1 /* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004
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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 /* This file is read twice in order to produce debugging versions of ceval and
22 * scm_apply. These functions, deval and scm_dapply, are produced when we
23 * define the preprocessor macro DEVAL. The file is divided into sections
24 * which are treated differently with respect to DEVAL. The heads of these
25 * sections are marked with the string "SECTION:". */
27 /* SECTION: This code is compiled once.
34 #include "libguile/__scm.h"
38 /* AIX requires this to be the first thing in the file. The #pragma
39 directive is indented so pre-ANSI compilers will ignore it, rather
48 # ifndef alloca /* predefined by HP cc +Olibcalls */
56 #include "libguile/_scm.h"
57 #include "libguile/alist.h"
58 #include "libguile/async.h"
59 #include "libguile/continuations.h"
60 #include "libguile/debug.h"
61 #include "libguile/deprecation.h"
62 #include "libguile/dynwind.h"
63 #include "libguile/eq.h"
64 #include "libguile/feature.h"
65 #include "libguile/fluids.h"
66 #include "libguile/futures.h"
67 #include "libguile/goops.h"
68 #include "libguile/hash.h"
69 #include "libguile/hashtab.h"
70 #include "libguile/lang.h"
71 #include "libguile/list.h"
72 #include "libguile/macros.h"
73 #include "libguile/modules.h"
74 #include "libguile/objects.h"
75 #include "libguile/ports.h"
76 #include "libguile/print.h"
77 #include "libguile/procprop.h"
78 #include "libguile/root.h"
79 #include "libguile/smob.h"
80 #include "libguile/srcprop.h"
81 #include "libguile/stackchk.h"
82 #include "libguile/strings.h"
83 #include "libguile/throw.h"
84 #include "libguile/validate.h"
85 #include "libguile/values.h"
86 #include "libguile/vectors.h"
88 #include "libguile/eval.h"
92 static SCM
unmemoize_exprs (SCM expr
, SCM env
);
93 static SCM
canonicalize_define (SCM expr
);
94 static SCM
*scm_lookupcar1 (SCM vloc
, SCM genv
, int check
);
95 static SCM
unmemoize_builtin_macro (SCM expr
, SCM env
);
101 * This section defines the message strings for the syntax errors that can be
102 * detected during memoization and the functions and macros that shall be
103 * called by the memoizer code to signal syntax errors. */
106 /* Syntax errors that can be detected during memoization: */
108 /* Circular or improper lists do not form valid scheme expressions. If a
109 * circular list or an improper list is detected in a place where a scheme
110 * expression is expected, a 'Bad expression' error is signalled. */
111 static const char s_bad_expression
[] = "Bad expression";
113 /* If a form is detected that holds a different number of expressions than are
114 * required in that context, a 'Missing or extra expression' error is
116 static const char s_expression
[] = "Missing or extra expression in";
118 /* If a form is detected that holds less expressions than are required in that
119 * context, a 'Missing expression' error is signalled. */
120 static const char s_missing_expression
[] = "Missing expression in";
122 /* If a form is detected that holds more expressions than are allowed in that
123 * context, an 'Extra expression' error is signalled. */
124 static const char s_extra_expression
[] = "Extra expression in";
126 /* The empty combination '()' is not allowed as an expression in scheme. If
127 * it is detected in a place where an expression is expected, an 'Illegal
128 * empty combination' error is signalled. Note: If you encounter this error
129 * message, it is very likely that you intended to denote the empty list. To
130 * do so, you need to quote the empty list like (quote ()) or '(). */
131 static const char s_empty_combination
[] = "Illegal empty combination";
133 /* A body may hold an arbitrary number of internal defines, followed by a
134 * non-empty sequence of expressions. If a body with an empty sequence of
135 * expressions is detected, a 'Missing body expression' error is signalled.
137 static const char s_missing_body_expression
[] = "Missing body expression in";
139 /* A body may hold an arbitrary number of internal defines, followed by a
140 * non-empty sequence of expressions. Each the definitions and the
141 * expressions may be grouped arbitraryly with begin, but it is not allowed to
142 * mix definitions and expressions. If a define form in a body mixes
143 * definitions and expressions, a 'Mixed definitions and expressions' error is
145 static const char s_mixed_body_forms
[] = "Mixed definitions and expressions in";
146 /* Definitions are only allowed on the top level and at the start of a body.
147 * If a definition is detected anywhere else, a 'Bad define placement' error
149 static const char s_bad_define
[] = "Bad define placement";
151 /* Case or cond expressions must have at least one clause. If a case or cond
152 * expression without any clauses is detected, a 'Missing clauses' error is
154 static const char s_missing_clauses
[] = "Missing clauses";
156 /* If there is an 'else' clause in a case or a cond statement, it must be the
157 * last clause. If after the 'else' case clause further clauses are detected,
158 * a 'Misplaced else clause' error is signalled. */
159 static const char s_misplaced_else_clause
[] = "Misplaced else clause";
161 /* If a case clause is detected that is not in the format
162 * (<label(s)> <expression1> <expression2> ...)
163 * a 'Bad case clause' error is signalled. */
164 static const char s_bad_case_clause
[] = "Bad case clause";
166 /* If a case clause is detected where the <label(s)> element is neither a
167 * proper list nor (in case of the last clause) the syntactic keyword 'else',
168 * a 'Bad case labels' error is signalled. Note: If you encounter this error
169 * for an else-clause which seems to be syntactically correct, check if 'else'
170 * is really a syntactic keyword in that context. If 'else' is bound in the
171 * local or global environment, it is not considered a syntactic keyword, but
172 * will be treated as any other variable. */
173 static const char s_bad_case_labels
[] = "Bad case labels";
175 /* In a case statement all labels have to be distinct. If in a case statement
176 * a label occurs more than once, a 'Duplicate case label' error is
178 static const char s_duplicate_case_label
[] = "Duplicate case label";
180 /* If a cond clause is detected that is not in one of the formats
181 * (<test> <expression1> ...) or (else <expression1> <expression2> ...)
182 * a 'Bad cond clause' error is signalled. */
183 static const char s_bad_cond_clause
[] = "Bad cond clause";
185 /* If a cond clause is detected that uses the alternate '=>' form, but does
186 * not hold a recipient element for the test result, a 'Missing recipient'
187 * error is signalled. */
188 static const char s_missing_recipient
[] = "Missing recipient in";
190 /* If in a position where a variable name is required some other object is
191 * detected, a 'Bad variable' error is signalled. */
192 static const char s_bad_variable
[] = "Bad variable";
194 /* Bindings for forms like 'let' and 'do' have to be given in a proper,
195 * possibly empty list. If any other object is detected in a place where a
196 * list of bindings was required, a 'Bad bindings' error is signalled. */
197 static const char s_bad_bindings
[] = "Bad bindings";
199 /* Depending on the syntactic context, a binding has to be in the format
200 * (<variable> <expression>) or (<variable> <expression1> <expression2>).
201 * If anything else is detected in a place where a binding was expected, a
202 * 'Bad binding' error is signalled. */
203 static const char s_bad_binding
[] = "Bad binding";
205 /* Some syntactic forms don't allow variable names to appear more than once in
206 * a list of bindings. If such a situation is nevertheless detected, a
207 * 'Duplicate binding' error is signalled. */
208 static const char s_duplicate_binding
[] = "Duplicate binding";
210 /* If the exit form of a 'do' expression is not in the format
211 * (<test> <expression> ...)
212 * a 'Bad exit clause' error is signalled. */
213 static const char s_bad_exit_clause
[] = "Bad exit clause";
215 /* The formal function arguments of a lambda expression have to be either a
216 * single symbol or a non-cyclic list. For anything else a 'Bad formals'
217 * error is signalled. */
218 static const char s_bad_formals
[] = "Bad formals";
220 /* If in a lambda expression something else than a symbol is detected at a
221 * place where a formal function argument is required, a 'Bad formal' error is
223 static const char s_bad_formal
[] = "Bad formal";
225 /* If in the arguments list of a lambda expression an argument name occurs
226 * more than once, a 'Duplicate formal' error is signalled. */
227 static const char s_duplicate_formal
[] = "Duplicate formal";
229 /* If the evaluation of an unquote-splicing expression gives something else
230 * than a proper list, a 'Non-list result for unquote-splicing' error is
232 static const char s_splicing
[] = "Non-list result for unquote-splicing";
234 /* If something else than an exact integer is detected as the argument for
235 * @slot-ref and @slot-set!, a 'Bad slot number' error is signalled. */
236 static const char s_bad_slot_number
[] = "Bad slot number";
239 /* Signal a syntax error. We distinguish between the form that caused the
240 * error and the enclosing expression. The error message will print out as
241 * shown in the following pattern. The file name and line number are only
242 * given when they can be determined from the erroneous form or from the
243 * enclosing expression.
245 * <filename>: In procedure memoization:
246 * <filename>: In file <name>, line <nr>: <error-message> in <expression>. */
248 SCM_SYMBOL (syntax_error_key
, "syntax-error");
250 /* The prototype is needed to indicate that the function does not return. */
252 syntax_error (const char* const, const SCM
, const SCM
) SCM_NORETURN
;
255 syntax_error (const char* const msg
, const SCM form
, const SCM expr
)
257 SCM msg_string
= scm_from_locale_string (msg
);
258 SCM filename
= SCM_BOOL_F
;
259 SCM linenr
= SCM_BOOL_F
;
263 if (scm_is_pair (form
))
265 filename
= scm_source_property (form
, scm_sym_filename
);
266 linenr
= scm_source_property (form
, scm_sym_line
);
269 if (scm_is_false (filename
) && scm_is_false (linenr
) && scm_is_pair (expr
))
271 filename
= scm_source_property (expr
, scm_sym_filename
);
272 linenr
= scm_source_property (expr
, scm_sym_line
);
275 if (!SCM_UNBNDP (expr
))
277 if (scm_is_true (filename
))
279 format
= "In file ~S, line ~S: ~A ~S in expression ~S.";
280 args
= scm_list_5 (filename
, linenr
, msg_string
, form
, expr
);
282 else if (scm_is_true (linenr
))
284 format
= "In line ~S: ~A ~S in expression ~S.";
285 args
= scm_list_4 (linenr
, msg_string
, form
, expr
);
289 format
= "~A ~S in expression ~S.";
290 args
= scm_list_3 (msg_string
, form
, expr
);
295 if (scm_is_true (filename
))
297 format
= "In file ~S, line ~S: ~A ~S.";
298 args
= scm_list_4 (filename
, linenr
, msg_string
, form
);
300 else if (scm_is_true (linenr
))
302 format
= "In line ~S: ~A ~S.";
303 args
= scm_list_3 (linenr
, msg_string
, form
);
308 args
= scm_list_2 (msg_string
, form
);
312 scm_error (syntax_error_key
, "memoization", format
, args
, SCM_BOOL_F
);
316 /* Shortcut macros to simplify syntax error handling. */
317 #define ASSERT_SYNTAX(cond, message, form) \
318 { if (!(cond)) syntax_error (message, form, SCM_UNDEFINED); }
319 #define ASSERT_SYNTAX_2(cond, message, form, expr) \
320 { if (!(cond)) syntax_error (message, form, expr); }
326 * Ilocs are memoized references to variables in local environment frames.
327 * They are represented as three values: The relative offset of the
328 * environment frame, the number of the binding within that frame, and a
329 * boolean value indicating whether the binding is the last binding in the
332 * Frame numbers have 11 bits, relative offsets have 12 bits.
335 #define SCM_ILOC00 SCM_MAKE_ITAG8(0L, scm_tc8_iloc)
336 #define SCM_IFRINC (0x00000100L)
337 #define SCM_ICDR (0x00080000L)
338 #define SCM_IDINC (0x00100000L)
339 #define SCM_IFRAME(n) ((long)((SCM_ICDR-SCM_IFRINC)>>8) \
340 & (SCM_UNPACK (n) >> 8))
341 #define SCM_IDIST(n) (SCM_UNPACK (n) >> 20)
342 #define SCM_ICDRP(n) (SCM_ICDR & SCM_UNPACK (n))
343 #define SCM_IDSTMSK (-SCM_IDINC)
344 #define SCM_IFRAMEMAX ((1<<11)-1)
345 #define SCM_IDISTMAX ((1<<12)-1)
346 #define SCM_MAKE_ILOC(frame_nr, binding_nr, last_p) \
349 + ((binding_nr) << 20) \
350 + ((last_p) ? SCM_ICDR : 0) \
354 scm_i_print_iloc (SCM iloc
, SCM port
)
356 scm_puts ("#@", port
);
357 scm_intprint ((long) SCM_IFRAME (iloc
), 10, port
);
358 scm_putc (SCM_ICDRP (iloc
) ? '-' : '+', port
);
359 scm_intprint ((long) SCM_IDIST (iloc
), 10, port
);
362 #if (SCM_DEBUG_DEBUGGING_SUPPORT == 1)
364 SCM
scm_dbg_make_iloc (SCM frame
, SCM binding
, SCM cdrp
);
366 SCM_DEFINE (scm_dbg_make_iloc
, "dbg-make-iloc", 3, 0, 0,
367 (SCM frame
, SCM binding
, SCM cdrp
),
368 "Return a new iloc with frame offset @var{frame}, binding\n"
369 "offset @var{binding} and the cdr flag @var{cdrp}.")
370 #define FUNC_NAME s_scm_dbg_make_iloc
372 return SCM_MAKE_ILOC (scm_to_unsigned_integer (frame
, 0, SCM_IFRAME_MAX
),
373 scm_to_unsigned_integer (binding
, 0, SCM_IDIST_MAX
),
378 SCM
scm_dbg_iloc_p (SCM obj
);
380 SCM_DEFINE (scm_dbg_iloc_p
, "dbg-iloc?", 1, 0, 0,
382 "Return @code{#t} if @var{obj} is an iloc.")
383 #define FUNC_NAME s_scm_dbg_iloc_p
385 return scm_from_bool (SCM_ILOCP (obj
));
393 /* {Evaluator byte codes (isyms)}
396 #define ISYMNUM(n) (SCM_ITAG8_DATA (n))
398 /* This table must agree with the list of SCM_IM_ constants in tags.h */
399 static const char *const isymnames
[] =
416 "#@call-with-current-continuation",
422 "#@call-with-values",
430 scm_i_print_isym (SCM isym
, SCM port
)
432 const size_t isymnum
= ISYMNUM (isym
);
433 if (isymnum
< (sizeof isymnames
/ sizeof (char *)))
434 scm_puts (isymnames
[isymnum
], port
);
436 scm_ipruk ("isym", isym
, port
);
441 /* The function lookup_symbol is used during memoization: Lookup the symbol in
442 * the environment. If there is no binding for the symbol, SCM_UNDEFINED is
443 * returned. If the symbol is a global variable, the variable object to which
444 * the symbol is bound is returned. Finally, if the symbol is a local
445 * variable the corresponding iloc object is returned. */
447 /* A helper function for lookup_symbol: Try to find the symbol in the top
448 * level environment frame. The function returns SCM_UNDEFINED if the symbol
449 * is unbound and it returns a variable object if the symbol is a global
452 lookup_global_symbol (const SCM symbol
, const SCM top_level
)
454 const SCM variable
= scm_sym2var (symbol
, top_level
, SCM_BOOL_F
);
455 if (scm_is_false (variable
))
456 return SCM_UNDEFINED
;
462 lookup_symbol (const SCM symbol
, const SCM env
)
465 unsigned int frame_nr
;
467 for (frame_idx
= env
, frame_nr
= 0;
468 !scm_is_null (frame_idx
);
469 frame_idx
= SCM_CDR (frame_idx
), ++frame_nr
)
471 const SCM frame
= SCM_CAR (frame_idx
);
472 if (scm_is_pair (frame
))
474 /* frame holds a local environment frame */
476 unsigned int symbol_nr
;
478 for (symbol_idx
= SCM_CAR (frame
), symbol_nr
= 0;
479 scm_is_pair (symbol_idx
);
480 symbol_idx
= SCM_CDR (symbol_idx
), ++symbol_nr
)
482 if (scm_is_eq (SCM_CAR (symbol_idx
), symbol
))
483 /* found the symbol, therefore return the iloc */
484 return SCM_MAKE_ILOC (frame_nr
, symbol_nr
, 0);
486 if (scm_is_eq (symbol_idx
, symbol
))
487 /* found the symbol as the last element of the current frame */
488 return SCM_MAKE_ILOC (frame_nr
, symbol_nr
, 1);
492 /* no more local environment frames */
493 return lookup_global_symbol (symbol
, frame
);
497 return lookup_global_symbol (symbol
, SCM_BOOL_F
);
501 /* Return true if the symbol is - from the point of view of a macro
502 * transformer - a literal in the sense specified in chapter "pattern
503 * language" of R5RS. In the code below, however, we don't match the
504 * definition of R5RS exactly: It returns true if the identifier has no
505 * binding or if it is a syntactic keyword. */
507 literal_p (const SCM symbol
, const SCM env
)
509 const SCM variable
= lookup_symbol (symbol
, env
);
510 if (SCM_UNBNDP (variable
))
512 if (SCM_VARIABLEP (variable
) && SCM_MACROP (SCM_VARIABLE_REF (variable
)))
519 /* Return true if the expression is self-quoting in the memoized code. Thus,
520 * some other objects (like e. g. vectors) are reported as self-quoting, which
521 * according to R5RS would need to be quoted. */
523 is_self_quoting_p (const SCM expr
)
525 if (scm_is_pair (expr
))
527 else if (scm_is_symbol (expr
))
529 else if (scm_is_null (expr
))
535 SCM_SYMBOL (sym_three_question_marks
, "???");
538 unmemoize_expression (const SCM expr
, const SCM env
)
540 if (SCM_ILOCP (expr
))
543 unsigned long int frame_nr
;
545 unsigned long int symbol_nr
;
547 for (frame_idx
= env
, frame_nr
= SCM_IFRAME (expr
);
549 frame_idx
= SCM_CDR (frame_idx
), --frame_nr
)
551 for (symbol_idx
= SCM_CAAR (frame_idx
), symbol_nr
= SCM_IDIST (expr
);
553 symbol_idx
= SCM_CDR (symbol_idx
), --symbol_nr
)
555 return SCM_ICDRP (expr
) ? symbol_idx
: SCM_CAR (symbol_idx
);
557 else if (SCM_VARIABLEP (expr
))
559 const SCM sym
= scm_module_reverse_lookup (scm_env_module (env
), expr
);
560 return scm_is_true (sym
) ? sym
: sym_three_question_marks
;
562 else if (scm_is_simple_vector (expr
))
564 return scm_list_2 (scm_sym_quote
, expr
);
566 else if (!scm_is_pair (expr
))
570 else if (SCM_ISYMP (SCM_CAR (expr
)))
572 return unmemoize_builtin_macro (expr
, env
);
576 return unmemoize_exprs (expr
, env
);
582 unmemoize_exprs (const SCM exprs
, const SCM env
)
584 SCM r_result
= SCM_EOL
;
585 SCM expr_idx
= exprs
;
588 /* Note that due to the current lazy memoizer we may find partially memoized
589 * code during execution. In such code we have to expect improper lists of
590 * expressions: On the one hand, for such code syntax checks have not yet
591 * fully been performed, on the other hand, there may be even legal code
592 * like '(a . b) appear as an improper list of expressions as long as the
593 * quote expression is still in its unmemoized form. For this reason, the
594 * following code handles improper lists of expressions until memoization
595 * and execution have been completely separated. */
596 for (; scm_is_pair (expr_idx
); expr_idx
= SCM_CDR (expr_idx
))
598 const SCM expr
= SCM_CAR (expr_idx
);
600 /* In partially memoized code, lists of expressions that stem from a
601 * body form may start with an ISYM if the body itself has not yet been
602 * memoized. This isym is just an internal marker to indicate that the
603 * body still needs to be memoized. An isym may occur at the very
604 * beginning of the body or after one or more comment strings. It is
605 * dropped during unmemoization. */
606 if (!SCM_ISYMP (expr
))
608 um_expr
= unmemoize_expression (expr
, env
);
609 r_result
= scm_cons (um_expr
, r_result
);
612 um_expr
= unmemoize_expression (expr_idx
, env
);
613 if (!scm_is_null (r_result
))
615 const SCM result
= scm_reverse_x (r_result
, SCM_UNDEFINED
);
616 SCM_SETCDR (r_result
, um_expr
);
626 /* Rewrite the body (which is given as the list of expressions forming the
627 * body) into its internal form. The internal form of a body (<expr> ...) is
628 * just the body itself, but prefixed with an ISYM that denotes to what kind
629 * of outer construct this body belongs: (<ISYM> <expr> ...). A lambda body
630 * starts with SCM_IM_LAMBDA, for example, a body of a let starts with
633 * It is assumed that the calling expression has already made sure that the
634 * body is a proper list. */
636 m_body (SCM op
, SCM exprs
)
638 /* Don't add another ISYM if one is present already. */
639 if (SCM_ISYMP (SCM_CAR (exprs
)))
642 return scm_cons (op
, exprs
);
646 /* The function m_expand_body memoizes a proper list of expressions forming a
647 * body. This function takes care of dealing with internal defines and
648 * transforming them into an equivalent letrec expression. The list of
649 * expressions is rewritten in place. */
651 /* This is a helper function for m_expand_body. If the argument expression is
652 * a symbol that denotes a syntactic keyword, the corresponding macro object
653 * is returned, in all other cases the function returns SCM_UNDEFINED. */
655 try_macro_lookup (const SCM expr
, const SCM env
)
657 if (scm_is_symbol (expr
))
659 const SCM variable
= lookup_symbol (expr
, env
);
660 if (SCM_VARIABLEP (variable
))
662 const SCM value
= SCM_VARIABLE_REF (variable
);
663 if (SCM_MACROP (value
))
668 return SCM_UNDEFINED
;
671 /* This is a helper function for m_expand_body. It expands user macros,
672 * because for the correct translation of a body we need to know whether they
673 * expand to a definition. */
675 expand_user_macros (SCM expr
, const SCM env
)
677 while (scm_is_pair (expr
))
679 const SCM car_expr
= SCM_CAR (expr
);
680 const SCM new_car
= expand_user_macros (car_expr
, env
);
681 const SCM value
= try_macro_lookup (new_car
, env
);
683 if (SCM_MACROP (value
) && SCM_MACRO_TYPE (value
) == 2)
685 /* User macros transform code into code. */
686 expr
= scm_call_2 (SCM_MACRO_CODE (value
), expr
, env
);
687 /* We need to reiterate on the transformed code. */
691 /* No user macro: return. */
692 SCM_SETCAR (expr
, new_car
);
700 /* This is a helper function for m_expand_body. It determines if a given form
701 * represents an application of a given built-in macro. The built-in macro to
702 * check for is identified by its syntactic keyword. The form is an
703 * application of the given macro if looking up the car of the form in the
704 * given environment actually returns the built-in macro. */
706 is_system_macro_p (const SCM syntactic_keyword
, const SCM form
, const SCM env
)
708 if (scm_is_pair (form
))
710 const SCM car_form
= SCM_CAR (form
);
711 const SCM value
= try_macro_lookup (car_form
, env
);
712 if (SCM_BUILTIN_MACRO_P (value
))
714 const SCM macro_name
= scm_macro_name (value
);
715 return scm_is_eq (macro_name
, syntactic_keyword
);
723 m_expand_body (const SCM forms
, const SCM env
)
725 /* The first body form can be skipped since it is known to be the ISYM that
726 * was prepended to the body by m_body. */
727 SCM cdr_forms
= SCM_CDR (forms
);
728 SCM form_idx
= cdr_forms
;
729 SCM definitions
= SCM_EOL
;
730 SCM sequence
= SCM_EOL
;
732 /* According to R5RS, the list of body forms consists of two parts: a number
733 * (maybe zero) of definitions, followed by a non-empty sequence of
734 * expressions. Each the definitions and the expressions may be grouped
735 * arbitrarily with begin, but it is not allowed to mix definitions and
736 * expressions. The task of the following loop therefore is to split the
737 * list of body forms into the list of definitions and the sequence of
739 while (!scm_is_null (form_idx
))
741 const SCM form
= SCM_CAR (form_idx
);
742 const SCM new_form
= expand_user_macros (form
, env
);
743 if (is_system_macro_p (scm_sym_define
, new_form
, env
))
745 definitions
= scm_cons (new_form
, definitions
);
746 form_idx
= SCM_CDR (form_idx
);
748 else if (is_system_macro_p (scm_sym_begin
, new_form
, env
))
750 /* We have encountered a group of forms. This has to be either a
751 * (possibly empty) group of (possibly further grouped) definitions,
752 * or a non-empty group of (possibly further grouped)
754 const SCM grouped_forms
= SCM_CDR (new_form
);
755 unsigned int found_definition
= 0;
756 unsigned int found_expression
= 0;
757 SCM grouped_form_idx
= grouped_forms
;
758 while (!found_expression
&& !scm_is_null (grouped_form_idx
))
760 const SCM inner_form
= SCM_CAR (grouped_form_idx
);
761 const SCM new_inner_form
= expand_user_macros (inner_form
, env
);
762 if (is_system_macro_p (scm_sym_define
, new_inner_form
, env
))
764 found_definition
= 1;
765 definitions
= scm_cons (new_inner_form
, definitions
);
766 grouped_form_idx
= SCM_CDR (grouped_form_idx
);
768 else if (is_system_macro_p (scm_sym_begin
, new_inner_form
, env
))
770 const SCM inner_group
= SCM_CDR (new_inner_form
);
772 = scm_append (scm_list_2 (inner_group
,
773 SCM_CDR (grouped_form_idx
)));
777 /* The group marks the start of the expressions of the body.
