond */
1100 else if (length
>= 3
1101 && scm_is_eq (SCM_CADDR (clause
), scm_sym_arrow
)
1104 ASSERT_SYNTAX_2 (length
> 3, s_missing_recipient
, clause
, expr
);
1105 ASSERT_SYNTAX_2 (length
== 4, s_extra_expression
, clause
, expr
);
1106 SCM_SETCAR (SCM_CDDR (clause
), SCM_IM_ARROW
);
1110 SCM_SETCAR (expr
, SCM_IM_COND
);
1115 unmemoize_cond (const SCM expr
, const SCM env
)
1117 SCM um_clauses
= SCM_EOL
;
1120 for (clause_idx
= SCM_CDR (expr
);
1121 !scm_is_null (clause_idx
);
1122 clause_idx
= SCM_CDR (clause_idx
))
1124 const SCM clause
= SCM_CAR (clause_idx
);
1125 const SCM sequence
= SCM_CDR (clause
);
1126 const SCM test
= SCM_CAR (clause
);
1131 if (scm_is_eq (test
, SCM_IM_ELSE
))
1132 um_test
= scm_sym_else
;
1134 um_test
= unmemoize_expression (test
, env
);
1136 if (!scm_is_null (sequence
) && scm_is_eq (SCM_CAR (sequence
),
1139 const SCM target
= SCM_CADR (sequence
);
1140 const SCM um_target
= unmemoize_expression (target
, env
);
1141 um_sequence
= scm_list_2 (scm_sym_arrow
, um_target
);
1145 um_sequence
= unmemoize_exprs (sequence
, env
);
1148 um_clause
= scm_cons (um_test
, um_sequence
);
1149 um_clauses
= scm_cons (um_clause
, um_clauses
);
1151 um_clauses
= scm_reverse_x (um_clauses
, SCM_UNDEFINED
);
1153 return scm_cons (scm_sym_cond
, um_clauses
);
1157 SCM_SYNTAX (s_define
, "define", scm_i_makbimacro
, scm_m_define
);
1158 SCM_GLOBAL_SYMBOL (scm_sym_define
, s_define
);
1160 /* Guile provides an extension to R5RS' define syntax to represent function
1161 * currying in a compact way. With this extension, it is allowed to write
1162 * (define <nested-variable> <body>), where <nested-variable> has of one of
1163 * the forms (<nested-variable> <formals>), (<nested-variable> . <formal>),
1164 * (<variable> <formals>) or (<variable> . <formal>). As in R5RS, <formals>
1165 * should be either a sequence of zero or more variables, or a sequence of one
1166 * or more variables followed by a space-delimited period and another
1167 * variable. Each level of argument nesting wraps the <body> within another
1168 * lambda expression. For example, the following forms are allowed, each one
1169 * followed by an equivalent, more explicit implementation.
1171 * (define ((a b . c) . d) <body>) is equivalent to
1172 * (define a (lambda (b . c) (lambda d <body>)))
1174 * (define (((a) b) c . d) <body>) is equivalent to
1175 * (define a (lambda () (lambda (b) (lambda (c . d) <body>))))
1177 /* Dirk:FIXME:: We should provide an implementation for 'define' in the R5RS
1178 * module that does not implement this extension. */
1180 canonicalize_define (const SCM expr
)
1185 const SCM cdr_expr
= SCM_CDR (expr
);
1186 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1187 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
1189 body
= SCM_CDR (cdr_expr
);
1190 variable
= SCM_CAR (cdr_expr
);
1191 while (scm_is_pair (variable
))
1193 /* This while loop realizes function currying by variable nesting.
1194 * Variable is known to be a nested-variable. In every iteration of the
1195 * loop another level of lambda expression is created, starting with the
1196 * innermost one. Note that we don't check for duplicate formals here:
1197 * This will be done by the memoizer of the lambda expression. */
1198 const SCM formals
= SCM_CDR (variable
);
1199 const SCM tail
= scm_cons (formals
, body
);
1201 /* Add source properties to each new lambda expression: */
1202 const SCM lambda
= scm_cons_source (variable
, scm_sym_lambda
, tail
);
1204 body
= scm_list_1 (lambda
);
1205 variable
= SCM_CAR (variable
);
1207 ASSERT_SYNTAX_2 (scm_is_symbol (variable
), s_bad_variable
, variable
, expr
);
1208 ASSERT_SYNTAX (scm_ilength (body
) == 1, s_expression
, expr
);
1210 SCM_SETCAR (cdr_expr
, variable
);
1211 SCM_SETCDR (cdr_expr
, body
);
1215 /* According to section 5.2.1 of R5RS we first have to make sure that the
1216 * variable is bound, and then perform the (set! variable expression)
1217 * operation. This means, that within the expression we may already assign
1218 * values to variable: (define foo (begin (set! foo 1) (+ foo 1))) */
1220 scm_m_define (SCM expr
, SCM env
)
1222 ASSERT_SYNTAX (SCM_TOP_LEVEL (env
), s_bad_define
, expr
);
1225 const SCM canonical_definition
= canonicalize_define (expr
);
1226 const SCM cdr_canonical_definition
= SCM_CDR (canonical_definition
);
1227 const SCM variable
= SCM_CAR (cdr_canonical_definition
);
1229 = scm_sym2var (variable
, scm_env_top_level (env
), SCM_BOOL_T
);
1230 const SCM value
= scm_eval_car (SCM_CDR (cdr_canonical_definition
), env
);
1232 if (SCM_REC_PROCNAMES_P
)
1235 while (SCM_MACROP (tmp
))
1236 tmp
= SCM_MACRO_CODE (tmp
);
1237 if (SCM_CLOSUREP (tmp
)
1238 /* Only the first definition determines the name. */
1239 && scm_is_false (scm_procedure_property (tmp
, scm_sym_name
)))
1240 scm_set_procedure_property_x (tmp
, scm_sym_name
, variable
);
1243 SCM_VARIABLE_SET (location
, value
);
1245 return SCM_UNSPECIFIED
;
1250 /* This is a helper function for forms (<keyword> <expression>) that are
1251 * transformed into (#@<keyword> '() <memoized_expression>) in order to allow
1252 * for easy creation of a thunk (i. e. a closure without arguments) using the
1253 * ('() <memoized_expression>) tail of the memoized form. */
1255 memoize_as_thunk_prototype (const SCM expr
, const SCM env SCM_UNUSED
)
1257 const SCM cdr_expr
= SCM_CDR (expr
);
1258 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1259 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
1261 SCM_SETCDR (expr
, scm_cons (SCM_EOL
, cdr_expr
));
1267 SCM_SYNTAX (s_delay
, "delay", scm_i_makbimacro
, scm_m_delay
);
1268 SCM_GLOBAL_SYMBOL (scm_sym_delay
, s_delay
);
1270 /* Promises are implemented as closures with an empty parameter list. Thus,
1271 * (delay <expression>) is transformed into (#@delay '() <expression>), where
1272 * the empty list represents the empty parameter list. This representation
1273 * allows for easy creation of the closure during evaluation. */
1275 scm_m_delay (SCM expr
, SCM env
)
1277 const SCM new_expr
= memoize_as_thunk_prototype (expr
, env
);
1278 SCM_SETCAR (new_expr
, SCM_IM_DELAY
);
1283 unmemoize_delay (const SCM expr
, const SCM env
)
1285 const SCM thunk_expr
= SCM_CADDR (expr
);
1286 return scm_list_2 (scm_sym_delay
, unmemoize_expression (thunk_expr
, env
));
1290 SCM_SYNTAX(s_do
, "do", scm_i_makbimacro
, scm_m_do
);
1291 SCM_GLOBAL_SYMBOL(scm_sym_do
, s_do
);
1293 /* DO gets the most radically altered syntax. The order of the vars is
1294 * reversed here. During the evaluation this allows for simple consing of the
1295 * results of the inits and steps:
1297 (do ((<var1> <init1> <step1>)
1305 (#@do (<init1> <init2> ... <initn>)
1306 (varn ... var2 var1)
1309 <step1> <step2> ... <stepn>) ;; missing steps replaced by var
1312 scm_m_do (SCM expr
, SCM env SCM_UNUSED
)
1314 SCM variables
= SCM_EOL
;
1315 SCM init_forms
= SCM_EOL
;
1316 SCM step_forms
= SCM_EOL
;
1323 const SCM cdr_expr
= SCM_CDR (expr
);
1324 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1325 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
1327 /* Collect variables, init and step forms. */
1328 binding_idx
= SCM_CAR (cdr_expr
);
1329 ASSERT_SYNTAX_2 (scm_ilength (binding_idx
) >= 0,
1330 s_bad_bindings
, binding_idx
, expr
);
1331 for (; !scm_is_null (binding_idx
); binding_idx
= SCM_CDR (binding_idx
))
1333 const SCM binding
= SCM_CAR (binding_idx
);
1334 const long length
= scm_ilength (binding
);
1335 ASSERT_SYNTAX_2 (length
== 2 || length
== 3,
1336 s_bad_binding
, binding
, expr
);
1339 const SCM name
= SCM_CAR (binding
);
1340 const SCM init
= SCM_CADR (binding
);
1341 const SCM step
= (length
== 2) ? name
: SCM_CADDR (binding
);
1342 ASSERT_SYNTAX_2 (scm_is_symbol (name
), s_bad_variable
, name
, expr
);
1343 ASSERT_SYNTAX_2 (scm_is_false (scm_c_memq (name
, variables
)),
1344 s_duplicate_binding
, name
, expr
);
1346 variables
= scm_cons (name
, variables
);
1347 init_forms
= scm_cons (init
, init_forms
);
1348 step_forms
= scm_cons (step
, step_forms
);
1351 init_forms
= scm_reverse_x (init_forms
, SCM_UNDEFINED
);
1352 step_forms
= scm_reverse_x (step_forms
, SCM_UNDEFINED
);
1354 /* Memoize the test form and the exit sequence. */
1355 cddr_expr
= SCM_CDR (cdr_expr
);
1356 exit_clause
= SCM_CAR (cddr_expr
);
1357 ASSERT_SYNTAX_2 (scm_ilength (exit_clause
) >= 1,
1358 s_bad_exit_clause
, exit_clause
, expr
);
1360 commands
= SCM_CDR (cddr_expr
);
1361 tail
= scm_cons2 (exit_clause
, commands
, step_forms
);
1362 tail
= scm_cons2 (init_forms
, variables
, tail
);
1363 SCM_SETCAR (expr
, SCM_IM_DO
);
1364 SCM_SETCDR (expr
, tail
);
1369 unmemoize_do (const SCM expr
, const SCM env
)
1371 const SCM cdr_expr
= SCM_CDR (expr
);
1372 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
1373 const SCM rnames
= SCM_CAR (cddr_expr
);
1374 const SCM extended_env
= SCM_EXTEND_ENV (rnames
, SCM_EOL
, env
);
1375 const SCM cdddr_expr
= SCM_CDR (cddr_expr
);
1376 const SCM exit_sequence
= SCM_CAR (cdddr_expr
);
1377 const SCM um_exit_sequence
= unmemoize_exprs (exit_sequence
, extended_env
);
1378 const SCM cddddr_expr
= SCM_CDR (cdddr_expr
);
1379 const SCM um_body
= unmemoize_exprs (SCM_CAR (cddddr_expr
), extended_env
);
1381 /* build transformed binding list */
1382 SCM um_names
= scm_reverse (rnames
);
1383 SCM um_inits
= unmemoize_exprs (SCM_CAR (cdr_expr
), env
);
1384 SCM um_steps
= unmemoize_exprs (SCM_CDR (cddddr_expr
), extended_env
);
1385 SCM um_bindings
= SCM_EOL
;
1386 while (!scm_is_null (um_names
))
1388 const SCM name
= SCM_CAR (um_names
);
1389 const SCM init
= SCM_CAR (um_inits
);
1390 SCM step
= SCM_CAR (um_steps
);
1391 step
= scm_is_eq (step
, name
) ? SCM_EOL
: scm_list_1 (step
);
1393 um_bindings
= scm_cons (scm_cons2 (name
, init
, step
), um_bindings
);
1395 um_names
= SCM_CDR (um_names
);
1396 um_inits
= SCM_CDR (um_inits
);
1397 um_steps
= SCM_CDR (um_steps
);
1399 um_bindings
= scm_reverse_x (um_bindings
, SCM_UNDEFINED
);
1401 return scm_cons (scm_sym_do
,
1402 scm_cons2 (um_bindings
, um_exit_sequence
, um_body
));
1406 SCM_SYNTAX (s_if
, "if", scm_i_makbimacro
, scm_m_if
);
1407 SCM_GLOBAL_SYMBOL (scm_sym_if
, s_if
);
1410 scm_m_if (SCM expr
, SCM env SCM_UNUSED
)
1412 const SCM cdr_expr
= SCM_CDR (expr
);
1413 const long length
= scm_ilength (cdr_expr
);
1414 ASSERT_SYNTAX (length
== 2 || length
== 3, s_expression
, expr
);
1415 SCM_SETCAR (expr
, SCM_IM_IF
);
1420 unmemoize_if (const SCM expr
, const SCM env
)
1422 const SCM cdr_expr
= SCM_CDR (expr
);
1423 const SCM um_condition
= unmemoize_expression (SCM_CAR (cdr_expr
), env
);
1424 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
1425 const SCM um_then
= unmemoize_expression (SCM_CAR (cddr_expr
), env
);
1426 const SCM cdddr_expr
= SCM_CDR (cddr_expr
);
1428 if (scm_is_null (cdddr_expr
))
1430 return scm_list_3 (scm_sym_if
, um_condition
, um_then
);
1434 const SCM um_else
= unmemoize_expression (SCM_CAR (cdddr_expr
), env
);
1435 return scm_list_4 (scm_sym_if
, um_condition
, um_then
, um_else
);
1440 SCM_SYNTAX (s_lambda
, "lambda", scm_i_makbimacro
, scm_m_lambda
);
1441 SCM_GLOBAL_SYMBOL (scm_sym_lambda
, s_lambda
);
1443 /* A helper function for memoize_lambda to support checking for duplicate
1444 * formal arguments: Return true if OBJ is `eq?' to one of the elements of
1445 * LIST or to the cdr of the last cons. Therefore, LIST may have any of the
1446 * forms that a formal argument can have:
1447 * <rest>, (<arg1> ...), (<arg1> ... . <rest>) */
1449 c_improper_memq (SCM obj
, SCM list
)
1451 for (; scm_is_pair (list
); list
= SCM_CDR (list
))
1453 if (scm_is_eq (SCM_CAR (list
), obj
))
1456 return scm_is_eq (list
, obj
);
1460 scm_m_lambda (SCM expr
, SCM env SCM_UNUSED
)
1469 const SCM cdr_expr
= SCM_CDR (expr
);
1470 const long length
= scm_ilength (cdr_expr
);
1471 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
1472 ASSERT_SYNTAX (length
>= 2, s_missing_expression
, expr
);
1474 /* Before iterating the list of formal arguments, make sure the formals
1475 * actually are given as either a symbol or a non-cyclic list. */
1476 formals
= SCM_CAR (cdr_expr
);
1477 if (scm_is_pair (formals
))
1479 /* Dirk:FIXME:: We should check for a cyclic list of formals, and if
1480 * detected, report a 'Bad formals' error. */
1484 ASSERT_SYNTAX_2 (scm_is_symbol (formals
) || scm_is_null (formals
),
1485 s_bad_formals
, formals
, expr
);
1488 /* Now iterate the list of formal arguments to check if all formals are
1489 * symbols, and that there are no duplicates. */
1490 formals_idx
= formals
;
1491 while (scm_is_pair (formals_idx
))
1493 const SCM formal
= SCM_CAR (formals_idx
);
1494 const SCM next_idx
= SCM_CDR (formals_idx
);
1495 ASSERT_SYNTAX_2 (scm_is_symbol (formal
), s_bad_formal
, formal
, expr
);
1496 ASSERT_SYNTAX_2 (!c_improper_memq (formal
, next_idx
),
1497 s_duplicate_formal
, formal
, expr
);
1498 formals_idx
= next_idx
;
1500 ASSERT_SYNTAX_2 (scm_is_null (formals_idx
) || scm_is_symbol (formals_idx
),
1501 s_bad_formal
, formals_idx
, expr
);
1503 /* Memoize the body. Keep a potential documentation string. */
1504 /* Dirk:FIXME:: We should probably extract the documentation string to
1505 * some external database. Otherwise it will slow down execution, since
1506 * the documentation string will have to be skipped with every execution
1507 * of the closure. */
1508 cddr_expr
= SCM_CDR (cdr_expr
);
1509 documentation
= (length
>= 3 && scm_is_string (SCM_CAR (cddr_expr
)));
1510 body
= documentation
? SCM_CDR (cddr_expr
) : cddr_expr
;
1511 new_body
= m_body (SCM_IM_LAMBDA
, body
);
1513 SCM_SETCAR (expr
, SCM_IM_LAMBDA
);
1515 SCM_SETCDR (cddr_expr
, new_body
);
1517 SCM_SETCDR (cdr_expr
, new_body
);
1522 unmemoize_lambda (const SCM expr
, const SCM env
)
1524 const SCM formals
= SCM_CADR (expr
);
1525 const SCM body
= SCM_CDDR (expr
);
1527 const SCM new_env
= SCM_EXTEND_ENV (formals
, SCM_EOL
, env
);
1528 const SCM um_formals
= scm_i_finite_list_copy (formals
);
1529 const SCM um_body
= unmemoize_exprs (body
, new_env
);
1531 return scm_cons2 (scm_sym_lambda
, um_formals
, um_body
);
1535 /* Check if the format of the bindings is ((<symbol> <init-form>) ...). */
1537 check_bindings (const SCM bindings
, const SCM expr
)
1541 ASSERT_SYNTAX_2 (scm_ilength (bindings
) >= 0,
1542 s_bad_bindings
, bindings
, expr
);
1544 binding_idx
= bindings
;
1545 for (; !scm_is_null (binding_idx
); binding_idx
= SCM_CDR (binding_idx
))
1547 SCM name
; /* const */
1549 const SCM binding
= SCM_CAR (binding_idx
);
1550 ASSERT_SYNTAX_2 (scm_ilength (binding
) == 2,
1551 s_bad_binding
, binding
, expr
);
1553 name
= SCM_CAR (binding
);
1554 ASSERT_SYNTAX_2 (scm_is_symbol (name
), s_bad_variable
, name
, expr
);
1559 /* The bindings, which must have the format ((v1 i1) (v2 i2) ... (vn in)), are
1560 * transformed to the lists (vn ... v2 v1) and (i1 i2 ... in). That is, the
1561 * variables are returned in a list with their order reversed, and the init
1562 * forms are returned in a list in the same order as they are given in the
1563 * bindings. If a duplicate variable name is detected, an error is
1566 transform_bindings (
1567 const SCM bindings
, const SCM expr
,
1568 SCM
*const rvarptr
, SCM
*const initptr
)
1570 SCM rvariables
= SCM_EOL
;
1571 SCM rinits
= SCM_EOL
;
1572 SCM binding_idx
= bindings
;
1573 for (; !scm_is_null (binding_idx
); binding_idx
= SCM_CDR (binding_idx
))
1575 const SCM binding
= SCM_CAR (binding_idx
);
1576 const SCM cdr_binding
= SCM_CDR (binding
);
1577 const SCM name
= SCM_CAR (binding
);
1578 ASSERT_SYNTAX_2 (scm_is_false (scm_c_memq (name
, rvariables
)),
1579 s_duplicate_binding
, name
, expr
);
1580 rvariables
= scm_cons (name
, rvariables
);
1581 rinits
= scm_cons (SCM_CAR (cdr_binding
), rinits
);
1583 *rvarptr
= rvariables
;
1584 *initptr
= scm_reverse_x (rinits
, SCM_UNDEFINED
);
1588 SCM_SYNTAX(s_let
, "let", scm_i_makbimacro
, scm_m_let
);
1589 SCM_GLOBAL_SYMBOL(scm_sym_let
, s_let
);
1591 /* This function is a helper function for memoize_let. It transforms
1592 * (let name ((var init) ...) body ...) into
1593 * ((letrec ((name (lambda (var ...) body ...))) name) init ...)