778 * We have to make sure that within the same group we have
779 * not encountered a definition before. */
780 ASSERT_SYNTAX (!found_definition
, s_mixed_body_forms
, form
);
781 found_expression
= 1;
782 grouped_form_idx
= SCM_EOL
;
786 /* We have finished processing the group. If we have not yet
787 * encountered an expression we continue processing the forms of the
788 * body to collect further definition forms. Otherwise, the group
789 * marks the start of the sequence of expressions of the body. */
790 if (!found_expression
)
792 form_idx
= SCM_CDR (form_idx
);
802 /* We have detected a form which is no definition. This marks the
803 * start of the sequence of expressions of the body. */
809 /* FIXME: forms does not hold information about the file location. */
810 ASSERT_SYNTAX (scm_is_pair (sequence
), s_missing_body_expression
, cdr_forms
);
812 if (!scm_is_null (definitions
))
816 SCM letrec_expression
;
817 SCM new_letrec_expression
;
819 SCM bindings
= SCM_EOL
;
820 for (definition_idx
= definitions
;
821 !scm_is_null (definition_idx
);
822 definition_idx
= SCM_CDR (definition_idx
))
824 const SCM definition
= SCM_CAR (definition_idx
);
825 const SCM canonical_definition
= canonicalize_define (definition
);
826 const SCM binding
= SCM_CDR (canonical_definition
);
827 bindings
= scm_cons (binding
, bindings
);
830 letrec_tail
= scm_cons (bindings
, sequence
);
831 /* FIXME: forms does not hold information about the file location. */
832 letrec_expression
= scm_cons_source (forms
, scm_sym_letrec
, letrec_tail
);
833 new_letrec_expression
= scm_m_letrec (letrec_expression
, env
);
834 SCM_SETCAR (forms
, new_letrec_expression
);
835 SCM_SETCDR (forms
, SCM_EOL
);
839 SCM_SETCAR (forms
, SCM_CAR (sequence
));
840 SCM_SETCDR (forms
, SCM_CDR (sequence
));
845 macroexp (SCM x
, SCM env
)
847 SCM res
, proc
, orig_sym
;
849 /* Don't bother to produce error messages here. We get them when we
850 eventually execute the code for real. */
853 orig_sym
= SCM_CAR (x
);
854 if (!scm_is_symbol (orig_sym
))
858 SCM
*proc_ptr
= scm_lookupcar1 (x
, env
, 0);
859 if (proc_ptr
== NULL
)
861 /* We have lost the race. */
867 /* Only handle memoizing macros. `Acros' and `macros' are really
868 special forms and should not be evaluated here. */
870 if (!SCM_MACROP (proc
)
871 || (SCM_MACRO_TYPE (proc
) != 2 && !SCM_BUILTIN_MACRO_P (proc
)))
874 SCM_SETCAR (x
, orig_sym
); /* Undo memoizing effect of lookupcar */
875 res
= scm_call_2 (SCM_MACRO_CODE (proc
), x
, env
);
877 if (scm_ilength (res
) <= 0)
878 res
= scm_list_2 (SCM_IM_BEGIN
, res
);
881 SCM_SETCAR (x
, SCM_CAR (res
));
882 SCM_SETCDR (x
, SCM_CDR (res
));
888 /* Start of the memoizers for the standard R5RS builtin macros. */
891 SCM_SYNTAX (s_and
, "and", scm_i_makbimacro
, scm_m_and
);
892 SCM_GLOBAL_SYMBOL (scm_sym_and
, s_and
);
895 scm_m_and (SCM expr
, SCM env SCM_UNUSED
)
897 const SCM cdr_expr
= SCM_CDR (expr
);
898 const long length
= scm_ilength (cdr_expr
);
900 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
904 /* Special case: (and) is replaced by #t. */
909 SCM_SETCAR (expr
, SCM_IM_AND
);
915 unmemoize_and (const SCM expr
, const SCM env
)
917 return scm_cons (scm_sym_and
, unmemoize_exprs (SCM_CDR (expr
), env
));
921 SCM_SYNTAX (s_begin
, "begin", scm_i_makbimacro
, scm_m_begin
);
922 SCM_GLOBAL_SYMBOL (scm_sym_begin
, s_begin
);
925 scm_m_begin (SCM expr
, SCM env SCM_UNUSED
)
927 const SCM cdr_expr
= SCM_CDR (expr
);
928 /* Dirk:FIXME:: An empty begin clause is not generally allowed by R5RS.
929 * That means, there should be a distinction between uses of begin where an
930 * empty clause is OK and where it is not. */
931 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
933 SCM_SETCAR (expr
, SCM_IM_BEGIN
);
938 unmemoize_begin (const SCM expr
, const SCM env
)
940 return scm_cons (scm_sym_begin
, unmemoize_exprs (SCM_CDR (expr
), env
));
944 SCM_SYNTAX (s_case
, "case", scm_i_makbimacro
, scm_m_case
);
945 SCM_GLOBAL_SYMBOL (scm_sym_case
, s_case
);
946 SCM_GLOBAL_SYMBOL (scm_sym_else
, "else");
949 scm_m_case (SCM expr
, SCM env
)
952 SCM all_labels
= SCM_EOL
;
954 /* Check, whether 'else is a literal, i. e. not bound to a value. */
955 const int else_literal_p
= literal_p (scm_sym_else
, env
);
957 const SCM cdr_expr
= SCM_CDR (expr
);
958 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
959 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_clauses
, expr
);
961 clauses
= SCM_CDR (cdr_expr
);
962 while (!scm_is_null (clauses
))
966 const SCM clause
= SCM_CAR (clauses
);
967 ASSERT_SYNTAX_2 (scm_ilength (clause
) >= 2,
968 s_bad_case_clause
, clause
, expr
);
970 labels
= SCM_CAR (clause
);
971 if (scm_is_pair (labels
))
973 ASSERT_SYNTAX_2 (scm_ilength (labels
) >= 0,
974 s_bad_case_labels
, labels
, expr
);
975 all_labels
= scm_append (scm_list_2 (labels
, all_labels
));
977 else if (scm_is_null (labels
))
979 /* The list of labels is empty. According to R5RS this is allowed.
980 * It means that the sequence of expressions will never be executed.
981 * Therefore, as an optimization, we could remove the whole
986 ASSERT_SYNTAX_2 (scm_is_eq (labels
, scm_sym_else
) && else_literal_p
,
987 s_bad_case_labels
, labels
, expr
);
988 ASSERT_SYNTAX_2 (scm_is_null (SCM_CDR (clauses
)),
989 s_misplaced_else_clause
, clause
, expr
);
992 /* build the new clause */
993 if (scm_is_eq (labels
, scm_sym_else
))
994 SCM_SETCAR (clause
, SCM_IM_ELSE
);
996 clauses
= SCM_CDR (clauses
);
999 /* Check whether all case labels are distinct. */
1000 for (; !scm_is_null (all_labels
); all_labels
= SCM_CDR (all_labels
))
1002 const SCM label
= SCM_CAR (all_labels
);
1003 ASSERT_SYNTAX_2 (scm_is_false (scm_c_memq (label
, SCM_CDR (all_labels
))),
1004 s_duplicate_case_label
, label
, expr
);
1007 SCM_SETCAR (expr
, SCM_IM_CASE
);
1012 unmemoize_case (const SCM expr
, const SCM env
)
1014 const SCM um_key_expr
= unmemoize_expression (SCM_CADR (expr
), env
);
1015 SCM um_clauses
= SCM_EOL
;
1018 for (clause_idx
= SCM_CDDR (expr
);
1019 !scm_is_null (clause_idx
);
1020 clause_idx
= SCM_CDR (clause_idx
))
1022 const SCM clause
= SCM_CAR (clause_idx
);
1023 const SCM labels
= SCM_CAR (clause
);
1024 const SCM exprs
= SCM_CDR (clause
);
1026 const SCM um_exprs
= unmemoize_exprs (exprs
, env
);
1027 const SCM um_labels
= (scm_is_eq (labels
, SCM_IM_ELSE
))
1029 : scm_i_finite_list_copy (labels
);
1030 const SCM um_clause
= scm_cons (um_labels
, um_exprs
);
1032 um_clauses
= scm_cons (um_clause
, um_clauses
);
1034 um_clauses
= scm_reverse_x (um_clauses
, SCM_UNDEFINED
);
1036 return scm_cons2 (scm_sym_case
, um_key_expr
, um_clauses
);
1040 SCM_SYNTAX (s_cond
, "cond", scm_i_makbimacro
, scm_m_cond
);
1041 SCM_GLOBAL_SYMBOL (scm_sym_cond
, s_cond
);
1042 SCM_GLOBAL_SYMBOL (scm_sym_arrow
, "=>");
1045 scm_m_cond (SCM expr
, SCM env
)
1047 /* Check, whether 'else or '=> is a literal, i. e. not bound to a value. */
1048 const int else_literal_p
= literal_p (scm_sym_else
, env
);
1049 const int arrow_literal_p
= literal_p (scm_sym_arrow
, env
);
1051 const SCM clauses
= SCM_CDR (expr
);
1054 ASSERT_SYNTAX (scm_ilength (clauses
) >= 0, s_bad_expression
, expr
);
1055 ASSERT_SYNTAX (scm_ilength (clauses
) >= 1, s_missing_clauses
, expr
);
1057 for (clause_idx
= clauses
;
1058 !scm_is_null (clause_idx
);
1059 clause_idx
= SCM_CDR (clause_idx
))
1063 const SCM clause
= SCM_CAR (clause_idx
);
1064 const long length
= scm_ilength (clause
);
1065 ASSERT_SYNTAX_2 (length
>= 1, s_bad_cond_clause
, clause
, expr
);
1067 test
= SCM_CAR (clause
);
1068 if (scm_is_eq (test
, scm_sym_else
) && else_literal_p
)
1070 const int last_clause_p
= scm_is_null (SCM_CDR (clause_idx
));
1071 ASSERT_SYNTAX_2 (length
>= 2,
1072 s_bad_cond_clause
, clause
, expr
);
1073 ASSERT_SYNTAX_2 (last_clause_p
,
1074 s_misplaced_else_clause
, clause
, expr
);
1075 SCM_SETCAR (clause
, SCM_IM_ELSE
);
1077 else if (length
>= 2
1078 && scm_is_eq (SCM_CADR (clause
), scm_sym_arrow
)
1081 ASSERT_SYNTAX_2 (length
> 2, s_missing_recipient
, clause
, expr
);
1082 ASSERT_SYNTAX_2 (length
== 3, s_extra_expression
, clause
, expr
);
1083 SCM_SETCAR (SCM_CDR (clause
), SCM_IM_ARROW
);
1087 SCM_SETCAR (expr
, SCM_IM_COND
);
1092 unmemoize_cond (const SCM expr
, const SCM env
)
1094 SCM um_clauses
= SCM_EOL
;
1097 for (clause_idx
= SCM_CDR (expr
);
1098 !scm_is_null (clause_idx
);
1099 clause_idx
= SCM_CDR (clause_idx
))
1101 const SCM clause
= SCM_CAR (clause_idx
);
1102 const SCM sequence
= SCM_CDR (clause
);
1103 const SCM test
= SCM_CAR (clause
);
1108 if (scm_is_eq (test
, SCM_IM_ELSE
))
1109 um_test
= scm_sym_else
;
1111 um_test
= unmemoize_expression (test
, env
);
1113 if (!scm_is_null (sequence
) && scm_is_eq (SCM_CAR (sequence
),
1116 const SCM target
= SCM_CADR (sequence
);
1117 const SCM um_target
= unmemoize_expression (target
, env
);
1118 um_sequence
= scm_list_2 (scm_sym_arrow
, um_target
);
1122 um_sequence
= unmemoize_exprs (sequence
, env
);
1125 um_clause
= scm_cons (um_test
, um_sequence
);
1126 um_clauses
= scm_cons (um_clause
, um_clauses
);
1128 um_clauses
= scm_reverse_x (um_clauses
, SCM_UNDEFINED
);
1130 return scm_cons (scm_sym_cond
, um_clauses
);
1134 SCM_SYNTAX (s_define
, "define", scm_i_makbimacro
, scm_m_define
);
1135 SCM_GLOBAL_SYMBOL (scm_sym_define
, s_define
);
1137 /* Guile provides an extension to R5RS' define syntax to represent function
1138 * currying in a compact way. With this extension, it is allowed to write
1139 * (define <nested-variable> <body>), where <nested-variable> has of one of
1140 * the forms (<nested-variable> <formals>), (<nested-variable> . <formal>),
1141 * (<variable> <formals>) or (<variable> . <formal>). As in R5RS, <formals>
1142 * should be either a sequence of zero or more variables, or a sequence of one
1143 * or more variables followed by a space-delimited period and another
1144 * variable. Each level of argument nesting wraps the <body> within another
1145 * lambda expression. For example, the following forms are allowed, each one
1146 * followed by an equivalent, more explicit implementation.
1148 * (define ((a b . c) . d) <body>) is equivalent to
1149 * (define a (lambda (b . c) (lambda d <body>)))
1151 * (define (((a) b) c . d) <body>) is equivalent to
1152 * (define a (lambda () (lambda (b) (lambda (c . d) <body>))))
1154 /* Dirk:FIXME:: We should provide an implementation for 'define' in the R5RS
1155 * module that does not implement this extension. */
1157 canonicalize_define (const SCM expr
)
1162 const SCM cdr_expr
= SCM_CDR (expr
);
1163 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1164 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
1166 body
= SCM_CDR (cdr_expr
);
1167 variable
= SCM_CAR (cdr_expr
);
1168 while (scm_is_pair (variable
))
1170 /* This while loop realizes function currying by variable nesting.
1171 * Variable is known to be a nested-variable. In every iteration of the
1172 * loop another level of lambda expression is created, starting with the
1173 * innermost one. Note that we don't check for duplicate formals here:
1174 * This will be done by the memoizer of the lambda expression. */
1175 const SCM formals
= SCM_CDR (variable
);
1176 const SCM tail
= scm_cons (formals
, body
);
1178 /* Add source properties to each new lambda expression: */
1179 const SCM lambda
= scm_cons_source (variable
, scm_sym_lambda
, tail
);
1181 body
= scm_list_1 (lambda
);
1182 variable
= SCM_CAR (variable
);
1184 ASSERT_SYNTAX_2 (scm_is_symbol (variable
), s_bad_variable
, variable
, expr
);
1185 ASSERT_SYNTAX (scm_ilength (body
) == 1, s_expression
, expr
);
1187 SCM_SETCAR (cdr_expr
, variable
);
1188 SCM_SETCDR (cdr_expr
, body
);
1192 /* According to section 5.2.1 of R5RS we first have to make sure that the
1193 * variable is bound, and then perform the (set! variable expression)
1194 * operation. This means, that within the expression we may already assign
1195 * values to variable: (define foo (begin (set! foo 1) (+ foo 1))) */
1197 scm_m_define (SCM expr
, SCM env
)
1199 ASSERT_SYNTAX (SCM_TOP_LEVEL (env
), s_bad_define
, expr
);
1202 const SCM canonical_definition
= canonicalize_define (expr
);
1203 const SCM cdr_canonical_definition
= SCM_CDR (canonical_definition
);
1204 const SCM variable
= SCM_CAR (cdr_canonical_definition
);
1206 = scm_sym2var (variable
, scm_env_top_level (env
), SCM_BOOL_T
);
1207 const SCM value
= scm_eval_car (SCM_CDR (cdr_canonical_definition
), env
);
1209 if (SCM_REC_PROCNAMES_P
)
1212 while (SCM_MACROP (tmp
))
1213 tmp
= SCM_MACRO_CODE (tmp
);
1214 if (SCM_CLOSUREP (tmp
)
1215 /* Only the first definition determines the name. */
1216 && scm_is_false (scm_procedure_property (tmp
, scm_sym_name
)))
1217 scm_set_procedure_property_x (tmp
, scm_sym_name
, variable
);
1220 SCM_VARIABLE_SET (location
, value
);
1222 return SCM_UNSPECIFIED
;
1227 /* This is a helper function for forms (<keyword> <expression>) that are
1228 * transformed into (#@<keyword> '() <memoized_expression>) in order to allow
1229 * for easy creation of a thunk (i. e. a closure without arguments) using the
1230 * ('() <memoized_expression>) tail of the memoized form. */
1232 memoize_as_thunk_prototype (const SCM expr
, const SCM env SCM_UNUSED
)
1234 const SCM cdr_expr
= SCM_CDR (expr
);
1235 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1236 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
1238 SCM_SETCDR (expr
, scm_cons (SCM_EOL
, cdr_expr
));
1244 SCM_SYNTAX (s_delay
, "delay", scm_i_makbimacro
, scm_m_delay
);
1245 SCM_GLOBAL_SYMBOL (scm_sym_delay
, s_delay
);
1247 /* Promises are implemented as closures with an empty parameter list. Thus,
1248 * (delay <expression>) is transformed into (#@delay '() <expression>), where
1249 * the empty list represents the empty parameter list. This representation
1250 * allows for easy creation of the closure during evaluation. */
1252 scm_m_delay (SCM expr
, SCM env
)
1254 const SCM new_expr
= memoize_as_thunk_prototype (expr
, env
);
1255 SCM_SETCAR (new_expr
, SCM_IM_DELAY
);
1260 unmemoize_delay (const SCM expr
, const SCM env
)
1262 const SCM thunk_expr
= SCM_CADDR (expr
);
1263 return scm_list_2 (scm_sym_delay
, unmemoize_expression (thunk_expr
, env
));
1267 SCM_SYNTAX(s_do
, "do", scm_i_makbimacro
, scm_m_do
);
1268 SCM_GLOBAL_SYMBOL(scm_sym_do
, s_do
);
1270 /* DO gets the most radically altered syntax. The order of the vars is
1271 * reversed here. During the evaluation this allows for simple consing of the
1272 * results of the inits and steps:
1274 (do ((<var1> <init1> <step1>)
1282 (#@do (<init1> <init2> ... <initn>)
1283 (varn ... var2 var1)
1286 <step1> <step2> ... <stepn>) ;; missing steps replaced by var
1289 scm_m_do (SCM expr
, SCM env SCM_UNUSED
)
1291 SCM variables
= SCM_EOL
;
1292 SCM init_forms
= SCM_EOL
;
1293 SCM step_forms
= SCM_EOL
;
1300 const SCM cdr_expr
= SCM_CDR (expr
);
1301 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1302 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
1304 /* Collect variables, init and step forms. */
1305 binding_idx
= SCM_CAR (cdr_expr
);
1306 ASSERT_SYNTAX_2 (scm_ilength (binding_idx
) >= 0,
1307 s_bad_bindings
, binding_idx
, expr
);
1308 for (; !scm_is_null (binding_idx
); binding_idx
= SCM_CDR (binding_idx
))
1310 const SCM binding
= SCM_CAR (binding_idx
);
1311 const long length
= scm_ilength (binding
);
1312 ASSERT_SYNTAX_2 (length
== 2 || length
== 3,
1313 s_bad_binding
, binding
, expr
);
1316 const SCM name
= SCM_CAR (binding
);
1317 const SCM init
= SCM_CADR (binding
);
1318 const SCM step
= (length
== 2) ? name
: SCM_CADDR (binding
);
1319 ASSERT_SYNTAX_2 (scm_is_symbol (name
), s_bad_variable
, name
, expr
);
1320 ASSERT_SYNTAX_2 (scm_is_false (scm_c_memq (name
, variables
)),
1321 s_duplicate_binding
, name
, expr
);
1323 variables
= scm_cons (name
, variables
);
1324 init_forms
= scm_cons (init
, init_forms
);
1325 step_forms
= scm_cons (step
, step_forms
);
1328 init_forms
= scm_reverse_x (init_forms
, SCM_UNDEFINED
);
1329 step_forms
= scm_reverse_x (step_forms
, SCM_UNDEFINED
);
1331 /* Memoize the test form and the exit sequence. */
1332 cddr_expr
= SCM_CDR (cdr_expr
);
1333 exit_clause
= SCM_CAR (cddr_expr
);
1334 ASSERT_SYNTAX_2 (scm_ilength (exit_clause
) >= 1,
1335 s_bad_exit_clause
, exit_clause
, expr
);
1337 commands
= SCM_CDR (cddr_expr
);
1338 tail
= scm_cons2 (exit_clause
, commands
, step_forms
);
1339 tail
= scm_cons2 (init_forms
, variables
, tail
);
1340 SCM_SETCAR (expr
, SCM_IM_DO
);
1341 SCM_SETCDR (expr
, tail
);
1346 unmemoize_do (const SCM expr
, const SCM env
)
1348 const SCM cdr_expr
= SCM_CDR (expr
);
1349 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
1350 const SCM rnames
= SCM_CAR (cddr_expr
);
1351 const SCM extended_env
= SCM_EXTEND_ENV (rnames
, SCM_EOL
, env
);
1352 const SCM cdddr_expr
= SCM_CDR (cddr_expr
);
1353 const SCM exit_sequence
= SCM_CAR (cdddr_expr
);
1354 const SCM um_exit_sequence
= unmemoize_exprs (exit_sequence
, extended_env
);
1355 const SCM cddddr_expr
= SCM_CDR (cdddr_expr
);
1356 const SCM um_body
= unmemoize_exprs (SCM_CAR (cddddr_expr
), extended_env
);
1358 /* build transformed binding list */
1359 SCM um_names
= scm_reverse (rnames
);
1360 SCM um_inits
= unmemoize_exprs (SCM_CAR (cdr_expr
), env
);
1361 SCM um_steps
= unmemoize_exprs (SCM_CDR (cddddr_expr
), extended_env
);
1362 SCM um_bindings
= SCM_EOL
;
1363 while (!scm_is_null (um_names
))
1365 const SCM name
= SCM_CAR (um_names
);
1366 const SCM init
= SCM_CAR (um_inits
);
1367 SCM step
= SCM_CAR (um_steps
);
1368 step
= scm_is_eq (step
, name
) ? SCM_EOL
: scm_list_1 (step
);
1370 um_bindings
= scm_cons (scm_cons2 (name
, init
, step
), um_bindings
);
1372 um_names
= SCM_CDR (um_names
);
1373 um_inits
= SCM_CDR (um_inits
);
1374 um_steps
= SCM_CDR (um_steps
);
1376 um_bindings
= scm_reverse_x (um_bindings
, SCM_UNDEFINED
);
1378 return scm_cons (scm_sym_do
,
1379 scm_cons2 (um_bindings
, um_exit_sequence
, um_body
));
1383 SCM_SYNTAX (s_if
, "if", scm_i_makbimacro
, scm_m_if
);
1384 SCM_GLOBAL_SYMBOL (scm_sym_if
, s_if
);
1387 scm_m_if (SCM expr
, SCM env SCM_UNUSED
)
1389 const SCM cdr_expr
= SCM_CDR (expr
);
1390 const long length
= scm_ilength (cdr_expr
);
1391 ASSERT_SYNTAX (length
== 2 || length
== 3, s_expression
, expr
);
1392 SCM_SETCAR (expr
, SCM_IM_IF
);
1397 unmemoize_if (const SCM expr
, const SCM env
)
1399 const SCM cdr_expr
= SCM_CDR (expr
);
1400 const SCM um_condition
= unmemoize_expression (SCM_CAR (cdr_expr
), env
);
1401 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
1402 const SCM um_then
= unmemoize_expression (SCM_CAR (cddr_expr
), env
);
1403 const SCM cdddr_expr
= SCM_CDR (cddr_expr
);
1405 if (scm_is_null (cdddr_expr
))
1407 return scm_list_3 (scm_sym_if
, um_condition
, um_then
);
1411 const SCM um_else
= unmemoize_expression (SCM_CAR (cdddr_expr
), env
);
1412 return scm_list_4 (scm_sym_if
, um_condition
, um_then
, um_else
);
1417 SCM_SYNTAX (s_lambda
, "lambda", scm_i_makbimacro
, scm_m_lambda
);
1418 SCM_GLOBAL_SYMBOL (scm_sym_lambda
, s_lambda
);
1420 /* A helper function for memoize_lambda to support checking for duplicate
1421 * formal arguments: Return true if OBJ is `eq?' to one of the elements of
1422 * LIST or to the cdr of the last cons. Therefore, LIST may have any of the
1423 * forms that a formal argument can have:
1424 * <rest>, (<arg1> ...), (<arg1> ... . <rest>) */
1426 c_improper_memq (SCM obj
, SCM list
)
1428 for (; scm_is_pair (list
); list
= SCM_CDR (list
))
1430 if (scm_is_eq (SCM_CAR (list
), obj
))
1433 return scm_is_eq (list
, obj
);
1437 scm_m_lambda (SCM expr
, SCM env SCM_UNUSED
)
1446 const SCM cdr_expr
= SCM_CDR (expr
);
1447 const long length
= scm_ilength (cdr_expr
);
1448 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
1449 ASSERT_SYNTAX (length
>= 2, s_missing_expression
, expr
);
1451 /* Before iterating the list of formal arguments, make sure the formals
1452 * actually are given as either a symbol or a non-cyclic list. */
1453 formals
= SCM_CAR (cdr_expr
);
1454 if (scm_is_pair (formals
))
1456 /* Dirk:FIXME:: We should check for a cyclic list of formals, and if
1457 * detected, report a 'Bad formals' error. */
1461 ASSERT_SYNTAX_2 (scm_is_symbol (formals
) || scm_is_null (formals
),
1462 s_bad_formals
, formals
, expr
);
1465 /* Now iterate the list of formal arguments to check if all formals are
1466 * symbols, and that there are no duplicates. */
1467 formals_idx
= formals
;
1468 while (scm_is_pair (formals_idx
))
1470 const SCM formal
= SCM_CAR (formals_idx
);
1471 const SCM next_idx
= SCM_CDR (formals_idx
);
1472 ASSERT_SYNTAX_2 (scm_is_symbol (formal
), s_bad_formal
, formal
, expr
);
1473 ASSERT_SYNTAX_2 (!c_improper_memq (formal
, next_idx
),
1474 s_duplicate_formal
, formal
, expr
);
1475 formals_idx
= next_idx
;
1477 ASSERT_SYNTAX_2 (scm_is_null (formals_idx
) || scm_is_symbol (formals_idx
),
1478 s_bad_formal
, formals_idx
, expr
);
1480 /* Memoize the body. Keep a potential documentation string. */
1481 /* Dirk:FIXME:: We should probably extract the documentation string to
1482 * some external database. Otherwise it will slow down execution, since
1483 * the documentation string will have to be skipped with every execution
1484 * of the closure. */
1485 cddr_expr
= SCM_CDR (cdr_expr
);
1486 documentation
= (length
>= 3 && scm_is_string (SCM_CAR (cddr_expr
)));
1487 body
= documentation
? SCM_CDR (cddr_expr
) : cddr_expr
;
1488 new_body
= m_body (SCM_IM_LAMBDA
, body
);
1490 SCM_SETCAR (expr
, SCM_IM_LAMBDA
);
1492 SCM_SETCDR (cddr_expr
, new_body
);
1494 SCM_SETCDR (cdr_expr
, new_body
);
1499 unmemoize_lambda (const SCM expr
, const SCM env
)
1501 const SCM formals
= SCM_CADR (expr
);
1502 const SCM body
= SCM_CDDR (expr
);
1504 const SCM new_env
= SCM_EXTEND_ENV (formals
, SCM_EOL
, env
);
1505 const SCM um_formals
= scm_i_finite_list_copy (formals
);
1506 const SCM um_body
= unmemoize_exprs (body
, new_env
);
1508 return scm_cons2 (scm_sym_lambda
, um_formals
, um_body
);
1512 /* Check if the format of the bindings is ((<symbol> <init-form>) ...). */
1514 check_bindings (const SCM bindings
, const SCM expr
)
1518 ASSERT_SYNTAX_2 (scm_ilength (bindings
) >= 0,
1519 s_bad_bindings
, bindings
, expr
);
1521 binding_idx
= bindings
;
1522 for (; !scm_is_null (binding_idx
); binding_idx
= SCM_CDR (binding_idx
))
1524 SCM name
; /* const */
1526 const SCM binding
= SCM_CAR (binding_idx
);
1527 ASSERT_SYNTAX_2 (scm_ilength (binding
) == 2,
1528 s_bad_binding
, binding
, expr
);
1530 name
= SCM_CAR (binding
);
1531 ASSERT_SYNTAX_2 (scm_is_symbol (name
), s_bad_variable
, name
, expr
);
1536 /* The bindings, which must have the format ((v1 i1) (v2 i2) ... (vn in)), are
1537 * transformed to the lists (vn ... v2 v1) and (i1 i2 ... in). That is, the
1538 * variables are returned in a list with their order reversed, and the init
1539 * forms are returned in a list in the same order as they are given in the
1540 * bindings. If a duplicate variable name is detected, an error is
1543 transform_bindings (
1544 const SCM bindings
, const SCM expr
,
1545 SCM
*const rvarptr
, SCM
*const initptr
)
1547 SCM rvariables
= SCM_EOL
;
1548 SCM rinits
= SCM_EOL
;
1549 SCM binding_idx
= bindings
;
1550 for (; !scm_is_null (binding_idx
); binding_idx
= SCM_CDR (binding_idx
))
1552 const SCM binding
= SCM_CAR (binding_idx
);
1553 const SCM cdr_binding
= SCM_CDR (binding
);
1554 const SCM name
= SCM_CAR (binding
);
1555 ASSERT_SYNTAX_2 (scm_is_false (scm_c_memq (name
, rvariables
)),
1556 s_duplicate_binding
, name
, expr
);
1557 rvariables
= scm_cons (name
, rvariables
);
1558 rinits
= scm_cons (SCM_CAR (cdr_binding
), rinits
);
1560 *rvarptr
= rvariables
;
1561 *initptr
= scm_reverse_x (rinits
, SCM_UNDEFINED
);
1565 SCM_SYNTAX(s_let
, "let", scm_i_makbimacro
, scm_m_let
);
1566 SCM_GLOBAL_SYMBOL(scm_sym_let
, s_let
);
1568 /* This function is a helper function for memoize_let. It transforms
1569 * (let name ((var init) ...) body ...) into
1570 * ((letrec ((name (lambda (var ...) body ...))) name) init ...)