1594 * and memoizes the expression. It is assumed that the caller has checked
1595 * that name is a symbol and that there are bindings and a body. */
1597 memoize_named_let (const SCM expr
, const SCM env SCM_UNUSED
)
1603 const SCM cdr_expr
= SCM_CDR (expr
);
1604 const SCM name
= SCM_CAR (cdr_expr
);
1605 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
1606 const SCM bindings
= SCM_CAR (cddr_expr
);
1607 check_bindings (bindings
, expr
);
1609 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
1610 variables
= scm_reverse_x (rvariables
, SCM_UNDEFINED
);
1613 const SCM let_body
= SCM_CDR (cddr_expr
);
1614 const SCM lambda_body
= m_body (SCM_IM_LET
, let_body
);
1615 const SCM lambda_tail
= scm_cons (variables
, lambda_body
);
1616 const SCM lambda_form
= scm_cons_source (expr
, scm_sym_lambda
, lambda_tail
);
1618 const SCM rvar
= scm_list_1 (name
);
1619 const SCM init
= scm_list_1 (lambda_form
);
1620 const SCM body
= m_body (SCM_IM_LET
, scm_list_1 (name
));
1621 const SCM letrec_tail
= scm_cons (rvar
, scm_cons (init
, body
));
1622 const SCM letrec_form
= scm_cons_source (expr
, SCM_IM_LETREC
, letrec_tail
);
1623 return scm_cons_source (expr
, letrec_form
, inits
);
1627 /* (let ((v1 i1) (v2 i2) ...) body) with variables v1 .. vn and initializers
1628 * i1 .. in is transformed to (#@let (vn ... v2 v1) (i1 i2 ...) body). */
1630 scm_m_let (SCM expr
, SCM env
)
1634 const SCM cdr_expr
= SCM_CDR (expr
);
1635 const long length
= scm_ilength (cdr_expr
);
1636 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
1637 ASSERT_SYNTAX (length
>= 2, s_missing_expression
, expr
);
1639 bindings
= SCM_CAR (cdr_expr
);
1640 if (scm_is_symbol (bindings
))
1642 ASSERT_SYNTAX (length
>= 3, s_missing_expression
, expr
);
1643 return memoize_named_let (expr
, env
);
1646 check_bindings (bindings
, expr
);
1647 if (scm_is_null (bindings
) || scm_is_null (SCM_CDR (bindings
)))
1649 /* Special case: no bindings or single binding => let* is faster. */
1650 const SCM body
= m_body (SCM_IM_LET
, SCM_CDR (cdr_expr
));
1651 return scm_m_letstar (scm_cons2 (SCM_CAR (expr
), bindings
, body
), env
);
1658 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
1661 const SCM new_body
= m_body (SCM_IM_LET
, SCM_CDR (cdr_expr
));
1662 const SCM new_tail
= scm_cons2 (rvariables
, inits
, new_body
);
1663 SCM_SETCAR (expr
, SCM_IM_LET
);
1664 SCM_SETCDR (expr
, new_tail
);
1671 build_binding_list (SCM rnames
, SCM rinits
)
1673 SCM bindings
= SCM_EOL
;
1674 while (!scm_is_null (rnames
))
1676 const SCM binding
= scm_list_2 (SCM_CAR (rnames
), SCM_CAR (rinits
));
1677 bindings
= scm_cons (binding
, bindings
);
1678 rnames
= SCM_CDR (rnames
);
1679 rinits
= SCM_CDR (rinits
);
1685 unmemoize_let (const SCM expr
, const SCM env
)
1687 const SCM cdr_expr
= SCM_CDR (expr
);
1688 const SCM um_rnames
= SCM_CAR (cdr_expr
);
1689 const SCM extended_env
= SCM_EXTEND_ENV (um_rnames
, SCM_EOL
, env
);
1690 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
1691 const SCM um_inits
= unmemoize_exprs (SCM_CAR (cddr_expr
), env
);
1692 const SCM um_rinits
= scm_reverse_x (um_inits
, SCM_UNDEFINED
);
1693 const SCM um_bindings
= build_binding_list (um_rnames
, um_rinits
);
1694 const SCM um_body
= unmemoize_exprs (SCM_CDR (cddr_expr
), extended_env
);
1696 return scm_cons2 (scm_sym_let
, um_bindings
, um_body
);
1700 SCM_SYNTAX(s_letrec
, "letrec", scm_i_makbimacro
, scm_m_letrec
);
1701 SCM_GLOBAL_SYMBOL(scm_sym_letrec
, s_letrec
);
1704 scm_m_letrec (SCM expr
, SCM env
)
1708 const SCM cdr_expr
= SCM_CDR (expr
);
1709 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1710 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
1712 bindings
= SCM_CAR (cdr_expr
);
1713 if (scm_is_null (bindings
))
1715 /* no bindings, let* is executed faster */
1716 SCM body
= m_body (SCM_IM_LETREC
, SCM_CDR (cdr_expr
));
1717 return scm_m_letstar (scm_cons2 (SCM_CAR (expr
), SCM_EOL
, body
), env
);
1725 check_bindings (bindings
, expr
);
1726 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
1727 new_body
= m_body (SCM_IM_LETREC
, SCM_CDR (cdr_expr
));
1728 return scm_cons2 (SCM_IM_LETREC
, rvariables
, scm_cons (inits
, new_body
));
1733 unmemoize_letrec (const SCM expr
, const SCM env
)
1735 const SCM cdr_expr
= SCM_CDR (expr
);
1736 const SCM um_rnames
= SCM_CAR (cdr_expr
);
1737 const SCM extended_env
= SCM_EXTEND_ENV (um_rnames
, SCM_EOL
, env
);
1738 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
1739 const SCM um_inits
= unmemoize_exprs (SCM_CAR (cddr_expr
), extended_env
);
1740 const SCM um_rinits
= scm_reverse_x (um_inits
, SCM_UNDEFINED
);
1741 const SCM um_bindings
= build_binding_list (um_rnames
, um_rinits
);
1742 const SCM um_body
= unmemoize_exprs (SCM_CDR (cddr_expr
), extended_env
);
1744 return scm_cons2 (scm_sym_letrec
, um_bindings
, um_body
);
1749 SCM_SYNTAX (s_letstar
, "let*", scm_i_makbimacro
, scm_m_letstar
);
1750 SCM_GLOBAL_SYMBOL (scm_sym_letstar
, s_letstar
);
1752 /* (let* ((v1 i1) (v2 i2) ...) body) with variables v1 .. vn and initializers
1753 * i1 .. in is transformed into the form (#@let* (v1 i1 v2 i2 ...) body). */
1755 scm_m_letstar (SCM expr
, SCM env SCM_UNUSED
)
1760 const SCM cdr_expr
= SCM_CDR (expr
);
1761 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1762 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
1764 binding_idx
= SCM_CAR (cdr_expr
);
1765 check_bindings (binding_idx
, expr
);
1767 /* Transform ((v1 i1) (v2 i2) ...) into (v1 i1 v2 i2 ...). The
1768 * transformation is done in place. At the beginning of one iteration of
1769 * the loop the variable binding_idx holds the form
1770 * P1:( (vn . P2:(in . ())) . P3:( (vn+1 in+1) ... ) ),
1771 * where P1, P2 and P3 indicate the pairs, that are relevant for the
1772 * transformation. P1 and P2 are modified in the loop, P3 remains
1773 * untouched. After the execution of the loop, P1 will hold
1774 * P1:( vn . P2:(in . P3:( (vn+1 in+1) ... )) )
1775 * and binding_idx will hold P3. */
1776 while (!scm_is_null (binding_idx
))
1778 const SCM cdr_binding_idx
= SCM_CDR (binding_idx
); /* remember P3 */
1779 const SCM binding
= SCM_CAR (binding_idx
);
1780 const SCM name
= SCM_CAR (binding
);
1781 const SCM cdr_binding
= SCM_CDR (binding
);
1783 SCM_SETCDR (cdr_binding
, cdr_binding_idx
); /* update P2 */
1784 SCM_SETCAR (binding_idx
, name
); /* update P1 */
1785 SCM_SETCDR (binding_idx
, cdr_binding
); /* update P1 */
1787 binding_idx
= cdr_binding_idx
; /* continue with P3 */
1790 new_body
= m_body (SCM_IM_LETSTAR
, SCM_CDR (cdr_expr
));
1791 SCM_SETCAR (expr
, SCM_IM_LETSTAR
);
1792 /* the bindings have been changed in place */
1793 SCM_SETCDR (cdr_expr
, new_body
);
1798 unmemoize_letstar (const SCM expr
, const SCM env
)
1800 const SCM cdr_expr
= SCM_CDR (expr
);
1801 const SCM body
= SCM_CDR (cdr_expr
);
1802 SCM bindings
= SCM_CAR (cdr_expr
);
1803 SCM um_bindings
= SCM_EOL
;
1804 SCM extended_env
= env
;
1807 while (!scm_is_null (bindings
))
1809 const SCM variable
= SCM_CAR (bindings
);
1810 const SCM init
= SCM_CADR (bindings
);
1811 const SCM um_init
= unmemoize_expression (init
, extended_env
);
1812 um_bindings
= scm_cons (scm_list_2 (variable
, um_init
), um_bindings
);
1813 extended_env
= SCM_EXTEND_ENV (variable
, SCM_BOOL_F
, extended_env
);
1814 bindings
= SCM_CDDR (bindings
);
1816 um_bindings
= scm_reverse_x (um_bindings
, SCM_UNDEFINED
);
1818 um_body
= unmemoize_exprs (body
, extended_env
);
1820 return scm_cons2 (scm_sym_letstar
, um_bindings
, um_body
);
1824 SCM_SYNTAX (s_or
, "or", scm_i_makbimacro
, scm_m_or
);
1825 SCM_GLOBAL_SYMBOL (scm_sym_or
, s_or
);
1828 scm_m_or (SCM expr
, SCM env SCM_UNUSED
)
1830 const SCM cdr_expr
= SCM_CDR (expr
);
1831 const long length
= scm_ilength (cdr_expr
);
1833 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
1837 /* Special case: (or) is replaced by #f. */
1842 SCM_SETCAR (expr
, SCM_IM_OR
);
1848 unmemoize_or (const SCM expr
, const SCM env
)
1850 return scm_cons (scm_sym_or
, unmemoize_exprs (SCM_CDR (expr
), env
));
1854 SCM_SYNTAX (s_quasiquote
, "quasiquote", scm_makacro
, scm_m_quasiquote
);
1855 SCM_GLOBAL_SYMBOL (scm_sym_quasiquote
, s_quasiquote
);
1856 SCM_GLOBAL_SYMBOL (scm_sym_unquote
, "unquote");
1857 SCM_GLOBAL_SYMBOL (scm_sym_uq_splicing
, "unquote-splicing");
1859 /* Internal function to handle a quasiquotation: 'form' is the parameter in
1860 * the call (quasiquotation form), 'env' is the environment where unquoted
1861 * expressions will be evaluated, and 'depth' is the current quasiquotation
1862 * nesting level and is known to be greater than zero. */
1864 iqq (SCM form
, SCM env
, unsigned long int depth
)
1866 if (scm_is_pair (form
))
1868 const SCM tmp
= SCM_CAR (form
);
1869 if (scm_is_eq (tmp
, scm_sym_quasiquote
))
1871 const SCM args
= SCM_CDR (form
);
1872 ASSERT_SYNTAX (scm_ilength (args
) == 1, s_expression
, form
);
1873 return scm_list_2 (tmp
, iqq (SCM_CAR (args
), env
, depth
+ 1));
1875 else if (scm_is_eq (tmp
, scm_sym_unquote
))
1877 const SCM args
= SCM_CDR (form
);
1878 ASSERT_SYNTAX (scm_ilength (args
) == 1, s_expression
, form
);
1880 return scm_eval_car (args
, env
);
1882 return scm_list_2 (tmp
, iqq (SCM_CAR (args
), env
, depth
- 1));
1884 else if (scm_is_pair (tmp
)
1885 && scm_is_eq (SCM_CAR (tmp
), scm_sym_uq_splicing
))
1887 const SCM args
= SCM_CDR (tmp
);
1888 ASSERT_SYNTAX (scm_ilength (args
) == 1, s_expression
, form
);
1891 const SCM list
= scm_eval_car (args
, env
);
1892 const SCM rest
= SCM_CDR (form
);
1893 ASSERT_SYNTAX_2 (scm_ilength (list
) >= 0,
1894 s_splicing
, list
, form
);
1895 return scm_append (scm_list_2 (list
, iqq (rest
, env
, depth
)));
1898 return scm_cons (iqq (SCM_CAR (form
), env
, depth
- 1),
1899 iqq (SCM_CDR (form
), env
, depth
));
1902 return scm_cons (iqq (SCM_CAR (form
), env
, depth
),
1903 iqq (SCM_CDR (form
), env
, depth
));
1905 else if (scm_is_vector (form
))
1906 return scm_vector (iqq (scm_vector_to_list (form
), env
, depth
));
1912 scm_m_quasiquote (SCM expr
, SCM env
)
1914 const SCM cdr_expr
= SCM_CDR (expr
);
1915 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1916 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
1917 return iqq (SCM_CAR (cdr_expr
), env
, 1);
1921 SCM_SYNTAX (s_quote
, "quote", scm_i_makbimacro
, scm_m_quote
);
1922 SCM_GLOBAL_SYMBOL (scm_sym_quote
, s_quote
);
1925 scm_m_quote (SCM expr
, SCM env SCM_UNUSED
)
1929 const SCM cdr_expr
= SCM_CDR (expr
);
1930 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1931 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
1932 quotee
= SCM_CAR (cdr_expr
);
1933 if (is_self_quoting_p (quotee
))
1936 SCM_SETCAR (expr
, SCM_IM_QUOTE
);
1937 SCM_SETCDR (expr
, quotee
);
1942 unmemoize_quote (const SCM expr
, const SCM env SCM_UNUSED
)
1944 return scm_list_2 (scm_sym_quote
, SCM_CDR (expr
));
1948 /* Will go into the RnRS module when Guile is factorized.
1949 SCM_SYNTAX (s_set_x, "set!", scm_i_makbimacro, scm_m_set_x); */
1950 static const char s_set_x
[] = "set!";
1951 SCM_GLOBAL_SYMBOL (scm_sym_set_x
, s_set_x
);
1954 scm_m_set_x (SCM expr
, SCM env SCM_UNUSED
)
1959 const SCM cdr_expr
= SCM_CDR (expr
);
1960 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1961 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
1962 variable
= SCM_CAR (cdr_expr
);
1964 /* Memoize the variable form. */
1965 ASSERT_SYNTAX_2 (scm_is_symbol (variable
), s_bad_variable
, variable
, expr
);
1966 new_variable
= lookup_symbol (variable
, env
);
1967 /* Leave the memoization of unbound symbols to lazy memoization: */
1968 if (SCM_UNBNDP (new_variable
))
1969 new_variable
= variable
;
1971 SCM_SETCAR (expr
, SCM_IM_SET_X
);
1972 SCM_SETCAR (cdr_expr
, new_variable
);
1977 unmemoize_set_x (const SCM expr
, const SCM env
)
1979 return scm_cons (scm_sym_set_x
, unmemoize_exprs (SCM_CDR (expr
), env
));
1983 /* Start of the memoizers for non-R5RS builtin macros. */
1986 SCM_SYNTAX (s_atapply
, "@apply", scm_i_makbimacro
, scm_m_apply
);
1987 SCM_GLOBAL_SYMBOL (scm_sym_atapply
, s_atapply
);
1988 SCM_GLOBAL_SYMBOL (scm_sym_apply
, s_atapply
+ 1);
1991 scm_m_apply (SCM expr
, SCM env SCM_UNUSED
)
1993 const SCM cdr_expr
= SCM_CDR (expr
);
1994 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1995 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_missing_expression
, expr
);
1997 SCM_SETCAR (expr
, SCM_IM_APPLY
);
2002 unmemoize_apply (const SCM expr
, const SCM env
)
2004 return scm_list_2 (scm_sym_atapply
, unmemoize_exprs (SCM_CDR (expr
), env
));
2008 SCM_SYNTAX (s_atbind
, "@bind", scm_i_makbimacro
, scm_m_atbind
);
2010 /* FIXME: The following explanation should go into the documentation: */
2011 /* (@bind ((var init) ...) body ...) will assign the values of the `init's to
2012 * the global variables named by `var's (symbols, not evaluated), creating
2013 * them if they don't exist, executes body, and then restores the previous
2014 * values of the `var's. Additionally, whenever control leaves body, the
2015 * values of the `var's are saved and restored when control returns. It is an
2016 * error when a symbol appears more than once among the `var's. All `init's
2017 * are evaluated before any `var' is set.
2019 * Think of this as `let' for dynamic scope.
2022 /* (@bind ((var1 exp1) ... (varn expn)) body ...) is memoized into
2023 * (#@bind ((varn ... var1) . (exp1 ... expn)) body ...).
2025 * FIXME - also implement `@bind*'.
2028 scm_m_atbind (SCM expr
, SCM env
)
2035 const SCM top_level
= scm_env_top_level (env
);
2037 const SCM cdr_expr
= SCM_CDR (expr
);
2038 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2039 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
2040 bindings
= SCM_CAR (cdr_expr
);
2041 check_bindings (bindings
, expr
);
2042 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
2044 for (variable_idx
= rvariables
;
2045 !scm_is_null (variable_idx
);
2046 variable_idx
= SCM_CDR (variable_idx
))
2048 /* The first call to scm_sym2var will look beyond the current module,
2049 * while the second call wont. */
2050 const SCM variable
= SCM_CAR (variable_idx
);
2051 SCM new_variable
= scm_sym2var (variable
, top_level
, SCM_BOOL_F
);
2052 if (scm_is_false (new_variable
))
2053 new_variable
= scm_sym2var (variable
, top_level
, SCM_BOOL_T
);
2054 SCM_SETCAR (variable_idx
, new_variable
);
2057 SCM_SETCAR (expr
, SCM_IM_BIND
);
2058 SCM_SETCAR (cdr_expr
, scm_cons (rvariables
, inits
));
2063 SCM_SYNTAX(s_atcall_cc
, "@call-with-current-continuation", scm_i_makbimacro
, scm_m_cont
);
2064 SCM_GLOBAL_SYMBOL(scm_sym_atcall_cc
, s_atcall_cc
);
2067 scm_m_cont (SCM expr
, SCM env SCM_UNUSED
)
2069 const SCM cdr_expr
= SCM_CDR (expr
);
2070 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2071 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
2073 SCM_SETCAR (expr
, SCM_IM_CONT
);
2078 unmemoize_atcall_cc (const SCM expr
, const SCM env
)
2080 return scm_list_2 (scm_sym_atcall_cc
, unmemoize_exprs (SCM_CDR (expr
), env
));
2084 SCM_SYNTAX (s_at_call_with_values
, "@call-with-values", scm_i_makbimacro
, scm_m_at_call_with_values
);
2085 SCM_GLOBAL_SYMBOL(scm_sym_at_call_with_values
, s_at_call_with_values
);
2088 scm_m_at_call_with_values (SCM expr
, SCM env SCM_UNUSED
)
2090 const SCM cdr_expr
= SCM_CDR (expr
);
2091 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2092 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
2094 SCM_SETCAR (expr
, SCM_IM_CALL_WITH_VALUES
);
2099 unmemoize_at_call_with_values (const SCM expr
, const SCM env
)
2101 return scm_list_2 (scm_sym_at_call_with_values
,
2102 unmemoize_exprs (SCM_CDR (expr
), env
));
2107 /* See futures.h for a comment why futures are not enabled.
2110 SCM_SYNTAX (s_future
, "future", scm_i_makbimacro
, scm_m_future
);
2111 SCM_GLOBAL_SYMBOL (scm_sym_future
, s_future
);
2113 /* Like promises, futures are implemented as closures with an empty
2114 * parameter list. Thus, (future <expression>) is transformed into
2115 * (#@future '() <expression>), where the empty list represents the
2116 * empty parameter list. This representation allows for easy creation
2117 * of the closure during evaluation. */
2119 scm_m_future (SCM expr
, SCM env
)
2121 const SCM new_expr
= memoize_as_thunk_prototype (expr
, env
);
2122 SCM_SETCAR (new_expr
, SCM_IM_FUTURE
);
2127 unmemoize_future (const SCM expr
, const SCM env
)
2129 const SCM thunk_expr
= SCM_CADDR (expr
);
2130 return scm_list_2 (scm_sym_future
, unmemoize_expression (thunk_expr
, env
));
2135 SCM_SYNTAX (s_gset_x
, "set!", scm_i_makbimacro
, scm_m_generalized_set_x
);
2136 SCM_SYMBOL (scm_sym_setter
, "setter");
2139 scm_m_generalized_set_x (SCM expr
, SCM env
)
2141 SCM target
, exp_target
;
2143 const SCM cdr_expr
= SCM_CDR (expr
);
2144 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2145 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
2147 target
= SCM_CAR (cdr_expr
);
2148 if (!scm_is_pair (target
))
2151 return scm_m_set_x (expr
, env
);
2155 /* (set! (foo bar ...) baz) becomes ((setter foo) bar ... baz) */
2156 /* Macroexpanding the target might return things of the form
2157 (begin <atom>). In that case, <atom> must be a symbol or a
2158 variable and we memoize to (set! <atom> ...).
2160 exp_target
= macroexp (target
, env
);
2161 if (scm_is_eq (SCM_CAR (exp_target
), SCM_IM_BEGIN
)
2162 && !scm_is_null (SCM_CDR (exp_target
))
2163 && scm_is_null (SCM_CDDR (exp_target
)))
2165 exp_target
= SCM_CADR (exp_target
);
2166 ASSERT_SYNTAX_2 (scm_is_symbol (exp_target
)
2167 || SCM_VARIABLEP (exp_target
),
2168 s_bad_variable
, exp_target
, expr
);
2169 return scm_cons (SCM_IM_SET_X
, scm_cons (exp_target
,
2170 SCM_CDR (cdr_expr
)));
2174 const SCM setter_proc_tail
= scm_list_1 (SCM_CAR (target
));
2175 const SCM setter_proc
= scm_cons_source (expr
, scm_sym_setter
,
2178 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
2179 const SCM setter_args
= scm_append_x (scm_list_2 (SCM_CDR (target
),
2182 SCM_SETCAR (expr
, setter_proc
);
2183 SCM_SETCDR (expr
, setter_args
);
2190 /* @slot-ref is bound privately in the (oop goops) module from goops.c. As
2191 * soon as the module system allows us to more freely create bindings in
2192 * arbitrary modules during the startup phase, the code from goops.c should be
2195 SCM_SYMBOL (sym_atslot_ref
, "@slot-ref");
2198 scm_m_atslot_ref (SCM expr
, SCM env SCM_UNUSED
)
2202 const SCM cdr_expr
= SCM_CDR (expr
);
2203 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2204 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
2205 slot_nr
= SCM_CADR (cdr_expr
);
2206 ASSERT_SYNTAX_2 (SCM_I_INUMP (slot_nr
), s_bad_slot_number
, slot_nr
, expr
);
2208 SCM_SETCAR (expr
, SCM_IM_SLOT_REF
);
2209 SCM_SETCDR (cdr_expr
, slot_nr
);
2214 unmemoize_atslot_ref (const SCM expr
, const SCM env
)
2216 const SCM instance
= SCM_CADR (expr
);
2217 const SCM um_instance
= unmemoize_expression (instance
, env
);
2218 const SCM slot_nr
= SCM_CDDR (expr
);
2219 return scm_list_3 (sym_atslot_ref
, um_instance
, slot_nr
);
2223 /* @slot-set! is bound privately in the (oop goops) module from goops.c. As
2224 * soon as the module system allows us to more freely create bindings in
2225 * arbitrary modules during the startup phase, the code from goops.c should be
2228 SCM_SYMBOL (sym_atslot_set_x
, "@slot-set!");
2231 scm_m_atslot_set_x (SCM expr
, SCM env SCM_UNUSED
)
2235 const SCM cdr_expr
= SCM_CDR (expr
);
2236 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2237 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 3, s_expression
, expr
);
2238 slot_nr
= SCM_CADR (cdr_expr
);
2239 ASSERT_SYNTAX_2 (SCM_I_INUMP (slot_nr
), s_bad_slot_number
, slot_nr
, expr
);
2241 SCM_SETCAR (expr
, SCM_IM_SLOT_SET_X
);
2246 unmemoize_atslot_set_x (const SCM expr
, const SCM env
)
2248 const SCM cdr_expr
= SCM_CDR (expr
);
2249 const SCM instance
= SCM_CAR (cdr_expr
);
2250 const SCM um_instance
= unmemoize_expression (instance
, env
);
2251 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
2252 const SCM slot_nr
= SCM_CAR (cddr_expr
);
2253 const SCM cdddr_expr
= SCM_CDR (cddr_expr
);
2254 const SCM value
= SCM_CAR (cdddr_expr
);
2255 const SCM um_value
= unmemoize_expression (value
, env
);
2256 return scm_list_4 (sym_atslot_set_x
, um_instance
, slot_nr
, um_value
);
2260 #if SCM_ENABLE_ELISP
2262 static const char s_defun
[] = "Symbol's function definition is void";
2264 SCM_SYNTAX (s_nil_cond
, "nil-cond", scm_i_makbimacro
, scm_m_nil_cond
);
2266 /* nil-cond expressions have the form
2267 * (nil-cond COND VAL COND VAL ... ELSEVAL) */
2269 scm_m_nil_cond (SCM expr
, SCM env SCM_UNUSED
)
2271 const long length
= scm_ilength (SCM_CDR (expr
));
2272 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
2273 ASSERT_SYNTAX (length
>= 1 && (length
% 2) == 1, s_expression
, expr
);
2275 SCM_SETCAR (expr
, SCM_IM_NIL_COND
);
2280 SCM_SYNTAX (s_atfop
, "@fop", scm_i_makbimacro
, scm_m_atfop
);
2282 /* The @fop-macro handles procedure and macro applications for elisp. The
2283 * input expression must have the form
2284 * (@fop <var> (transformer-macro <expr> ...))
2285 * where <var> must be a symbol. The expression is transformed into the
2286 * memoized form of either
2287 * (apply <un-aliased var> (transformer-macro <expr> ...))
2288 * if the value of var (across all aliasing) is not a macro, or
2289 * (<un-aliased var> <expr> ...)
2290 * if var is a macro. */
2292 scm_m_atfop (SCM expr
, SCM env SCM_UNUSED
)
2297 const SCM cdr_expr
= SCM_CDR (expr
);
2298 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2299 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 1, s_missing_expression
, expr
);
2301 symbol
= SCM_CAR (cdr_expr
);
2302 ASSERT_SYNTAX_2 (scm_is_symbol (symbol
), s_bad_variable
, symbol
, expr
);
2304 location
= scm_symbol_fref (symbol
);
2305 ASSERT_SYNTAX_2 (SCM_VARIABLEP (location
), s_defun
, symbol
, expr
);
2307 /* The elisp function `defalias' allows to define aliases for symbols. To
2308 * look up such definitions, the chain of symbol definitions has to be
2309 * followed up to the terminal symbol. */
2310 while (scm_is_symbol (SCM_VARIABLE_REF (location
)))
2312 const SCM alias
= SCM_VARIABLE_REF (location
);
2313 location
= scm_symbol_fref (alias
);
2314 ASSERT_SYNTAX_2 (SCM_VARIABLEP (location
), s_defun
, symbol
, expr
);
2317 /* Memoize the value location belonging to the terminal symbol. */
2318 SCM_SETCAR (cdr_expr
, location
);
2320 if (!SCM_MACROP (SCM_VARIABLE_REF (location
)))
2322 /* Since the location does not contain a macro, the form is a procedure
2323 * application. Replace `@fop' by `@apply' and transform the expression
2324 * including the `transformer-macro'. */
2325 SCM_SETCAR (expr
, SCM_IM_APPLY
);
2330 /* Since the location contains a macro, the arguments should not be
2331 * transformed, so the `transformer-macro' is cut out. The resulting
2332 * expression starts with the memoized variable, that is at the cdr of
2333 * the input expression. */
2334 SCM_SETCDR (cdr_expr
, SCM_CDADR (cdr_expr
));
2339 #endif /* SCM_ENABLE_ELISP */
2343 unmemoize_builtin_macro (const SCM expr
, const SCM env
)
2345 switch (ISYMNUM (SCM_CAR (expr
)))
2347 case (ISYMNUM (SCM_IM_AND
)):
2348 return unmemoize_and (expr
, env
);
2350 case (ISYMNUM (SCM_IM_BEGIN
)):
2351 return unmemoize_begin (expr
, env
);
2353 case (ISYMNUM (SCM_IM_CASE
)):
2354 return unmemoize_case (expr
, env
);
2356 case (ISYMNUM (SCM_IM_COND
)):
2357 return unmemoize_cond (expr
, env
);
2359 case (ISYMNUM (SCM_IM_DELAY
)):
2360 return unmemoize_delay (expr
, env
);
2362 case (ISYMNUM (SCM_IM_DO
)):
2363 return unmemoize_do (expr
, env
);
2365 case (ISYMNUM (SCM_IM_IF
)):
2366 return unmemoize_if (expr
, env
);
2368 case (ISYMNUM (SCM_IM_LAMBDA
)):
2369 return unmemoize_lambda (expr
, env
);
2371 case (ISYMNUM (SCM_IM_LET
)):
2372 return unmemoize_let (expr
, env
);
2374 case (ISYMNUM (SCM_IM_LETREC
)):
2375 return unmemoize_letrec (expr
, env
);
2377 case (ISYMNUM (SCM_IM_LETSTAR
)):
2378 return unmemoize_letstar (expr
, env
);
2380 case (ISYMNUM (SCM_IM_OR
)):
2381 return unmemoize_or (expr
, env
);
2383 case (ISYMNUM (SCM_IM_QUOTE
)):
2384 return unmemoize_quote (expr
, env
);
2386 case (ISYMNUM (SCM_IM_SET_X
)):
2387 return unmemoize_set_x (expr
, env
);
2389 case (ISYMNUM (SCM_IM_APPLY
)):
2390 return unmemoize_apply (expr
, env
);
2392 case (ISYMNUM (SCM_IM_BIND
)):
2393 return unmemoize_exprs (expr
, env
); /* FIXME */
2395 case (ISYMNUM (SCM_IM_CONT
)):
2396 return unmemoize_atcall_cc (expr
, env
);
2398 case (ISYMNUM (SCM_IM_CALL_WITH_VALUES
)):
2399 return unmemoize_at_call_with_values (expr
, env
);
2402 /* See futures.h for a comment why futures are not enabled.
2404 case (ISYMNUM (SCM_IM_FUTURE
)):
2405 return unmemoize_future (expr
, env
);
2408 case (ISYMNUM (SCM_IM_SLOT_REF
)):
2409 return unmemoize_atslot_ref (expr
, env
);
2411 case (ISYMNUM (SCM_IM_SLOT_SET_X
)):
2412 return unmemoize_atslot_set_x (expr
, env
);
2414 case (ISYMNUM (SCM_IM_NIL_COND
)):
2415 return unmemoize_exprs (expr
, env
); /* FIXME */
2418 return unmemoize_exprs (expr
, env
); /* FIXME */
2423 /* scm_i_unmemocopy_expr and scm_i_unmemocopy_body take a memoized expression
2424 * respectively a memoized body together with its environment and rewrite it
2425 * to its original form. Thus, these functions are the inversion of the
2426 * rewrite rules above. The procedure is not optimized for speed. It's used
2427 * in scm_i_unmemoize_expr, scm_procedure_source, macro_print and scm_iprin1.
2429 * Unmemoizing is not a reliable process. You cannot in general expect to get
2430 * the original source back.
2432 * However, GOOPS currently relies on this for method compilation. This ought
2436 scm_i_unmemocopy_expr (SCM expr
, SCM env
)
2438 const SCM source_properties
= scm_whash_lookup (scm_source_whash
, expr
);
2439 const SCM um_expr
= unmemoize_expression (expr
, env
);
2441 if (scm_is_true (source_properties
))
2442 scm_whash_insert (scm_source_whash
, um_expr
, source_properties
);
2448 scm_i_unmemocopy_body (SCM forms
, SCM env
)
2450 const SCM source_properties
= scm_whash_lookup (scm_source_whash
, forms
);
2451 const SCM um_forms
= unmemoize_exprs (forms
, env
);
2453 if (scm_is_true (source_properties
))
2454 scm_whash_insert (scm_source_whash
, um_forms
, source_properties
);
2460 #if (SCM_ENABLE_DEPRECATED == 1)
2462 /* Deprecated in guile 1.7.0 on 2003-11-09. */
2464 scm_m_expand_body (SCM exprs
, SCM env
)
2466 scm_c_issue_deprecation_warning
2467 ("`scm_m_expand_body' is deprecated.");
2468 m_expand_body (exprs
, env
);
2473 SCM_SYNTAX (s_undefine
, "undefine", scm_makacro
, scm_m_undefine
);
2476 scm_m_undefine (SCM expr
, SCM env
)
2481 const SCM cdr_expr
= SCM_CDR (expr
);
2482 ASSERT_SYNTAX (SCM_TOP_LEVEL (env
), "Bad undefine placement in", expr
);
2483 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2484 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
2486 scm_c_issue_deprecation_warning
2487 ("`undefine' is deprecated.\n");
2489 variable
= SCM_CAR (cdr_expr
);
2490 ASSERT_SYNTAX_2 (scm_is_symbol (variable
), s_bad_variable
, variable
, expr
);
2491 location
= scm_sym2var (variable
, scm_env_top_level (env
), SCM_BOOL_F
);
2492 ASSERT_SYNTAX_2 (scm_is_true (location
)
2493 && !SCM_UNBNDP (SCM_VARIABLE_REF (location
)),
2494 "variable already unbound ", variable
, expr
);
2495 SCM_VARIABLE_SET (location
, SCM_UNDEFINED
);
2496 return SCM_UNSPECIFIED
;
2500 scm_macroexp (SCM x
, SCM env
)
2502 scm_c_issue_deprecation_warning
2503 ("`scm_macroexp' is deprecated.");
2504 return macroexp (x
, env
);
2510 #if (SCM_ENABLE_DEPRECATED == 1)
2513 scm_unmemocar (SCM form
, SCM env
)
2515 scm_c_issue_deprecation_warning
2516 ("`scm_unmemocar' is deprecated.");
2518 if (!scm_is_pair (form
))
2522 SCM c
= SCM_CAR (form
);
2523 if (SCM_VARIABLEP (c
))
2525 SCM sym
= scm_module_reverse_lookup (scm_env_module (env
), c
);
2526 if (scm_is_false (sym
))
2527 sym
= sym_three_question_marks
;
2528 SCM_SETCAR (form
, sym
);
2530 else if (SCM_ILOCP (c
))
2532 unsigned long int ir
;
2534 for (ir
= SCM_IFRAME (c
); ir
!= 0; --ir
)
2535 env
= SCM_CDR (env
);
2536 env
= SCM_CAAR (env
);
2537 for (ir
= SCM_IDIST (c
); ir
!= 0; --ir
)
2538 env
= SCM_CDR (env
);
2540 SCM_SETCAR (form
, SCM_ICDRP (c
) ? env
: SCM_CAR (env
));
2548 /*****************************************************************************/
2549 /*****************************************************************************/
2550 /* The definitions for execution start here. */
2551 /*****************************************************************************/
2552 /*****************************************************************************/
2554 SCM_GLOBAL_SYMBOL (scm_sym_enter_frame
, "enter-frame");
2555 SCM_GLOBAL_SYMBOL (scm_sym_apply_frame
, "apply-frame");
2556 SCM_GLOBAL_SYMBOL (scm_sym_exit_frame
, "exit-frame");
2557 SCM_GLOBAL_SYMBOL (scm_sym_trace
, "trace");
2558 SCM_SYMBOL (sym_instead
, "instead");
2560 /* A function object to implement "apply" for non-closure functions. */
2562 /* An endless list consisting of #<undefined> objects: */
2563 static SCM undefineds
;
2567 scm_badargsp (SCM formals
, SCM args
)
2569 while (!scm_is_null (formals
))
2571 if (!scm_is_pair (formals
))
2573 if (scm_is_null (args
))
2575 formals
= SCM_CDR (formals
);
2576 args
= SCM_CDR (args
);
2578 return !scm_is_null (args
) ? 1 : 0;
2583 /* The evaluator contains a plethora of EVAL symbols. This is an attempt at
2586 * The following macros should be used in code which is read twice (where the
2587 * choice of evaluator is hard soldered):
2589 * CEVAL is the symbol used within one evaluator to call itself.
2590 * Originally, it is defined to ceval, but is redefined to deval during the
2593 * SCM_I_EVALIM is used when it is known that the expression is an
2594 * immediate. (This macro never calls an evaluator.)
2596 * EVAL evaluates an expression that is expected to have its symbols already
2597 * memoized. Expressions that are not of the form '(<form> <form> ...)' are
2598 * evaluated inline without calling an evaluator.
2600 * EVALCAR evaluates the car of an expression 'X:(Y:<form> <form> ...)',
2601 * potentially replacing a symbol at the position Y:<form> by its memoized
2602 * variable. If Y:<form> is not of the form '(<form> <form> ...)', the
2603 * evaluation is performed inline without calling an evaluator.
2605 * The following macros should be used in code which is read once
2606 * (where the choice of evaluator is dynamic):
2608 * SCM_I_XEVAL corresponds to EVAL, but uses ceval *or* deval depending on the
2611 * SCM_I_XEVALCAR corresponds to EVALCAR, but uses ceval *or* deval depending
2612 * on the debugging mode.
2614 * The main motivation for keeping this plethora is efficiency
2615 * together with maintainability (=> locality of code).
2618 static SCM
ceval (SCM x
, SCM env
);
2619 static SCM
deval (SCM x
, SCM env
);
2623 #define SCM_I_EVALIM2(x) \
2624 ((scm_is_eq ((x), SCM_EOL) \
2625 ? syntax_error (s_empty_combination, (x), SCM_UNDEFINED), 0 \
2629 #define SCM_I_EVALIM(x, env) (SCM_ILOCP (x) \
2630 ? *scm_ilookup ((x), (env)) \
2633 #define SCM_I_XEVAL(x, env) \
2635 ? SCM_I_EVALIM2 (x) \
2636 : (SCM_VARIABLEP (x) \
2637 ? SCM_VARIABLE_REF (x) \
2638 : (scm_is_pair (x) \
2639 ? (scm_debug_mode_p \
2640 ? deval ((x), (env)) \
2641 : ceval ((x), (env))) \
2644 #define SCM_I_XEVALCAR(x, env) \
2645 (SCM_IMP (SCM_CAR (x)) \
2646 ? SCM_I_EVALIM (SCM_CAR (x), (env)) \
2647 : (SCM_VARIABLEP (SCM_CAR (x)) \
2648 ? SCM_VARIABLE_REF (SCM_CAR (x)) \
2649 : (scm_is_pair (SCM_CAR (x)) \
2650 ? (scm_debug_mode_p \
2651 ? deval (SCM_CAR (x), (env)) \
2652 : ceval (SCM_CAR (x), (env))) \
2653 : (!scm_is_symbol (SCM_CAR (x)) \
2655 : *scm_lookupcar ((x), (env), 1)))))
2657 #define EVAL(x, env) \
2659 ? SCM_I_EVALIM ((x), (env)) \
2660 : (SCM_VARIABLEP (x) \
2661 ? SCM_VARIABLE_REF (x) \
2662 : (scm_is_pair (x) \
2663 ? CEVAL ((x), (env)) \
2666 #define EVALCAR(x, env) \
2667 (SCM_IMP (SCM_CAR (x)) \
2668 ? SCM_I_EVALIM (SCM_CAR (x), (env)) \
2669 : (SCM_VARIABLEP (SCM_CAR (x)) \
2670 ? SCM_VARIABLE_REF (SCM_CAR (x)) \
2671 : (scm_is_pair (SCM_CAR (x)) \
2672 ? CEVAL (SCM_CAR (x), (env)) \
2673 : (!scm_is_symbol (SCM_CAR (x)) \
2675 : *scm_lookupcar ((x), (env), 1)))))
2677 scm_i_pthread_mutex_t source_mutex
;
2680 /* Lookup a given local variable in an environment. The local variable is
2681 * given as an iloc, that is a triple <frame, binding, last?>, where frame
2682 * indicates the relative number of the environment frame (counting upwards
2683 * from the innermost environment frame), binding indicates the number of the
2684 * binding within the frame, and last? (which is extracted from the iloc using
2685 * the macro SCM_ICDRP) indicates whether the binding forms the binding at the
2686 * very end of the improper list of bindings. */
2688 scm_ilookup (SCM iloc
, SCM env
)
2690 unsigned int frame_nr
= SCM_IFRAME (iloc
);
2691 unsigned int binding_nr
= SCM_IDIST (iloc
);
2695 for (; 0 != frame_nr
; --frame_nr
)
2696 frames
= SCM_CDR (frames
);
2698 bindings
= SCM_CAR (frames
);
2699 for (; 0 != binding_nr
; --binding_nr
)
2700 bindings
= SCM_CDR (bindings
);
2702 if (SCM_ICDRP (iloc
))
2703 return SCM_CDRLOC (bindings
);
2704 return SCM_CARLOC (SCM_CDR (bindings
));
2708 SCM_SYMBOL (scm_unbound_variable_key
, "unbound-variable");
2710 static void error_unbound_variable (SCM symbol
) SCM_NORETURN
;
2711 static void error_defined_variable (SCM symbol
) SCM_NORETURN
;
2713 /* Call this for variables that are unfound.
2716 error_unbound_variable (SCM symbol
)
2718 scm_error (scm_unbound_variable_key
, NULL
,
2719 "Unbound variable: ~S",
2720 scm_list_1 (symbol
), SCM_BOOL_F
);
2723 /* Call this for variables that are found but contain SCM_UNDEFINED.
2726 error_defined_variable (SCM symbol
)
2728 /* We use the 'unbound-variable' key here as well, since it
2729 basically is the same kind of error, with a slight variation in
2730 the displayed message.
2732 scm_error (scm_unbound_variable_key
, NULL
,
2733 "Variable used before given a value: ~S",
2734 scm_list_1 (symbol
), SCM_BOOL_F
);
2738 /* The Lookup Car Race
2741 Memoization of variables and special forms is done while executing
2742 the code for the first time. As long as there is only one thread
2743 everything is fine, but as soon as two threads execute the same
2744 code concurrently `for the first time' they can come into conflict.
2746 This memoization includes rewriting variable references into more
2747 efficient forms and expanding macros. Furthermore, macro expansion
2748 includes `compiling' special forms like `let', `cond', etc. into
2749 tree-code instructions.
2751 There shouldn't normally be a problem with memoizing local and
2752 global variable references (into ilocs and variables), because all
2753 threads will mutate the code in *exactly* the same way and (if I
2754 read the C code correctly) it is not possible to observe a half-way
2755 mutated cons cell. The lookup procedure can handle this
2756 transparently without any critical sections.
2758 It is different with macro expansion, because macro expansion
2759 happens outside of the lookup procedure and can't be
2760 undone. Therefore the lookup procedure can't cope with it. It has
2761 to indicate failure when it detects a lost race and hope that the
2762 caller can handle it. Luckily, it turns out that this is the case.
2764 An example to illustrate this: Suppose that the following form will
2765 be memoized concurrently by two threads
2769 Let's first examine the lookup of X in the body. The first thread
2770 decides that it has to find the symbol "x" in the environment and
2771 starts to scan it. Then the other thread takes over and actually
2772 overtakes the first. It looks up "x" and substitutes an
2773 appropriate iloc for it. Now the first thread continues and
2774 completes its lookup. It comes to exactly the same conclusions as
2775 the second one and could - without much ado - just overwrite the
2776 iloc with the same iloc.