1571 * and memoizes the expression. It is assumed that the caller has checked
1572 * that name is a symbol and that there are bindings and a body. */
1574 memoize_named_let (const SCM expr
, const SCM env SCM_UNUSED
)
1580 const SCM cdr_expr
= SCM_CDR (expr
);
1581 const SCM name
= SCM_CAR (cdr_expr
);
1582 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
1583 const SCM bindings
= SCM_CAR (cddr_expr
);
1584 check_bindings (bindings
, expr
);
1586 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
1587 variables
= scm_reverse_x (rvariables
, SCM_UNDEFINED
);
1590 const SCM let_body
= SCM_CDR (cddr_expr
);
1591 const SCM lambda_body
= m_body (SCM_IM_LET
, let_body
);
1592 const SCM lambda_tail
= scm_cons (variables
, lambda_body
);
1593 const SCM lambda_form
= scm_cons_source (expr
, scm_sym_lambda
, lambda_tail
);
1595 const SCM rvar
= scm_list_1 (name
);
1596 const SCM init
= scm_list_1 (lambda_form
);
1597 const SCM body
= m_body (SCM_IM_LET
, scm_list_1 (name
));
1598 const SCM letrec_tail
= scm_cons (rvar
, scm_cons (init
, body
));
1599 const SCM letrec_form
= scm_cons_source (expr
, SCM_IM_LETREC
, letrec_tail
);
1600 return scm_cons_source (expr
, letrec_form
, inits
);
1604 /* (let ((v1 i1) (v2 i2) ...) body) with variables v1 .. vn and initializers
1605 * i1 .. in is transformed to (#@let (vn ... v2 v1) (i1 i2 ...) body). */
1607 scm_m_let (SCM expr
, SCM env
)
1611 const SCM cdr_expr
= SCM_CDR (expr
);
1612 const long length
= scm_ilength (cdr_expr
);
1613 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
1614 ASSERT_SYNTAX (length
>= 2, s_missing_expression
, expr
);
1616 bindings
= SCM_CAR (cdr_expr
);
1617 if (scm_is_symbol (bindings
))
1619 ASSERT_SYNTAX (length
>= 3, s_missing_expression
, expr
);
1620 return memoize_named_let (expr
, env
);
1623 check_bindings (bindings
, expr
);
1624 if (scm_is_null (bindings
) || scm_is_null (SCM_CDR (bindings
)))
1626 /* Special case: no bindings or single binding => let* is faster. */
1627 const SCM body
= m_body (SCM_IM_LET
, SCM_CDR (cdr_expr
));
1628 return scm_m_letstar (scm_cons2 (SCM_CAR (expr
), bindings
, body
), env
);
1635 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
1638 const SCM new_body
= m_body (SCM_IM_LET
, SCM_CDR (cdr_expr
));
1639 const SCM new_tail
= scm_cons2 (rvariables
, inits
, new_body
);
1640 SCM_SETCAR (expr
, SCM_IM_LET
);
1641 SCM_SETCDR (expr
, new_tail
);
1648 build_binding_list (SCM rnames
, SCM rinits
)
1650 SCM bindings
= SCM_EOL
;
1651 while (!scm_is_null (rnames
))
1653 const SCM binding
= scm_list_2 (SCM_CAR (rnames
), SCM_CAR (rinits
));
1654 bindings
= scm_cons (binding
, bindings
);
1655 rnames
= SCM_CDR (rnames
);
1656 rinits
= SCM_CDR (rinits
);
1662 unmemoize_let (const SCM expr
, const SCM env
)
1664 const SCM cdr_expr
= SCM_CDR (expr
);
1665 const SCM um_rnames
= SCM_CAR (cdr_expr
);
1666 const SCM extended_env
= SCM_EXTEND_ENV (um_rnames
, SCM_EOL
, env
);
1667 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
1668 const SCM um_inits
= unmemoize_exprs (SCM_CAR (cddr_expr
), env
);
1669 const SCM um_rinits
= scm_reverse_x (um_inits
, SCM_UNDEFINED
);
1670 const SCM um_bindings
= build_binding_list (um_rnames
, um_rinits
);
1671 const SCM um_body
= unmemoize_exprs (SCM_CDR (cddr_expr
), extended_env
);
1673 return scm_cons2 (scm_sym_let
, um_bindings
, um_body
);
1677 SCM_SYNTAX(s_letrec
, "letrec", scm_i_makbimacro
, scm_m_letrec
);
1678 SCM_GLOBAL_SYMBOL(scm_sym_letrec
, s_letrec
);
1681 scm_m_letrec (SCM expr
, SCM env
)
1685 const SCM cdr_expr
= SCM_CDR (expr
);
1686 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1687 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
1689 bindings
= SCM_CAR (cdr_expr
);
1690 if (scm_is_null (bindings
))
1692 /* no bindings, let* is executed faster */
1693 SCM body
= m_body (SCM_IM_LETREC
, SCM_CDR (cdr_expr
));
1694 return scm_m_letstar (scm_cons2 (SCM_CAR (expr
), SCM_EOL
, body
), env
);
1702 check_bindings (bindings
, expr
);
1703 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
1704 new_body
= m_body (SCM_IM_LETREC
, SCM_CDR (cdr_expr
));
1705 return scm_cons2 (SCM_IM_LETREC
, rvariables
, scm_cons (inits
, new_body
));
1710 unmemoize_letrec (const SCM expr
, const SCM env
)
1712 const SCM cdr_expr
= SCM_CDR (expr
);
1713 const SCM um_rnames
= SCM_CAR (cdr_expr
);
1714 const SCM extended_env
= SCM_EXTEND_ENV (um_rnames
, SCM_EOL
, env
);
1715 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
1716 const SCM um_inits
= unmemoize_exprs (SCM_CAR (cddr_expr
), extended_env
);
1717 const SCM um_rinits
= scm_reverse_x (um_inits
, SCM_UNDEFINED
);
1718 const SCM um_bindings
= build_binding_list (um_rnames
, um_rinits
);
1719 const SCM um_body
= unmemoize_exprs (SCM_CDR (cddr_expr
), extended_env
);
1721 return scm_cons2 (scm_sym_letrec
, um_bindings
, um_body
);
1726 SCM_SYNTAX (s_letstar
, "let*", scm_i_makbimacro
, scm_m_letstar
);
1727 SCM_GLOBAL_SYMBOL (scm_sym_letstar
, s_letstar
);
1729 /* (let* ((v1 i1) (v2 i2) ...) body) with variables v1 .. vn and initializers
1730 * i1 .. in is transformed into the form (#@let* (v1 i1 v2 i2 ...) body). */
1732 scm_m_letstar (SCM expr
, SCM env SCM_UNUSED
)
1737 const SCM cdr_expr
= SCM_CDR (expr
);
1738 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1739 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
1741 binding_idx
= SCM_CAR (cdr_expr
);
1742 check_bindings (binding_idx
, expr
);
1744 /* Transform ((v1 i1) (v2 i2) ...) into (v1 i1 v2 i2 ...). The
1745 * transformation is done in place. At the beginning of one iteration of
1746 * the loop the variable binding_idx holds the form
1747 * P1:( (vn . P2:(in . ())) . P3:( (vn+1 in+1) ... ) ),
1748 * where P1, P2 and P3 indicate the pairs, that are relevant for the
1749 * transformation. P1 and P2 are modified in the loop, P3 remains
1750 * untouched. After the execution of the loop, P1 will hold
1751 * P1:( vn . P2:(in . P3:( (vn+1 in+1) ... )) )
1752 * and binding_idx will hold P3. */
1753 while (!scm_is_null (binding_idx
))
1755 const SCM cdr_binding_idx
= SCM_CDR (binding_idx
); /* remember P3 */
1756 const SCM binding
= SCM_CAR (binding_idx
);
1757 const SCM name
= SCM_CAR (binding
);
1758 const SCM cdr_binding
= SCM_CDR (binding
);
1760 SCM_SETCDR (cdr_binding
, cdr_binding_idx
); /* update P2 */
1761 SCM_SETCAR (binding_idx
, name
); /* update P1 */
1762 SCM_SETCDR (binding_idx
, cdr_binding
); /* update P1 */
1764 binding_idx
= cdr_binding_idx
; /* continue with P3 */
1767 new_body
= m_body (SCM_IM_LETSTAR
, SCM_CDR (cdr_expr
));
1768 SCM_SETCAR (expr
, SCM_IM_LETSTAR
);
1769 /* the bindings have been changed in place */
1770 SCM_SETCDR (cdr_expr
, new_body
);
1775 unmemoize_letstar (const SCM expr
, const SCM env
)
1777 const SCM cdr_expr
= SCM_CDR (expr
);
1778 const SCM body
= SCM_CDR (cdr_expr
);
1779 SCM bindings
= SCM_CAR (cdr_expr
);
1780 SCM um_bindings
= SCM_EOL
;
1781 SCM extended_env
= env
;
1784 while (!scm_is_null (bindings
))
1786 const SCM variable
= SCM_CAR (bindings
);
1787 const SCM init
= SCM_CADR (bindings
);
1788 const SCM um_init
= unmemoize_expression (init
, extended_env
);
1789 um_bindings
= scm_cons (scm_list_2 (variable
, um_init
), um_bindings
);
1790 extended_env
= SCM_EXTEND_ENV (variable
, SCM_BOOL_F
, extended_env
);
1791 bindings
= SCM_CDDR (bindings
);
1793 um_bindings
= scm_reverse_x (um_bindings
, SCM_UNDEFINED
);
1795 um_body
= unmemoize_exprs (body
, extended_env
);
1797 return scm_cons2 (scm_sym_letstar
, um_bindings
, um_body
);
1801 SCM_SYNTAX (s_or
, "or", scm_i_makbimacro
, scm_m_or
);
1802 SCM_GLOBAL_SYMBOL (scm_sym_or
, s_or
);
1805 scm_m_or (SCM expr
, SCM env SCM_UNUSED
)
1807 const SCM cdr_expr
= SCM_CDR (expr
);
1808 const long length
= scm_ilength (cdr_expr
);
1810 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
1814 /* Special case: (or) is replaced by #f. */
1819 SCM_SETCAR (expr
, SCM_IM_OR
);
1825 unmemoize_or (const SCM expr
, const SCM env
)
1827 return scm_cons (scm_sym_or
, unmemoize_exprs (SCM_CDR (expr
), env
));
1831 SCM_SYNTAX (s_quasiquote
, "quasiquote", scm_makacro
, scm_m_quasiquote
);
1832 SCM_GLOBAL_SYMBOL (scm_sym_quasiquote
, s_quasiquote
);
1833 SCM_GLOBAL_SYMBOL (scm_sym_unquote
, "unquote");
1834 SCM_GLOBAL_SYMBOL (scm_sym_uq_splicing
, "unquote-splicing");
1836 /* Internal function to handle a quasiquotation: 'form' is the parameter in
1837 * the call (quasiquotation form), 'env' is the environment where unquoted
1838 * expressions will be evaluated, and 'depth' is the current quasiquotation
1839 * nesting level and is known to be greater than zero. */
1841 iqq (SCM form
, SCM env
, unsigned long int depth
)
1843 if (scm_is_pair (form
))
1845 const SCM tmp
= SCM_CAR (form
);
1846 if (scm_is_eq (tmp
, scm_sym_quasiquote
))
1848 const SCM args
= SCM_CDR (form
);
1849 ASSERT_SYNTAX (scm_ilength (args
) == 1, s_expression
, form
);
1850 return scm_list_2 (tmp
, iqq (SCM_CAR (args
), env
, depth
+ 1));
1852 else if (scm_is_eq (tmp
, scm_sym_unquote
))
1854 const SCM args
= SCM_CDR (form
);
1855 ASSERT_SYNTAX (scm_ilength (args
) == 1, s_expression
, form
);
1857 return scm_eval_car (args
, env
);
1859 return scm_list_2 (tmp
, iqq (SCM_CAR (args
), env
, depth
- 1));
1861 else if (scm_is_pair (tmp
)
1862 && scm_is_eq (SCM_CAR (tmp
), scm_sym_uq_splicing
))
1864 const SCM args
= SCM_CDR (tmp
);
1865 ASSERT_SYNTAX (scm_ilength (args
) == 1, s_expression
, form
);
1868 const SCM list
= scm_eval_car (args
, env
);
1869 const SCM rest
= SCM_CDR (form
);
1870 ASSERT_SYNTAX_2 (scm_ilength (list
) >= 0,
1871 s_splicing
, list
, form
);
1872 return scm_append (scm_list_2 (list
, iqq (rest
, env
, depth
)));
1875 return scm_cons (iqq (SCM_CAR (form
), env
, depth
- 1),
1876 iqq (SCM_CDR (form
), env
, depth
));
1879 return scm_cons (iqq (SCM_CAR (form
), env
, depth
),
1880 iqq (SCM_CDR (form
), env
, depth
));
1882 else if (scm_is_vector (form
))
1883 return scm_vector (iqq (scm_vector_to_list (form
), env
, depth
));
1889 scm_m_quasiquote (SCM expr
, SCM env
)
1891 const SCM cdr_expr
= SCM_CDR (expr
);
1892 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1893 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
1894 return iqq (SCM_CAR (cdr_expr
), env
, 1);
1898 SCM_SYNTAX (s_quote
, "quote", scm_i_makbimacro
, scm_m_quote
);
1899 SCM_GLOBAL_SYMBOL (scm_sym_quote
, s_quote
);
1902 scm_m_quote (SCM expr
, SCM env SCM_UNUSED
)
1906 const SCM cdr_expr
= SCM_CDR (expr
);
1907 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1908 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
1909 quotee
= SCM_CAR (cdr_expr
);
1910 if (is_self_quoting_p (quotee
))
1913 SCM_SETCAR (expr
, SCM_IM_QUOTE
);
1914 SCM_SETCDR (expr
, quotee
);
1919 unmemoize_quote (const SCM expr
, const SCM env SCM_UNUSED
)
1921 return scm_list_2 (scm_sym_quote
, SCM_CDR (expr
));
1925 /* Will go into the RnRS module when Guile is factorized.
1926 SCM_SYNTAX (s_set_x, "set!", scm_i_makbimacro, scm_m_set_x); */
1927 static const char s_set_x
[] = "set!";
1928 SCM_GLOBAL_SYMBOL (scm_sym_set_x
, s_set_x
);
1931 scm_m_set_x (SCM expr
, SCM env SCM_UNUSED
)
1936 const SCM cdr_expr
= SCM_CDR (expr
);
1937 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1938 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
1939 variable
= SCM_CAR (cdr_expr
);
1941 /* Memoize the variable form. */
1942 ASSERT_SYNTAX_2 (scm_is_symbol (variable
), s_bad_variable
, variable
, expr
);
1943 new_variable
= lookup_symbol (variable
, env
);
1944 /* Leave the memoization of unbound symbols to lazy memoization: */
1945 if (SCM_UNBNDP (new_variable
))
1946 new_variable
= variable
;
1948 SCM_SETCAR (expr
, SCM_IM_SET_X
);
1949 SCM_SETCAR (cdr_expr
, new_variable
);
1954 unmemoize_set_x (const SCM expr
, const SCM env
)
1956 return scm_cons (scm_sym_set_x
, unmemoize_exprs (SCM_CDR (expr
), env
));
1960 /* Start of the memoizers for non-R5RS builtin macros. */
1963 SCM_SYNTAX (s_atapply
, "@apply", scm_i_makbimacro
, scm_m_apply
);
1964 SCM_GLOBAL_SYMBOL (scm_sym_atapply
, s_atapply
);
1965 SCM_GLOBAL_SYMBOL (scm_sym_apply
, s_atapply
+ 1);
1968 scm_m_apply (SCM expr
, SCM env SCM_UNUSED
)
1970 const SCM cdr_expr
= SCM_CDR (expr
);
1971 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
1972 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_missing_expression
, expr
);
1974 SCM_SETCAR (expr
, SCM_IM_APPLY
);
1979 unmemoize_apply (const SCM expr
, const SCM env
)
1981 return scm_list_2 (scm_sym_atapply
, unmemoize_exprs (SCM_CDR (expr
), env
));
1985 SCM_SYNTAX (s_atbind
, "@bind", scm_i_makbimacro
, scm_m_atbind
);
1987 /* FIXME: The following explanation should go into the documentation: */
1988 /* (@bind ((var init) ...) body ...) will assign the values of the `init's to
1989 * the global variables named by `var's (symbols, not evaluated), creating
1990 * them if they don't exist, executes body, and then restores the previous
1991 * values of the `var's. Additionally, whenever control leaves body, the
1992 * values of the `var's are saved and restored when control returns. It is an
1993 * error when a symbol appears more than once among the `var's. All `init's
1994 * are evaluated before any `var' is set.
1996 * Think of this as `let' for dynamic scope.
1999 /* (@bind ((var1 exp1) ... (varn expn)) body ...) is memoized into
2000 * (#@bind ((varn ... var1) . (exp1 ... expn)) body ...).
2002 * FIXME - also implement `@bind*'.