2778 But let's see what will happen when the race occurs while looking
2779 up the symbol "let" at the start of the form. It could happen that
2780 the second thread interrupts the lookup of the first thread and not
2781 only substitutes a variable for it but goes right ahead and
2782 replaces it with the compiled form (#@let* (x 12) x). Now, when
2783 the first thread completes its lookup, it would replace the #@let*
2784 with a variable containing the "let" binding, effectively reverting
2785 the form to (let (x 12) x). This is wrong. It has to detect that
2786 it has lost the race and the evaluator has to reconsider the
2787 changed form completely.
2789 This race condition could be resolved with some kind of traffic
2790 light (like mutexes) around scm_lookupcar, but I think that it is
2791 best to avoid them in this case. They would serialize memoization
2792 completely and because lookup involves calling arbitrary Scheme
2793 code (via the lookup-thunk), threads could be blocked for an
2794 arbitrary amount of time or even deadlock. But with the current
2795 solution a lot of unnecessary work is potentially done. */
2797 /* SCM_LOOKUPCAR1 is what SCM_LOOKUPCAR used to be but is allowed to
2798 return NULL to indicate a failed lookup due to some race conditions
2799 between threads. This only happens when VLOC is the first cell of
2800 a special form that will eventually be memoized (like `let', etc.)
2801 In that case the whole lookup is bogus and the caller has to
2802 reconsider the complete special form.
2804 SCM_LOOKUPCAR is still there, of course. It just calls
2805 SCM_LOOKUPCAR1 and aborts on receiving NULL. So SCM_LOOKUPCAR
2806 should only be called when it is known that VLOC is not the first
2807 pair of a special form. Otherwise, use SCM_LOOKUPCAR1 and check
2808 for NULL. I think I've found the only places where this
2812 scm_lookupcar1 (SCM vloc
, SCM genv
, int check
)
2815 register SCM
*al
, fl
, var
= SCM_CAR (vloc
);
2816 register SCM iloc
= SCM_ILOC00
;
2817 for (; SCM_NIMP (env
); env
= SCM_CDR (env
))
2819 if (!scm_is_pair (SCM_CAR (env
)))
2821 al
= SCM_CARLOC (env
);
2822 for (fl
= SCM_CAR (*al
); SCM_NIMP (fl
); fl
= SCM_CDR (fl
))
2824 if (!scm_is_pair (fl
))
2826 if (scm_is_eq (fl
, var
))
2828 if (!scm_is_eq (SCM_CAR (vloc
), var
))
2830 SCM_SET_CELL_WORD_0 (vloc
, SCM_UNPACK (iloc
) + SCM_ICDR
);
2831 return SCM_CDRLOC (*al
);
2836 al
= SCM_CDRLOC (*al
);
2837 if (scm_is_eq (SCM_CAR (fl
), var
))
2839 if (SCM_UNBNDP (SCM_CAR (*al
)))
2840 error_defined_variable (var
);
2841 if (!scm_is_eq (SCM_CAR (vloc
), var
))
2843 SCM_SETCAR (vloc
, iloc
);
2844 return SCM_CARLOC (*al
);
2846 iloc
= SCM_PACK (SCM_UNPACK (iloc
) + SCM_IDINC
);
2848 iloc
= SCM_PACK ((~SCM_IDSTMSK
) & (SCM_UNPACK(iloc
) + SCM_IFRINC
));
2851 SCM top_thunk
, real_var
;
2854 top_thunk
= SCM_CAR (env
); /* env now refers to a
2855 top level env thunk */
2856 env
= SCM_CDR (env
);
2859 top_thunk
= SCM_BOOL_F
;
2860 real_var
= scm_sym2var (var
, top_thunk
, SCM_BOOL_F
);
2861 if (scm_is_false (real_var
))
2864 if (!scm_is_null (env
) || SCM_UNBNDP (SCM_VARIABLE_REF (real_var
)))
2869 if (scm_is_null (env
))
2870 error_unbound_variable (var
);
2872 scm_misc_error (NULL
, "Damaged environment: ~S",
2877 /* A variable could not be found, but we shall
2878 not throw an error. */
2879 static SCM undef_object
= SCM_UNDEFINED
;
2880 return &undef_object
;
2884 if (!scm_is_eq (SCM_CAR (vloc
), var
))
2886 /* Some other thread has changed the very cell we are working
2887 on. In effect, it must have done our job or messed it up
2890 var
= SCM_CAR (vloc
);
2891 if (SCM_VARIABLEP (var
))
2892 return SCM_VARIABLE_LOC (var
);
2893 if (SCM_ILOCP (var
))
2894 return scm_ilookup (var
, genv
);
2895 /* We can't cope with anything else than variables and ilocs. When
2896 a special form has been memoized (i.e. `let' into `#@let') we
2897 return NULL and expect the calling function to do the right
2898 thing. For the evaluator, this means going back and redoing
2899 the dispatch on the car of the form. */
2903 SCM_SETCAR (vloc
, real_var
);
2904 return SCM_VARIABLE_LOC (real_var
);
2909 scm_lookupcar (SCM vloc
, SCM genv
, int check
)
2911 SCM
*loc
= scm_lookupcar1 (vloc
, genv
, check
);
2918 /* During execution, look up a symbol in the top level of the given local
2919 * environment and return the corresponding variable object. If no binding
2920 * for the symbol can be found, an 'Unbound variable' error is signalled. */
2922 lazy_memoize_variable (const SCM symbol
, const SCM environment
)
2924 const SCM top_level
= scm_env_top_level (environment
);
2925 const SCM variable
= scm_sym2var (symbol
, top_level
, SCM_BOOL_F
);
2927 if (scm_is_false (variable
))
2928 error_unbound_variable (symbol
);
2935 scm_eval_car (SCM pair
, SCM env
)
2937 return SCM_I_XEVALCAR (pair
, env
);
2942 scm_eval_args (SCM l
, SCM env
, SCM proc
)
2944 SCM results
= SCM_EOL
, *lloc
= &results
, res
;
2945 while (scm_is_pair (l
))
2947 res
= EVALCAR (l
, env
);
2949 *lloc
= scm_list_1 (res
);
2950 lloc
= SCM_CDRLOC (*lloc
);
2953 if (!scm_is_null (l
))
2954 scm_wrong_num_args (proc
);
2960 scm_eval_body (SCM code
, SCM env
)
2965 next
= SCM_CDR (code
);
2966 while (!scm_is_null (next
))
2968 if (SCM_IMP (SCM_CAR (code
)))
2970 if (SCM_ISYMP (SCM_CAR (code
)))
2972 scm_dynwind_begin (0);
2973 scm_dynwind_pthread_mutex_lock (&source_mutex
);
2974 /* check for race condition */
2975 if (SCM_ISYMP (SCM_CAR (code
)))
2976 m_expand_body (code
, env
);
2982 SCM_I_XEVAL (SCM_CAR (code
), env
);
2984 next
= SCM_CDR (code
);
2986 return SCM_I_XEVALCAR (code
, env
);
2992 /* SECTION: This code is specific for the debugging support. One
2993 * branch is read when DEVAL isn't defined, the other when DEVAL is
2999 #define SCM_APPLY scm_apply
3000 #define PREP_APPLY(proc, args)
3002 #define RETURN(x) do { return x; } while (0)
3003 #ifdef STACK_CHECKING
3004 #ifndef NO_CEVAL_STACK_CHECKING
3005 #define EVAL_STACK_CHECKING
3012 #define CEVAL deval /* Substitute all uses of ceval */
3015 #define SCM_APPLY scm_dapply
3018 #define PREP_APPLY(p, l) \
3019 { ++debug.info; debug.info->a.proc = p; debug.info->a.args = l; }
3022 #define ENTER_APPLY \
3024 SCM_SET_ARGSREADY (debug);\
3025 if (scm_check_apply_p && SCM_TRAPS_P)\
3026 if (SCM_APPLY_FRAME_P || (SCM_TRACE_P && PROCTRACEP (proc)))\
3028 SCM tmp, tail = scm_from_bool(SCM_TRACED_FRAME_P (debug)); \
3029 SCM_SET_TRACED_FRAME (debug); \
3031 tmp = scm_make_debugobj (&debug);\
3032 scm_call_3 (SCM_APPLY_FRAME_HDLR, scm_sym_apply_frame, tmp, tail);\
3038 #define RETURN(e) do { proc = (e); goto exit; } while (0)
3040 #ifdef STACK_CHECKING
3041 #ifndef EVAL_STACK_CHECKING
3042 #define EVAL_STACK_CHECKING
3047 /* scm_last_debug_frame contains a pointer to the last debugging information
3048 * stack frame. It is accessed very often from the debugging evaluator, so it
3049 * should probably not be indirectly addressed. Better to save and restore it
3050 * from the current root at any stack swaps.
3053 /* scm_debug_eframe_size is the number of slots available for pseudo
3054 * stack frames at each real stack frame.
3057 long scm_debug_eframe_size
;
3059 int scm_debug_mode_p
;
3060 int scm_check_entry_p
;
3061 int scm_check_apply_p
;
3062 int scm_check_exit_p
;
3064 long scm_eval_stack
;
3066 scm_t_option scm_eval_opts
[] = {
3067 { SCM_OPTION_INTEGER
, "stack", 22000, "Size of thread stacks (in machine words)." }
3070 scm_t_option scm_debug_opts
[] = {
3071 { SCM_OPTION_BOOLEAN
, "cheap", 1,
3072 "*This option is now obsolete. Setting it has no effect." },
3073 { SCM_OPTION_BOOLEAN
, "breakpoints", 0, "*Check for breakpoints." },
3074 { SCM_OPTION_BOOLEAN
, "trace", 0, "*Trace mode." },
3075 { SCM_OPTION_BOOLEAN
, "procnames", 1,
3076 "Record procedure names at definition." },
3077 { SCM_OPTION_BOOLEAN
, "backwards", 0,
3078 "Display backtrace in anti-chronological order." },
3079 { SCM_OPTION_INTEGER
, "width", 79, "Maximal width of backtrace." },
3080 { SCM_OPTION_INTEGER
, "indent", 10, "Maximal indentation in backtrace." },
3081 { SCM_OPTION_INTEGER
, "frames", 3,
3082 "Maximum number of tail-recursive frames in backtrace." },
3083 { SCM_OPTION_INTEGER
, "maxdepth", 1000,
3084 "Maximal number of stored backtrace frames." },
3085 { SCM_OPTION_INTEGER
, "depth", 20, "Maximal length of printed backtrace." },
3086 { SCM_OPTION_BOOLEAN
, "backtrace", 0, "Show backtrace on error." },
3087 { SCM_OPTION_BOOLEAN
, "debug", 0, "Use the debugging evaluator." },
3088 { SCM_OPTION_INTEGER
, "stack", 20000, "Stack size limit (measured in words; 0 = no check)." },
3089 { SCM_OPTION_SCM
, "show-file-name", (unsigned long)SCM_BOOL_T
, "Show file names and line numbers in backtraces when not `#f'. A value of `base' displays only base names, while `#t' displays full names."},
3090 { SCM_OPTION_BOOLEAN
, "warn-deprecated", 0, "Warn when deprecated features are used." }
3093 scm_t_option scm_evaluator_trap_table
[] = {
3094 { SCM_OPTION_BOOLEAN
, "traps", 0, "Enable evaluator traps." },
3095 { SCM_OPTION_BOOLEAN
, "enter-frame", 0, "Trap when eval enters new frame." },
3096 { SCM_OPTION_BOOLEAN
, "apply-frame", 0, "Trap when entering apply." },
3097 { SCM_OPTION_BOOLEAN
, "exit-frame", 0, "Trap when exiting eval or apply." },
3098 { SCM_OPTION_SCM
, "enter-frame-handler", (unsigned long)SCM_BOOL_F
, "Handler for enter-frame traps." },
3099 { SCM_OPTION_SCM
, "apply-frame-handler", (unsigned long)SCM_BOOL_F
, "Handler for apply-frame traps." },
3100 { SCM_OPTION_SCM
, "exit-frame-handler", (unsigned long)SCM_BOOL_F
, "Handler for exit-frame traps." }
3103 SCM_DEFINE (scm_eval_options_interface
, "eval-options-interface", 0, 1, 0,
3105 "Option interface for the evaluation options. Instead of using\n"
3106 "this procedure directly, use the procedures @code{eval-enable},\n"
3107 "@code{eval-disable}, @code{eval-set!} and @code{eval-options}.")
3108 #define FUNC_NAME s_scm_eval_options_interface
3112 scm_dynwind_begin (0);
3113 scm_dynwind_critical_section (SCM_BOOL_F
);
3114 ans
= scm_options (setting
,
3118 scm_eval_stack
= SCM_EVAL_STACK
* sizeof (void *);
3126 SCM_DEFINE (scm_evaluator_traps
, "evaluator-traps-interface", 0, 1, 0,
3128 "Option interface for the evaluator trap options.")
3129 #define FUNC_NAME s_scm_evaluator_traps
3132 SCM_CRITICAL_SECTION_START
;
3133 ans
= scm_options (setting
,
3134 scm_evaluator_trap_table
,
3135 SCM_N_EVALUATOR_TRAPS
,
3137 /* njrev: same again. */
3138 SCM_RESET_DEBUG_MODE
;
3139 SCM_CRITICAL_SECTION_END
;
3146 deval_args (SCM l
, SCM env
, SCM proc
, SCM
*lloc
)
3148 SCM
*results
= lloc
;
3149 while (scm_is_pair (l
))
3151 const SCM res
= EVALCAR (l
, env
);
3153 *lloc
= scm_list_1 (res
);
3154 lloc
= SCM_CDRLOC (*lloc
);
3157 if (!scm_is_null (l
))
3158 scm_wrong_num_args (proc
);
3163 eval_letrec_inits (SCM env
, SCM init_forms
, SCM
**init_values_eol
)
3166 int i
= 0, imax
= sizeof (argv
) / sizeof (SCM
);
3168 while (!scm_is_null (init_forms
))
3172 eval_letrec_inits (env
, init_forms
, init_values_eol
);
3175 argv
[i
++] = EVALCAR (init_forms
, env
);
3176 init_forms
= SCM_CDR (init_forms
);
3179 for (i
--; i
>= 0; i
--)
3181 **init_values_eol
= scm_list_1 (argv
[i
]);
3182 *init_values_eol
= SCM_CDRLOC (**init_values_eol
);
3189 /* SECTION: This code is compiled twice.
3193 /* Update the toplevel environment frame ENV so that it refers to the
3194 * current module. */
3195 #define UPDATE_TOPLEVEL_ENV(env) \
3197 SCM p = scm_current_module_lookup_closure (); \
3198 if (p != SCM_CAR (env)) \
3199 env = scm_top_level_env (p); \
3203 #define SCM_VALIDATE_NON_EMPTY_COMBINATION(x) \
3204 ASSERT_SYNTAX (!scm_is_eq ((x), SCM_EOL), s_empty_combination, x)
3207 /* This is the evaluator. Like any real monster, it has three heads:
3209 * ceval is the non-debugging evaluator, deval is the debugging version. Both
3210 * are implemented using a common code base, using the following mechanism:
3211 * CEVAL is a macro, which is either defined to ceval or deval. Thus, there
3212 * is no function CEVAL, but the code for CEVAL actually compiles to either
3213 * ceval or deval. When CEVAL is defined to ceval, it is known that the macro
3214 * DEVAL is not defined. When CEVAL is defined to deval, then the macro DEVAL
3215 * is known to be defined. Thus, in CEVAL parts for the debugging evaluator
3216 * are enclosed within #ifdef DEVAL ... #endif.
3218 * All three (ceval, deval and their common implementation CEVAL) take two
3219 * input parameters, x and env: x is a single expression to be evalutated.
3220 * env is the environment in which bindings are searched.
3222 * x is known to be a pair. Since x is a single expression, it is necessarily
3223 * in a tail position. If x is just a call to another function like in the
3224 * expression (foo exp1 exp2 ...), the realization of that call therefore
3225 * _must_not_ increase stack usage (the evaluation of exp1, exp2 etc.,
3226 * however, may do so). This is realized by making extensive use of 'goto'
3227 * statements within the evaluator: The gotos replace recursive calls to
3228 * CEVAL, thus re-using the same stack frame that CEVAL was already using.
3229 * If, however, x represents some form that requires to evaluate a sequence of
3230 * expressions like (begin exp1 exp2 ...), then recursive calls to CEVAL are
3231 * performed for all but the last expression of that sequence. */
3234 CEVAL (SCM x
, SCM env
)
3238 scm_t_debug_frame debug
;
3239 scm_t_debug_info
*debug_info_end
;
3240 debug
.prev
= scm_i_last_debug_frame ();
3243 * The debug.vect contains twice as much scm_t_debug_info frames as the
3244 * user has specified with (debug-set! frames <n>).
3246 * Even frames are eval frames, odd frames are apply frames.
3248 debug
.vect
= (scm_t_debug_info
*) alloca (scm_debug_eframe_size
3249 * sizeof (scm_t_debug_info
));
3250 debug
.info
= debug
.vect
;
3251 debug_info_end
= debug
.vect
+ scm_debug_eframe_size
;
3252 scm_i_set_last_debug_frame (&debug
);
3254 #ifdef EVAL_STACK_CHECKING
3255 if (scm_stack_checking_enabled_p
&& SCM_STACK_OVERFLOW_P (&proc
))
3258 debug
.info
->e
.exp
= x
;
3259 debug
.info
->e
.env
= env
;
3261 scm_report_stack_overflow ();
3271 SCM_CLEAR_ARGSREADY (debug
);
3272 if (SCM_OVERFLOWP (debug
))
3275 * In theory, this should be the only place where it is necessary to
3276 * check for space in debug.vect since both eval frames and
3277 * available space are even.
3279 * For this to be the case, however, it is necessary that primitive
3280 * special forms which jump back to `loop', `begin' or some similar
3281 * label call PREP_APPLY.
3283 else if (++debug
.info
>= debug_info_end
)
3285 SCM_SET_OVERFLOW (debug
);
3290 debug
.info
->e
.exp
= x
;
3291 debug
.info
->e
.env
= env
;
3292 if (scm_check_entry_p
&& SCM_TRAPS_P
)
3294 if (SCM_ENTER_FRAME_P
3295 || (SCM_BREAKPOINTS_P
&& scm_c_source_property_breakpoint_p (x
)))
3298 SCM tail
= scm_from_bool (SCM_TAILRECP (debug
));
3299 SCM_SET_TAILREC (debug
);
3300 stackrep
= scm_make_debugobj (&debug
);
3302 stackrep
= scm_call_4 (SCM_ENTER_FRAME_HDLR
,
3303 scm_sym_enter_frame
,
3306 unmemoize_expression (x
, env
));
3308 if (scm_is_pair (stackrep
) &&
3309 scm_is_eq (SCM_CAR (stackrep
), sym_instead
))
3311 /* This gives the possibility for the debugger to modify
3312 the source expression before evaluation. */
3313 x
= SCM_CDR (stackrep
);
3322 if (SCM_ISYMP (SCM_CAR (x
)))
3324 switch (ISYMNUM (SCM_CAR (x
)))
3326 case (ISYMNUM (SCM_IM_AND
)):
3328 while (!scm_is_null (SCM_CDR (x
)))
3330 SCM test_result
= EVALCAR (x
, env
);
3331 if (scm_is_false (test_result
) || SCM_NILP (test_result
))
3332 RETURN (SCM_BOOL_F
);
3336 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3339 case (ISYMNUM (SCM_IM_BEGIN
)):
3341 if (scm_is_null (x
))
3342 RETURN (SCM_UNSPECIFIED
);
3344 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3347 /* If we are on toplevel with a lookup closure, we need to sync
3348 with the current module. */
3349 if (scm_is_pair (env
) && !scm_is_pair (SCM_CAR (env
)))
3351 UPDATE_TOPLEVEL_ENV (env
);
3352 while (!scm_is_null (SCM_CDR (x
)))
3355 UPDATE_TOPLEVEL_ENV (env
);
3361 goto nontoplevel_begin
;
3364 while (!scm_is_null (SCM_CDR (x
)))
3366 const SCM form
= SCM_CAR (x
);
3369 if (SCM_ISYMP (form
))
3371 scm_dynwind_begin (0);
3372 scm_dynwind_pthread_mutex_lock (&source_mutex
);
3373 /* check for race condition */
3374 if (SCM_ISYMP (SCM_CAR (x
)))
3375 m_expand_body (x
, env
);
3377 goto nontoplevel_begin
;
3380 SCM_VALIDATE_NON_EMPTY_COMBINATION (form
);
3383 (void) EVAL (form
, env
);
3389 /* scm_eval last form in list */
3390 const SCM last_form
= SCM_CAR (x
);
3392 if (scm_is_pair (last_form
))
3394 /* This is by far the most frequent case. */
3396 goto loop
; /* tail recurse */
3398 else if (SCM_IMP (last_form
))
3399 RETURN (SCM_I_EVALIM (last_form
, env
));
3400 else if (SCM_VARIABLEP (last_form
))
3401 RETURN (SCM_VARIABLE_REF (last_form
));
3402 else if (scm_is_symbol (last_form
))
3403 RETURN (*scm_lookupcar (x
, env
, 1));
3409 case (ISYMNUM (SCM_IM_CASE
)):
3412 const SCM key
= EVALCAR (x
, env
);
3414 while (!scm_is_null (x
))
3416 const SCM clause
= SCM_CAR (x
);
3417 SCM labels
= SCM_CAR (clause
);
3418 if (scm_is_eq (labels
, SCM_IM_ELSE
))
3420 x
= SCM_CDR (clause
);
3421 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3424 while (!scm_is_null (labels
))
3426 const SCM label
= SCM_CAR (labels
);
3427 if (scm_is_eq (label
, key
)
3428 || scm_is_true (scm_eqv_p (label
, key
)))
3430 x
= SCM_CDR (clause
);
3431 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3434 labels
= SCM_CDR (labels
);
3439 RETURN (SCM_UNSPECIFIED
);
3442 case (ISYMNUM (SCM_IM_COND
)):
3444 while (!scm_is_null (x
))
3446 const SCM clause
= SCM_CAR (x
);
3447 if (scm_is_eq (SCM_CAR (clause
), SCM_IM_ELSE
))
3449 x
= SCM_CDR (clause
);
3450 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3455 arg1
= EVALCAR (clause
, env
);
3456 /* SRFI 61 extended cond */
3457 if (!scm_is_null (SCM_CDR (clause
))
3458 && !scm_is_null (SCM_CDDR (clause
))
3459 && scm_is_eq (SCM_CADDR (clause
), SCM_IM_ARROW
))
3461 SCM xx
, guard_result
;
3462 if (SCM_VALUESP (arg1
))
3463 arg1
= scm_struct_ref (arg1
, SCM_INUM0
);
3465 arg1
= scm_list_1 (arg1
);
3466 xx
= SCM_CDR (clause
);
3467 proc
= EVALCAR (xx
, env
);
3468 guard_result
= SCM_APPLY (proc
, arg1
, SCM_EOL
);
3469 if (scm_is_true (guard_result
)
3470 && !SCM_NILP (guard_result
))
3472 proc
= SCM_CDDR (xx
);
3473 proc
= EVALCAR (proc
, env
);
3474 PREP_APPLY (proc
, arg1
);
3478 else if (scm_is_true (arg1
) && !SCM_NILP (arg1
))
3480 x
= SCM_CDR (clause
);
3481 if (scm_is_null (x
))
3483 else if (!scm_is_eq (SCM_CAR (x
), SCM_IM_ARROW
))
3485 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3491 proc
= EVALCAR (proc
, env
);
3492 PREP_APPLY (proc
, scm_list_1 (arg1
));
3500 RETURN (SCM_UNSPECIFIED
);
3503 case (ISYMNUM (SCM_IM_DO
)):
3506 /* Compute the initialization values and the initial environment. */
3507 SCM init_forms
= SCM_CAR (x
);
3508 SCM init_values
= SCM_EOL
;
3509 while (!scm_is_null (init_forms
))
3511 init_values
= scm_cons (EVALCAR (init_forms
, env
), init_values
);
3512 init_forms
= SCM_CDR (init_forms
);
3515 env
= SCM_EXTEND_ENV (SCM_CAR (x
), init_values
, env
);
3519 SCM test_form
= SCM_CAR (x
);
3520 SCM body_forms
= SCM_CADR (x
);
3521 SCM step_forms
= SCM_CDDR (x
);
3523 SCM test_result
= EVALCAR (test_form
, env
);
3525 while (scm_is_false (test_result
) || SCM_NILP (test_result
))
3528 /* Evaluate body forms. */
3530 for (temp_forms
= body_forms
;
3531 !scm_is_null (temp_forms
);
3532 temp_forms
= SCM_CDR (temp_forms
))
3534 SCM form
= SCM_CAR (temp_forms
);
3535 /* Dirk:FIXME: We only need to eval forms that may have
3536 * a side effect here. This is only true for forms that
3537 * start with a pair. All others are just constants.
3538 * Since with the current memoizer 'form' may hold a
3539 * constant, we call EVAL here to handle the constant
3540 * cases. In the long run it would make sense to have
3541 * the macro transformer of 'do' eliminate all forms
3542 * that have no sideeffect. Then instead of EVAL we
3543 * could call CEVAL directly here. */
3544 (void) EVAL (form
, env
);
3549 /* Evaluate the step expressions. */
3551 SCM step_values
= SCM_EOL
;
3552 for (temp_forms
= step_forms
;
3553 !scm_is_null (temp_forms
);
3554 temp_forms
= SCM_CDR (temp_forms
))
3556 const SCM value
= EVALCAR (temp_forms
, env
);
3557 step_values
= scm_cons (value
, step_values
);
3559 env
= SCM_EXTEND_ENV (SCM_CAAR (env
),
3564 test_result
= EVALCAR (test_form
, env
);
3568 if (scm_is_null (x
))
3569 RETURN (SCM_UNSPECIFIED
);
3570 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3571 goto nontoplevel_begin
;
3574 case (ISYMNUM (SCM_IM_IF
)):
3577 SCM test_result
= EVALCAR (x
, env
);
3578 x
= SCM_CDR (x
); /* then expression */
3579 if (scm_is_false (test_result
) || SCM_NILP (test_result
))
3581 x
= SCM_CDR (x
); /* else expression */
3582 if (scm_is_null (x
))
3583 RETURN (SCM_UNSPECIFIED
);
3586 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3590 case (ISYMNUM (SCM_IM_LET
)):
3593 SCM init_forms
= SCM_CADR (x
);
3594 SCM init_values
= SCM_EOL
;
3597 init_values
= scm_cons (EVALCAR (init_forms
, env
), init_values
);
3598 init_forms
= SCM_CDR (init_forms
);
3600 while (!scm_is_null (init_forms
));
3601 env
= SCM_EXTEND_ENV (SCM_CAR (x
), init_values
, env
);
3604 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3605 goto nontoplevel_begin
;
3608 case (ISYMNUM (SCM_IM_LETREC
)):
3610 env
= SCM_EXTEND_ENV (SCM_CAR (x
), undefineds
, env
);
3613 SCM init_forms
= SCM_CAR (x
);
3614 SCM init_values
= scm_list_1 (SCM_BOOL_T
);
3615 SCM
*init_values_eol
= SCM_CDRLOC (init_values
);
3616 eval_letrec_inits (env
, init_forms
, &init_values_eol
);
3617 SCM_SETCDR (SCM_CAR (env
), SCM_CDR (init_values
));
3620 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3621 goto nontoplevel_begin
;
3624 case (ISYMNUM (SCM_IM_LETSTAR
)):
3627 SCM bindings
= SCM_CAR (x
);
3628 if (!scm_is_null (bindings
))
3632 SCM name
= SCM_CAR (bindings
);
3633 SCM init
= SCM_CDR (bindings
);
3634 env
= SCM_EXTEND_ENV (name
, EVALCAR (init
, env
), env
);
3635 bindings
= SCM_CDR (init
);
3637 while (!scm_is_null (bindings
));
3641 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3642 goto nontoplevel_begin
;
3645 case (ISYMNUM (SCM_IM_OR
)):
3647 while (!scm_is_null (SCM_CDR (x
)))
3649 SCM val
= EVALCAR (x
, env
);
3650 if (scm_is_true (val
) && !SCM_NILP (val
))
3655 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3659 case (ISYMNUM (SCM_IM_LAMBDA
)):
3660 RETURN (scm_closure (SCM_CDR (x
), env
));
3663 case (ISYMNUM (SCM_IM_QUOTE
)):
3664 RETURN (SCM_CDR (x
));
3667 case (ISYMNUM (SCM_IM_SET_X
)):
3671 SCM variable
= SCM_CAR (x
);
3672 if (SCM_ILOCP (variable
))
3673 location
= scm_ilookup (variable
, env
);
3674 else if (SCM_VARIABLEP (variable
))
3675 location
= SCM_VARIABLE_LOC (variable
);
3678 /* (scm_is_symbol (variable)) is known to be true */
3679 variable
= lazy_memoize_variable (variable
, env
);
3680 SCM_SETCAR (x
, variable
);
3681 location
= SCM_VARIABLE_LOC (variable
);
3684 *location
= EVALCAR (x
, env
);
3686 RETURN (SCM_UNSPECIFIED
);
3689 case (ISYMNUM (SCM_IM_APPLY
)):
3690 /* Evaluate the procedure to be applied. */
3692 proc
= EVALCAR (x
, env
);
3693 PREP_APPLY (proc
, SCM_EOL
);
3695 /* Evaluate the argument holding the list of arguments */
3697 arg1
= EVALCAR (x
, env
);
3700 /* Go here to tail-apply a procedure. PROC is the procedure and
3701 * ARG1 is the list of arguments. PREP_APPLY must have been called
3702 * before jumping to apply_proc. */
3703 if (SCM_CLOSUREP (proc
))
3705 SCM formals
= SCM_CLOSURE_FORMALS (proc
);
3707 debug
.info
->a
.args
= arg1
;
3709 if (scm_badargsp (formals
, arg1
))
3710 scm_wrong_num_args (proc
);
3712 /* Copy argument list */
3713 if (SCM_NULL_OR_NIL_P (arg1
))
3714 env
= SCM_EXTEND_ENV (formals
, SCM_EOL
, SCM_ENV (proc
));
3717 SCM args
= scm_list_1 (SCM_CAR (arg1
));
3719 arg1
= SCM_CDR (arg1
);
3720 while (!SCM_NULL_OR_NIL_P (arg1
))
3722 SCM new_tail
= scm_list_1 (SCM_CAR (arg1
));
3723 SCM_SETCDR (tail
, new_tail
);
3725 arg1
= SCM_CDR (arg1
);
3727 env
= SCM_EXTEND_ENV (formals
, args
, SCM_ENV (proc
));
3730 x
= SCM_CLOSURE_BODY (proc
);
3731 goto nontoplevel_begin
;
3736 RETURN (SCM_APPLY (proc
, arg1
, SCM_EOL
));
3740 case (ISYMNUM (SCM_IM_CONT
)):
3743 SCM val
= scm_make_continuation (&first
);
3751 proc
= EVALCAR (proc
, env
);
3752 PREP_APPLY (proc
, scm_list_1 (arg1
));
3759 case (ISYMNUM (SCM_IM_DELAY
)):
3760 RETURN (scm_makprom (scm_closure (SCM_CDR (x
), env
)));
3763 /* See futures.h for a comment why futures are not enabled.
3765 case (ISYMNUM (SCM_IM_FUTURE
)):
3766 RETURN (scm_i_make_future (scm_closure (SCM_CDR (x
), env
)));
3769 /* PLACEHOLDER for case (ISYMNUM (SCM_IM_DISPATCH)): The following
3770 code (type_dispatch) is intended to be the tail of the case
3771 clause for the internal macro SCM_IM_DISPATCH. Please don't
3772 remove it from this location without discussing it with Mikael
3773 <djurfeldt@nada.kth.se> */
3775 /* The type dispatch code is duplicated below
3776 * (c.f. objects.c:scm_mcache_compute_cmethod) since that
3777 * cuts down execution time for type dispatch to 50%. */
3778 type_dispatch
: /* inputs: x, arg1 */
3779 /* Type dispatch means to determine from the types of the function
3780 * arguments (i. e. the 'signature' of the call), which method from
3781 * a generic function is to be called. This process of selecting
3782 * the right method takes some time. To speed it up, guile uses
3783 * caching: Together with the macro call to dispatch the signatures
3784 * of some previous calls to that generic function from the same
3785 * place are stored (in the code!) in a cache that we call the
3786 * 'method cache'. This is done since it is likely, that
3787 * consecutive calls to dispatch from that position in the code will
3788 * have the same signature. Thus, the type dispatch works as
3789 * follows: First, determine a hash value from the signature of the
3790 * actual arguments. Second, use this hash value as an index to
3791 * find that same signature in the method cache stored at this
3792 * position in the code. If found, you have also found the
3793 * corresponding method that belongs to that signature. If the
3794 * signature is not found in the method cache, you have to perform a
3795 * full search over all signatures stored with the generic
3798 unsigned long int specializers
;
3799 unsigned long int hash_value
;
3800 unsigned long int cache_end_pos
;
3801 unsigned long int mask
;
3805 SCM z
= SCM_CDDR (x
);
3806 SCM tmp
= SCM_CADR (z
);
3807 specializers
= scm_to_ulong (SCM_CAR (z
));
3809 /* Compute a hash value for searching the method cache. There
3810 * are two variants for computing the hash value, a (rather)
3811 * complicated one, and a simple one. For the complicated one
3812 * explained below, tmp holds a number that is used in the
3814 if (scm_is_simple_vector (tmp
))
3816 /* This method of determining the hash value is much
3817 * simpler: Set the hash value to zero and just perform a
3818 * linear search through the method cache. */
3820 mask
= (unsigned long int) ((long) -1);
3822 cache_end_pos
= SCM_SIMPLE_VECTOR_LENGTH (method_cache
);
3826 /* Use the signature of the actual arguments to determine
3827 * the hash value. This is done as follows: Each class has
3828 * an array of random numbers, that are determined when the
3829 * class is created. The integer 'hashset' is an index into
3830 * that array of random numbers. Now, from all classes that
3831 * are part of the signature of the actual arguments, the
3832 * random numbers at index 'hashset' are taken and summed
3833 * up, giving the hash value. The value of 'hashset' is
3834 * stored at the call to dispatch. This allows to have
3835 * different 'formulas' for calculating the hash value at
3836 * different places where dispatch is called. This allows
3837 * to optimize the hash formula at every individual place
3838 * where dispatch is called, such that hopefully the hash
3839 * value that is computed will directly point to the right
3840 * method in the method cache. */
3841 unsigned long int hashset
= scm_to_ulong (tmp
);
3842 unsigned long int counter
= specializers
+ 1;
3845 while (!scm_is_null (tmp_arg
) && counter
!= 0)
3847 SCM
class = scm_class_of (SCM_CAR (tmp_arg
));
3848 hash_value
+= SCM_INSTANCE_HASH (class, hashset
);
3849 tmp_arg
= SCM_CDR (tmp_arg
);
3853 method_cache
= SCM_CADR (z
);
3854 mask
= scm_to_ulong (SCM_CAR (z
));
3856 cache_end_pos
= hash_value
;
3861 /* Search the method cache for a method with a matching
3862 * signature. Start the search at position 'hash_value'. The
3863 * hashing implementation uses linear probing for conflict
3864 * resolution, that is, if the signature in question is not
3865 * found at the starting index in the hash table, the next table
3866 * entry is tried, and so on, until in the worst case the whole
3867 * cache has been searched, but still the signature has not been
3872 SCM args
= arg1
; /* list of arguments */
3873 z
= SCM_SIMPLE_VECTOR_REF (method_cache
, hash_value
);
3874 while (!scm_is_null (args
))
3876 /* More arguments than specifiers => CLASS != ENV */
3877 SCM class_of_arg
= scm_class_of (SCM_CAR (args
));
3878 if (!scm_is_eq (class_of_arg
, SCM_CAR (z
)))
3880 args
= SCM_CDR (args
);
3883 /* Fewer arguments than specifiers => CAR != ENV */
3884 if (scm_is_null (SCM_CAR (z
)) || scm_is_pair (SCM_CAR (z
)))
3887 hash_value
= (hash_value
+ 1) & mask
;
3888 } while (hash_value
!= cache_end_pos
);
3890 /* No appropriate method was found in the cache. */
3891 z
= scm_memoize_method (x
, arg1
);
3893 apply_cmethod
: /* inputs: z, arg1 */
3895 SCM formals
= SCM_CMETHOD_FORMALS (z
);
3896 env
= SCM_EXTEND_ENV (formals
, arg1
, SCM_CMETHOD_ENV (z
));
3897 x
= SCM_CMETHOD_BODY (z
);
3898 goto nontoplevel_begin
;
3904 case (ISYMNUM (SCM_IM_SLOT_REF
)):
3907 SCM instance
= EVALCAR (x
, env
);
3908 unsigned long int slot
= SCM_I_INUM (SCM_CDR (x
));
3909 RETURN (SCM_PACK (SCM_STRUCT_DATA (instance
) [slot
]));
3913 case (ISYMNUM (SCM_IM_SLOT_SET_X
)):
3916 SCM instance
= EVALCAR (x
, env
);
3917 unsigned long int slot
= SCM_I_INUM (SCM_CADR (x
));
3918 SCM value
= EVALCAR (SCM_CDDR (x
), env
);
3919 SCM_STRUCT_DATA (instance
) [slot
] = SCM_UNPACK (value
);
3920 RETURN (SCM_UNSPECIFIED
);
3924 #if SCM_ENABLE_ELISP
3926 case (ISYMNUM (SCM_IM_NIL_COND
)):
3928 SCM test_form
= SCM_CDR (x
);
3929 x
= SCM_CDR (test_form
);
3930 while (!SCM_NULL_OR_NIL_P (x
))
3932 SCM test_result
= EVALCAR (test_form
, env
);
3933 if (!(scm_is_false (test_result
)
3934 || SCM_NULL_OR_NIL_P (test_result
)))
3936 if (scm_is_eq (SCM_CAR (x
), SCM_UNSPECIFIED
))
3937 RETURN (test_result
);
3938 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3943 test_form
= SCM_CDR (x
);
3944 x
= SCM_CDR (test_form
);
3948 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3952 #endif /* SCM_ENABLE_ELISP */
3954 case (ISYMNUM (SCM_IM_BIND
)):
3956 SCM vars
, exps
, vals
;
3959 vars
= SCM_CAAR (x
);
3960 exps
= SCM_CDAR (x
);
3962 while (!scm_is_null (exps
))
3964 vals
= scm_cons (EVALCAR (exps
, env
), vals
);
3965 exps
= SCM_CDR (exps
);
3968 scm_swap_bindings (vars
, vals
);
3969 scm_i_set_dynwinds (scm_acons (vars
, vals
, scm_i_dynwinds ()));
3971 /* Ignore all but the last evaluation result. */
3972 for (x
= SCM_CDR (x
); !scm_is_null (SCM_CDR (x
)); x
= SCM_CDR (x
))
3974 if (scm_is_pair (SCM_CAR (x
)))
3975 CEVAL (SCM_CAR (x
), env
);
3977 proc
= EVALCAR (x
, env
);
3979 scm_i_set_dynwinds (SCM_CDR (scm_i_dynwinds ()));
3980 scm_swap_bindings (vars
, vals
);
3986 case (ISYMNUM (SCM_IM_CALL_WITH_VALUES
)):
3991 producer
= EVALCAR (x
, env
);
3993 proc
= EVALCAR (x
, env
); /* proc is the consumer. */
3994 arg1
= SCM_APPLY (producer
, SCM_EOL
, SCM_EOL
);
3995 if (SCM_VALUESP (arg1
))
3997 /* The list of arguments is not copied. Rather, it is assumed
3998 * that this has been done by the 'values' procedure. */
3999 arg1
= scm_struct_ref (arg1
, SCM_INUM0
);
4003 arg1
= scm_list_1 (arg1
);
4005 PREP_APPLY (proc
, arg1
);
4016 if (SCM_VARIABLEP (SCM_CAR (x
)))
4017 proc
= SCM_VARIABLE_REF (SCM_CAR (x
));
4018 else if (SCM_ILOCP (SCM_CAR (x
)))
4019 proc
= *scm_ilookup (SCM_CAR (x
), env
);
4020 else if (scm_is_pair (SCM_CAR (x
)))
4021 proc
= CEVAL (SCM_CAR (x
), env
);
4022 else if (scm_is_symbol (SCM_CAR (x
)))
4024 SCM orig_sym
= SCM_CAR (x
);
4026 SCM
*location
= scm_lookupcar1 (x
, env
, 1);
4027 if (location
== NULL
)
4029 /* we have lost the race, start again. */
4035 if (SCM_MACROP (proc
))
4037 SCM_SETCAR (x
, orig_sym
); /* Undo memoizing effect of
4039 handle_a_macro
: /* inputs: x, env, proc */
4041 /* Set a flag during macro expansion so that macro
4042 application frames can be deleted from the backtrace. */
4043 SCM_SET_MACROEXP (debug
);
4045 arg1
= SCM_APPLY (SCM_MACRO_CODE (proc
), x
,
4046 scm_cons (env
, scm_listofnull
));
4048 SCM_CLEAR_MACROEXP (debug
);
4050 switch (SCM_MACRO_TYPE (proc
))
4054 if (!scm_is_pair (arg1
))
4055 arg1
= scm_list_2 (SCM_IM_BEGIN
, arg1
);
4057 assert (!scm_is_eq (x
, SCM_CAR (arg1
))
4058 && !scm_is_eq (x
, SCM_CDR (arg1
)));
4061 if (!SCM_CLOSUREP (SCM_MACRO_CODE (proc
)))
4063 SCM_CRITICAL_SECTION_START
;
4064 SCM_SETCAR (x
, SCM_CAR (arg1
));
4065 SCM_SETCDR (x
, SCM_CDR (arg1
));
4066 SCM_CRITICAL_SECTION_END
;
4069 /* Prevent memoizing of debug info expression. */
4070 debug
.info
->e
.exp
= scm_cons_source (debug
.info
->e
.exp
,
4074 SCM_CRITICAL_SECTION_START
;
4075 SCM_SETCAR (x
, SCM_CAR (arg1
));
4076 SCM_SETCDR (x
, SCM_CDR (arg1
));
4077 SCM_CRITICAL_SECTION_END
;
4078 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
4080 #if SCM_ENABLE_DEPRECATED == 1
4085 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
4099 if (SCM_MACROP (proc
))
4100 goto handle_a_macro
;
4104 /* When reaching this part of the code, the following is granted: Variable x
4105 * holds the first pair of an expression of the form (<function> arg ...).