2005 scm_m_atbind (SCM expr
, SCM env
)
2012 const SCM top_level
= scm_env_top_level (env
);
2014 const SCM cdr_expr
= SCM_CDR (expr
);
2015 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2016 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 2, s_missing_expression
, expr
);
2017 bindings
= SCM_CAR (cdr_expr
);
2018 check_bindings (bindings
, expr
);
2019 transform_bindings (bindings
, expr
, &rvariables
, &inits
);
2021 for (variable_idx
= rvariables
;
2022 !scm_is_null (variable_idx
);
2023 variable_idx
= SCM_CDR (variable_idx
))
2025 /* The first call to scm_sym2var will look beyond the current module,
2026 * while the second call wont. */
2027 const SCM variable
= SCM_CAR (variable_idx
);
2028 SCM new_variable
= scm_sym2var (variable
, top_level
, SCM_BOOL_F
);
2029 if (scm_is_false (new_variable
))
2030 new_variable
= scm_sym2var (variable
, top_level
, SCM_BOOL_T
);
2031 SCM_SETCAR (variable_idx
, new_variable
);
2034 SCM_SETCAR (expr
, SCM_IM_BIND
);
2035 SCM_SETCAR (cdr_expr
, scm_cons (rvariables
, inits
));
2040 SCM_SYNTAX(s_atcall_cc
, "@call-with-current-continuation", scm_i_makbimacro
, scm_m_cont
);
2041 SCM_GLOBAL_SYMBOL(scm_sym_atcall_cc
, s_atcall_cc
);
2044 scm_m_cont (SCM expr
, SCM env SCM_UNUSED
)
2046 const SCM cdr_expr
= SCM_CDR (expr
);
2047 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2048 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
2050 SCM_SETCAR (expr
, SCM_IM_CONT
);
2055 unmemoize_atcall_cc (const SCM expr
, const SCM env
)
2057 return scm_list_2 (scm_sym_atcall_cc
, unmemoize_exprs (SCM_CDR (expr
), env
));
2061 SCM_SYNTAX (s_at_call_with_values
, "@call-with-values", scm_i_makbimacro
, scm_m_at_call_with_values
);
2062 SCM_GLOBAL_SYMBOL(scm_sym_at_call_with_values
, s_at_call_with_values
);
2065 scm_m_at_call_with_values (SCM expr
, SCM env SCM_UNUSED
)
2067 const SCM cdr_expr
= SCM_CDR (expr
);
2068 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2069 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
2071 SCM_SETCAR (expr
, SCM_IM_CALL_WITH_VALUES
);
2076 unmemoize_at_call_with_values (const SCM expr
, const SCM env
)
2078 return scm_list_2 (scm_sym_at_call_with_values
,
2079 unmemoize_exprs (SCM_CDR (expr
), env
));
2083 SCM_SYNTAX (s_future
, "future", scm_i_makbimacro
, scm_m_future
);
2084 SCM_GLOBAL_SYMBOL (scm_sym_future
, s_future
);
2086 /* Like promises, futures are implemented as closures with an empty
2087 * parameter list. Thus, (future <expression>) is transformed into
2088 * (#@future '() <expression>), where the empty list represents the
2089 * empty parameter list. This representation allows for easy creation
2090 * of the closure during evaluation. */
2092 scm_m_future (SCM expr
, SCM env
)
2094 const SCM new_expr
= memoize_as_thunk_prototype (expr
, env
);
2095 SCM_SETCAR (new_expr
, SCM_IM_FUTURE
);
2100 unmemoize_future (const SCM expr
, const SCM env
)
2102 const SCM thunk_expr
= SCM_CADDR (expr
);
2103 return scm_list_2 (scm_sym_future
, unmemoize_expression (thunk_expr
, env
));
2107 SCM_SYNTAX (s_gset_x
, "set!", scm_i_makbimacro
, scm_m_generalized_set_x
);
2108 SCM_SYMBOL (scm_sym_setter
, "setter");
2111 scm_m_generalized_set_x (SCM expr
, SCM env
)
2113 SCM target
, exp_target
;
2115 const SCM cdr_expr
= SCM_CDR (expr
);
2116 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2117 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
2119 target
= SCM_CAR (cdr_expr
);
2120 if (!scm_is_pair (target
))
2123 return scm_m_set_x (expr
, env
);
2127 /* (set! (foo bar ...) baz) becomes ((setter foo) bar ... baz) */
2128 /* Macroexpanding the target might return things of the form
2129 (begin <atom>). In that case, <atom> must be a symbol or a
2130 variable and we memoize to (set! <atom> ...).
2132 exp_target
= macroexp (target
, env
);
2133 if (scm_is_eq (SCM_CAR (exp_target
), SCM_IM_BEGIN
)
2134 && !scm_is_null (SCM_CDR (exp_target
))
2135 && scm_is_null (SCM_CDDR (exp_target
)))
2137 exp_target
= SCM_CADR (exp_target
);
2138 ASSERT_SYNTAX_2 (scm_is_symbol (exp_target
)
2139 || SCM_VARIABLEP (exp_target
),
2140 s_bad_variable
, exp_target
, expr
);
2141 return scm_cons (SCM_IM_SET_X
, scm_cons (exp_target
,
2142 SCM_CDR (cdr_expr
)));
2146 const SCM setter_proc_tail
= scm_list_1 (SCM_CAR (target
));
2147 const SCM setter_proc
= scm_cons_source (expr
, scm_sym_setter
,
2150 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
2151 const SCM setter_args
= scm_append_x (scm_list_2 (SCM_CDR (target
),
2154 SCM_SETCAR (expr
, setter_proc
);
2155 SCM_SETCDR (expr
, setter_args
);
2162 /* @slot-ref is bound privately in the (oop goops) module from goops.c. As
2163 * soon as the module system allows us to more freely create bindings in
2164 * arbitrary modules during the startup phase, the code from goops.c should be
2167 SCM_SYMBOL (sym_atslot_ref
, "@slot-ref");
2170 scm_m_atslot_ref (SCM expr
, SCM env SCM_UNUSED
)
2174 const SCM cdr_expr
= SCM_CDR (expr
);
2175 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2176 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 2, s_expression
, expr
);
2177 slot_nr
= SCM_CADR (cdr_expr
);
2178 ASSERT_SYNTAX_2 (SCM_I_INUMP (slot_nr
), s_bad_slot_number
, slot_nr
, expr
);
2180 SCM_SETCAR (expr
, SCM_IM_SLOT_REF
);
2181 SCM_SETCDR (cdr_expr
, slot_nr
);
2186 unmemoize_atslot_ref (const SCM expr
, const SCM env
)
2188 const SCM instance
= SCM_CADR (expr
);
2189 const SCM um_instance
= unmemoize_expression (instance
, env
);
2190 const SCM slot_nr
= SCM_CDDR (expr
);
2191 return scm_list_3 (sym_atslot_ref
, um_instance
, slot_nr
);
2195 /* @slot-set! is bound privately in the (oop goops) module from goops.c. As
2196 * soon as the module system allows us to more freely create bindings in
2197 * arbitrary modules during the startup phase, the code from goops.c should be
2200 SCM_SYMBOL (sym_atslot_set_x
, "@slot-set!");
2203 scm_m_atslot_set_x (SCM expr
, SCM env SCM_UNUSED
)
2207 const SCM cdr_expr
= SCM_CDR (expr
);
2208 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2209 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 3, s_expression
, expr
);
2210 slot_nr
= SCM_CADR (cdr_expr
);
2211 ASSERT_SYNTAX_2 (SCM_I_INUMP (slot_nr
), s_bad_slot_number
, slot_nr
, expr
);
2213 SCM_SETCAR (expr
, SCM_IM_SLOT_SET_X
);
2218 unmemoize_atslot_set_x (const SCM expr
, const SCM env
)
2220 const SCM cdr_expr
= SCM_CDR (expr
);
2221 const SCM instance
= SCM_CAR (cdr_expr
);
2222 const SCM um_instance
= unmemoize_expression (instance
, env
);
2223 const SCM cddr_expr
= SCM_CDR (cdr_expr
);
2224 const SCM slot_nr
= SCM_CAR (cddr_expr
);
2225 const SCM cdddr_expr
= SCM_CDR (cddr_expr
);
2226 const SCM value
= SCM_CAR (cdddr_expr
);
2227 const SCM um_value
= unmemoize_expression (value
, env
);
2228 return scm_list_4 (sym_atslot_set_x
, um_instance
, slot_nr
, um_value
);
2232 #if SCM_ENABLE_ELISP
2234 static const char s_defun
[] = "Symbol's function definition is void";
2236 SCM_SYNTAX (s_nil_cond
, "nil-cond", scm_i_makbimacro
, scm_m_nil_cond
);
2238 /* nil-cond expressions have the form
2239 * (nil-cond COND VAL COND VAL ... ELSEVAL) */
2241 scm_m_nil_cond (SCM expr
, SCM env SCM_UNUSED
)
2243 const long length
= scm_ilength (SCM_CDR (expr
));
2244 ASSERT_SYNTAX (length
>= 0, s_bad_expression
, expr
);
2245 ASSERT_SYNTAX (length
>= 1 && (length
% 2) == 1, s_expression
, expr
);
2247 SCM_SETCAR (expr
, SCM_IM_NIL_COND
);
2252 SCM_SYNTAX (s_atfop
, "@fop", scm_i_makbimacro
, scm_m_atfop
);
2254 /* The @fop-macro handles procedure and macro applications for elisp. The
2255 * input expression must have the form
2256 * (@fop <var> (transformer-macro <expr> ...))
2257 * where <var> must be a symbol. The expression is transformed into the
2258 * memoized form of either
2259 * (apply <un-aliased var> (transformer-macro <expr> ...))
2260 * if the value of var (across all aliasing) is not a macro, or
2261 * (<un-aliased var> <expr> ...)
2262 * if var is a macro. */
2264 scm_m_atfop (SCM expr
, SCM env SCM_UNUSED
)
2269 const SCM cdr_expr
= SCM_CDR (expr
);
2270 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2271 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 1, s_missing_expression
, expr
);
2273 symbol
= SCM_CAR (cdr_expr
);
2274 ASSERT_SYNTAX_2 (scm_is_symbol (symbol
), s_bad_variable
, symbol
, expr
);
2276 location
= scm_symbol_fref (symbol
);
2277 ASSERT_SYNTAX_2 (SCM_VARIABLEP (location
), s_defun
, symbol
, expr
);
2279 /* The elisp function `defalias' allows to define aliases for symbols. To
2280 * look up such definitions, the chain of symbol definitions has to be
2281 * followed up to the terminal symbol. */
2282 while (scm_is_symbol (SCM_VARIABLE_REF (location
)))
2284 const SCM alias
= SCM_VARIABLE_REF (location
);
2285 location
= scm_symbol_fref (alias
);
2286 ASSERT_SYNTAX_2 (SCM_VARIABLEP (location
), s_defun
, symbol
, expr
);
2289 /* Memoize the value location belonging to the terminal symbol. */
2290 SCM_SETCAR (cdr_expr
, location
);
2292 if (!SCM_MACROP (SCM_VARIABLE_REF (location
)))
2294 /* Since the location does not contain a macro, the form is a procedure
2295 * application. Replace `@fop' by `@apply' and transform the expression
2296 * including the `transformer-macro'. */
2297 SCM_SETCAR (expr
, SCM_IM_APPLY
);
2302 /* Since the location contains a macro, the arguments should not be
2303 * transformed, so the `transformer-macro' is cut out. The resulting
2304 * expression starts with the memoized variable, that is at the cdr of
2305 * the input expression. */
2306 SCM_SETCDR (cdr_expr
, SCM_CDADR (cdr_expr
));
2311 #endif /* SCM_ENABLE_ELISP */
2315 unmemoize_builtin_macro (const SCM expr
, const SCM env
)
2317 switch (ISYMNUM (SCM_CAR (expr
)))
2319 case (ISYMNUM (SCM_IM_AND
)):
2320 return unmemoize_and (expr
, env
);
2322 case (ISYMNUM (SCM_IM_BEGIN
)):
2323 return unmemoize_begin (expr
, env
);
2325 case (ISYMNUM (SCM_IM_CASE
)):
2326 return unmemoize_case (expr
, env
);
2328 case (ISYMNUM (SCM_IM_COND
)):
2329 return unmemoize_cond (expr
, env
);
2331 case (ISYMNUM (SCM_IM_DELAY
)):
2332 return unmemoize_delay (expr
, env
);
2334 case (ISYMNUM (SCM_IM_DO
)):
2335 return unmemoize_do (expr
, env
);
2337 case (ISYMNUM (SCM_IM_IF
)):
2338 return unmemoize_if (expr
, env
);
2340 case (ISYMNUM (SCM_IM_LAMBDA
)):
2341 return unmemoize_lambda (expr
, env
);
2343 case (ISYMNUM (SCM_IM_LET
)):
2344 return unmemoize_let (expr
, env
);
2346 case (ISYMNUM (SCM_IM_LETREC
)):
2347 return unmemoize_letrec (expr
, env
);
2349 case (ISYMNUM (SCM_IM_LETSTAR
)):
2350 return unmemoize_letstar (expr
, env
);
2352 case (ISYMNUM (SCM_IM_OR
)):
2353 return unmemoize_or (expr
, env
);
2355 case (ISYMNUM (SCM_IM_QUOTE
)):
2356 return unmemoize_quote (expr
, env
);
2358 case (ISYMNUM (SCM_IM_SET_X
)):
2359 return unmemoize_set_x (expr
, env
);
2361 case (ISYMNUM (SCM_IM_APPLY
)):
2362 return unmemoize_apply (expr
, env
);
2364 case (ISYMNUM (SCM_IM_BIND
)):
2365 return unmemoize_exprs (expr
, env
); /* FIXME */
2367 case (ISYMNUM (SCM_IM_CONT
)):
2368 return unmemoize_atcall_cc (expr
, env
);
2370 case (ISYMNUM (SCM_IM_CALL_WITH_VALUES
)):
2371 return unmemoize_at_call_with_values (expr
, env
);
2373 case (ISYMNUM (SCM_IM_FUTURE
)):
2374 return unmemoize_future (expr
, env
);
2376 case (ISYMNUM (SCM_IM_SLOT_REF
)):
2377 return unmemoize_atslot_ref (expr
, env
);
2379 case (ISYMNUM (SCM_IM_SLOT_SET_X
)):
2380 return unmemoize_atslot_set_x (expr
, env
);
2382 case (ISYMNUM (SCM_IM_NIL_COND
)):
2383 return unmemoize_exprs (expr
, env
); /* FIXME */
2386 return unmemoize_exprs (expr
, env
); /* FIXME */
2391 /* scm_i_unmemocopy_expr and scm_i_unmemocopy_body take a memoized expression
2392 * respectively a memoized body together with its environment and rewrite it
2393 * to its original form. Thus, these functions are the inversion of the
2394 * rewrite rules above. The procedure is not optimized for speed. It's used
2395 * in scm_i_unmemoize_expr, scm_procedure_source, macro_print and scm_iprin1.
2397 * Unmemoizing is not a reliable process. You cannot in general expect to get
2398 * the original source back.
2400 * However, GOOPS currently relies on this for method compilation. This ought
2404 scm_i_unmemocopy_expr (SCM expr
, SCM env
)
2406 const SCM source_properties
= scm_whash_lookup (scm_source_whash
, expr
);
2407 const SCM um_expr
= unmemoize_expression (expr
, env
);
2409 if (scm_is_true (source_properties
))
2410 scm_whash_insert (scm_source_whash
, um_expr
, source_properties
);
2416 scm_i_unmemocopy_body (SCM forms
, SCM env
)
2418 const SCM source_properties
= scm_whash_lookup (scm_source_whash
, forms
);
2419 const SCM um_forms
= unmemoize_exprs (forms
, env
);
2421 if (scm_is_true (source_properties
))
2422 scm_whash_insert (scm_source_whash
, um_forms
, source_properties
);
2428 #if (SCM_ENABLE_DEPRECATED == 1)
2430 /* Deprecated in guile 1.7.0 on 2003-11-09. */
2432 scm_m_expand_body (SCM exprs
, SCM env
)
2434 scm_c_issue_deprecation_warning
2435 ("`scm_m_expand_body' is deprecated.");
2436 m_expand_body (exprs
, env
);
2441 SCM_SYNTAX (s_undefine
, "undefine", scm_makacro
, scm_m_undefine
);
2444 scm_m_undefine (SCM expr
, SCM env
)
2449 const SCM cdr_expr
= SCM_CDR (expr
);
2450 ASSERT_SYNTAX (SCM_TOP_LEVEL (env
), "Bad undefine placement in", expr
);
2451 ASSERT_SYNTAX (scm_ilength (cdr_expr
) >= 0, s_bad_expression
, expr
);
2452 ASSERT_SYNTAX (scm_ilength (cdr_expr
) == 1, s_expression
, expr
);
2454 scm_c_issue_deprecation_warning
2455 ("`undefine' is deprecated.\n");
2457 variable
= SCM_CAR (cdr_expr
);
2458 ASSERT_SYNTAX_2 (scm_is_symbol (variable
), s_bad_variable
, variable
, expr
);
2459 location
= scm_sym2var (variable
, scm_env_top_level (env
), SCM_BOOL_F
);
2460 ASSERT_SYNTAX_2 (scm_is_true (location
)
2461 && !SCM_UNBNDP (SCM_VARIABLE_REF (location
)),
2462 "variable already unbound ", variable
, expr
);
2463 SCM_VARIABLE_SET (location
, SCM_UNDEFINED
);
2464 return SCM_UNSPECIFIED
;
2468 scm_macroexp (SCM x
, SCM env
)
2470 scm_c_issue_deprecation_warning
2471 ("`scm_macroexp' is deprecated.");
2472 return macroexp (x
, env
);
2478 #if (SCM_ENABLE_DEPRECATED == 1)
2481 scm_unmemocar (SCM form
, SCM env
)
2483 scm_c_issue_deprecation_warning
2484 ("`scm_unmemocar' is deprecated.");
2486 if (!scm_is_pair (form
))
2490 SCM c
= SCM_CAR (form
);
2491 if (SCM_VARIABLEP (c
))
2493 SCM sym
= scm_module_reverse_lookup (scm_env_module (env
), c
);
2494 if (scm_is_false (sym
))
2495 sym
= sym_three_question_marks
;
2496 SCM_SETCAR (form
, sym
);
2498 else if (SCM_ILOCP (c
))
2500 unsigned long int ir
;
2502 for (ir
= SCM_IFRAME (c
); ir
!= 0; --ir
)
2503 env
= SCM_CDR (env
);
2504 env
= SCM_CAAR (env
);
2505 for (ir
= SCM_IDIST (c
); ir
!= 0; --ir
)
2506 env
= SCM_CDR (env
);
2508 SCM_SETCAR (form
, SCM_ICDRP (c
) ? env
: SCM_CAR (env
));
2516 /*****************************************************************************/
2517 /*****************************************************************************/
2518 /* The definitions for execution start here. */
2519 /*****************************************************************************/
2520 /*****************************************************************************/
2522 SCM_GLOBAL_SYMBOL (scm_sym_enter_frame
, "enter-frame");
2523 SCM_GLOBAL_SYMBOL (scm_sym_apply_frame
, "apply-frame");
2524 SCM_GLOBAL_SYMBOL (scm_sym_exit_frame
, "exit-frame");
2525 SCM_GLOBAL_SYMBOL (scm_sym_trace
, "trace");
2527 /* A function object to implement "apply" for non-closure functions. */
2529 /* An endless list consisting of #<undefined> objects: */
2530 static SCM undefineds
;
2534 scm_badargsp (SCM formals
, SCM args
)
2536 while (!scm_is_null (formals
))
2538 if (!scm_is_pair (formals
))
2540 if (scm_is_null (args
))
2542 formals
= SCM_CDR (formals
);
2543 args
= SCM_CDR (args
);
2545 return !scm_is_null (args
) ? 1 : 0;
2550 /* The evaluator contains a plethora of EVAL symbols. This is an attempt at
2553 * The following macros should be used in code which is read twice (where the
2554 * choice of evaluator is hard soldered):
2556 * CEVAL is the symbol used within one evaluator to call itself.
2557 * Originally, it is defined to ceval, but is redefined to deval during the
2560 * SCM_I_EVALIM is used when it is known that the expression is an
2561 * immediate. (This macro never calls an evaluator.)
2563 * EVAL evaluates an expression that is expected to have its symbols already
2564 * memoized. Expressions that are not of the form '(<form> <form> ...)' are
2565 * evaluated inline without calling an evaluator.
2567 * EVALCAR evaluates the car of an expression 'X:(Y:<form> <form> ...)',
2568 * potentially replacing a symbol at the position Y:<form> by its memoized
2569 * variable. If Y:<form> is not of the form '(<form> <form> ...)', the
2570 * evaluation is performed inline without calling an evaluator.
2572 * The following macros should be used in code which is read once
2573 * (where the choice of evaluator is dynamic):
2575 * SCM_I_XEVAL corresponds to EVAL, but uses ceval *or* deval depending on the
2578 * SCM_I_XEVALCAR corresponds to EVALCAR, but uses ceval *or* deval depending
2579 * on the debugging mode.
2581 * The main motivation for keeping this plethora is efficiency
2582 * together with maintainability (=> locality of code).
2585 static SCM
ceval (SCM x
, SCM env
);
2586 static SCM
deval (SCM x
, SCM env
);
2590 #define SCM_I_EVALIM2(x) \
2591 ((scm_is_eq ((x), SCM_EOL) \
2592 ? syntax_error (s_empty_combination, (x), SCM_UNDEFINED), 0 \
2596 #define SCM_I_EVALIM(x, env) (SCM_ILOCP (x) \
2597 ? *scm_ilookup ((x), (env)) \
2600 #define SCM_I_XEVAL(x, env) \
2602 ? SCM_I_EVALIM2 (x) \
2603 : (SCM_VARIABLEP (x) \
2604 ? SCM_VARIABLE_REF (x) \
2605 : (scm_is_pair (x) \
2606 ? (scm_debug_mode_p \
2607 ? deval ((x), (env)) \
2608 : ceval ((x), (env))) \
2611 #define SCM_I_XEVALCAR(x, env) \
2612 (SCM_IMP (SCM_CAR (x)) \
2613 ? SCM_I_EVALIM (SCM_CAR (x), (env)) \
2614 : (SCM_VARIABLEP (SCM_CAR (x)) \
2615 ? SCM_VARIABLE_REF (SCM_CAR (x)) \
2616 : (scm_is_pair (SCM_CAR (x)) \
2617 ? (scm_debug_mode_p \
2618 ? deval (SCM_CAR (x), (env)) \
2619 : ceval (SCM_CAR (x), (env))) \
2620 : (!scm_is_symbol (SCM_CAR (x)) \
2622 : *scm_lookupcar ((x), (env), 1)))))
2624 #define EVAL(x, env) \
2626 ? SCM_I_EVALIM ((x), (env)) \
2627 : (SCM_VARIABLEP (x) \
2628 ? SCM_VARIABLE_REF (x) \
2629 : (scm_is_pair (x) \
2630 ? CEVAL ((x), (env)) \
2633 #define EVALCAR(x, env) \
2634 (SCM_IMP (SCM_CAR (x)) \
2635 ? SCM_I_EVALIM (SCM_CAR (x), (env)) \
2636 : (SCM_VARIABLEP (SCM_CAR (x)) \
2637 ? SCM_VARIABLE_REF (SCM_CAR (x)) \
2638 : (scm_is_pair (SCM_CAR (x)) \
2639 ? CEVAL (SCM_CAR (x), (env)) \
2640 : (!scm_is_symbol (SCM_CAR (x)) \
2642 : *scm_lookupcar ((x), (env), 1)))))
2644 SCM_REC_MUTEX (source_mutex
);
2647 /* Lookup a given local variable in an environment. The local variable is
2648 * given as an iloc, that is a triple <frame, binding, last?>, where frame
2649 * indicates the relative number of the environment frame (counting upwards
2650 * from the innermost environment frame), binding indicates the number of the
2651 * binding within the frame, and last? (which is extracted from the iloc using
2652 * the macro SCM_ICDRP) indicates whether the binding forms the binding at the
2653 * very end of the improper list of bindings. */
2655 scm_ilookup (SCM iloc
, SCM env
)
2657 unsigned int frame_nr
= SCM_IFRAME (iloc
);
2658 unsigned int binding_nr
= SCM_IDIST (iloc
);
2662 for (; 0 != frame_nr
; --frame_nr
)
2663 frames
= SCM_CDR (frames
);
2665 bindings
= SCM_CAR (frames
);
2666 for (; 0 != binding_nr
; --binding_nr
)
2667 bindings
= SCM_CDR (bindings
);
2669 if (SCM_ICDRP (iloc
))
2670 return SCM_CDRLOC (bindings
);
2671 return SCM_CARLOC (SCM_CDR (bindings
));
2675 SCM_SYMBOL (scm_unbound_variable_key
, "unbound-variable");
2677 static void error_unbound_variable (SCM symbol
) SCM_NORETURN
;
2678 static void error_defined_variable (SCM symbol
) SCM_NORETURN
;
2680 /* Call this for variables that are unfound.
2683 error_unbound_variable (SCM symbol
)
2685 scm_error (scm_unbound_variable_key
, NULL
,
2686 "Unbound variable: ~S",
2687 scm_list_1 (symbol
), SCM_BOOL_F
);
2690 /* Call this for variables that are found but contain SCM_UNDEFINED.
2693 error_defined_variable (SCM symbol
)
2695 /* We use the 'unbound-variable' key here as well, since it
2696 basically is the same kind of error, with a slight variation in
2697 the displayed message.
2699 scm_error (scm_unbound_variable_key
, NULL
,
2700 "Variable used before given a value: ~S",
2701 scm_list_1 (symbol
), SCM_BOOL_F
);
2705 /* The Lookup Car Race
2708 Memoization of variables and special forms is done while executing
2709 the code for the first time. As long as there is only one thread
2710 everything is fine, but as soon as two threads execute the same
2711 code concurrently `for the first time' they can come into conflict.
2713 This memoization includes rewriting variable references into more
2714 efficient forms and expanding macros. Furthermore, macro expansion
2715 includes `compiling' special forms like `let', `cond', etc. into
2716 tree-code instructions.
2718 There shouldn't normally be a problem with memoizing local and
2719 global variable references (into ilocs and variables), because all
2720 threads will mutate the code in *exactly* the same way and (if I
2721 read the C code correctly) it is not possible to observe a half-way
2722 mutated cons cell. The lookup procedure can handle this
2723 transparently without any critical sections.