4106 * Variable proc holds the object that resulted from the evaluation of
4107 * <function>. In the following, the arguments (if any) will be evaluated,
4108 * and proc will be applied to them. If proc does not really hold a
4109 * function object, this will be signalled as an error on the scheme
4110 * level. If the number of arguments does not match the number of arguments
4111 * that are allowed to be passed to proc, also an error on the scheme level
4112 * will be signalled. */
4113 PREP_APPLY (proc
, SCM_EOL
);
4114 if (scm_is_null (SCM_CDR (x
))) {
4117 SCM_ASRTGO (!SCM_IMP (proc
), badfun
);
4118 switch (SCM_TYP7 (proc
))
4119 { /* no arguments given */
4120 case scm_tc7_subr_0
:
4121 RETURN (SCM_SUBRF (proc
) ());
4122 case scm_tc7_subr_1o
:
4123 RETURN (SCM_SUBRF (proc
) (SCM_UNDEFINED
));
4125 RETURN (SCM_SUBRF (proc
) (SCM_EOL
));
4126 case scm_tc7_rpsubr
:
4127 RETURN (SCM_BOOL_T
);
4129 RETURN (SCM_SUBRF (proc
) (SCM_UNDEFINED
, SCM_UNDEFINED
));
4131 if (!SCM_SMOB_APPLICABLE_P (proc
))
4133 RETURN (SCM_SMOB_APPLY_0 (proc
));
4136 proc
= SCM_CCLO_SUBR (proc
);
4138 debug
.info
->a
.proc
= proc
;
4139 debug
.info
->a
.args
= scm_list_1 (arg1
);
4143 proc
= SCM_PROCEDURE (proc
);
4145 debug
.info
->a
.proc
= proc
;
4147 if (!SCM_CLOSUREP (proc
))
4150 case scm_tcs_closures
:
4152 const SCM formals
= SCM_CLOSURE_FORMALS (proc
);
4153 if (scm_is_pair (formals
))
4155 x
= SCM_CLOSURE_BODY (proc
);
4156 env
= SCM_EXTEND_ENV (formals
, SCM_EOL
, SCM_ENV (proc
));
4157 goto nontoplevel_begin
;
4159 case scm_tcs_struct
:
4160 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
4162 x
= SCM_ENTITY_PROCEDURE (proc
);
4166 else if (SCM_I_OPERATORP (proc
))
4169 proc
= (SCM_I_ENTITYP (proc
)
4170 ? SCM_ENTITY_PROCEDURE (proc
)
4171 : SCM_OPERATOR_PROCEDURE (proc
));
4173 debug
.info
->a
.proc
= proc
;
4174 debug
.info
->a
.args
= scm_list_1 (arg1
);
4180 case scm_tc7_subr_1
:
4181 case scm_tc7_subr_2
:
4182 case scm_tc7_subr_2o
:
4185 case scm_tc7_subr_3
:
4186 case scm_tc7_lsubr_2
:
4188 scm_wrong_num_args (proc
);
4191 scm_misc_error (NULL
, "Wrong type to apply: ~S", scm_list_1 (proc
));
4195 /* must handle macros by here */
4197 if (scm_is_pair (x
))
4198 arg1
= EVALCAR (x
, env
);
4200 scm_wrong_num_args (proc
);
4202 debug
.info
->a
.args
= scm_list_1 (arg1
);
4207 if (scm_is_null (x
))
4210 evap1
: /* inputs: proc, arg1 */
4211 SCM_ASRTGO (!SCM_IMP (proc
), badfun
);
4212 switch (SCM_TYP7 (proc
))
4213 { /* have one argument in arg1 */
4214 case scm_tc7_subr_2o
:
4215 RETURN (SCM_SUBRF (proc
) (arg1
, SCM_UNDEFINED
));
4216 case scm_tc7_subr_1
:
4217 case scm_tc7_subr_1o
:
4218 RETURN (SCM_SUBRF (proc
) (arg1
));
4220 if (SCM_I_INUMP (arg1
))
4222 RETURN (scm_from_double (SCM_DSUBRF (proc
) ((double) SCM_I_INUM (arg1
))));
4224 else if (SCM_REALP (arg1
))
4226 RETURN (scm_from_double (SCM_DSUBRF (proc
) (SCM_REAL_VALUE (arg1
))));
4228 else if (SCM_BIGP (arg1
))
4230 RETURN (scm_from_double (SCM_DSUBRF (proc
) (scm_i_big2dbl (arg1
))));
4232 else if (SCM_FRACTIONP (arg1
))
4234 RETURN (scm_from_double (SCM_DSUBRF (proc
) (scm_i_fraction2double (arg1
))));
4236 SCM_WTA_DISPATCH_1 (*SCM_SUBR_GENERIC (proc
), arg1
,
4238 scm_i_symbol_chars (SCM_SNAME (proc
)));
4240 RETURN (scm_i_chase_pairs (arg1
, (scm_t_bits
) SCM_SUBRF (proc
)));
4241 case scm_tc7_rpsubr
:
4242 RETURN (SCM_BOOL_T
);
4244 RETURN (SCM_SUBRF (proc
) (arg1
, SCM_UNDEFINED
));
4247 RETURN (SCM_SUBRF (proc
) (debug
.info
->a
.args
));
4249 RETURN (SCM_SUBRF (proc
) (scm_list_1 (arg1
)));
4252 if (!SCM_SMOB_APPLICABLE_P (proc
))
4254 RETURN (SCM_SMOB_APPLY_1 (proc
, arg1
));
4258 proc
= SCM_CCLO_SUBR (proc
);
4260 debug
.info
->a
.args
= scm_cons (arg1
, debug
.info
->a
.args
);
4261 debug
.info
->a
.proc
= proc
;
4265 proc
= SCM_PROCEDURE (proc
);
4267 debug
.info
->a
.proc
= proc
;
4269 if (!SCM_CLOSUREP (proc
))
4272 case scm_tcs_closures
:
4275 const SCM formals
= SCM_CLOSURE_FORMALS (proc
);
4276 if (scm_is_null (formals
)
4277 || (scm_is_pair (formals
) && scm_is_pair (SCM_CDR (formals
))))
4279 x
= SCM_CLOSURE_BODY (proc
);
4281 env
= SCM_EXTEND_ENV (formals
,
4285 env
= SCM_EXTEND_ENV (formals
,
4289 goto nontoplevel_begin
;
4291 case scm_tcs_struct
:
4292 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
4294 x
= SCM_ENTITY_PROCEDURE (proc
);
4296 arg1
= debug
.info
->a
.args
;
4298 arg1
= scm_list_1 (arg1
);
4302 else if (SCM_I_OPERATORP (proc
))
4306 proc
= (SCM_I_ENTITYP (proc
)
4307 ? SCM_ENTITY_PROCEDURE (proc
)
4308 : SCM_OPERATOR_PROCEDURE (proc
));
4310 debug
.info
->a
.args
= scm_cons (arg1
, debug
.info
->a
.args
);
4311 debug
.info
->a
.proc
= proc
;
4317 case scm_tc7_subr_2
:
4318 case scm_tc7_subr_0
:
4319 case scm_tc7_subr_3
:
4320 case scm_tc7_lsubr_2
:
4321 scm_wrong_num_args (proc
);
4326 if (scm_is_pair (x
))
4327 arg2
= EVALCAR (x
, env
);
4329 scm_wrong_num_args (proc
);
4331 { /* have two or more arguments */
4333 debug
.info
->a
.args
= scm_list_2 (arg1
, arg2
);
4336 if (scm_is_null (x
)) {
4339 SCM_ASRTGO (!SCM_IMP (proc
), badfun
);
4340 switch (SCM_TYP7 (proc
))
4341 { /* have two arguments */
4342 case scm_tc7_subr_2
:
4343 case scm_tc7_subr_2o
:
4344 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
));
4347 RETURN (SCM_SUBRF (proc
) (debug
.info
->a
.args
));
4349 RETURN (SCM_SUBRF (proc
) (scm_list_2 (arg1
, arg2
)));
4351 case scm_tc7_lsubr_2
:
4352 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
, SCM_EOL
));
4353 case scm_tc7_rpsubr
:
4355 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
));
4357 if (!SCM_SMOB_APPLICABLE_P (proc
))
4359 RETURN (SCM_SMOB_APPLY_2 (proc
, arg1
, arg2
));
4363 RETURN (SCM_APPLY (SCM_CCLO_SUBR (proc
),
4364 scm_cons (proc
, debug
.info
->a
.args
),
4367 RETURN (SCM_APPLY (SCM_CCLO_SUBR (proc
),
4368 scm_cons2 (proc
, arg1
,
4375 case scm_tcs_struct
:
4376 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
4378 x
= SCM_ENTITY_PROCEDURE (proc
);
4380 arg1
= debug
.info
->a
.args
;
4382 arg1
= scm_list_2 (arg1
, arg2
);
4386 else if (SCM_I_OPERATORP (proc
))
4390 RETURN (SCM_APPLY (SCM_I_ENTITYP (proc
)
4391 ? SCM_ENTITY_PROCEDURE (proc
)
4392 : SCM_OPERATOR_PROCEDURE (proc
),
4393 scm_cons (proc
, debug
.info
->a
.args
),
4396 RETURN (SCM_APPLY (SCM_I_ENTITYP (proc
)
4397 ? SCM_ENTITY_PROCEDURE (proc
)
4398 : SCM_OPERATOR_PROCEDURE (proc
),
4399 scm_cons2 (proc
, arg1
,
4409 case scm_tc7_subr_0
:
4412 case scm_tc7_subr_1o
:
4413 case scm_tc7_subr_1
:
4414 case scm_tc7_subr_3
:
4415 scm_wrong_num_args (proc
);
4419 proc
= SCM_PROCEDURE (proc
);
4421 debug
.info
->a
.proc
= proc
;
4423 if (!SCM_CLOSUREP (proc
))
4426 case scm_tcs_closures
:
4429 const SCM formals
= SCM_CLOSURE_FORMALS (proc
);
4430 if (scm_is_null (formals
)
4431 || (scm_is_pair (formals
)
4432 && (scm_is_null (SCM_CDR (formals
))
4433 || (scm_is_pair (SCM_CDR (formals
))
4434 && scm_is_pair (SCM_CDDR (formals
))))))
4437 env
= SCM_EXTEND_ENV (formals
,
4441 env
= SCM_EXTEND_ENV (formals
,
4442 scm_list_2 (arg1
, arg2
),
4445 x
= SCM_CLOSURE_BODY (proc
);
4446 goto nontoplevel_begin
;
4450 if (!scm_is_pair (x
))
4451 scm_wrong_num_args (proc
);
4453 debug
.info
->a
.args
= scm_cons2 (arg1
, arg2
,
4454 deval_args (x
, env
, proc
,
4455 SCM_CDRLOC (SCM_CDR (debug
.info
->a
.args
))));
4459 SCM_ASRTGO (!SCM_IMP (proc
), badfun
);
4460 switch (SCM_TYP7 (proc
))
4461 { /* have 3 or more arguments */
4463 case scm_tc7_subr_3
:
4464 if (!scm_is_null (SCM_CDR (x
)))
4465 scm_wrong_num_args (proc
);
4467 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
,
4468 SCM_CADDR (debug
.info
->a
.args
)));
4470 arg1
= SCM_SUBRF(proc
)(arg1
, arg2
);
4471 arg2
= SCM_CDDR (debug
.info
->a
.args
);
4474 arg1
= SCM_SUBRF(proc
)(arg1
, SCM_CAR (arg2
));
4475 arg2
= SCM_CDR (arg2
);
4477 while (SCM_NIMP (arg2
));
4479 case scm_tc7_rpsubr
:
4480 if (scm_is_false (SCM_SUBRF (proc
) (arg1
, arg2
)))
4481 RETURN (SCM_BOOL_F
);
4482 arg1
= SCM_CDDR (debug
.info
->a
.args
);
4485 if (scm_is_false (SCM_SUBRF (proc
) (arg2
, SCM_CAR (arg1
))))
4486 RETURN (SCM_BOOL_F
);
4487 arg2
= SCM_CAR (arg1
);
4488 arg1
= SCM_CDR (arg1
);
4490 while (SCM_NIMP (arg1
));
4491 RETURN (SCM_BOOL_T
);
4492 case scm_tc7_lsubr_2
:
4493 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
,
4494 SCM_CDDR (debug
.info
->a
.args
)));
4496 RETURN (SCM_SUBRF (proc
) (debug
.info
->a
.args
));
4498 if (!SCM_SMOB_APPLICABLE_P (proc
))
4500 RETURN (SCM_SMOB_APPLY_3 (proc
, arg1
, arg2
,
4501 SCM_CDDR (debug
.info
->a
.args
)));
4505 proc
= SCM_PROCEDURE (proc
);
4506 debug
.info
->a
.proc
= proc
;
4507 if (!SCM_CLOSUREP (proc
))
4510 case scm_tcs_closures
:
4512 const SCM formals
= SCM_CLOSURE_FORMALS (proc
);
4513 if (scm_is_null (formals
)
4514 || (scm_is_pair (formals
)
4515 && (scm_is_null (SCM_CDR (formals
))
4516 || (scm_is_pair (SCM_CDR (formals
))
4517 && scm_badargsp (SCM_CDDR (formals
), x
)))))
4519 SCM_SET_ARGSREADY (debug
);
4520 env
= SCM_EXTEND_ENV (formals
,
4523 x
= SCM_CLOSURE_BODY (proc
);
4524 goto nontoplevel_begin
;
4527 case scm_tc7_subr_3
:
4528 if (!scm_is_null (SCM_CDR (x
)))
4529 scm_wrong_num_args (proc
);
4531 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
, EVALCAR (x
, env
)));
4533 arg1
= SCM_SUBRF (proc
) (arg1
, arg2
);
4536 arg1
= SCM_SUBRF(proc
)(arg1
, EVALCAR(x
, env
));
4539 while (!scm_is_null (x
));
4541 case scm_tc7_rpsubr
:
4542 if (scm_is_false (SCM_SUBRF (proc
) (arg1
, arg2
)))
4543 RETURN (SCM_BOOL_F
);
4546 arg1
= EVALCAR (x
, env
);
4547 if (scm_is_false (SCM_SUBRF (proc
) (arg2
, arg1
)))
4548 RETURN (SCM_BOOL_F
);
4552 while (!scm_is_null (x
));
4553 RETURN (SCM_BOOL_T
);
4554 case scm_tc7_lsubr_2
:
4555 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
, scm_eval_args (x
, env
, proc
)));
4557 RETURN (SCM_SUBRF (proc
) (scm_cons2 (arg1
,
4559 scm_eval_args (x
, env
, proc
))));
4561 if (!SCM_SMOB_APPLICABLE_P (proc
))
4563 RETURN (SCM_SMOB_APPLY_3 (proc
, arg1
, arg2
,
4564 scm_eval_args (x
, env
, proc
)));
4568 proc
= SCM_PROCEDURE (proc
);
4569 if (!SCM_CLOSUREP (proc
))
4572 case scm_tcs_closures
:
4574 const SCM formals
= SCM_CLOSURE_FORMALS (proc
);
4575 if (scm_is_null (formals
)
4576 || (scm_is_pair (formals
)
4577 && (scm_is_null (SCM_CDR (formals
))
4578 || (scm_is_pair (SCM_CDR (formals
))
4579 && scm_badargsp (SCM_CDDR (formals
), x
)))))
4581 env
= SCM_EXTEND_ENV (formals
,
4584 scm_eval_args (x
, env
, proc
)),
4586 x
= SCM_CLOSURE_BODY (proc
);
4587 goto nontoplevel_begin
;
4590 case scm_tcs_struct
:
4591 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
4594 arg1
= debug
.info
->a
.args
;
4596 arg1
= scm_cons2 (arg1
, arg2
, scm_eval_args (x
, env
, proc
));
4598 x
= SCM_ENTITY_PROCEDURE (proc
);
4601 else if (SCM_I_OPERATORP (proc
))
4605 case scm_tc7_subr_2
:
4606 case scm_tc7_subr_1o
:
4607 case scm_tc7_subr_2o
:
4608 case scm_tc7_subr_0
:
4611 case scm_tc7_subr_1
:
4612 scm_wrong_num_args (proc
);
4620 if (scm_check_exit_p
&& SCM_TRAPS_P
)
4621 if (SCM_EXIT_FRAME_P
|| (SCM_TRACE_P
&& SCM_TRACED_FRAME_P (debug
)))
4623 SCM_CLEAR_TRACED_FRAME (debug
);
4624 arg1
= scm_make_debugobj (&debug
);
4626 arg1
= scm_call_3 (SCM_EXIT_FRAME_HDLR
, scm_sym_exit_frame
, arg1
, proc
);
4628 if (scm_is_pair (arg1
) && scm_is_eq (SCM_CAR (arg1
), sym_instead
))
4629 proc
= SCM_CDR (arg1
);
4631 scm_i_set_last_debug_frame (debug
.prev
);
4637 /* SECTION: This code is compiled once.
4644 /* Simple procedure calls
4648 scm_call_0 (SCM proc
)
4650 return scm_apply (proc
, SCM_EOL
, SCM_EOL
);
4654 scm_call_1 (SCM proc
, SCM arg1
)
4656 return scm_apply (proc
, arg1
, scm_listofnull
);
4660 scm_call_2 (SCM proc
, SCM arg1
, SCM arg2
)
4662 return scm_apply (proc
, arg1
, scm_cons (arg2
, scm_listofnull
));
4666 scm_call_3 (SCM proc
, SCM arg1
, SCM arg2
, SCM arg3
)
4668 return scm_apply (proc
, arg1
, scm_cons2 (arg2
, arg3
, scm_listofnull
));
4672 scm_call_4 (SCM proc
, SCM arg1
, SCM arg2
, SCM arg3
, SCM arg4
)
4674 return scm_apply (proc
, arg1
, scm_cons2 (arg2
, arg3
,
4675 scm_cons (arg4
, scm_listofnull
)));
4678 /* Simple procedure applies
4682 scm_apply_0 (SCM proc
, SCM args
)
4684 return scm_apply (proc
, args
, SCM_EOL
);
4688 scm_apply_1 (SCM proc
, SCM arg1
, SCM args
)
4690 return scm_apply (proc
, scm_cons (arg1
, args
), SCM_EOL
);
4694 scm_apply_2 (SCM proc
, SCM arg1
, SCM arg2
, SCM args
)
4696 return scm_apply (proc
, scm_cons2 (arg1
, arg2
, args
), SCM_EOL
);
4700 scm_apply_3 (SCM proc
, SCM arg1
, SCM arg2
, SCM arg3
, SCM args
)
4702 return scm_apply (proc
, scm_cons (arg1
, scm_cons2 (arg2
, arg3
, args
)),
4706 /* This code processes the arguments to apply:
4708 (apply PROC ARG1 ... ARGS)
4710 Given a list (ARG1 ... ARGS), this function conses the ARG1
4711 ... arguments onto the front of ARGS, and returns the resulting
4712 list. Note that ARGS is a list; thus, the argument to this
4713 function is a list whose last element is a list.
4715 Apply calls this function, and applies PROC to the elements of the
4716 result. apply:nconc2last takes care of building the list of
4717 arguments, given (ARG1 ... ARGS).
4719 Rather than do new consing, apply:nconc2last destroys its argument.
4720 On that topic, this code came into my care with the following
4721 beautifully cryptic comment on that topic: "This will only screw
4722 you if you do (scm_apply scm_apply '( ... ))" If you know what
4723 they're referring to, send me a patch to this comment. */
4725 SCM_DEFINE (scm_nconc2last
, "apply:nconc2last", 1, 0, 0,
4727 "Given a list (@var{arg1} @dots{} @var{args}), this function\n"
4728 "conses the @var{arg1} @dots{} arguments onto the front of\n"
4729 "@var{args}, and returns the resulting list. Note that\n"
4730 "@var{args} is a list; thus, the argument to this function is\n"
4731 "a list whose last element is a list.\n"
4732 "Note: Rather than do new consing, @code{apply:nconc2last}\n"
4733 "destroys its argument, so use with care.")
4734 #define FUNC_NAME s_scm_nconc2last
4737 SCM_VALIDATE_NONEMPTYLIST (1, lst
);
4739 while (!scm_is_null (SCM_CDR (*lloc
))) /* Perhaps should be
4740 SCM_NULL_OR_NIL_P, but not
4741 needed in 99.99% of cases,
4742 and it could seriously hurt
4743 performance. - Neil */
4744 lloc
= SCM_CDRLOC (*lloc
);
4745 SCM_ASSERT (scm_ilength (SCM_CAR (*lloc
)) >= 0, lst
, SCM_ARG1
, FUNC_NAME
);
4746 *lloc
= SCM_CAR (*lloc
);
4754 /* SECTION: When DEVAL is defined this code yields scm_dapply.
4755 * It is compiled twice.
4760 scm_apply (SCM proc
, SCM arg1
, SCM args
)
4766 scm_dapply (SCM proc
, SCM arg1
, SCM args
)
4771 /* Apply a function to a list of arguments.
4773 This function is exported to the Scheme level as taking two
4774 required arguments and a tail argument, as if it were:
4775 (lambda (proc arg1 . args) ...)
4776 Thus, if you just have a list of arguments to pass to a procedure,
4777 pass the list as ARG1, and '() for ARGS. If you have some fixed
4778 args, pass the first as ARG1, then cons any remaining fixed args
4779 onto the front of your argument list, and pass that as ARGS. */
4782 SCM_APPLY (SCM proc
, SCM arg1
, SCM args
)
4785 scm_t_debug_frame debug
;
4786 scm_t_debug_info debug_vect_body
;
4787 debug
.prev
= scm_i_last_debug_frame ();
4788 debug
.status
= SCM_APPLYFRAME
;
4789 debug
.vect
= &debug_vect_body
;
4790 debug
.vect
[0].a
.proc
= proc
;
4791 debug
.vect
[0].a
.args
= SCM_EOL
;
4792 scm_i_set_last_debug_frame (&debug
);
4794 if (scm_debug_mode_p
)
4795 return scm_dapply (proc
, arg1
, args
);
4798 SCM_ASRTGO (SCM_NIMP (proc
), badproc
);
4800 /* If ARGS is the empty list, then we're calling apply with only two
4801 arguments --- ARG1 is the list of arguments for PROC. Whatever
4802 the case, futz with things so that ARG1 is the first argument to
4803 give to PROC (or SCM_UNDEFINED if no args), and ARGS contains the
4806 Setting the debug apply frame args this way is pretty messy.
4807 Perhaps we should store arg1 and args directly in the frame as
4808 received, and let scm_frame_arguments unpack them, because that's
4809 a relatively rare operation. This works for now; if the Guile
4810 developer archives are still around, see Mikael's post of
4812 if (scm_is_null (args
))
4814 if (scm_is_null (arg1
))
4816 arg1
= SCM_UNDEFINED
;
4818 debug
.vect
[0].a
.args
= SCM_EOL
;
4824 debug
.vect
[0].a
.args
= arg1
;
4826 args
= SCM_CDR (arg1
);
4827 arg1
= SCM_CAR (arg1
);
4832 args
= scm_nconc2last (args
);
4834 debug
.vect
[0].a
.args
= scm_cons (arg1
, args
);
4838 if (SCM_ENTER_FRAME_P
&& SCM_TRAPS_P
)
4840 SCM tmp
= scm_make_debugobj (&debug
);
4842 scm_call_2 (SCM_ENTER_FRAME_HDLR
, scm_sym_enter_frame
, tmp
);
4848 switch (SCM_TYP7 (proc
))
4850 case scm_tc7_subr_2o
:
4851 args
= scm_is_null (args
) ? SCM_UNDEFINED
: SCM_CAR (args
);
4852 RETURN (SCM_SUBRF (proc
) (arg1
, args
));
4853 case scm_tc7_subr_2
:
4854 if (scm_is_null (args
) || !scm_is_null (SCM_CDR (args
)))
4855 scm_wrong_num_args (proc
);
4856 args
= SCM_CAR (args
);
4857 RETURN (SCM_SUBRF (proc
) (arg1
, args
));
4858 case scm_tc7_subr_0
:
4859 if (!SCM_UNBNDP (arg1
))
4860 scm_wrong_num_args (proc
);
4862 RETURN (SCM_SUBRF (proc
) ());
4863 case scm_tc7_subr_1
:
4864 if (SCM_UNBNDP (arg1
))
4865 scm_wrong_num_args (proc
);
4866 case scm_tc7_subr_1o
:
4867 if (!scm_is_null (args
))
4868 scm_wrong_num_args (proc
);
4870 RETURN (SCM_SUBRF (proc
) (arg1
));
4872 if (SCM_UNBNDP (arg1
) || !scm_is_null (args
))
4873 scm_wrong_num_args (proc
);
4874 if (SCM_I_INUMP (arg1
))
4876 RETURN (scm_from_double (SCM_DSUBRF (proc
) ((double) SCM_I_INUM (arg1
))));
4878 else if (SCM_REALP (arg1
))
4880 RETURN (scm_from_double (SCM_DSUBRF (proc
) (SCM_REAL_VALUE (arg1
))));
4882 else if (SCM_BIGP (arg1
))
4884 RETURN (scm_from_double (SCM_DSUBRF (proc
) (scm_i_big2dbl (arg1
))));
4886 else if (SCM_FRACTIONP (arg1
))
4888 RETURN (scm_from_double (SCM_DSUBRF (proc
) (scm_i_fraction2double (arg1
))));
4890 SCM_WTA_DISPATCH_1 (*SCM_SUBR_GENERIC (proc
), arg1
,
4891 SCM_ARG1
, scm_i_symbol_chars (SCM_SNAME (proc
)));
4893 if (SCM_UNBNDP (arg1
) || !scm_is_null (args
))
4894 scm_wrong_num_args (proc
);
4895 RETURN (scm_i_chase_pairs (arg1
, (scm_t_bits
) SCM_SUBRF (proc
)));
4896 case scm_tc7_subr_3
:
4897 if (scm_is_null (args
)
4898 || scm_is_null (SCM_CDR (args
))
4899 || !scm_is_null (SCM_CDDR (args
)))
4900 scm_wrong_num_args (proc
);
4902 RETURN (SCM_SUBRF (proc
) (arg1
, SCM_CAR (args
), SCM_CADR (args
)));
4905 RETURN (SCM_SUBRF (proc
) (SCM_UNBNDP (arg1
) ? SCM_EOL
: debug
.vect
[0].a
.args
));
4907 RETURN (SCM_SUBRF (proc
) (SCM_UNBNDP (arg1
) ? SCM_EOL
: scm_cons (arg1
, args
)));
4909 case scm_tc7_lsubr_2
:
4910 if (!scm_is_pair (args
))
4911 scm_wrong_num_args (proc
);
4913 RETURN (SCM_SUBRF (proc
) (arg1
, SCM_CAR (args
), SCM_CDR (args
)));
4915 if (scm_is_null (args
))
4916 RETURN (SCM_SUBRF (proc
) (arg1
, SCM_UNDEFINED
));
4917 while (SCM_NIMP (args
))
4919 SCM_ASSERT (scm_is_pair (args
), args
, SCM_ARG2
, "apply");
4920 arg1
= SCM_SUBRF (proc
) (arg1
, SCM_CAR (args
));
4921 args
= SCM_CDR (args
);
4924 case scm_tc7_rpsubr
:
4925 if (scm_is_null (args
))
4926 RETURN (SCM_BOOL_T
);
4927 while (SCM_NIMP (args
))
4929 SCM_ASSERT (scm_is_pair (args
), args
, SCM_ARG2
, "apply");
4930 if (scm_is_false (SCM_SUBRF (proc
) (arg1
, SCM_CAR (args
))))
4931 RETURN (SCM_BOOL_F
);
4932 arg1
= SCM_CAR (args
);
4933 args
= SCM_CDR (args
);
4935 RETURN (SCM_BOOL_T
);
4936 case scm_tcs_closures
:
4938 arg1
= (SCM_UNBNDP (arg1
) ? SCM_EOL
: debug
.vect
[0].a
.args
);
4940 arg1
= (SCM_UNBNDP (arg1
) ? SCM_EOL
: scm_cons (arg1
, args
));
4942 if (scm_badargsp (SCM_CLOSURE_FORMALS (proc
), arg1
))
4943 scm_wrong_num_args (proc
);
4945 /* Copy argument list */
4950 SCM tl
= args
= scm_cons (SCM_CAR (arg1
), SCM_UNSPECIFIED
);
4951 for (arg1
= SCM_CDR (arg1
); scm_is_pair (arg1
); arg1
= SCM_CDR (arg1
))
4953 SCM_SETCDR (tl
, scm_cons (SCM_CAR (arg1
), SCM_UNSPECIFIED
));
4956 SCM_SETCDR (tl
, arg1
);
4959 args
= SCM_EXTEND_ENV (SCM_CLOSURE_FORMALS (proc
),
4962 proc
= SCM_CLOSURE_BODY (proc
);
4964 arg1
= SCM_CDR (proc
);
4965 while (!scm_is_null (arg1
))
4967 if (SCM_IMP (SCM_CAR (proc
)))
4969 if (SCM_ISYMP (SCM_CAR (proc
)))
4971 scm_dynwind_begin (0);
4972 scm_dynwind_pthread_mutex_lock (&source_mutex
);
4973 /* check for race condition */
4974 if (SCM_ISYMP (SCM_CAR (proc
)))
4975 m_expand_body (proc
, args
);
4980 SCM_VALIDATE_NON_EMPTY_COMBINATION (SCM_CAR (proc
));
4983 (void) EVAL (SCM_CAR (proc
), args
);
4985 arg1
= SCM_CDR (proc
);
4987 RETURN (EVALCAR (proc
, args
));
4989 if (!SCM_SMOB_APPLICABLE_P (proc
))
4991 if (SCM_UNBNDP (arg1
))
4992 RETURN (SCM_SMOB_APPLY_0 (proc
));
4993 else if (scm_is_null (args
))
4994 RETURN (SCM_SMOB_APPLY_1 (proc
, arg1
));
4995 else if (scm_is_null (SCM_CDR (args
)))
4996 RETURN (SCM_SMOB_APPLY_2 (proc
, arg1
, SCM_CAR (args
)));
4998 RETURN (SCM_SMOB_APPLY_3 (proc
, arg1
, SCM_CAR (args
), SCM_CDR (args
)));
5001 args
= (SCM_UNBNDP(arg1
) ? SCM_EOL
: debug
.vect
[0].a
.args
);
5003 proc
= SCM_CCLO_SUBR (proc
);
5004 debug
.vect
[0].a
.proc
= proc
;
5005 debug
.vect
[0].a
.args
= scm_cons (arg1
, args
);
5007 args
= (SCM_UNBNDP(arg1
) ? SCM_EOL
: scm_cons (arg1
, args
));
5009 proc
= SCM_CCLO_SUBR (proc
);
5013 proc
= SCM_PROCEDURE (proc
);
5015 debug
.vect
[0].a
.proc
= proc
;
5018 case scm_tcs_struct
:
5019 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
5022 args
= (SCM_UNBNDP(arg1
) ? SCM_EOL
: debug
.vect
[0].a
.args
);
5024 args
= (SCM_UNBNDP(arg1
) ? SCM_EOL
: scm_cons (arg1
, args
));
5026 RETURN (scm_apply_generic (proc
, args
));
5028 else if (SCM_I_OPERATORP (proc
))
5032 args
= (SCM_UNBNDP(arg1
) ? SCM_EOL
: debug
.vect
[0].a
.args
);
5034 args
= (SCM_UNBNDP(arg1
) ? SCM_EOL
: scm_cons (arg1
, args
));
5037 proc
= (SCM_I_ENTITYP (proc
)
5038 ? SCM_ENTITY_PROCEDURE (proc
)
5039 : SCM_OPERATOR_PROCEDURE (proc
));
5041 debug
.vect
[0].a
.proc
= proc
;
5042 debug
.vect
[0].a
.args
= scm_cons (arg1
, args
);
5044 if (SCM_NIMP (proc
))
5053 scm_wrong_type_arg ("apply", SCM_ARG1
, proc
);
5057 if (scm_check_exit_p
&& SCM_TRAPS_P
)
5058 if (SCM_EXIT_FRAME_P
|| (SCM_TRACE_P
&& SCM_TRACED_FRAME_P (debug
)))
5060 SCM_CLEAR_TRACED_FRAME (debug
);
5061 arg1
= scm_make_debugobj (&debug
);
5063 arg1
= scm_call_3 (SCM_EXIT_FRAME_HDLR
, scm_sym_exit_frame
, arg1
, proc
);
5065 if (scm_is_pair (arg1
) && scm_is_eq (SCM_CAR (arg1
), sym_instead
))
5066 proc
= SCM_CDR (arg1
);
5068 scm_i_set_last_debug_frame (debug
.prev
);
5074 /* SECTION: The rest of this file is only read once.
5081 * Trampolines make it possible to move procedure application dispatch
5082 * outside inner loops. The motivation was clean implementation of
5083 * efficient replacements of R5RS primitives in SRFI-1.
5085 * The semantics is clear: scm_trampoline_N returns an optimized
5086 * version of scm_call_N (or NULL if the procedure isn't applicable
5089 * Applying the optimization to map and for-each increased efficiency
5090 * noticeably. For example, (map abs ls) is now 8 times faster than
5095 call_subr0_0 (SCM proc
)
5097 return SCM_SUBRF (proc
) ();
5101 call_subr1o_0 (SCM proc
)
5103 return SCM_SUBRF (proc
) (SCM_UNDEFINED
);
5107 call_lsubr_0 (SCM proc
)
5109 return SCM_SUBRF (proc
) (SCM_EOL
);
5113 scm_i_call_closure_0 (SCM proc
)
5115 const SCM env
= SCM_EXTEND_ENV (SCM_CLOSURE_FORMALS (proc
),
5118 const SCM result
= scm_eval_body (SCM_CLOSURE_BODY (proc
), env
);
5123 scm_trampoline_0 (SCM proc
)
5125 scm_t_trampoline_0 trampoline
;
5130 switch (SCM_TYP7 (proc
))
5132 case scm_tc7_subr_0
:
5133 trampoline
= call_subr0_0
;
5135 case scm_tc7_subr_1o
:
5136 trampoline
= call_subr1o_0
;
5139 trampoline
= call_lsubr_0
;
5141 case scm_tcs_closures
:
5143 SCM formals
= SCM_CLOSURE_FORMALS (proc
);
5144 if (scm_is_null (formals
) || !scm_is_pair (formals
))
5145 trampoline
= scm_i_call_closure_0
;
5150 case scm_tcs_struct
:
5151 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
5152 trampoline
= scm_call_generic_0
;
5153 else if (SCM_I_OPERATORP (proc
))
5154 trampoline
= scm_call_0
;
5159 if (SCM_SMOB_APPLICABLE_P (proc
))
5160 trampoline
= SCM_SMOB_DESCRIPTOR (proc
).apply_0
;
5165 case scm_tc7_rpsubr
:
5168 trampoline
= scm_call_0
;
5171 return NULL
; /* not applicable on zero arguments */
5173 /* We only reach this point if a valid trampoline was determined. */
5175 /* If debugging is enabled, we want to see all calls to proc on the stack.
5176 * Thus, we replace the trampoline shortcut with scm_call_0. */
5177 if (scm_debug_mode_p
)
5184 call_subr1_1 (SCM proc
, SCM arg1
)
5186 return SCM_SUBRF (proc
) (arg1
);
5190 call_subr2o_1 (SCM proc
, SCM arg1
)
5192 return SCM_SUBRF (proc
) (arg1
, SCM_UNDEFINED
);
5196 call_lsubr_1 (SCM proc
, SCM arg1
)
5198 return SCM_SUBRF (proc
) (scm_list_1 (arg1
));
5202 call_dsubr_1 (SCM proc
, SCM arg1
)
5204 if (SCM_I_INUMP (arg1
))
5206 RETURN (scm_from_double (SCM_DSUBRF (proc
) ((double) SCM_I_INUM (arg1
))));
5208 else if (SCM_REALP (arg1
))
5210 RETURN (scm_from_double (SCM_DSUBRF (proc
) (SCM_REAL_VALUE (arg1
))));
5212 else if (SCM_BIGP (arg1
))
5214 RETURN (scm_from_double (SCM_DSUBRF (proc
) (scm_i_big2dbl (arg1
))));
5216 else if (SCM_FRACTIONP (arg1
))
5218 RETURN (scm_from_double (SCM_DSUBRF (proc
) (scm_i_fraction2double (arg1
))));
5220 SCM_WTA_DISPATCH_1 (*SCM_SUBR_GENERIC (proc
), arg1
,
5221 SCM_ARG1
, scm_i_symbol_chars (SCM_SNAME (proc
)));
5225 call_cxr_1 (SCM proc
, SCM arg1
)
5227 return scm_i_chase_pairs (arg1
, (scm_t_bits
) SCM_SUBRF (proc
));
5231 call_closure_1 (SCM proc
, SCM arg1
)
5233 const SCM env
= SCM_EXTEND_ENV (SCM_CLOSURE_FORMALS (proc
),
5236 const SCM result
= scm_eval_body (SCM_CLOSURE_BODY (proc
), env
);
5241 scm_trampoline_1 (SCM proc
)
5243 scm_t_trampoline_1 trampoline
;
5248 switch (SCM_TYP7 (proc
))
5250 case scm_tc7_subr_1
:
5251 case scm_tc7_subr_1o
:
5252 trampoline
= call_subr1_1
;
5254 case scm_tc7_subr_2o
:
5255 trampoline
= call_subr2o_1
;
5258 trampoline
= call_lsubr_1
;
5261 trampoline
= call_dsubr_1
;
5264 trampoline
= call_cxr_1
;
5266 case scm_tcs_closures
:
5268 SCM formals
= SCM_CLOSURE_FORMALS (proc
);
5269 if (!scm_is_null (formals
)
5270 && (!scm_is_pair (formals
) || !scm_is_pair (SCM_CDR (formals
))))
5271 trampoline
= call_closure_1
;
5276 case scm_tcs_struct
:
5277 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
5278 trampoline
= scm_call_generic_1
;
5279 else if (SCM_I_OPERATORP (proc
))
5280 trampoline
= scm_call_1
;
5285 if (SCM_SMOB_APPLICABLE_P (proc
))
5286 trampoline
= SCM_SMOB_DESCRIPTOR (proc
).apply_1
;
5291 case scm_tc7_rpsubr
:
5294 trampoline
= scm_call_1
;
5297 return NULL
; /* not applicable on one arg */
5299 /* We only reach this point if a valid trampoline was determined. */
5301 /* If debugging is enabled, we want to see all calls to proc on the stack.
5302 * Thus, we replace the trampoline shortcut with scm_call_1. */
5303 if (scm_debug_mode_p
)
5310 call_subr2_2 (SCM proc
, SCM arg1
, SCM arg2
)
5312 return SCM_SUBRF (proc
) (arg1
, arg2
);
5316 call_lsubr2_2 (SCM proc
, SCM arg1
, SCM arg2
)
5318 return SCM_SUBRF (proc
) (arg1
, arg2
, SCM_EOL
);
5322 call_lsubr_2 (SCM proc
, SCM arg1
, SCM arg2
)
5324 return SCM_SUBRF (proc
) (scm_list_2 (arg1
, arg2
));
5328 call_closure_2 (SCM proc
, SCM arg1
, SCM arg2
)
5330 const SCM env
= SCM_EXTEND_ENV (SCM_CLOSURE_FORMALS (proc
),
5331 scm_list_2 (arg1
, arg2
),
5333 const SCM result
= scm_eval_body (SCM_CLOSURE_BODY (proc
), env
);
5338 scm_trampoline_2 (SCM proc
)
5340 scm_t_trampoline_2 trampoline
;
5345 switch (SCM_TYP7 (proc
))
5347 case scm_tc7_subr_2
:
5348 case scm_tc7_subr_2o
:
5349 case scm_tc7_rpsubr
:
5351 trampoline
= call_subr2_2
;
5353 case scm_tc7_lsubr_2
:
5354 trampoline
= call_lsubr2_2
;
5357 trampoline
= call_lsubr_2
;
5359 case scm_tcs_closures
:
5361 SCM formals
= SCM_CLOSURE_FORMALS (proc
);
5362 if (!scm_is_null (formals
)
5363 && (!scm_is_pair (formals
)
5364 || (!scm_is_null (SCM_CDR (formals
))
5365 && (!scm_is_pair (SCM_CDR (formals
))
5366 || !scm_is_pair (SCM_CDDR (formals
))))))
5367 trampoline
= call_closure_2
;
5372 case scm_tcs_struct
:
5373 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
5374 trampoline
= scm_call_generic_2
;
5375 else if (SCM_I_OPERATORP (proc
))
5376 trampoline
= scm_call_2
;
5381 if (SCM_SMOB_APPLICABLE_P (proc
))
5382 trampoline
= SCM_SMOB_DESCRIPTOR (proc
).apply_2
;
5388 trampoline
= scm_call_2
;
5391 return NULL
; /* not applicable on two args */
5393 /* We only reach this point if a valid trampoline was determined. */
5395 /* If debugging is enabled, we want to see all calls to proc on the stack.
5396 * Thus, we replace the trampoline shortcut with scm_call_2. */
5397 if (scm_debug_mode_p
)
5403 /* Typechecking for multi-argument MAP and FOR-EACH.
5405 Verify that each element of the vector ARGV, except for the first,
5406 is a proper list whose length is LEN. Attribute errors to WHO,
5407 and claim that the i'th element of ARGV is WHO's i+2'th argument. */
5409 check_map_args (SCM argv
,
5418 for (i
= SCM_SIMPLE_VECTOR_LENGTH (argv
) - 1; i
>= 1; i
--)
5420 SCM elt
= SCM_SIMPLE_VECTOR_REF (argv
, i
);
5421 long elt_len
= scm_ilength (elt
);
5426 scm_apply_generic (gf
, scm_cons (proc
, args
));
5428 scm_wrong_type_arg (who
, i
+ 2, elt
);
5432 scm_out_of_range_pos (who
, elt
, scm_from_long (i
+ 2));
5437 SCM_GPROC (s_map
, "map", 2, 0, 1, scm_map
, g_map
);
5439 /* Note: Currently, scm_map applies PROC to the argument list(s)
5440 sequentially, starting with the first element(s). This is used in
5441 evalext.c where the Scheme procedure `map-in-order', which guarantees
5442 sequential behaviour, is implemented using scm_map. If the
5443 behaviour changes, we need to update `map-in-order'.