2725 It is different with macro expansion, because macro expansion
2726 happens outside of the lookup procedure and can't be
2727 undone. Therefore the lookup procedure can't cope with it. It has
2728 to indicate failure when it detects a lost race and hope that the
2729 caller can handle it. Luckily, it turns out that this is the case.
2731 An example to illustrate this: Suppose that the following form will
2732 be memoized concurrently by two threads
2736 Let's first examine the lookup of X in the body. The first thread
2737 decides that it has to find the symbol "x" in the environment and
2738 starts to scan it. Then the other thread takes over and actually
2739 overtakes the first. It looks up "x" and substitutes an
2740 appropriate iloc for it. Now the first thread continues and
2741 completes its lookup. It comes to exactly the same conclusions as
2742 the second one and could - without much ado - just overwrite the
2743 iloc with the same iloc.
2745 But let's see what will happen when the race occurs while looking
2746 up the symbol "let" at the start of the form. It could happen that
2747 the second thread interrupts the lookup of the first thread and not
2748 only substitutes a variable for it but goes right ahead and
2749 replaces it with the compiled form (#@let* (x 12) x). Now, when
2750 the first thread completes its lookup, it would replace the #@let*
2751 with a variable containing the "let" binding, effectively reverting
2752 the form to (let (x 12) x). This is wrong. It has to detect that
2753 it has lost the race and the evaluator has to reconsider the
2754 changed form completely.
2756 This race condition could be resolved with some kind of traffic
2757 light (like mutexes) around scm_lookupcar, but I think that it is
2758 best to avoid them in this case. They would serialize memoization
2759 completely and because lookup involves calling arbitrary Scheme
2760 code (via the lookup-thunk), threads could be blocked for an
2761 arbitrary amount of time or even deadlock. But with the current
2762 solution a lot of unnecessary work is potentially done. */
2764 /* SCM_LOOKUPCAR1 is what SCM_LOOKUPCAR used to be but is allowed to
2765 return NULL to indicate a failed lookup due to some race conditions
2766 between threads. This only happens when VLOC is the first cell of
2767 a special form that will eventually be memoized (like `let', etc.)
2768 In that case the whole lookup is bogus and the caller has to
2769 reconsider the complete special form.
2771 SCM_LOOKUPCAR is still there, of course. It just calls
2772 SCM_LOOKUPCAR1 and aborts on receiving NULL. So SCM_LOOKUPCAR
2773 should only be called when it is known that VLOC is not the first
2774 pair of a special form. Otherwise, use SCM_LOOKUPCAR1 and check
2775 for NULL. I think I've found the only places where this
2779 scm_lookupcar1 (SCM vloc
, SCM genv
, int check
)
2782 register SCM
*al
, fl
, var
= SCM_CAR (vloc
);
2783 register SCM iloc
= SCM_ILOC00
;
2784 for (; SCM_NIMP (env
); env
= SCM_CDR (env
))
2786 if (!scm_is_pair (SCM_CAR (env
)))
2788 al
= SCM_CARLOC (env
);
2789 for (fl
= SCM_CAR (*al
); SCM_NIMP (fl
); fl
= SCM_CDR (fl
))
2791 if (!scm_is_pair (fl
))
2793 if (scm_is_eq (fl
, var
))
2795 if (!scm_is_eq (SCM_CAR (vloc
), var
))
2797 SCM_SET_CELL_WORD_0 (vloc
, SCM_UNPACK (iloc
) + SCM_ICDR
);
2798 return SCM_CDRLOC (*al
);
2803 al
= SCM_CDRLOC (*al
);
2804 if (scm_is_eq (SCM_CAR (fl
), var
))
2806 if (SCM_UNBNDP (SCM_CAR (*al
)))
2807 error_defined_variable (var
);
2808 if (!scm_is_eq (SCM_CAR (vloc
), var
))
2810 SCM_SETCAR (vloc
, iloc
);
2811 return SCM_CARLOC (*al
);
2813 iloc
= SCM_PACK (SCM_UNPACK (iloc
) + SCM_IDINC
);
2815 iloc
= SCM_PACK ((~SCM_IDSTMSK
) & (SCM_UNPACK(iloc
) + SCM_IFRINC
));
2818 SCM top_thunk
, real_var
;
2821 top_thunk
= SCM_CAR (env
); /* env now refers to a
2822 top level env thunk */
2823 env
= SCM_CDR (env
);
2826 top_thunk
= SCM_BOOL_F
;
2827 real_var
= scm_sym2var (var
, top_thunk
, SCM_BOOL_F
);
2828 if (scm_is_false (real_var
))
2831 if (!scm_is_null (env
) || SCM_UNBNDP (SCM_VARIABLE_REF (real_var
)))
2836 if (scm_is_null (env
))
2837 error_unbound_variable (var
);
2839 scm_misc_error (NULL
, "Damaged environment: ~S",
2844 /* A variable could not be found, but we shall
2845 not throw an error. */
2846 static SCM undef_object
= SCM_UNDEFINED
;
2847 return &undef_object
;
2851 if (!scm_is_eq (SCM_CAR (vloc
), var
))
2853 /* Some other thread has changed the very cell we are working
2854 on. In effect, it must have done our job or messed it up
2857 var
= SCM_CAR (vloc
);
2858 if (SCM_VARIABLEP (var
))
2859 return SCM_VARIABLE_LOC (var
);
2860 if (SCM_ILOCP (var
))
2861 return scm_ilookup (var
, genv
);
2862 /* We can't cope with anything else than variables and ilocs. When
2863 a special form has been memoized (i.e. `let' into `#@let') we
2864 return NULL and expect the calling function to do the right
2865 thing. For the evaluator, this means going back and redoing
2866 the dispatch on the car of the form. */
2870 SCM_SETCAR (vloc
, real_var
);
2871 return SCM_VARIABLE_LOC (real_var
);
2876 scm_lookupcar (SCM vloc
, SCM genv
, int check
)
2878 SCM
*loc
= scm_lookupcar1 (vloc
, genv
, check
);
2885 /* During execution, look up a symbol in the top level of the given local
2886 * environment and return the corresponding variable object. If no binding
2887 * for the symbol can be found, an 'Unbound variable' error is signalled. */
2889 lazy_memoize_variable (const SCM symbol
, const SCM environment
)
2891 const SCM top_level
= scm_env_top_level (environment
);
2892 const SCM variable
= scm_sym2var (symbol
, top_level
, SCM_BOOL_F
);
2894 if (scm_is_false (variable
))
2895 error_unbound_variable (symbol
);
2902 scm_eval_car (SCM pair
, SCM env
)
2904 return SCM_I_XEVALCAR (pair
, env
);
2909 scm_eval_args (SCM l
, SCM env
, SCM proc
)
2911 SCM results
= SCM_EOL
, *lloc
= &results
, res
;
2912 while (scm_is_pair (l
))
2914 res
= EVALCAR (l
, env
);
2916 *lloc
= scm_list_1 (res
);
2917 lloc
= SCM_CDRLOC (*lloc
);
2920 if (!scm_is_null (l
))
2921 scm_wrong_num_args (proc
);
2927 scm_eval_body (SCM code
, SCM env
)
2932 next
= SCM_CDR (code
);
2933 while (!scm_is_null (next
))
2935 if (SCM_IMP (SCM_CAR (code
)))
2937 if (SCM_ISYMP (SCM_CAR (code
)))
2939 scm_rec_mutex_lock (&source_mutex
);
2940 /* check for race condition */
2941 if (SCM_ISYMP (SCM_CAR (code
)))
2942 m_expand_body (code
, env
);
2943 scm_rec_mutex_unlock (&source_mutex
);
2948 SCM_I_XEVAL (SCM_CAR (code
), env
);
2950 next
= SCM_CDR (code
);
2952 return SCM_I_XEVALCAR (code
, env
);
2958 /* SECTION: This code is specific for the debugging support. One
2959 * branch is read when DEVAL isn't defined, the other when DEVAL is
2965 #define SCM_APPLY scm_apply
2966 #define PREP_APPLY(proc, args)
2968 #define RETURN(x) do { return x; } while (0)
2969 #ifdef STACK_CHECKING
2970 #ifndef NO_CEVAL_STACK_CHECKING
2971 #define EVAL_STACK_CHECKING
2978 #define CEVAL deval /* Substitute all uses of ceval */
2981 #define SCM_APPLY scm_dapply
2984 #define PREP_APPLY(p, l) \
2985 { ++debug.info; debug.info->a.proc = p; debug.info->a.args = l; }
2988 #define ENTER_APPLY \
2990 SCM_SET_ARGSREADY (debug);\
2991 if (scm_check_apply_p && SCM_TRAPS_P)\
2992 if (SCM_APPLY_FRAME_P || (SCM_TRACE_P && PROCTRACEP (proc)))\
2994 SCM tmp, tail = scm_from_bool(SCM_TRACED_FRAME_P (debug)); \
2995 SCM_SET_TRACED_FRAME (debug); \
2997 if (SCM_CHEAPTRAPS_P)\
2999 tmp = scm_make_debugobj (&debug);\
3000 scm_call_3 (SCM_APPLY_FRAME_HDLR, scm_sym_apply_frame, tmp, tail);\
3005 tmp = scm_make_continuation (&first);\
3007 scm_call_3 (SCM_APPLY_FRAME_HDLR, scm_sym_apply_frame, tmp, tail);\
3014 #define RETURN(e) do { proc = (e); goto exit; } while (0)
3016 #ifdef STACK_CHECKING
3017 #ifndef EVAL_STACK_CHECKING
3018 #define EVAL_STACK_CHECKING
3023 /* scm_last_debug_frame contains a pointer to the last debugging information
3024 * stack frame. It is accessed very often from the debugging evaluator, so it
3025 * should probably not be indirectly addressed. Better to save and restore it
3026 * from the current root at any stack swaps.
3029 /* scm_debug_eframe_size is the number of slots available for pseudo
3030 * stack frames at each real stack frame.
3033 long scm_debug_eframe_size
;
3035 int scm_debug_mode_p
;
3036 int scm_check_entry_p
;
3037 int scm_check_apply_p
;
3038 int scm_check_exit_p
;
3040 long scm_eval_stack
;
3042 scm_t_option scm_eval_opts
[] = {
3043 { SCM_OPTION_INTEGER
, "stack", 22000, "Size of thread stacks (in machine words)." }
3046 scm_t_option scm_debug_opts
[] = {
3047 { SCM_OPTION_BOOLEAN
, "cheap", 1,
3048 "*Flyweight representation of the stack at traps." },
3049 { SCM_OPTION_BOOLEAN
, "breakpoints", 0, "*Check for breakpoints." },
3050 { SCM_OPTION_BOOLEAN
, "trace", 0, "*Trace mode." },
3051 { SCM_OPTION_BOOLEAN
, "procnames", 1,
3052 "Record procedure names at definition." },
3053 { SCM_OPTION_BOOLEAN
, "backwards", 0,
3054 "Display backtrace in anti-chronological order." },
3055 { SCM_OPTION_INTEGER
, "width", 79, "Maximal width of backtrace." },
3056 { SCM_OPTION_INTEGER
, "indent", 10, "Maximal indentation in backtrace." },
3057 { SCM_OPTION_INTEGER
, "frames", 3,
3058 "Maximum number of tail-recursive frames in backtrace." },
3059 { SCM_OPTION_INTEGER
, "maxdepth", 1000,
3060 "Maximal number of stored backtrace frames." },
3061 { SCM_OPTION_INTEGER
, "depth", 20, "Maximal length of printed backtrace." },
3062 { SCM_OPTION_BOOLEAN
, "backtrace", 0, "Show backtrace on error." },
3063 { SCM_OPTION_BOOLEAN
, "debug", 0, "Use the debugging evaluator." },
3064 { SCM_OPTION_INTEGER
, "stack", 20000, "Stack size limit (measured in words; 0 = no check)." },
3065 { 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."},
3066 { SCM_OPTION_BOOLEAN
, "warn-deprecated", 0, "Warn when deprecated features are used." }
3069 scm_t_option scm_evaluator_trap_table
[] = {
3070 { SCM_OPTION_BOOLEAN
, "traps", 0, "Enable evaluator traps." },
3071 { SCM_OPTION_BOOLEAN
, "enter-frame", 0, "Trap when eval enters new frame." },
3072 { SCM_OPTION_BOOLEAN
, "apply-frame", 0, "Trap when entering apply." },
3073 { SCM_OPTION_BOOLEAN
, "exit-frame", 0, "Trap when exiting eval or apply." },
3074 { SCM_OPTION_SCM
, "enter-frame-handler", (unsigned long)SCM_BOOL_F
, "Handler for enter-frame traps." },
3075 { SCM_OPTION_SCM
, "apply-frame-handler", (unsigned long)SCM_BOOL_F
, "Handler for apply-frame traps." },
3076 { SCM_OPTION_SCM
, "exit-frame-handler", (unsigned long)SCM_BOOL_F
, "Handler for exit-frame traps." }
3079 SCM_DEFINE (scm_eval_options_interface
, "eval-options-interface", 0, 1, 0,
3081 "Option interface for the evaluation options. Instead of using\n"
3082 "this procedure directly, use the procedures @code{eval-enable},\n"
3083 "@code{eval-disable}, @code{eval-set!} and @code{eval-options}.")
3084 #define FUNC_NAME s_scm_eval_options_interface
3088 ans
= scm_options (setting
,
3092 scm_eval_stack
= SCM_EVAL_STACK
* sizeof (void *);
3099 SCM_DEFINE (scm_evaluator_traps
, "evaluator-traps-interface", 0, 1, 0,
3101 "Option interface for the evaluator trap options.")
3102 #define FUNC_NAME s_scm_evaluator_traps
3106 ans
= scm_options (setting
,
3107 scm_evaluator_trap_table
,
3108 SCM_N_EVALUATOR_TRAPS
,
3110 SCM_RESET_DEBUG_MODE
;
3118 deval_args (SCM l
, SCM env
, SCM proc
, SCM
*lloc
)
3120 SCM
*results
= lloc
;
3121 while (scm_is_pair (l
))
3123 const SCM res
= EVALCAR (l
, env
);
3125 *lloc
= scm_list_1 (res
);
3126 lloc
= SCM_CDRLOC (*lloc
);
3129 if (!scm_is_null (l
))
3130 scm_wrong_num_args (proc
);
3137 /* SECTION: This code is compiled twice.
3141 /* Update the toplevel environment frame ENV so that it refers to the
3142 * current module. */
3143 #define UPDATE_TOPLEVEL_ENV(env) \
3145 SCM p = scm_current_module_lookup_closure (); \
3146 if (p != SCM_CAR (env)) \
3147 env = scm_top_level_env (p); \
3151 #define SCM_VALIDATE_NON_EMPTY_COMBINATION(x) \
3152 ASSERT_SYNTAX (!scm_is_eq ((x), SCM_EOL), s_empty_combination, x)
3155 /* This is the evaluator. Like any real monster, it has three heads:
3157 * ceval is the non-debugging evaluator, deval is the debugging version. Both
3158 * are implemented using a common code base, using the following mechanism:
3159 * CEVAL is a macro, which is either defined to ceval or deval. Thus, there
3160 * is no function CEVAL, but the code for CEVAL actually compiles to either
3161 * ceval or deval. When CEVAL is defined to ceval, it is known that the macro
3162 * DEVAL is not defined. When CEVAL is defined to deval, then the macro DEVAL
3163 * is known to be defined. Thus, in CEVAL parts for the debugging evaluator
3164 * are enclosed within #ifdef DEVAL ... #endif.
3166 * All three (ceval, deval and their common implementation CEVAL) take two
3167 * input parameters, x and env: x is a single expression to be evalutated.
3168 * env is the environment in which bindings are searched.
3170 * x is known to be a pair. Since x is a single expression, it is necessarily
3171 * in a tail position. If x is just a call to another function like in the
3172 * expression (foo exp1 exp2 ...), the realization of that call therefore
3173 * _must_not_ increase stack usage (the evaluation of exp1, exp2 etc.,
3174 * however, may do so). This is realized by making extensive use of 'goto'
3175 * statements within the evaluator: The gotos replace recursive calls to
3176 * CEVAL, thus re-using the same stack frame that CEVAL was already using.
3177 * If, however, x represents some form that requires to evaluate a sequence of
3178 * expressions like (begin exp1 exp2 ...), then recursive calls to CEVAL are
3179 * performed for all but the last expression of that sequence. */
3182 CEVAL (SCM x
, SCM env
)
3186 scm_t_debug_frame debug
;
3187 scm_t_debug_info
*debug_info_end
;
3188 debug
.prev
= scm_last_debug_frame
;
3191 * The debug.vect contains twice as much scm_t_debug_info frames as the
3192 * user has specified with (debug-set! frames <n>).
3194 * Even frames are eval frames, odd frames are apply frames.
3196 debug
.vect
= (scm_t_debug_info
*) alloca (scm_debug_eframe_size
3197 * sizeof (scm_t_debug_info
));
3198 debug
.info
= debug
.vect
;
3199 debug_info_end
= debug
.vect
+ scm_debug_eframe_size
;
3200 scm_last_debug_frame
= &debug
;
3202 #ifdef EVAL_STACK_CHECKING
3203 if (scm_stack_checking_enabled_p
&& SCM_STACK_OVERFLOW_P (&proc
))
3206 debug
.info
->e
.exp
= x
;
3207 debug
.info
->e
.env
= env
;
3209 scm_report_stack_overflow ();
3219 SCM_CLEAR_ARGSREADY (debug
);
3220 if (SCM_OVERFLOWP (debug
))
3223 * In theory, this should be the only place where it is necessary to
3224 * check for space in debug.vect since both eval frames and
3225 * available space are even.
3227 * For this to be the case, however, it is necessary that primitive
3228 * special forms which jump back to `loop', `begin' or some similar
3229 * label call PREP_APPLY.
3231 else if (++debug
.info
>= debug_info_end
)
3233 SCM_SET_OVERFLOW (debug
);
3238 debug
.info
->e
.exp
= x
;
3239 debug
.info
->e
.env
= env
;
3240 if (scm_check_entry_p
&& SCM_TRAPS_P
)
3242 if (SCM_ENTER_FRAME_P
3243 || (SCM_BREAKPOINTS_P
&& scm_c_source_property_breakpoint_p (x
)))
3246 SCM tail
= scm_from_bool (SCM_TAILRECP (debug
));
3247 SCM_SET_TAILREC (debug
);
3248 if (SCM_CHEAPTRAPS_P
)
3249 stackrep
= scm_make_debugobj (&debug
);
3253 SCM val
= scm_make_continuation (&first
);
3263 /* This gives the possibility for the debugger to
3264 modify the source expression before evaluation. */
3269 scm_call_4 (SCM_ENTER_FRAME_HDLR
,
3270 scm_sym_enter_frame
,
3273 unmemoize_expression (x
, env
));
3280 if (SCM_ISYMP (SCM_CAR (x
)))
3282 switch (ISYMNUM (SCM_CAR (x
)))
3284 case (ISYMNUM (SCM_IM_AND
)):
3286 while (!scm_is_null (SCM_CDR (x
)))
3288 SCM test_result
= EVALCAR (x
, env
);
3289 if (scm_is_false (test_result
) || SCM_NILP (test_result
))
3290 RETURN (SCM_BOOL_F
);
3294 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3297 case (ISYMNUM (SCM_IM_BEGIN
)):
3299 if (scm_is_null (x
))
3300 RETURN (SCM_UNSPECIFIED
);
3302 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3305 /* If we are on toplevel with a lookup closure, we need to sync
3306 with the current module. */
3307 if (scm_is_pair (env
) && !scm_is_pair (SCM_CAR (env
)))
3309 UPDATE_TOPLEVEL_ENV (env
);
3310 while (!scm_is_null (SCM_CDR (x
)))
3313 UPDATE_TOPLEVEL_ENV (env
);
3319 goto nontoplevel_begin
;
3322 while (!scm_is_null (SCM_CDR (x
)))
3324 const SCM form
= SCM_CAR (x
);
3327 if (SCM_ISYMP (form
))
3329 scm_rec_mutex_lock (&source_mutex
);
3330 /* check for race condition */
3331 if (SCM_ISYMP (SCM_CAR (x
)))
3332 m_expand_body (x
, env
);
3333 scm_rec_mutex_unlock (&source_mutex
);
3334 goto nontoplevel_begin
;
3337 SCM_VALIDATE_NON_EMPTY_COMBINATION (form
);
3340 (void) EVAL (form
, env
);
3346 /* scm_eval last form in list */
3347 const SCM last_form
= SCM_CAR (x
);
3349 if (scm_is_pair (last_form
))
3351 /* This is by far the most frequent case. */
3353 goto loop
; /* tail recurse */
3355 else if (SCM_IMP (last_form
))
3356 RETURN (SCM_I_EVALIM (last_form
, env
));
3357 else if (SCM_VARIABLEP (last_form
))
3358 RETURN (SCM_VARIABLE_REF (last_form
));
3359 else if (scm_is_symbol (last_form
))
3360 RETURN (*scm_lookupcar (x
, env
, 1));
3366 case (ISYMNUM (SCM_IM_CASE
)):
3369 const SCM key
= EVALCAR (x
, env
);
3371 while (!scm_is_null (x
))
3373 const SCM clause
= SCM_CAR (x
);
3374 SCM labels
= SCM_CAR (clause
);
3375 if (scm_is_eq (labels
, SCM_IM_ELSE
))
3377 x
= SCM_CDR (clause
);
3378 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3381 while (!scm_is_null (labels
))
3383 const SCM label
= SCM_CAR (labels
);
3384 if (scm_is_eq (label
, key
)
3385 || scm_is_true (scm_eqv_p (label
, key
)))
3387 x
= SCM_CDR (clause
);
3388 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3391 labels
= SCM_CDR (labels
);
3396 RETURN (SCM_UNSPECIFIED
);
3399 case (ISYMNUM (SCM_IM_COND
)):
3401 while (!scm_is_null (x
))
3403 const SCM clause
= SCM_CAR (x
);
3404 if (scm_is_eq (SCM_CAR (clause
), SCM_IM_ELSE
))
3406 x
= SCM_CDR (clause
);
3407 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3412 arg1
= EVALCAR (clause
, env
);
3413 if (scm_is_true (arg1
) && !SCM_NILP (arg1
))
3415 x
= SCM_CDR (clause
);
3416 if (scm_is_null (x
))
3418 else if (!scm_is_eq (SCM_CAR (x
), SCM_IM_ARROW
))
3420 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3426 proc
= EVALCAR (proc
, env
);
3427 PREP_APPLY (proc
, scm_list_1 (arg1
));
3435 RETURN (SCM_UNSPECIFIED
);
3438 case (ISYMNUM (SCM_IM_DO
)):
3441 /* Compute the initialization values and the initial environment. */
3442 SCM init_forms
= SCM_CAR (x
);
3443 SCM init_values
= SCM_EOL
;
3444 while (!scm_is_null (init_forms
))
3446 init_values
= scm_cons (EVALCAR (init_forms
, env
), init_values
);
3447 init_forms
= SCM_CDR (init_forms
);
3450 env
= SCM_EXTEND_ENV (SCM_CAR (x
), init_values
, env
);
3454 SCM test_form
= SCM_CAR (x
);
3455 SCM body_forms
= SCM_CADR (x
);
3456 SCM step_forms
= SCM_CDDR (x
);
3458 SCM test_result
= EVALCAR (test_form
, env
);
3460 while (scm_is_false (test_result
) || SCM_NILP (test_result
))
3463 /* Evaluate body forms. */
3465 for (temp_forms
= body_forms
;
3466 !scm_is_null (temp_forms
);
3467 temp_forms
= SCM_CDR (temp_forms
))
3469 SCM form
= SCM_CAR (temp_forms
);
3470 /* Dirk:FIXME: We only need to eval forms that may have
3471 * a side effect here. This is only true for forms that
3472 * start with a pair. All others are just constants.
3473 * Since with the current memoizer 'form' may hold a
3474 * constant, we call EVAL here to handle the constant
3475 * cases. In the long run it would make sense to have
3476 * the macro transformer of 'do' eliminate all forms
3477 * that have no sideeffect. Then instead of EVAL we
3478 * could call CEVAL directly here. */
3479 (void) EVAL (form
, env
);
3484 /* Evaluate the step expressions. */
3486 SCM step_values
= SCM_EOL
;
3487 for (temp_forms
= step_forms
;
3488 !scm_is_null (temp_forms
);
3489 temp_forms
= SCM_CDR (temp_forms
))
3491 const SCM value
= EVALCAR (temp_forms
, env
);
3492 step_values
= scm_cons (value
, step_values
);
3494 env
= SCM_EXTEND_ENV (SCM_CAAR (env
),
3499 test_result
= EVALCAR (test_form
, env
);
3503 if (scm_is_null (x
))
3504 RETURN (SCM_UNSPECIFIED
);
3505 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3506 goto nontoplevel_begin
;
3509 case (ISYMNUM (SCM_IM_IF
)):
3512 SCM test_result
= EVALCAR (x
, env
);
3513 x
= SCM_CDR (x
); /* then expression */
3514 if (scm_is_false (test_result
) || SCM_NILP (test_result
))
3516 x
= SCM_CDR (x
); /* else expression */
3517 if (scm_is_null (x
))
3518 RETURN (SCM_UNSPECIFIED
);
3521 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3525 case (ISYMNUM (SCM_IM_LET
)):
3528 SCM init_forms
= SCM_CADR (x
);
3529 SCM init_values
= SCM_EOL
;
3532 init_values
= scm_cons (EVALCAR (init_forms
, env
), init_values
);
3533 init_forms
= SCM_CDR (init_forms
);
3535 while (!scm_is_null (init_forms
));
3536 env
= SCM_EXTEND_ENV (SCM_CAR (x
), init_values
, env
);
3539 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3540 goto nontoplevel_begin
;
3543 case (ISYMNUM (SCM_IM_LETREC
)):
3545 env
= SCM_EXTEND_ENV (SCM_CAR (x
), undefineds
, env
);
3548 SCM init_forms
= SCM_CAR (x
);
3549 SCM init_values
= SCM_EOL
;
3552 init_values
= scm_cons (EVALCAR (init_forms
, env
), init_values
);
3553 init_forms
= SCM_CDR (init_forms
);
3555 while (!scm_is_null (init_forms
));
3556 SCM_SETCDR (SCM_CAR (env
), init_values
);
3559 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3560 goto nontoplevel_begin
;
3563 case (ISYMNUM (SCM_IM_LETSTAR
)):
3566 SCM bindings
= SCM_CAR (x
);
3567 if (!scm_is_null (bindings
))
3571 SCM name
= SCM_CAR (bindings
);
3572 SCM init
= SCM_CDR (bindings
);
3573 env
= SCM_EXTEND_ENV (name
, EVALCAR (init
, env
), env
);
3574 bindings
= SCM_CDR (init
);
3576 while (!scm_is_null (bindings
));
3580 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3581 goto nontoplevel_begin
;
3584 case (ISYMNUM (SCM_IM_OR
)):
3586 while (!scm_is_null (SCM_CDR (x
)))
3588 SCM val
= EVALCAR (x
, env
);
3589 if (scm_is_true (val
) && !SCM_NILP (val
))
3594 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3598 case (ISYMNUM (SCM_IM_LAMBDA
)):
3599 RETURN (scm_closure (SCM_CDR (x
), env
));
3602 case (ISYMNUM (SCM_IM_QUOTE
)):
3603 RETURN (SCM_CDR (x
));
3606 case (ISYMNUM (SCM_IM_SET_X
)):
3610 SCM variable
= SCM_CAR (x
);
3611 if (SCM_ILOCP (variable
))
3612 location
= scm_ilookup (variable
, env
);
3613 else if (SCM_VARIABLEP (variable
))
3614 location
= SCM_VARIABLE_LOC (variable
);
3617 /* (scm_is_symbol (variable)) is known to be true */
3618 variable
= lazy_memoize_variable (variable
, env
);
3619 SCM_SETCAR (x
, variable
);
3620 location
= SCM_VARIABLE_LOC (variable
);
3623 *location
= EVALCAR (x
, env
);
3625 RETURN (SCM_UNSPECIFIED
);
3628 case (ISYMNUM (SCM_IM_APPLY
)):
3629 /* Evaluate the procedure to be applied. */
3631 proc
= EVALCAR (x
, env
);
3632 PREP_APPLY (proc
, SCM_EOL
);
3634 /* Evaluate the argument holding the list of arguments */
3636 arg1
= EVALCAR (x
, env
);
3639 /* Go here to tail-apply a procedure. PROC is the procedure and
3640 * ARG1 is the list of arguments. PREP_APPLY must have been called
3641 * before jumping to apply_proc. */
3642 if (SCM_CLOSUREP (proc
))
3644 SCM formals
= SCM_CLOSURE_FORMALS (proc
);
3646 debug
.info
->a
.args
= arg1
;
3648 if (scm_badargsp (formals
, arg1
))
3649 scm_wrong_num_args (proc
);
3651 /* Copy argument list */
3652 if (SCM_NULL_OR_NIL_P (arg1
))
3653 env
= SCM_EXTEND_ENV (formals
, SCM_EOL
, SCM_ENV (proc
));
3656 SCM args
= scm_list_1 (SCM_CAR (arg1
));
3658 arg1
= SCM_CDR (arg1
);
3659 while (!SCM_NULL_OR_NIL_P (arg1
))
3661 SCM new_tail
= scm_list_1 (SCM_CAR (arg1
));
3662 SCM_SETCDR (tail
, new_tail
);
3664 arg1
= SCM_CDR (arg1
);
3666 env
= SCM_EXTEND_ENV (formals
, args
, SCM_ENV (proc
));
3669 x
= SCM_CLOSURE_BODY (proc
);
3670 goto nontoplevel_begin
;
3675 RETURN (SCM_APPLY (proc
, arg1
, SCM_EOL
));
3679 case (ISYMNUM (SCM_IM_CONT
)):
3682 SCM val
= scm_make_continuation (&first
);
3690 proc
= EVALCAR (proc
, env
);
3691 PREP_APPLY (proc
, scm_list_1 (arg1
));
3698 case (ISYMNUM (SCM_IM_DELAY
)):
3699 RETURN (scm_makprom (scm_closure (SCM_CDR (x
), env
)));
3702 case (ISYMNUM (SCM_IM_FUTURE
)):
3703 RETURN (scm_i_make_future (scm_closure (SCM_CDR (x
), env
)));
3706 /* PLACEHOLDER for case (ISYMNUM (SCM_IM_DISPATCH)): The following
3707 code (type_dispatch) is intended to be the tail of the case
3708 clause for the internal macro SCM_IM_DISPATCH. Please don't
3709 remove it from this location without discussing it with Mikael
3710 <djurfeldt@nada.kth.se> */
3712 /* The type dispatch code is duplicated below
3713 * (c.f. objects.c:scm_mcache_compute_cmethod) since that
3714 * cuts down execution time for type dispatch to 50%. */
3715 type_dispatch
: /* inputs: x, arg1 */
3716 /* Type dispatch means to determine from the types of the function
3717 * arguments (i. e. the 'signature' of the call), which method from
3718 * a generic function is to be called. This process of selecting
3719 * the right method takes some time. To speed it up, guile uses
3720 * caching: Together with the macro call to dispatch the signatures
3721 * of some previous calls to that generic function from the same
3722 * place are stored (in the code!) in a cache that we call the
3723 * 'method cache'. This is done since it is likely, that
3724 * consecutive calls to dispatch from that position in the code will
3725 * have the same signature. Thus, the type dispatch works as
3726 * follows: First, determine a hash value from the signature of the
3727 * actual arguments. Second, use this hash value as an index to
3728 * find that same signature in the method cache stored at this
3729 * position in the code. If found, you have also found the
3730 * corresponding method that belongs to that signature. If the
3731 * signature is not found in the method cache, you have to perform a
3732 * full search over all signatures stored with the generic
3735 unsigned long int specializers
;
3736 unsigned long int hash_value
;
3737 unsigned long int cache_end_pos
;
3738 unsigned long int mask
;
3742 SCM z
= SCM_CDDR (x
);
3743 SCM tmp
= SCM_CADR (z
);
3744 specializers
= scm_to_ulong (SCM_CAR (z
));
3746 /* Compute a hash value for searching the method cache. There
3747 * are two variants for computing the hash value, a (rather)
3748 * complicated one, and a simple one. For the complicated one
3749 * explained below, tmp holds a number that is used in the
3751 if (scm_is_simple_vector (tmp
))
3753 /* This method of determining the hash value is much
3754 * simpler: Set the hash value to zero and just perform a
3755 * linear search through the method cache. */
3757 mask
= (unsigned long int) ((long) -1);
3759 cache_end_pos
= SCM_SIMPLE_VECTOR_LENGTH (method_cache
);
3763 /* Use the signature of the actual arguments to determine
3764 * the hash value. This is done as follows: Each class has
3765 * an array of random numbers, that are determined when the
3766 * class is created. The integer 'hashset' is an index into
3767 * that array of random numbers. Now, from all classes that
3768 * are part of the signature of the actual arguments, the
3769 * random numbers at index 'hashset' are taken and summed
3770 * up, giving the hash value. The value of 'hashset' is
3771 * stored at the call to dispatch. This allows to have
3772 * different 'formulas' for calculating the hash value at
3773 * different places where dispatch is called. This allows
3774 * to optimize the hash formula at every individual place
3775 * where dispatch is called, such that hopefully the hash
3776 * value that is computed will directly point to the right
3777 * method in the method cache. */
3778 unsigned long int hashset
= scm_to_ulong (tmp
);
3779 unsigned long int counter
= specializers
+ 1;
3782 while (!scm_is_null (tmp_arg
) && counter
!= 0)
3784 SCM
class = scm_class_of (SCM_CAR (tmp_arg
));
3785 hash_value
+= SCM_INSTANCE_HASH (class, hashset
);
3786 tmp_arg
= SCM_CDR (tmp_arg
);
3790 method_cache
= SCM_CADR (z
);
3791 mask
= scm_to_ulong (SCM_CAR (z
));
3793 cache_end_pos
= hash_value
;
3798 /* Search the method cache for a method with a matching
3799 * signature. Start the search at position 'hash_value'. The
3800 * hashing implementation uses linear probing for conflict
3801 * resolution, that is, if the signature in question is not
3802 * found at the starting index in the hash table, the next table
3803 * entry is tried, and so on, until in the worst case the whole
3804 * cache has been searched, but still the signature has not been
3809 SCM args
= arg1
; /* list of arguments */
3810 z
= SCM_SIMPLE_VECTOR_REF (method_cache
, hash_value
);
3811 while (!scm_is_null (args
))
3813 /* More arguments than specifiers => CLASS != ENV */
3814 SCM class_of_arg
= scm_class_of (SCM_CAR (args
));
3815 if (!scm_is_eq (class_of_arg
, SCM_CAR (z
)))
3817 args
= SCM_CDR (args
);
3820 /* Fewer arguments than specifiers => CAR != ENV */
3821 if (scm_is_null (SCM_CAR (z
)) || scm_is_pair (SCM_CAR (z
)))
3824 hash_value
= (hash_value
+ 1) & mask
;
3825 } while (hash_value
!= cache_end_pos
);
3827 /* No appropriate method was found in the cache. */
3828 z
= scm_memoize_method (x
, arg1
);
3830 apply_cmethod
: /* inputs: z, arg1 */
3832 SCM formals
= SCM_CMETHOD_FORMALS (z
);
3833 env
= SCM_EXTEND_ENV (formals
, arg1
, SCM_CMETHOD_ENV (z
));
3834 x
= SCM_CMETHOD_BODY (z
);
3835 goto nontoplevel_begin
;
3841 case (ISYMNUM (SCM_IM_SLOT_REF
)):
3844 SCM instance
= EVALCAR (x
, env
);
3845 unsigned long int slot
= SCM_I_INUM (SCM_CDR (x
));
3846 RETURN (SCM_PACK (SCM_STRUCT_DATA (instance
) [slot
]));
3850 case (ISYMNUM (SCM_IM_SLOT_SET_X
)):
3853 SCM instance
= EVALCAR (x
, env
);
3854 unsigned long int slot
= SCM_I_INUM (SCM_CADR (x
));
3855 SCM value
= EVALCAR (SCM_CDDR (x
), env
);
3856 SCM_STRUCT_DATA (instance
) [slot
] = SCM_UNPACK (value
);
3857 RETURN (SCM_UNSPECIFIED
);
3861 #if SCM_ENABLE_ELISP
3863 case (ISYMNUM (SCM_IM_NIL_COND
)):
3865 SCM test_form
= SCM_CDR (x
);
3866 x
= SCM_CDR (test_form
);
3867 while (!SCM_NULL_OR_NIL_P (x
))
3869 SCM test_result
= EVALCAR (test_form
, env
);
3870 if (!(scm_is_false (test_result
)
3871 || SCM_NULL_OR_NIL_P (test_result
)))
3873 if (scm_is_eq (SCM_CAR (x
), SCM_UNSPECIFIED
))
3874 RETURN (test_result
);
3875 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3880 test_form
= SCM_CDR (x
);
3881 x
= SCM_CDR (test_form
);
3885 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
3889 #endif /* SCM_ENABLE_ELISP */
3891 case (ISYMNUM (SCM_IM_BIND
)):
3893 SCM vars
, exps
, vals
;
3896 vars
= SCM_CAAR (x
);
3897 exps
= SCM_CDAR (x
);
3899 while (!scm_is_null (exps
))
3901 vals
= scm_cons (EVALCAR (exps
, env
), vals
);
3902 exps
= SCM_CDR (exps
);
3905 scm_swap_bindings (vars
, vals
);
3906 scm_dynwinds
= scm_acons (vars
, vals
, scm_dynwinds
);
3908 /* Ignore all but the last evaluation result. */
3909 for (x
= SCM_CDR (x
); !scm_is_null (SCM_CDR (x
)); x
= SCM_CDR (x
))
3911 if (scm_is_pair (SCM_CAR (x
)))
3912 CEVAL (SCM_CAR (x
), env
);
3914 proc
= EVALCAR (x
, env
);
3916 scm_dynwinds
= SCM_CDR (scm_dynwinds
);
3917 scm_swap_bindings (vars
, vals
);
3923 case (ISYMNUM (SCM_IM_CALL_WITH_VALUES
)):
3928 producer
= EVALCAR (x
, env
);
3930 proc
= EVALCAR (x
, env
); /* proc is the consumer. */
3931 arg1
= SCM_APPLY (producer
, SCM_EOL
, SCM_EOL
);
3932 if (SCM_VALUESP (arg1
))
3934 /* The list of arguments is not copied. Rather, it is assumed
3935 * that this has been done by the 'values' procedure. */
3936 arg1
= scm_struct_ref (arg1
, SCM_INUM0
);
3940 arg1
= scm_list_1 (arg1
);
3942 PREP_APPLY (proc
, arg1
);
3953 if (SCM_VARIABLEP (SCM_CAR (x
)))
3954 proc
= SCM_VARIABLE_REF (SCM_CAR (x
));
3955 else if (SCM_ILOCP (SCM_CAR (x
)))
3956 proc
= *scm_ilookup (SCM_CAR (x
), env
);
3957 else if (scm_is_pair (SCM_CAR (x
)))
3958 proc
= CEVAL (SCM_CAR (x
), env
);
3959 else if (scm_is_symbol (SCM_CAR (x
)))
3961 SCM orig_sym
= SCM_CAR (x
);
3963 SCM
*location
= scm_lookupcar1 (x
, env
, 1);
3964 if (location
== NULL
)
3966 /* we have lost the race, start again. */
3972 if (SCM_MACROP (proc
))
3974 SCM_SETCAR (x
, orig_sym
); /* Undo memoizing effect of
3976 handle_a_macro
: /* inputs: x, env, proc */
3978 /* Set a flag during macro expansion so that macro
3979 application frames can be deleted from the backtrace. */
3980 SCM_SET_MACROEXP (debug
);
3982 arg1
= SCM_APPLY (SCM_MACRO_CODE (proc
), x
,
3983 scm_cons (env
, scm_listofnull
));
3985 SCM_CLEAR_MACROEXP (debug
);
3987 switch (SCM_MACRO_TYPE (proc
))
3991 if (!scm_is_pair (arg1
))
3992 arg1
= scm_list_2 (SCM_IM_BEGIN
, arg1
);
3994 assert (!scm_is_eq (x
, SCM_CAR (arg1
))
3995 && !scm_is_eq (x
, SCM_CDR (arg1
)));
3998 if (!SCM_CLOSUREP (SCM_MACRO_CODE (proc
)))
4001 SCM_SETCAR (x
, SCM_CAR (arg1
));
4002 SCM_SETCDR (x
, SCM_CDR (arg1
));
4006 /* Prevent memoizing of debug info expression. */
4007 debug
.info
->e
.exp
= scm_cons_source (debug
.info
->e
.exp
,
4012 SCM_SETCAR (x
, SCM_CAR (arg1
));
4013 SCM_SETCDR (x
, SCM_CDR (arg1
));
4015 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
4017 #if SCM_ENABLE_DEPRECATED == 1
4022 PREP_APPLY (SCM_UNDEFINED
, SCM_EOL
);
4036 if (SCM_MACROP (proc
))
4037 goto handle_a_macro
;
4041 /* When reaching this part of the code, the following is granted: Variable x
4042 * holds the first pair of an expression of the form (<function> arg ...).
4043 * Variable proc holds the object that resulted from the evaluation of
4044 * <function>. In the following, the arguments (if any) will be evaluated,
4045 * and proc will be applied to them. If proc does not really hold a
4046 * function object, this will be signalled as an error on the scheme
4047 * level. If the number of arguments does not match the number of arguments
4048 * that are allowed to be passed to proc, also an error on the scheme level
4049 * will be signalled. */
4050 PREP_APPLY (proc
, SCM_EOL
);
4051 if (scm_is_null (SCM_CDR (x
))) {
4054 SCM_ASRTGO (!SCM_IMP (proc
), badfun
);
4055 switch (SCM_TYP7 (proc
))
4056 { /* no arguments given */
4057 case scm_tc7_subr_0
:
4058 RETURN (SCM_SUBRF (proc
) ());
4059 case scm_tc7_subr_1o
:
4060 RETURN (SCM_SUBRF (proc
) (SCM_UNDEFINED
));
4062 RETURN (SCM_SUBRF (proc
) (SCM_EOL
));
4063 case scm_tc7_rpsubr
:
4064 RETURN (SCM_BOOL_T
);
4066 RETURN (SCM_SUBRF (proc
) (SCM_UNDEFINED
, SCM_UNDEFINED
));
4068 if (!SCM_SMOB_APPLICABLE_P (proc
))
4070 RETURN (SCM_SMOB_APPLY_0 (proc
));
4073 proc
= SCM_CCLO_SUBR (proc
);
4075 debug
.info
->a
.proc
= proc
;
4076 debug
.info
->a
.args
= scm_list_1 (arg1
);
4080 proc
= SCM_PROCEDURE (proc
);
4082 debug
.info
->a
.proc
= proc
;
4084 if (!SCM_CLOSUREP (proc
))
4087 case scm_tcs_closures
:
4089 const SCM formals
= SCM_CLOSURE_FORMALS (proc
);
4090 if (scm_is_pair (formals
))
4092 x
= SCM_CLOSURE_BODY (proc
);
4093 env
= SCM_EXTEND_ENV (formals
, SCM_EOL
, SCM_ENV (proc
));
4094 goto nontoplevel_begin
;
4096 case scm_tcs_struct
:
4097 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
4099 x
= SCM_ENTITY_PROCEDURE (proc
);
4103 else if (SCM_I_OPERATORP (proc
))
4106 proc
= (SCM_I_ENTITYP (proc
)
4107 ? SCM_ENTITY_PROCEDURE (proc
)
4108 : SCM_OPERATOR_PROCEDURE (proc
));
4110 debug
.info
->a
.proc
= proc
;
4111 debug
.info
->a
.args
= scm_list_1 (arg1
);
4117 case scm_tc7_subr_1
:
4118 case scm_tc7_subr_2
:
4119 case scm_tc7_subr_2o
:
4122 case scm_tc7_subr_3
:
4123 case scm_tc7_lsubr_2
:
4125 scm_wrong_num_args (proc
);
4128 scm_misc_error (NULL
, "Wrong type to apply: ~S", scm_list_1 (proc
));
4132 /* must handle macros by here */
4134 if (scm_is_pair (x
))
4135 arg1
= EVALCAR (x
, env
);
4137 scm_wrong_num_args (proc
);
4139 debug
.info
->a
.args
= scm_list_1 (arg1
);
4144 if (scm_is_null (x
))
4147 evap1
: /* inputs: proc, arg1 */
4148 SCM_ASRTGO (!SCM_IMP (proc
), badfun
);
4149 switch (SCM_TYP7 (proc
))
4150 { /* have one argument in arg1 */
4151 case scm_tc7_subr_2o
:
4152 RETURN (SCM_SUBRF (proc
) (arg1
, SCM_UNDEFINED
));
4153 case scm_tc7_subr_1
:
4154 case scm_tc7_subr_1o
:
4155 RETURN (SCM_SUBRF (proc
) (arg1
));
4157 if (SCM_I_INUMP (arg1
))
4159 RETURN (scm_from_double (SCM_DSUBRF (proc
) ((double) SCM_I_INUM (arg1
))));
4161 else if (SCM_REALP (arg1
))
4163 RETURN (scm_from_double (SCM_DSUBRF (proc
) (SCM_REAL_VALUE (arg1
))));
4165 else if (SCM_BIGP (arg1
))
4167 RETURN (scm_from_double (SCM_DSUBRF (proc
) (scm_i_big2dbl (arg1
))));
4169 else if (SCM_FRACTIONP (arg1
))
4171 RETURN (scm_from_double (SCM_DSUBRF (proc
) (scm_i_fraction2double (arg1
))));
4173 SCM_WTA_DISPATCH_1 (*SCM_SUBR_GENERIC (proc
), arg1
,
4175 scm_i_symbol_chars (SCM_SNAME (proc
)));
4177 RETURN (scm_i_chase_pairs (arg1
, (scm_t_bits
) SCM_SUBRF (proc
)));
4178 case scm_tc7_rpsubr
:
4179 RETURN (SCM_BOOL_T
);
4181 RETURN (SCM_SUBRF (proc
) (arg1
, SCM_UNDEFINED
));
4184 RETURN (SCM_SUBRF (proc
) (debug
.info
->a
.args
));
4186 RETURN (SCM_SUBRF (proc
) (scm_list_1 (arg1
)));
4189 if (!SCM_SMOB_APPLICABLE_P (proc
))
4191 RETURN (SCM_SMOB_APPLY_1 (proc
, arg1
));
4195 proc
= SCM_CCLO_SUBR (proc
);
4197 debug
.info
->a
.args
= scm_cons (arg1
, debug
.info
->a
.args
);
4198 debug
.info
->a
.proc
= proc
;
4202 proc
= SCM_PROCEDURE (proc
);
4204 debug
.info
->a
.proc
= proc
;
4206 if (!SCM_CLOSUREP (proc
))
4209 case scm_tcs_closures
:
4212 const SCM formals
= SCM_CLOSURE_FORMALS (proc
);
4213 if (scm_is_null (formals
)
4214 || (scm_is_pair (formals
) && scm_is_pair (SCM_CDR (formals
))))
4216 x
= SCM_CLOSURE_BODY (proc
);
4218 env
= SCM_EXTEND_ENV (formals
,
4222 env
= SCM_EXTEND_ENV (formals
,
4226 goto nontoplevel_begin
;