5447 scm_map (SCM proc
, SCM arg1
, SCM args
)
5448 #define FUNC_NAME s_map
5454 len
= scm_ilength (arg1
);
5455 SCM_GASSERTn (len
>= 0,
5456 g_map
, scm_cons2 (proc
, arg1
, args
), SCM_ARG2
, s_map
);
5457 SCM_VALIDATE_REST_ARGUMENT (args
);
5458 if (scm_is_null (args
))
5460 scm_t_trampoline_1 call
= scm_trampoline_1 (proc
);
5461 SCM_GASSERT2 (call
, g_map
, proc
, arg1
, SCM_ARG1
, s_map
);
5462 while (SCM_NIMP (arg1
))
5464 *pres
= scm_list_1 (call (proc
, SCM_CAR (arg1
)));
5465 pres
= SCM_CDRLOC (*pres
);
5466 arg1
= SCM_CDR (arg1
);
5470 if (scm_is_null (SCM_CDR (args
)))
5472 SCM arg2
= SCM_CAR (args
);
5473 int len2
= scm_ilength (arg2
);
5474 scm_t_trampoline_2 call
= scm_trampoline_2 (proc
);
5476 g_map
, scm_cons2 (proc
, arg1
, args
), SCM_ARG1
, s_map
);
5477 SCM_GASSERTn (len2
>= 0,
5478 g_map
, scm_cons2 (proc
, arg1
, args
), SCM_ARG3
, s_map
);
5480 SCM_OUT_OF_RANGE (3, arg2
);
5481 while (SCM_NIMP (arg1
))
5483 *pres
= scm_list_1 (call (proc
, SCM_CAR (arg1
), SCM_CAR (arg2
)));
5484 pres
= SCM_CDRLOC (*pres
);
5485 arg1
= SCM_CDR (arg1
);
5486 arg2
= SCM_CDR (arg2
);
5490 arg1
= scm_cons (arg1
, args
);
5491 args
= scm_vector (arg1
);
5492 check_map_args (args
, len
, g_map
, proc
, arg1
, s_map
);
5496 for (i
= SCM_SIMPLE_VECTOR_LENGTH (args
) - 1; i
>= 0; i
--)
5498 SCM elt
= SCM_SIMPLE_VECTOR_REF (args
, i
);
5501 arg1
= scm_cons (SCM_CAR (elt
), arg1
);
5502 SCM_SIMPLE_VECTOR_SET (args
, i
, SCM_CDR (elt
));
5504 *pres
= scm_list_1 (scm_apply (proc
, arg1
, SCM_EOL
));
5505 pres
= SCM_CDRLOC (*pres
);
5511 SCM_GPROC (s_for_each
, "for-each", 2, 0, 1, scm_for_each
, g_for_each
);
5514 scm_for_each (SCM proc
, SCM arg1
, SCM args
)
5515 #define FUNC_NAME s_for_each
5518 len
= scm_ilength (arg1
);
5519 SCM_GASSERTn (len
>= 0, g_for_each
, scm_cons2 (proc
, arg1
, args
),
5520 SCM_ARG2
, s_for_each
);
5521 SCM_VALIDATE_REST_ARGUMENT (args
);
5522 if (scm_is_null (args
))
5524 scm_t_trampoline_1 call
= scm_trampoline_1 (proc
);
5525 SCM_GASSERT2 (call
, g_for_each
, proc
, arg1
, SCM_ARG1
, s_for_each
);
5526 while (SCM_NIMP (arg1
))
5528 call (proc
, SCM_CAR (arg1
));
5529 arg1
= SCM_CDR (arg1
);
5531 return SCM_UNSPECIFIED
;
5533 if (scm_is_null (SCM_CDR (args
)))
5535 SCM arg2
= SCM_CAR (args
);
5536 int len2
= scm_ilength (arg2
);
5537 scm_t_trampoline_2 call
= scm_trampoline_2 (proc
);
5538 SCM_GASSERTn (call
, g_for_each
,
5539 scm_cons2 (proc
, arg1
, args
), SCM_ARG1
, s_for_each
);
5540 SCM_GASSERTn (len2
>= 0, g_for_each
,
5541 scm_cons2 (proc
, arg1
, args
), SCM_ARG3
, s_for_each
);
5543 SCM_OUT_OF_RANGE (3, arg2
);
5544 while (SCM_NIMP (arg1
))
5546 call (proc
, SCM_CAR (arg1
), SCM_CAR (arg2
));
5547 arg1
= SCM_CDR (arg1
);
5548 arg2
= SCM_CDR (arg2
);
5550 return SCM_UNSPECIFIED
;
5552 arg1
= scm_cons (arg1
, args
);
5553 args
= scm_vector (arg1
);
5554 check_map_args (args
, len
, g_for_each
, proc
, arg1
, s_for_each
);
5558 for (i
= SCM_SIMPLE_VECTOR_LENGTH (args
) - 1; i
>= 0; i
--)
5560 SCM elt
= SCM_SIMPLE_VECTOR_REF (args
, i
);
5562 return SCM_UNSPECIFIED
;
5563 arg1
= scm_cons (SCM_CAR (elt
), arg1
);
5564 SCM_SIMPLE_VECTOR_SET (args
, i
, SCM_CDR (elt
));
5566 scm_apply (proc
, arg1
, SCM_EOL
);
5573 scm_closure (SCM code
, SCM env
)
5576 SCM closcar
= scm_cons (code
, SCM_EOL
);
5577 z
= scm_cell (SCM_UNPACK (closcar
) + scm_tc3_closure
, (scm_t_bits
) env
);
5578 scm_remember_upto_here (closcar
);
5583 scm_t_bits scm_tc16_promise
;
5586 scm_makprom (SCM code
)
5588 SCM_RETURN_NEWSMOB2 (scm_tc16_promise
,
5590 scm_make_recursive_mutex ());
5594 promise_mark (SCM promise
)
5596 scm_gc_mark (SCM_PROMISE_MUTEX (promise
));
5597 return SCM_PROMISE_DATA (promise
);
5601 promise_free (SCM promise
)
5607 promise_print (SCM exp
, SCM port
, scm_print_state
*pstate
)
5609 int writingp
= SCM_WRITINGP (pstate
);
5610 scm_puts ("#<promise ", port
);
5611 SCM_SET_WRITINGP (pstate
, 1);
5612 scm_iprin1 (SCM_PROMISE_DATA (exp
), port
, pstate
);
5613 SCM_SET_WRITINGP (pstate
, writingp
);
5614 scm_putc ('>', port
);
5618 SCM_DEFINE (scm_force
, "force", 1, 0, 0,
5620 "If the promise @var{x} has not been computed yet, compute and\n"
5621 "return @var{x}, otherwise just return the previously computed\n"
5623 #define FUNC_NAME s_scm_force
5625 SCM_VALIDATE_SMOB (1, promise
, promise
);
5626 scm_lock_mutex (SCM_PROMISE_MUTEX (promise
));
5627 if (!SCM_PROMISE_COMPUTED_P (promise
))
5629 SCM ans
= scm_call_0 (SCM_PROMISE_DATA (promise
));
5630 if (!SCM_PROMISE_COMPUTED_P (promise
))
5632 SCM_SET_PROMISE_DATA (promise
, ans
);
5633 SCM_SET_PROMISE_COMPUTED (promise
);
5636 scm_unlock_mutex (SCM_PROMISE_MUTEX (promise
));
5637 return SCM_PROMISE_DATA (promise
);
5642 SCM_DEFINE (scm_promise_p
, "promise?", 1, 0, 0,
5644 "Return true if @var{obj} is a promise, i.e. a delayed computation\n"
5645 "(@pxref{Delayed evaluation,,,r5rs.info,The Revised^5 Report on Scheme}).")
5646 #define FUNC_NAME s_scm_promise_p
5648 return scm_from_bool (SCM_TYP16_PREDICATE (scm_tc16_promise
, obj
));
5653 SCM_DEFINE (scm_cons_source
, "cons-source", 3, 0, 0,
5654 (SCM xorig
, SCM x
, SCM y
),
5655 "Create and return a new pair whose car and cdr are @var{x} and @var{y}.\n"
5656 "Any source properties associated with @var{xorig} are also associated\n"
5657 "with the new pair.")
5658 #define FUNC_NAME s_scm_cons_source
5661 z
= scm_cons (x
, y
);
5662 /* Copy source properties possibly associated with xorig. */
5663 p
= scm_whash_lookup (scm_source_whash
, xorig
);
5664 if (scm_is_true (p
))
5665 scm_whash_insert (scm_source_whash
, z
, p
);
5671 /* The function scm_copy_tree is used to copy an expression tree to allow the
5672 * memoizer to modify the expression during memoization. scm_copy_tree
5673 * creates deep copies of pairs and vectors, but not of any other data types,
5674 * since only pairs and vectors will be parsed by the memoizer.
5676 * To avoid infinite recursion due to cyclic structures, the hare-and-tortoise
5677 * pattern is used to detect cycles. In fact, the pattern is used in two
5678 * dimensions, vertical (indicated in the code by the variable names 'hare'
5679 * and 'tortoise') and horizontal ('rabbit' and 'turtle'). In both
5680 * dimensions, the hare/rabbit will take two steps when the tortoise/turtle
5683 * The vertical dimension corresponds to recursive calls to function
5684 * copy_tree: This happens when descending into vector elements, into cars of
5685 * lists and into the cdr of an improper list. In this dimension, the
5686 * tortoise follows the hare by using the processor stack: Every stack frame
5687 * will hold an instance of struct t_trace. These instances are connected in
5688 * a way that represents the trace of the hare, which thus can be followed by
5689 * the tortoise. The tortoise will always point to struct t_trace instances
5690 * relating to SCM objects that have already been copied. Thus, a cycle is
5691 * detected if the tortoise and the hare point to the same object,
5693 * The horizontal dimension is within one execution of copy_tree, when the
5694 * function cdr's along the pairs of a list. This is the standard
5695 * hare-and-tortoise implementation, found several times in guile. */
5698 struct t_trace
*trace
; // These pointers form a trace along the stack.
5699 SCM obj
; // The object handled at the respective stack frame.
5704 struct t_trace
*const hare
,
5705 struct t_trace
*tortoise
,
5706 unsigned int tortoise_delay
)
5708 if (!scm_is_pair (hare
->obj
) && !scm_is_simple_vector (hare
->obj
))
5714 /* Prepare the trace along the stack. */
5715 struct t_trace new_hare
;
5716 hare
->trace
= &new_hare
;
5718 /* The tortoise will make its step after the delay has elapsed. Note
5719 * that in contrast to the typical hare-and-tortoise pattern, the step
5720 * of the tortoise happens before the hare takes its steps. This is, in
5721 * principle, no problem, except for the start of the algorithm: Then,
5722 * it has to be made sure that the hare actually gets its advantage of
5724 if (tortoise_delay
== 0)
5727 tortoise
= tortoise
->trace
;
5728 ASSERT_SYNTAX (!scm_is_eq (hare
->obj
, tortoise
->obj
),
5729 s_bad_expression
, hare
->obj
);
5736 if (scm_is_simple_vector (hare
->obj
))
5738 size_t length
= SCM_SIMPLE_VECTOR_LENGTH (hare
->obj
);
5739 SCM new_vector
= scm_c_make_vector (length
, SCM_UNSPECIFIED
);
5741 /* Each vector element is copied by recursing into copy_tree, having
5742 * the tortoise follow the hare into the depths of the stack. */
5743 unsigned long int i
;
5744 for (i
= 0; i
< length
; ++i
)
5747 new_hare
.obj
= SCM_SIMPLE_VECTOR_REF (hare
->obj
, i
);
5748 new_element
= copy_tree (&new_hare
, tortoise
, tortoise_delay
);
5749 SCM_SIMPLE_VECTOR_SET (new_vector
, i
, new_element
);
5754 else // scm_is_pair (hare->obj)
5759 SCM rabbit
= hare
->obj
;
5760 SCM turtle
= hare
->obj
;
5764 /* The first pair of the list is treated specially, in order to
5765 * preserve a potential source code position. */
5766 result
= tail
= scm_cons_source (rabbit
, SCM_EOL
, SCM_EOL
);
5767 new_hare
.obj
= SCM_CAR (rabbit
);
5768 copy
= copy_tree (&new_hare
, tortoise
, tortoise_delay
);
5769 SCM_SETCAR (tail
, copy
);
5771 /* The remaining pairs of the list are copied by, horizontally,
5772 * having the turtle follow the rabbit, and, vertically, having the
5773 * tortoise follow the hare into the depths of the stack. */
5774 rabbit
= SCM_CDR (rabbit
);
5775 while (scm_is_pair (rabbit
))
5777 new_hare
.obj
= SCM_CAR (rabbit
);
5778 copy
= copy_tree (&new_hare
, tortoise
, tortoise_delay
);
5779 SCM_SETCDR (tail
, scm_cons (copy
, SCM_UNDEFINED
));
5780 tail
= SCM_CDR (tail
);
5782 rabbit
= SCM_CDR (rabbit
);
5783 if (scm_is_pair (rabbit
))
5785 new_hare
.obj
= SCM_CAR (rabbit
);
5786 copy
= copy_tree (&new_hare
, tortoise
, tortoise_delay
);
5787 SCM_SETCDR (tail
, scm_cons (copy
, SCM_UNDEFINED
));
5788 tail
= SCM_CDR (tail
);
5789 rabbit
= SCM_CDR (rabbit
);
5791 turtle
= SCM_CDR (turtle
);
5792 ASSERT_SYNTAX (!scm_is_eq (rabbit
, turtle
),
5793 s_bad_expression
, rabbit
);
5797 /* We have to recurse into copy_tree again for the last cdr, in
5798 * order to handle the situation that it holds a vector. */
5799 new_hare
.obj
= rabbit
;
5800 copy
= copy_tree (&new_hare
, tortoise
, tortoise_delay
);
5801 SCM_SETCDR (tail
, copy
);
5808 SCM_DEFINE (scm_copy_tree
, "copy-tree", 1, 0, 0,
5810 "Recursively copy the data tree that is bound to @var{obj}, and return a\n"
5811 "the new data structure. @code{copy-tree} recurses down the\n"
5812 "contents of both pairs and vectors (since both cons cells and vector\n"
5813 "cells may point to arbitrary objects), and stops recursing when it hits\n"
5814 "any other object.")
5815 #define FUNC_NAME s_scm_copy_tree
5817 /* Prepare the trace along the stack. */
5818 struct t_trace trace
;
5821 /* In function copy_tree, if the tortoise makes its step, it will do this
5822 * before the hare has the chance to move. Thus, we have to make sure that
5823 * the very first step of the tortoise will not happen after the hare has
5824 * really made two steps. This is achieved by passing '2' as the initial
5825 * delay for the tortoise. NOTE: Since cycles are unlikely, giving the hare
5826 * a bigger advantage may improve performance slightly. */
5827 return copy_tree (&trace
, &trace
, 2);
5832 /* We have three levels of EVAL here:
5834 - scm_i_eval (exp, env)
5836 evaluates EXP in environment ENV. ENV is a lexical environment
5837 structure as used by the actual tree code evaluator. When ENV is
5838 a top-level environment, then changes to the current module are
5839 tracked by updating ENV so that it continues to be in sync with
5842 - scm_primitive_eval (exp)
5844 evaluates EXP in the top-level environment as determined by the
5845 current module. This is done by constructing a suitable
5846 environment and calling scm_i_eval. Thus, changes to the
5847 top-level module are tracked normally.
5849 - scm_eval (exp, mod_or_state)
5851 evaluates EXP while MOD_OR_STATE is the current module or current
5852 dynamic state (as appropriate). This is done by setting the
5853 current module (or dynamic state) to MOD_OR_STATE, invoking
5854 scm_primitive_eval on EXP, and then restoring the current module
5855 (or dynamic state) to the value it had previously. That is,
5856 while EXP is evaluated, changes to the current module (or dynamic
5857 state) are tracked, but these changes do not persist when
5860 For each level of evals, there are two variants, distinguished by a
5861 _x suffix: the ordinary variant does not modify EXP while the _x
5862 variant can destructively modify EXP into something completely
5863 unintelligible. A Scheme data structure passed as EXP to one of the
5864 _x variants should not ever be used again for anything. So when in
5865 doubt, use the ordinary variant.
5870 scm_i_eval_x (SCM exp
, SCM env
)
5872 if (scm_is_symbol (exp
))
5873 return *scm_lookupcar (scm_cons (exp
, SCM_UNDEFINED
), env
, 1);
5875 return SCM_I_XEVAL (exp
, env
);
5879 scm_i_eval (SCM exp
, SCM env
)
5881 exp
= scm_copy_tree (exp
);
5882 if (scm_is_symbol (exp
))
5883 return *scm_lookupcar (scm_cons (exp
, SCM_UNDEFINED
), env
, 1);
5885 return SCM_I_XEVAL (exp
, env
);
5889 scm_primitive_eval_x (SCM exp
)
5892 SCM transformer
= scm_current_module_transformer ();
5893 if (SCM_NIMP (transformer
))
5894 exp
= scm_call_1 (transformer
, exp
);
5895 env
= scm_top_level_env (scm_current_module_lookup_closure ());
5896 return scm_i_eval_x (exp
, env
);
5899 SCM_DEFINE (scm_primitive_eval
, "primitive-eval", 1, 0, 0,
5901 "Evaluate @var{exp} in the top-level environment specified by\n"
5902 "the current module.")
5903 #define FUNC_NAME s_scm_primitive_eval
5906 SCM transformer
= scm_current_module_transformer ();
5907 if (scm_is_true (transformer
))
5908 exp
= scm_call_1 (transformer
, exp
);
5909 env
= scm_top_level_env (scm_current_module_lookup_closure ());
5910 return scm_i_eval (exp
, env
);
5915 /* Eval does not take the second arg optionally. This is intentional
5916 * in order to be R5RS compatible, and to prepare for the new module
5917 * system, where we would like to make the choice of evaluation
5918 * environment explicit. */
5921 scm_eval_x (SCM exp
, SCM module_or_state
)
5925 scm_dynwind_begin (SCM_F_DYNWIND_REWINDABLE
);
5926 if (scm_is_dynamic_state (module_or_state
))
5927 scm_dynwind_current_dynamic_state (module_or_state
);
5929 scm_dynwind_current_module (module_or_state
);
5931 res
= scm_primitive_eval_x (exp
);
5937 SCM_DEFINE (scm_eval
, "eval", 2, 0, 0,
5938 (SCM exp
, SCM module_or_state
),
5939 "Evaluate @var{exp}, a list representing a Scheme expression,\n"
5940 "in the top-level environment specified by\n"
5941 "@var{module_or_state}.\n"
5942 "While @var{exp} is evaluated (using @code{primitive-eval}),\n"
5943 "@var{module_or_state} is made the current module when\n"
5944 "it is a module, or the current dynamic state when it is\n"
5946 "Example: (eval '(+ 1 2) (interaction-environment))")
5947 #define FUNC_NAME s_scm_eval
5951 scm_dynwind_begin (SCM_F_DYNWIND_REWINDABLE
);
5952 if (scm_is_dynamic_state (module_or_state
))
5953 scm_dynwind_current_dynamic_state (module_or_state
);
5955 scm_dynwind_current_module (module_or_state
);
5957 res
= scm_primitive_eval (exp
);
5965 /* At this point, deval and scm_dapply are generated.
5972 #if (SCM_ENABLE_DEPRECATED == 1)
5974 /* Deprecated in guile 1.7.0 on 2004-03-29. */
5975 SCM
scm_ceval (SCM x
, SCM env
)
5977 if (scm_is_pair (x
))
5978 return ceval (x
, env
);
5979 else if (scm_is_symbol (x
))
5980 return *scm_lookupcar (scm_cons (x
, SCM_UNDEFINED
), env
, 1);
5982 return SCM_I_XEVAL (x
, env
);
5985 /* Deprecated in guile 1.7.0 on 2004-03-29. */
5986 SCM
scm_deval (SCM x
, SCM env
)
5988 if (scm_is_pair (x
))
5989 return deval (x
, env
);
5990 else if (scm_is_symbol (x
))
5991 return *scm_lookupcar (scm_cons (x
, SCM_UNDEFINED
), env
, 1);
5993 return SCM_I_XEVAL (x
, env
);
5997 dispatching_eval (SCM x
, SCM env
)
5999 if (scm_debug_mode_p
)
6000 return scm_deval (x
, env
);
6002 return scm_ceval (x
, env
);
6005 /* Deprecated in guile 1.7.0 on 2004-03-29. */
6006 SCM (*scm_ceval_ptr
) (SCM x
, SCM env
) = dispatching_eval
;
6014 scm_i_pthread_mutex_init (&source_mutex
,
6015 scm_i_pthread_mutexattr_recursive
);
6017 scm_init_opts (scm_evaluator_traps
,
6018 scm_evaluator_trap_table
,
6019 SCM_N_EVALUATOR_TRAPS
);
6020 scm_init_opts (scm_eval_options_interface
,
6022 SCM_N_EVAL_OPTIONS
);
6024 scm_tc16_promise
= scm_make_smob_type ("promise", 0);
6025 scm_set_smob_mark (scm_tc16_promise
, promise_mark
);
6026 scm_set_smob_free (scm_tc16_promise
, promise_free
);
6027 scm_set_smob_print (scm_tc16_promise
, promise_print
);
6029 undefineds
= scm_list_1 (SCM_UNDEFINED
);
6030 SCM_SETCDR (undefineds
, undefineds
);
6031 scm_permanent_object (undefineds
);
6033 scm_listofnull
= scm_list_1 (SCM_EOL
);
6035 f_apply
= scm_c_define_subr ("apply", scm_tc7_lsubr_2
, scm_apply
);
6036 scm_permanent_object (f_apply
);
6038 #include "libguile/eval.x"
6040 scm_add_feature ("delay");