4228 case scm_tcs_struct
:
4229 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
4231 x
= SCM_ENTITY_PROCEDURE (proc
);
4233 arg1
= debug
.info
->a
.args
;
4235 arg1
= scm_list_1 (arg1
);
4239 else if (SCM_I_OPERATORP (proc
))
4243 proc
= (SCM_I_ENTITYP (proc
)
4244 ? SCM_ENTITY_PROCEDURE (proc
)
4245 : SCM_OPERATOR_PROCEDURE (proc
));
4247 debug
.info
->a
.args
= scm_cons (arg1
, debug
.info
->a
.args
);
4248 debug
.info
->a
.proc
= proc
;
4254 case scm_tc7_subr_2
:
4255 case scm_tc7_subr_0
:
4256 case scm_tc7_subr_3
:
4257 case scm_tc7_lsubr_2
:
4258 scm_wrong_num_args (proc
);
4263 if (scm_is_pair (x
))
4264 arg2
= EVALCAR (x
, env
);
4266 scm_wrong_num_args (proc
);
4268 { /* have two or more arguments */
4270 debug
.info
->a
.args
= scm_list_2 (arg1
, arg2
);
4273 if (scm_is_null (x
)) {
4276 SCM_ASRTGO (!SCM_IMP (proc
), badfun
);
4277 switch (SCM_TYP7 (proc
))
4278 { /* have two arguments */
4279 case scm_tc7_subr_2
:
4280 case scm_tc7_subr_2o
:
4281 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
));
4284 RETURN (SCM_SUBRF (proc
) (debug
.info
->a
.args
));
4286 RETURN (SCM_SUBRF (proc
) (scm_list_2 (arg1
, arg2
)));
4288 case scm_tc7_lsubr_2
:
4289 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
, SCM_EOL
));
4290 case scm_tc7_rpsubr
:
4292 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
));
4294 if (!SCM_SMOB_APPLICABLE_P (proc
))
4296 RETURN (SCM_SMOB_APPLY_2 (proc
, arg1
, arg2
));
4300 RETURN (SCM_APPLY (SCM_CCLO_SUBR (proc
),
4301 scm_cons (proc
, debug
.info
->a
.args
),
4304 RETURN (SCM_APPLY (SCM_CCLO_SUBR (proc
),
4305 scm_cons2 (proc
, arg1
,
4312 case scm_tcs_struct
:
4313 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
4315 x
= SCM_ENTITY_PROCEDURE (proc
);
4317 arg1
= debug
.info
->a
.args
;
4319 arg1
= scm_list_2 (arg1
, arg2
);
4323 else if (SCM_I_OPERATORP (proc
))
4327 RETURN (SCM_APPLY (SCM_I_ENTITYP (proc
)
4328 ? SCM_ENTITY_PROCEDURE (proc
)
4329 : SCM_OPERATOR_PROCEDURE (proc
),
4330 scm_cons (proc
, debug
.info
->a
.args
),
4333 RETURN (SCM_APPLY (SCM_I_ENTITYP (proc
)
4334 ? SCM_ENTITY_PROCEDURE (proc
)
4335 : SCM_OPERATOR_PROCEDURE (proc
),
4336 scm_cons2 (proc
, arg1
,
4346 case scm_tc7_subr_0
:
4349 case scm_tc7_subr_1o
:
4350 case scm_tc7_subr_1
:
4351 case scm_tc7_subr_3
:
4352 scm_wrong_num_args (proc
);
4356 proc
= SCM_PROCEDURE (proc
);
4358 debug
.info
->a
.proc
= proc
;
4360 if (!SCM_CLOSUREP (proc
))
4363 case scm_tcs_closures
:
4366 const SCM formals
= SCM_CLOSURE_FORMALS (proc
);
4367 if (scm_is_null (formals
)
4368 || (scm_is_pair (formals
)
4369 && (scm_is_null (SCM_CDR (formals
))
4370 || (scm_is_pair (SCM_CDR (formals
))
4371 && scm_is_pair (SCM_CDDR (formals
))))))
4374 env
= SCM_EXTEND_ENV (formals
,
4378 env
= SCM_EXTEND_ENV (formals
,
4379 scm_list_2 (arg1
, arg2
),
4382 x
= SCM_CLOSURE_BODY (proc
);
4383 goto nontoplevel_begin
;
4387 if (!scm_is_pair (x
))
4388 scm_wrong_num_args (proc
);
4390 debug
.info
->a
.args
= scm_cons2 (arg1
, arg2
,
4391 deval_args (x
, env
, proc
,
4392 SCM_CDRLOC (SCM_CDR (debug
.info
->a
.args
))));
4396 SCM_ASRTGO (!SCM_IMP (proc
), badfun
);
4397 switch (SCM_TYP7 (proc
))
4398 { /* have 3 or more arguments */
4400 case scm_tc7_subr_3
:
4401 if (!scm_is_null (SCM_CDR (x
)))
4402 scm_wrong_num_args (proc
);
4404 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
,
4405 SCM_CADDR (debug
.info
->a
.args
)));
4407 arg1
= SCM_SUBRF(proc
)(arg1
, arg2
);
4408 arg2
= SCM_CDDR (debug
.info
->a
.args
);
4411 arg1
= SCM_SUBRF(proc
)(arg1
, SCM_CAR (arg2
));
4412 arg2
= SCM_CDR (arg2
);
4414 while (SCM_NIMP (arg2
));
4416 case scm_tc7_rpsubr
:
4417 if (scm_is_false (SCM_SUBRF (proc
) (arg1
, arg2
)))
4418 RETURN (SCM_BOOL_F
);
4419 arg1
= SCM_CDDR (debug
.info
->a
.args
);
4422 if (scm_is_false (SCM_SUBRF (proc
) (arg2
, SCM_CAR (arg1
))))
4423 RETURN (SCM_BOOL_F
);
4424 arg2
= SCM_CAR (arg1
);
4425 arg1
= SCM_CDR (arg1
);
4427 while (SCM_NIMP (arg1
));
4428 RETURN (SCM_BOOL_T
);
4429 case scm_tc7_lsubr_2
:
4430 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
,
4431 SCM_CDDR (debug
.info
->a
.args
)));
4433 RETURN (SCM_SUBRF (proc
) (debug
.info
->a
.args
));
4435 if (!SCM_SMOB_APPLICABLE_P (proc
))
4437 RETURN (SCM_SMOB_APPLY_3 (proc
, arg1
, arg2
,
4438 SCM_CDDR (debug
.info
->a
.args
)));
4442 proc
= SCM_PROCEDURE (proc
);
4443 debug
.info
->a
.proc
= proc
;
4444 if (!SCM_CLOSUREP (proc
))
4447 case scm_tcs_closures
:
4449 const SCM formals
= SCM_CLOSURE_FORMALS (proc
);
4450 if (scm_is_null (formals
)
4451 || (scm_is_pair (formals
)
4452 && (scm_is_null (SCM_CDR (formals
))
4453 || (scm_is_pair (SCM_CDR (formals
))
4454 && scm_badargsp (SCM_CDDR (formals
), x
)))))
4456 SCM_SET_ARGSREADY (debug
);
4457 env
= SCM_EXTEND_ENV (formals
,
4460 x
= SCM_CLOSURE_BODY (proc
);
4461 goto nontoplevel_begin
;
4464 case scm_tc7_subr_3
:
4465 if (!scm_is_null (SCM_CDR (x
)))
4466 scm_wrong_num_args (proc
);
4468 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
, EVALCAR (x
, env
)));
4470 arg1
= SCM_SUBRF (proc
) (arg1
, arg2
);
4473 arg1
= SCM_SUBRF(proc
)(arg1
, EVALCAR(x
, env
));
4476 while (!scm_is_null (x
));
4478 case scm_tc7_rpsubr
:
4479 if (scm_is_false (SCM_SUBRF (proc
) (arg1
, arg2
)))
4480 RETURN (SCM_BOOL_F
);
4483 arg1
= EVALCAR (x
, env
);
4484 if (scm_is_false (SCM_SUBRF (proc
) (arg2
, arg1
)))
4485 RETURN (SCM_BOOL_F
);
4489 while (!scm_is_null (x
));
4490 RETURN (SCM_BOOL_T
);
4491 case scm_tc7_lsubr_2
:
4492 RETURN (SCM_SUBRF (proc
) (arg1
, arg2
, scm_eval_args (x
, env
, proc
)));
4494 RETURN (SCM_SUBRF (proc
) (scm_cons2 (arg1
,
4496 scm_eval_args (x
, env
, proc
))));
4498 if (!SCM_SMOB_APPLICABLE_P (proc
))
4500 RETURN (SCM_SMOB_APPLY_3 (proc
, arg1
, arg2
,
4501 scm_eval_args (x
, env
, proc
)));
4505 proc
= SCM_PROCEDURE (proc
);
4506 if (!SCM_CLOSUREP (proc
))
4509 case scm_tcs_closures
:
4511 const SCM formals
= SCM_CLOSURE_FORMALS (proc
);
4512 if (scm_is_null (formals
)
4513 || (scm_is_pair (formals
)
4514 && (scm_is_null (SCM_CDR (formals
))
4515 || (scm_is_pair (SCM_CDR (formals
))
4516 && scm_badargsp (SCM_CDDR (formals
), x
)))))
4518 env
= SCM_EXTEND_ENV (formals
,
4521 scm_eval_args (x
, env
, proc
)),
4523 x
= SCM_CLOSURE_BODY (proc
);
4524 goto nontoplevel_begin
;
4527 case scm_tcs_struct
:
4528 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
4531 arg1
= debug
.info
->a
.args
;
4533 arg1
= scm_cons2 (arg1
, arg2
, scm_eval_args (x
, env
, proc
));
4535 x
= SCM_ENTITY_PROCEDURE (proc
);
4538 else if (SCM_I_OPERATORP (proc
))
4542 case scm_tc7_subr_2
:
4543 case scm_tc7_subr_1o
:
4544 case scm_tc7_subr_2o
:
4545 case scm_tc7_subr_0
:
4548 case scm_tc7_subr_1
:
4549 scm_wrong_num_args (proc
);
4557 if (scm_check_exit_p
&& SCM_TRAPS_P
)
4558 if (SCM_EXIT_FRAME_P
|| (SCM_TRACE_P
&& SCM_TRACED_FRAME_P (debug
)))
4560 SCM_CLEAR_TRACED_FRAME (debug
);
4561 if (SCM_CHEAPTRAPS_P
)
4562 arg1
= scm_make_debugobj (&debug
);
4566 SCM val
= scm_make_continuation (&first
);
4577 scm_call_3 (SCM_EXIT_FRAME_HDLR
, scm_sym_exit_frame
, arg1
, proc
);
4581 scm_last_debug_frame
= debug
.prev
;
4587 /* SECTION: This code is compiled once.
4594 /* Simple procedure calls
4598 scm_call_0 (SCM proc
)
4600 return scm_apply (proc
, SCM_EOL
, SCM_EOL
);
4604 scm_call_1 (SCM proc
, SCM arg1
)
4606 return scm_apply (proc
, arg1
, scm_listofnull
);
4610 scm_call_2 (SCM proc
, SCM arg1
, SCM arg2
)
4612 return scm_apply (proc
, arg1
, scm_cons (arg2
, scm_listofnull
));
4616 scm_call_3 (SCM proc
, SCM arg1
, SCM arg2
, SCM arg3
)
4618 return scm_apply (proc
, arg1
, scm_cons2 (arg2
, arg3
, scm_listofnull
));
4622 scm_call_4 (SCM proc
, SCM arg1
, SCM arg2
, SCM arg3
, SCM arg4
)
4624 return scm_apply (proc
, arg1
, scm_cons2 (arg2
, arg3
,
4625 scm_cons (arg4
, scm_listofnull
)));
4628 /* Simple procedure applies
4632 scm_apply_0 (SCM proc
, SCM args
)
4634 return scm_apply (proc
, args
, SCM_EOL
);
4638 scm_apply_1 (SCM proc
, SCM arg1
, SCM args
)
4640 return scm_apply (proc
, scm_cons (arg1
, args
), SCM_EOL
);
4644 scm_apply_2 (SCM proc
, SCM arg1
, SCM arg2
, SCM args
)
4646 return scm_apply (proc
, scm_cons2 (arg1
, arg2
, args
), SCM_EOL
);
4650 scm_apply_3 (SCM proc
, SCM arg1
, SCM arg2
, SCM arg3
, SCM args
)
4652 return scm_apply (proc
, scm_cons (arg1
, scm_cons2 (arg2
, arg3
, args
)),
4656 /* This code processes the arguments to apply:
4658 (apply PROC ARG1 ... ARGS)
4660 Given a list (ARG1 ... ARGS), this function conses the ARG1
4661 ... arguments onto the front of ARGS, and returns the resulting
4662 list. Note that ARGS is a list; thus, the argument to this
4663 function is a list whose last element is a list.
4665 Apply calls this function, and applies PROC to the elements of the
4666 result. apply:nconc2last takes care of building the list of
4667 arguments, given (ARG1 ... ARGS).
4669 Rather than do new consing, apply:nconc2last destroys its argument.
4670 On that topic, this code came into my care with the following
4671 beautifully cryptic comment on that topic: "This will only screw
4672 you if you do (scm_apply scm_apply '( ... ))" If you know what
4673 they're referring to, send me a patch to this comment. */
4675 SCM_DEFINE (scm_nconc2last
, "apply:nconc2last", 1, 0, 0,
4677 "Given a list (@var{arg1} @dots{} @var{args}), this function\n"
4678 "conses the @var{arg1} @dots{} arguments onto the front of\n"
4679 "@var{args}, and returns the resulting list. Note that\n"
4680 "@var{args} is a list; thus, the argument to this function is\n"
4681 "a list whose last element is a list.\n"
4682 "Note: Rather than do new consing, @code{apply:nconc2last}\n"
4683 "destroys its argument, so use with care.")
4684 #define FUNC_NAME s_scm_nconc2last
4687 SCM_VALIDATE_NONEMPTYLIST (1, lst
);
4689 while (!scm_is_null (SCM_CDR (*lloc
))) /* Perhaps should be
4690 SCM_NULL_OR_NIL_P, but not
4691 needed in 99.99% of cases,
4692 and it could seriously hurt
4693 performance. - Neil */
4694 lloc
= SCM_CDRLOC (*lloc
);
4695 SCM_ASSERT (scm_ilength (SCM_CAR (*lloc
)) >= 0, lst
, SCM_ARG1
, FUNC_NAME
);
4696 *lloc
= SCM_CAR (*lloc
);
4704 /* SECTION: When DEVAL is defined this code yields scm_dapply.
4705 * It is compiled twice.
4710 scm_apply (SCM proc
, SCM arg1
, SCM args
)
4716 scm_dapply (SCM proc
, SCM arg1
, SCM args
)
4721 /* Apply a function to a list of arguments.
4723 This function is exported to the Scheme level as taking two
4724 required arguments and a tail argument, as if it were:
4725 (lambda (proc arg1 . args) ...)
4726 Thus, if you just have a list of arguments to pass to a procedure,
4727 pass the list as ARG1, and '() for ARGS. If you have some fixed
4728 args, pass the first as ARG1, then cons any remaining fixed args
4729 onto the front of your argument list, and pass that as ARGS. */
4732 SCM_APPLY (SCM proc
, SCM arg1
, SCM args
)
4735 scm_t_debug_frame debug
;
4736 scm_t_debug_info debug_vect_body
;
4737 debug
.prev
= scm_last_debug_frame
;
4738 debug
.status
= SCM_APPLYFRAME
;
4739 debug
.vect
= &debug_vect_body
;
4740 debug
.vect
[0].a
.proc
= proc
;
4741 debug
.vect
[0].a
.args
= SCM_EOL
;
4742 scm_last_debug_frame
= &debug
;
4744 if (scm_debug_mode_p
)
4745 return scm_dapply (proc
, arg1
, args
);
4748 SCM_ASRTGO (SCM_NIMP (proc
), badproc
);
4750 /* If ARGS is the empty list, then we're calling apply with only two
4751 arguments --- ARG1 is the list of arguments for PROC. Whatever
4752 the case, futz with things so that ARG1 is the first argument to
4753 give to PROC (or SCM_UNDEFINED if no args), and ARGS contains the
4756 Setting the debug apply frame args this way is pretty messy.
4757 Perhaps we should store arg1 and args directly in the frame as
4758 received, and let scm_frame_arguments unpack them, because that's
4759 a relatively rare operation. This works for now; if the Guile
4760 developer archives are still around, see Mikael's post of
4762 if (scm_is_null (args
))
4764 if (scm_is_null (arg1
))
4766 arg1
= SCM_UNDEFINED
;
4768 debug
.vect
[0].a
.args
= SCM_EOL
;
4774 debug
.vect
[0].a
.args
= arg1
;
4776 args
= SCM_CDR (arg1
);
4777 arg1
= SCM_CAR (arg1
);
4782 args
= scm_nconc2last (args
);
4784 debug
.vect
[0].a
.args
= scm_cons (arg1
, args
);
4788 if (SCM_ENTER_FRAME_P
&& SCM_TRAPS_P
)
4791 if (SCM_CHEAPTRAPS_P
)
4792 tmp
= scm_make_debugobj (&debug
);
4797 tmp
= scm_make_continuation (&first
);
4802 scm_call_2 (SCM_ENTER_FRAME_HDLR
, scm_sym_enter_frame
, tmp
);
4809 switch (SCM_TYP7 (proc
))
4811 case scm_tc7_subr_2o
:
4812 args
= scm_is_null (args
) ? SCM_UNDEFINED
: SCM_CAR (args
);
4813 RETURN (SCM_SUBRF (proc
) (arg1
, args
));
4814 case scm_tc7_subr_2
:
4815 if (scm_is_null (args
) || !scm_is_null (SCM_CDR (args
)))
4816 scm_wrong_num_args (proc
);
4817 args
= SCM_CAR (args
);
4818 RETURN (SCM_SUBRF (proc
) (arg1
, args
));
4819 case scm_tc7_subr_0
:
4820 if (!SCM_UNBNDP (arg1
))
4821 scm_wrong_num_args (proc
);
4823 RETURN (SCM_SUBRF (proc
) ());
4824 case scm_tc7_subr_1
:
4825 if (SCM_UNBNDP (arg1
))
4826 scm_wrong_num_args (proc
);
4827 case scm_tc7_subr_1o
:
4828 if (!scm_is_null (args
))
4829 scm_wrong_num_args (proc
);
4831 RETURN (SCM_SUBRF (proc
) (arg1
));
4833 if (SCM_UNBNDP (arg1
) || !scm_is_null (args
))
4834 scm_wrong_num_args (proc
);
4835 if (SCM_I_INUMP (arg1
))
4837 RETURN (scm_from_double (SCM_DSUBRF (proc
) ((double) SCM_I_INUM (arg1
))));
4839 else if (SCM_REALP (arg1
))
4841 RETURN (scm_from_double (SCM_DSUBRF (proc
) (SCM_REAL_VALUE (arg1
))));
4843 else if (SCM_BIGP (arg1
))
4845 RETURN (scm_from_double (SCM_DSUBRF (proc
) (scm_i_big2dbl (arg1
))));
4847 else if (SCM_FRACTIONP (arg1
))
4849 RETURN (scm_from_double (SCM_DSUBRF (proc
) (scm_i_fraction2double (arg1
))));
4851 SCM_WTA_DISPATCH_1 (*SCM_SUBR_GENERIC (proc
), arg1
,
4852 SCM_ARG1
, scm_i_symbol_chars (SCM_SNAME (proc
)));
4854 if (SCM_UNBNDP (arg1
) || !scm_is_null (args
))
4855 scm_wrong_num_args (proc
);
4856 RETURN (scm_i_chase_pairs (arg1
, (scm_t_bits
) SCM_SUBRF (proc
)));
4857 case scm_tc7_subr_3
:
4858 if (scm_is_null (args
)
4859 || scm_is_null (SCM_CDR (args
))
4860 || !scm_is_null (SCM_CDDR (args
)))
4861 scm_wrong_num_args (proc
);
4863 RETURN (SCM_SUBRF (proc
) (arg1
, SCM_CAR (args
), SCM_CADR (args
)));
4866 RETURN (SCM_SUBRF (proc
) (SCM_UNBNDP (arg1
) ? SCM_EOL
: debug
.vect
[0].a
.args
));
4868 RETURN (SCM_SUBRF (proc
) (SCM_UNBNDP (arg1
) ? SCM_EOL
: scm_cons (arg1
, args
)));
4870 case scm_tc7_lsubr_2
:
4871 if (!scm_is_pair (args
))
4872 scm_wrong_num_args (proc
);
4874 RETURN (SCM_SUBRF (proc
) (arg1
, SCM_CAR (args
), SCM_CDR (args
)));
4876 if (scm_is_null (args
))
4877 RETURN (SCM_SUBRF (proc
) (arg1
, SCM_UNDEFINED
));
4878 while (SCM_NIMP (args
))
4880 SCM_ASSERT (scm_is_pair (args
), args
, SCM_ARG2
, "apply");
4881 arg1
= SCM_SUBRF (proc
) (arg1
, SCM_CAR (args
));
4882 args
= SCM_CDR (args
);
4885 case scm_tc7_rpsubr
:
4886 if (scm_is_null (args
))
4887 RETURN (SCM_BOOL_T
);
4888 while (SCM_NIMP (args
))
4890 SCM_ASSERT (scm_is_pair (args
), args
, SCM_ARG2
, "apply");
4891 if (scm_is_false (SCM_SUBRF (proc
) (arg1
, SCM_CAR (args
))))
4892 RETURN (SCM_BOOL_F
);
4893 arg1
= SCM_CAR (args
);
4894 args
= SCM_CDR (args
);
4896 RETURN (SCM_BOOL_T
);
4897 case scm_tcs_closures
:
4899 arg1
= (SCM_UNBNDP (arg1
) ? SCM_EOL
: debug
.vect
[0].a
.args
);
4901 arg1
= (SCM_UNBNDP (arg1
) ? SCM_EOL
: scm_cons (arg1
, args
));
4903 if (scm_badargsp (SCM_CLOSURE_FORMALS (proc
), arg1
))
4904 scm_wrong_num_args (proc
);
4906 /* Copy argument list */
4911 SCM tl
= args
= scm_cons (SCM_CAR (arg1
), SCM_UNSPECIFIED
);
4912 for (arg1
= SCM_CDR (arg1
); scm_is_pair (arg1
); arg1
= SCM_CDR (arg1
))
4914 SCM_SETCDR (tl
, scm_cons (SCM_CAR (arg1
), SCM_UNSPECIFIED
));
4917 SCM_SETCDR (tl
, arg1
);
4920 args
= SCM_EXTEND_ENV (SCM_CLOSURE_FORMALS (proc
),
4923 proc
= SCM_CLOSURE_BODY (proc
);
4925 arg1
= SCM_CDR (proc
);
4926 while (!scm_is_null (arg1
))
4928 if (SCM_IMP (SCM_CAR (proc
)))
4930 if (SCM_ISYMP (SCM_CAR (proc
)))
4932 scm_rec_mutex_lock (&source_mutex
);
4933 /* check for race condition */
4934 if (SCM_ISYMP (SCM_CAR (proc
)))
4935 m_expand_body (proc
, args
);
4936 scm_rec_mutex_unlock (&source_mutex
);
4940 SCM_VALIDATE_NON_EMPTY_COMBINATION (SCM_CAR (proc
));
4943 (void) EVAL (SCM_CAR (proc
), args
);
4945 arg1
= SCM_CDR (proc
);
4947 RETURN (EVALCAR (proc
, args
));
4949 if (!SCM_SMOB_APPLICABLE_P (proc
))
4951 if (SCM_UNBNDP (arg1
))
4952 RETURN (SCM_SMOB_APPLY_0 (proc
));
4953 else if (scm_is_null (args
))
4954 RETURN (SCM_SMOB_APPLY_1 (proc
, arg1
));
4955 else if (scm_is_null (SCM_CDR (args
)))
4956 RETURN (SCM_SMOB_APPLY_2 (proc
, arg1
, SCM_CAR (args
)));
4958 RETURN (SCM_SMOB_APPLY_3 (proc
, arg1
, SCM_CAR (args
), SCM_CDR (args
)));
4961 args
= (SCM_UNBNDP(arg1
) ? SCM_EOL
: debug
.vect
[0].a
.args
);
4963 proc
= SCM_CCLO_SUBR (proc
);
4964 debug
.vect
[0].a
.proc
= proc
;
4965 debug
.vect
[0].a
.args
= scm_cons (arg1
, args
);
4967 args
= (SCM_UNBNDP(arg1
) ? SCM_EOL
: scm_cons (arg1
, args
));
4969 proc
= SCM_CCLO_SUBR (proc
);
4973 proc
= SCM_PROCEDURE (proc
);
4975 debug
.vect
[0].a
.proc
= proc
;
4978 case scm_tcs_struct
:
4979 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
4982 args
= (SCM_UNBNDP(arg1
) ? SCM_EOL
: debug
.vect
[0].a
.args
);
4984 args
= (SCM_UNBNDP(arg1
) ? SCM_EOL
: scm_cons (arg1
, args
));
4986 RETURN (scm_apply_generic (proc
, args
));
4988 else if (SCM_I_OPERATORP (proc
))
4992 args
= (SCM_UNBNDP(arg1
) ? SCM_EOL
: debug
.vect
[0].a
.args
);
4994 args
= (SCM_UNBNDP(arg1
) ? SCM_EOL
: scm_cons (arg1
, args
));
4997 proc
= (SCM_I_ENTITYP (proc
)
4998 ? SCM_ENTITY_PROCEDURE (proc
)
4999 : SCM_OPERATOR_PROCEDURE (proc
));
5001 debug
.vect
[0].a
.proc
= proc
;
5002 debug
.vect
[0].a
.args
= scm_cons (arg1
, args
);
5004 if (SCM_NIMP (proc
))
5013 scm_wrong_type_arg ("apply", SCM_ARG1
, proc
);
5017 if (scm_check_exit_p
&& SCM_TRAPS_P
)
5018 if (SCM_EXIT_FRAME_P
|| (SCM_TRACE_P
&& SCM_TRACED_FRAME_P (debug
)))
5020 SCM_CLEAR_TRACED_FRAME (debug
);
5021 if (SCM_CHEAPTRAPS_P
)
5022 arg1
= scm_make_debugobj (&debug
);
5026 SCM val
= scm_make_continuation (&first
);
5037 scm_call_3 (SCM_EXIT_FRAME_HDLR
, scm_sym_exit_frame
, arg1
, proc
);
5041 scm_last_debug_frame
= debug
.prev
;
5047 /* SECTION: The rest of this file is only read once.
5054 * Trampolines make it possible to move procedure application dispatch
5055 * outside inner loops. The motivation was clean implementation of
5056 * efficient replacements of R5RS primitives in SRFI-1.
5058 * The semantics is clear: scm_trampoline_N returns an optimized
5059 * version of scm_call_N (or NULL if the procedure isn't applicable
5062 * Applying the optimization to map and for-each increased efficiency
5063 * noticeably. For example, (map abs ls) is now 8 times faster than
5068 call_subr0_0 (SCM proc
)
5070 return SCM_SUBRF (proc
) ();
5074 call_subr1o_0 (SCM proc
)
5076 return SCM_SUBRF (proc
) (SCM_UNDEFINED
);
5080 call_lsubr_0 (SCM proc
)
5082 return SCM_SUBRF (proc
) (SCM_EOL
);
5086 scm_i_call_closure_0 (SCM proc
)
5088 const SCM env
= SCM_EXTEND_ENV (SCM_CLOSURE_FORMALS (proc
),
5091 const SCM result
= scm_eval_body (SCM_CLOSURE_BODY (proc
), env
);
5096 scm_trampoline_0 (SCM proc
)
5098 scm_t_trampoline_0 trampoline
;
5103 switch (SCM_TYP7 (proc
))
5105 case scm_tc7_subr_0
:
5106 trampoline
= call_subr0_0
;
5108 case scm_tc7_subr_1o
:
5109 trampoline
= call_subr1o_0
;
5112 trampoline
= call_lsubr_0
;
5114 case scm_tcs_closures
:
5116 SCM formals
= SCM_CLOSURE_FORMALS (proc
);
5117 if (scm_is_null (formals
) || !scm_is_pair (formals
))
5118 trampoline
= scm_i_call_closure_0
;
5123 case scm_tcs_struct
:
5124 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
5125 trampoline
= scm_call_generic_0
;
5126 else if (SCM_I_OPERATORP (proc
))
5127 trampoline
= scm_call_0
;
5132 if (SCM_SMOB_APPLICABLE_P (proc
))
5133 trampoline
= SCM_SMOB_DESCRIPTOR (proc
).apply_0
;
5138 case scm_tc7_rpsubr
:
5141 trampoline
= scm_call_0
;
5144 return NULL
; /* not applicable on zero arguments */
5146 /* We only reach this point if a valid trampoline was determined. */
5148 /* If debugging is enabled, we want to see all calls to proc on the stack.
5149 * Thus, we replace the trampoline shortcut with scm_call_0. */
5150 if (scm_debug_mode_p
)
5157 call_subr1_1 (SCM proc
, SCM arg1
)
5159 return SCM_SUBRF (proc
) (arg1
);
5163 call_subr2o_1 (SCM proc
, SCM arg1
)
5165 return SCM_SUBRF (proc
) (arg1
, SCM_UNDEFINED
);
5169 call_lsubr_1 (SCM proc
, SCM arg1
)
5171 return SCM_SUBRF (proc
) (scm_list_1 (arg1
));
5175 call_dsubr_1 (SCM proc
, SCM arg1
)
5177 if (SCM_I_INUMP (arg1
))
5179 RETURN (scm_from_double (SCM_DSUBRF (proc
) ((double) SCM_I_INUM (arg1
))));
5181 else if (SCM_REALP (arg1
))
5183 RETURN (scm_from_double (SCM_DSUBRF (proc
) (SCM_REAL_VALUE (arg1
))));
5185 else if (SCM_BIGP (arg1
))
5187 RETURN (scm_from_double (SCM_DSUBRF (proc
) (scm_i_big2dbl (arg1
))));
5189 else if (SCM_FRACTIONP (arg1
))
5191 RETURN (scm_from_double (SCM_DSUBRF (proc
) (scm_i_fraction2double (arg1
))));
5193 SCM_WTA_DISPATCH_1 (*SCM_SUBR_GENERIC (proc
), arg1
,
5194 SCM_ARG1
, scm_i_symbol_chars (SCM_SNAME (proc
)));
5198 call_cxr_1 (SCM proc
, SCM arg1
)
5200 return scm_i_chase_pairs (arg1
, (scm_t_bits
) SCM_SUBRF (proc
));
5204 call_closure_1 (SCM proc
, SCM arg1
)
5206 const SCM env
= SCM_EXTEND_ENV (SCM_CLOSURE_FORMALS (proc
),
5209 const SCM result
= scm_eval_body (SCM_CLOSURE_BODY (proc
), env
);
5214 scm_trampoline_1 (SCM proc
)
5216 scm_t_trampoline_1 trampoline
;
5221 switch (SCM_TYP7 (proc
))
5223 case scm_tc7_subr_1
:
5224 case scm_tc7_subr_1o
:
5225 trampoline
= call_subr1_1
;
5227 case scm_tc7_subr_2o
:
5228 trampoline
= call_subr2o_1
;
5231 trampoline
= call_lsubr_1
;
5234 trampoline
= call_dsubr_1
;
5237 trampoline
= call_cxr_1
;
5239 case scm_tcs_closures
:
5241 SCM formals
= SCM_CLOSURE_FORMALS (proc
);
5242 if (!scm_is_null (formals
)
5243 && (!scm_is_pair (formals
) || !scm_is_pair (SCM_CDR (formals
))))
5244 trampoline
= call_closure_1
;
5249 case scm_tcs_struct
:
5250 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
5251 trampoline
= scm_call_generic_1
;
5252 else if (SCM_I_OPERATORP (proc
))
5253 trampoline
= scm_call_1
;
5258 if (SCM_SMOB_APPLICABLE_P (proc
))
5259 trampoline
= SCM_SMOB_DESCRIPTOR (proc
).apply_1
;
5264 case scm_tc7_rpsubr
:
5267 trampoline
= scm_call_1
;
5270 return NULL
; /* not applicable on one arg */
5272 /* We only reach this point if a valid trampoline was determined. */
5274 /* If debugging is enabled, we want to see all calls to proc on the stack.
5275 * Thus, we replace the trampoline shortcut with scm_call_1. */
5276 if (scm_debug_mode_p
)
5283 call_subr2_2 (SCM proc
, SCM arg1
, SCM arg2
)
5285 return SCM_SUBRF (proc
) (arg1
, arg2
);
5289 call_lsubr2_2 (SCM proc
, SCM arg1
, SCM arg2
)
5291 return SCM_SUBRF (proc
) (arg1
, arg2
, SCM_EOL
);
5295 call_lsubr_2 (SCM proc
, SCM arg1
, SCM arg2
)
5297 return SCM_SUBRF (proc
) (scm_list_2 (arg1
, arg2
));
5301 call_closure_2 (SCM proc
, SCM arg1
, SCM arg2
)
5303 const SCM env
= SCM_EXTEND_ENV (SCM_CLOSURE_FORMALS (proc
),
5304 scm_list_2 (arg1
, arg2
),
5306 const SCM result
= scm_eval_body (SCM_CLOSURE_BODY (proc
), env
);
5311 scm_trampoline_2 (SCM proc
)
5313 scm_t_trampoline_2 trampoline
;
5318 switch (SCM_TYP7 (proc
))
5320 case scm_tc7_subr_2
:
5321 case scm_tc7_subr_2o
:
5322 case scm_tc7_rpsubr
:
5324 trampoline
= call_subr2_2
;
5326 case scm_tc7_lsubr_2
:
5327 trampoline
= call_lsubr2_2
;
5330 trampoline
= call_lsubr_2
;
5332 case scm_tcs_closures
:
5334 SCM formals
= SCM_CLOSURE_FORMALS (proc
);
5335 if (!scm_is_null (formals
)
5336 && (!scm_is_pair (formals
)
5337 || (!scm_is_null (SCM_CDR (formals
))
5338 && (!scm_is_pair (SCM_CDR (formals
))
5339 || !scm_is_pair (SCM_CDDR (formals
))))))
5340 trampoline
= call_closure_2
;
5345 case scm_tcs_struct
:
5346 if (SCM_OBJ_CLASS_FLAGS (proc
) & SCM_CLASSF_PURE_GENERIC
)
5347 trampoline
= scm_call_generic_2
;
5348 else if (SCM_I_OPERATORP (proc
))
5349 trampoline
= scm_call_2
;
5354 if (SCM_SMOB_APPLICABLE_P (proc
))
5355 trampoline
= SCM_SMOB_DESCRIPTOR (proc
).apply_2
;
5361 trampoline
= scm_call_2
;
5364 return NULL
; /* not applicable on two args */
5366 /* We only reach this point if a valid trampoline was determined. */
5368 /* If debugging is enabled, we want to see all calls to proc on the stack.
5369 * Thus, we replace the trampoline shortcut with scm_call_2. */
5370 if (scm_debug_mode_p
)
5376 /* Typechecking for multi-argument MAP and FOR-EACH.
5378 Verify that each element of the vector ARGV, except for the first,
5379 is a proper list whose length is LEN. Attribute errors to WHO,
5380 and claim that the i'th element of ARGV is WHO's i+2'th argument. */
5382 check_map_args (SCM argv
,
5391 for (i
= SCM_SIMPLE_VECTOR_LENGTH (argv
) - 1; i
>= 1; i
--)
5393 SCM elt
= SCM_SIMPLE_VECTOR_REF (argv
, i
);
5394 long elt_len
= scm_ilength (elt
);
5399 scm_apply_generic (gf
, scm_cons (proc
, args
));
5401 scm_wrong_type_arg (who
, i
+ 2, elt
);
5405 scm_out_of_range_pos (who
, elt
, scm_from_long (i
+ 2));
5410 SCM_GPROC (s_map
, "map", 2, 0, 1, scm_map
, g_map
);
5412 /* Note: Currently, scm_map applies PROC to the argument list(s)
5413 sequentially, starting with the first element(s). This is used in
5414 evalext.c where the Scheme procedure `map-in-order', which guarantees
5415 sequential behaviour, is implemented using scm_map. If the
5416 behaviour changes, we need to update `map-in-order'.
5420 scm_map (SCM proc
, SCM arg1
, SCM args
)
5421 #define FUNC_NAME s_map
5427 len
= scm_ilength (arg1
);
5428 SCM_GASSERTn (len
>= 0,
5429 g_map
, scm_cons2 (proc
, arg1
, args
), SCM_ARG2
, s_map
);
5430 SCM_VALIDATE_REST_ARGUMENT (args
);
5431 if (scm_is_null (args
))
5433 scm_t_trampoline_1 call
= scm_trampoline_1 (proc
);
5434 SCM_GASSERT2 (call
, g_map
, proc
, arg1
, SCM_ARG1
, s_map
);
5435 while (SCM_NIMP (arg1
))
5437 *pres
= scm_list_1 (call (proc
, SCM_CAR (arg1
)));
5438 pres
= SCM_CDRLOC (*pres
);
5439 arg1
= SCM_CDR (arg1
);
5443 if (scm_is_null (SCM_CDR (args
)))
5445 SCM arg2
= SCM_CAR (args
);
5446 int len2
= scm_ilength (arg2
);
5447 scm_t_trampoline_2 call
= scm_trampoline_2 (proc
);
5449 g_map
, scm_cons2 (proc
, arg1
, args
), SCM_ARG1
, s_map
);
5450 SCM_GASSERTn (len2
>= 0,
5451 g_map
, scm_cons2 (proc
, arg1
, args
), SCM_ARG3
, s_map
);
5453 SCM_OUT_OF_RANGE (3, arg2
);
5454 while (SCM_NIMP (arg1
))
5456 *pres
= scm_list_1 (call (proc
, SCM_CAR (arg1
), SCM_CAR (arg2
)));
5457 pres
= SCM_CDRLOC (*pres
);
5458 arg1
= SCM_CDR (arg1
);
5459 arg2
= SCM_CDR (arg2
);
5463 arg1
= scm_cons (arg1
, args
);
5464 args
= scm_vector (arg1
);
5465 check_map_args (args
, len
, g_map
, proc
, arg1
, s_map
);
5469 for (i
= SCM_SIMPLE_VECTOR_LENGTH (args
) - 1; i
>= 0; i
--)
5471 SCM elt
= SCM_SIMPLE_VECTOR_REF (args
, i
);
5474 arg1
= scm_cons (SCM_CAR (elt
), arg1
);
5475 SCM_SIMPLE_VECTOR_SET (args
, i
, SCM_CDR (elt
));
5477 *pres
= scm_list_1 (scm_apply (proc
, arg1
, SCM_EOL
));
5478 pres
= SCM_CDRLOC (*pres
);
5484 SCM_GPROC (s_for_each
, "for-each", 2, 0, 1, scm_for_each
, g_for_each
);
5487 scm_for_each (SCM proc
, SCM arg1
, SCM args
)
5488 #define FUNC_NAME s_for_each
5491 len
= scm_ilength (arg1
);
5492 SCM_GASSERTn (len
>= 0, g_for_each
, scm_cons2 (proc
, arg1
, args
),
5493 SCM_ARG2
, s_for_each
);
5494 SCM_VALIDATE_REST_ARGUMENT (args
);
5495 if (scm_is_null (args
))
5497 scm_t_trampoline_1 call
= scm_trampoline_1 (proc
);
5498 SCM_GASSERT2 (call
, g_for_each
, proc
, arg1
, SCM_ARG1
, s_for_each
);
5499 while (SCM_NIMP (arg1
))
5501 call (proc
, SCM_CAR (arg1
));
5502 arg1
= SCM_CDR (arg1
);
5504 return SCM_UNSPECIFIED
;
5506 if (scm_is_null (SCM_CDR (args
)))
5508 SCM arg2
= SCM_CAR (args
);
5509 int len2
= scm_ilength (arg2
);
5510 scm_t_trampoline_2 call
= scm_trampoline_2 (proc
);
5511 SCM_GASSERTn (call
, g_for_each
,
5512 scm_cons2 (proc
, arg1
, args
), SCM_ARG1
, s_for_each
);
5513 SCM_GASSERTn (len2
>= 0, g_for_each
,
5514 scm_cons2 (proc
, arg1
, args
), SCM_ARG3
, s_for_each
);
5516 SCM_OUT_OF_RANGE (3, arg2
);
5517 while (SCM_NIMP (arg1
))
5519 call (proc
, SCM_CAR (arg1
), SCM_CAR (arg2
));
5520 arg1
= SCM_CDR (arg1
);
5521 arg2
= SCM_CDR (arg2
);
5523 return SCM_UNSPECIFIED
;
5525 arg1
= scm_cons (arg1
, args
);
5526 args
= scm_vector (arg1
);
5527 check_map_args (args
, len
, g_for_each
, proc
, arg1
, s_for_each
);
5531 for (i
= SCM_SIMPLE_VECTOR_LENGTH (args
) - 1; i
>= 0; i
--)
5533 SCM elt
= SCM_SIMPLE_VECTOR_REF (args
, i
);
5535 return SCM_UNSPECIFIED
;
5536 arg1
= scm_cons (SCM_CAR (elt
), arg1
);
5537 SCM_SIMPLE_VECTOR_SET (args
, i
, SCM_CDR (elt
));
5539 scm_apply (proc
, arg1
, SCM_EOL
);
5546 scm_closure (SCM code
, SCM env
)
5549 SCM closcar
= scm_cons (code
, SCM_EOL
);
5550 z
= scm_cell (SCM_UNPACK (closcar
) + scm_tc3_closure
, (scm_t_bits
) env
);
5551 scm_remember_upto_here (closcar
);
5556 scm_t_bits scm_tc16_promise
;
5559 scm_makprom (SCM code
)
5561 SCM_RETURN_NEWSMOB2 (scm_tc16_promise
,
5563 scm_make_rec_mutex ());
5567 promise_free (SCM promise
)
5569 scm_rec_mutex_free (SCM_PROMISE_MUTEX (promise
));
5574 promise_print (SCM exp
, SCM port
, scm_print_state
*pstate
)
5576 int writingp
= SCM_WRITINGP (pstate
);
5577 scm_puts ("#<promise ", port
);
5578 SCM_SET_WRITINGP (pstate
, 1);
5579 scm_iprin1 (SCM_PROMISE_DATA (exp
), port
, pstate
);
5580 SCM_SET_WRITINGP (pstate
, writingp
);
5581 scm_putc ('>', port
);
5585 SCM_DEFINE (scm_force
, "force", 1, 0, 0,
5587 "If the promise @var{x} has not been computed yet, compute and\n"
5588 "return @var{x}, otherwise just return the previously computed\n"
5590 #define FUNC_NAME s_scm_force
5592 SCM_VALIDATE_SMOB (1, promise
, promise
);
5593 scm_rec_mutex_lock (SCM_PROMISE_MUTEX (promise
));
5594 if (!SCM_PROMISE_COMPUTED_P (promise
))
5596 SCM ans
= scm_call_0 (SCM_PROMISE_DATA (promise
));
5597 if (!SCM_PROMISE_COMPUTED_P (promise
))
5599 SCM_SET_PROMISE_DATA (promise
, ans
);
5600 SCM_SET_PROMISE_COMPUTED (promise
);
5603 scm_rec_mutex_unlock (SCM_PROMISE_MUTEX (promise
));
5604 return SCM_PROMISE_DATA (promise
);
5609 SCM_DEFINE (scm_promise_p
, "promise?", 1, 0, 0,
5611 "Return true if @var{obj} is a promise, i.e. a delayed computation\n"
5612 "(@pxref{Delayed evaluation,,,r5rs.info,The Revised^5 Report on Scheme}).")
5613 #define FUNC_NAME s_scm_promise_p
5615 return scm_from_bool (SCM_TYP16_PREDICATE (scm_tc16_promise
, obj
));
5620 SCM_DEFINE (scm_cons_source
, "cons-source", 3, 0, 0,
5621 (SCM xorig
, SCM x
, SCM y
),
5622 "Create and return a new pair whose car and cdr are @var{x} and @var{y}.\n"
5623 "Any source properties associated with @var{xorig} are also associated\n"
5624 "with the new pair.")
5625 #define FUNC_NAME s_scm_cons_source
5628 z
= scm_cons (x
, y
);
5629 /* Copy source properties possibly associated with xorig. */
5630 p
= scm_whash_lookup (scm_source_whash
, xorig
);
5631 if (scm_is_true (p
))
5632 scm_whash_insert (scm_source_whash
, z
, p
);
5638 /* The function scm_copy_tree is used to copy an expression tree to allow the
5639 * memoizer to modify the expression during memoization. scm_copy_tree
5640 * creates deep copies of pairs and vectors, but not of any other data types,
5641 * since only pairs and vectors will be parsed by the memoizer.
5643 * To avoid infinite recursion due to cyclic structures, the hare-and-tortoise
5644 * pattern is used to detect cycles. In fact, the pattern is used in two
5645 * dimensions, vertical (indicated in the code by the variable names 'hare'
5646 * and 'tortoise') and horizontal ('rabbit' and 'turtle'). In both
5647 * dimensions, the hare/rabbit will take two steps when the tortoise/turtle
5650 * The vertical dimension corresponds to recursive calls to function
5651 * copy_tree: This happens when descending into vector elements, into cars of
5652 * lists and into the cdr of an improper list. In this dimension, the
5653 * tortoise follows the hare by using the processor stack: Every stack frame
5654 * will hold an instance of struct t_trace. These instances are connected in
5655 * a way that represents the trace of the hare, which thus can be followed by
5656 * the tortoise. The tortoise will always point to struct t_trace instances
5657 * relating to SCM objects that have already been copied. Thus, a cycle is
5658 * detected if the tortoise and the hare point to the same object,
5660 * The horizontal dimension is within one execution of copy_tree, when the
5661 * function cdr's along the pairs of a list. This is the standard
5662 * hare-and-tortoise implementation, found several times in guile. */
5665 struct t_trace
*trace
; // These pointers form a trace along the stack.
5666 SCM obj
; // The object handled at the respective stack frame.
5671 struct t_trace
*const hare
,
5672 struct t_trace
*tortoise
,
5673 unsigned int tortoise_delay
)
5675 if (!scm_is_pair (hare
->obj
) && !scm_is_simple_vector (hare
->obj
))
5681 /* Prepare the trace along the stack. */
5682 struct t_trace new_hare
;
5683 hare
->trace
= &new_hare
;
5685 /* The tortoise will make its step after the delay has elapsed. Note
5686 * that in contrast to the typical hare-and-tortoise pattern, the step
5687 * of the tortoise happens before the hare takes its steps. This is, in
5688 * principle, no problem, except for the start of the algorithm: Then,
5689 * it has to be made sure that the hare actually gets its advantage of
5691 if (tortoise_delay
== 0)
5694 tortoise
= tortoise
->trace
;
5695 ASSERT_SYNTAX (!scm_is_eq (hare
->obj
, tortoise
->obj
),
5696 s_bad_expression
, hare
->obj
);
5703 if (scm_is_simple_vector (hare
->obj
))
5705 size_t length
= SCM_SIMPLE_VECTOR_LENGTH (hare
->obj
);
5706 SCM new_vector
= scm_c_make_vector (length
, SCM_UNSPECIFIED
);
5708 /* Each vector element is copied by recursing into copy_tree, having
5709 * the tortoise follow the hare into the depths of the stack. */
5710 unsigned long int i
;
5711 for (i
= 0; i
< length
; ++i
)
5714 new_hare
.obj
= SCM_SIMPLE_VECTOR_REF (hare
->obj
, i
);
5715 new_element
= copy_tree (&new_hare
, tortoise
, tortoise_delay
);
5716 SCM_SIMPLE_VECTOR_SET (new_vector
, i
, new_element
);
5721 else // scm_is_pair (hare->obj)
5726 SCM rabbit
= hare
->obj
;
5727 SCM turtle
= hare
->obj
;
5731 /* The first pair of the list is treated specially, in order to
5732 * preserve a potential source code position. */
5733 result
= tail
= scm_cons_source (rabbit
, SCM_EOL
, SCM_EOL
);
5734 new_hare
.obj
= SCM_CAR (rabbit
);
5735 copy
= copy_tree (&new_hare
, tortoise
, tortoise_delay
);
5736 SCM_SETCAR (tail
, copy
);
5738 /* The remaining pairs of the list are copied by, horizontally,
5739 * having the turtle follow the rabbit, and, vertically, having the
5740 * tortoise follow the hare into the depths of the stack. */
5741 rabbit
= SCM_CDR (rabbit
);
5742 while (scm_is_pair (rabbit
))
5744 new_hare
.obj
= SCM_CAR (rabbit
);
5745 copy
= copy_tree (&new_hare
, tortoise
, tortoise_delay
);
5746 SCM_SETCDR (tail
, scm_cons (copy
, SCM_UNDEFINED
));
5747 tail
= SCM_CDR (tail
);
5749 rabbit
= SCM_CDR (rabbit
);
5750 if (scm_is_pair (rabbit
))
5752 new_hare
.obj
= SCM_CAR (rabbit
);
5753 copy
= copy_tree (&new_hare
, tortoise
, tortoise_delay
);
5754 SCM_SETCDR (tail
, scm_cons (copy
, SCM_UNDEFINED
));
5755 tail
= SCM_CDR (tail
);
5756 rabbit
= SCM_CDR (rabbit
);
5758 turtle
= SCM_CDR (turtle
);
5759 ASSERT_SYNTAX (!scm_is_eq (rabbit
, turtle
),
5760 s_bad_expression
, rabbit
);
5764 /* We have to recurse into copy_tree again for the last cdr, in
5765 * order to handle the situation that it holds a vector. */
5766 new_hare
.obj
= rabbit
;
5767 copy
= copy_tree (&new_hare
, tortoise
, tortoise_delay
);
5768 SCM_SETCDR (tail
, copy
);
5775 SCM_DEFINE (scm_copy_tree
, "copy-tree", 1, 0, 0,
5777 "Recursively copy the data tree that is bound to @var{obj}, and return a\n"
5778 "the new data structure. @code{copy-tree} recurses down the\n"
5779 "contents of both pairs and vectors (since both cons cells and vector\n"
5780 "cells may point to arbitrary objects), and stops recursing when it hits\n"
5781 "any other object.")
5782 #define FUNC_NAME s_scm_copy_tree
5784 /* Prepare the trace along the stack. */
5785 struct t_trace trace
;
5788 /* In function copy_tree, if the tortoise makes its step, it will do this
5789 * before the hare has the chance to move. Thus, we have to make sure that
5790 * the very first step of the tortoise will not happen after the hare has
5791 * really made two steps. This is achieved by passing '2' as the initial
5792 * delay for the tortoise. NOTE: Since cycles are unlikely, giving the hare
5793 * a bigger advantage may improve performance slightly. */
5794 return copy_tree (&trace
, &trace
, 2);
5799 /* We have three levels of EVAL here:
5801 - scm_i_eval (exp, env)
5803 evaluates EXP in environment ENV. ENV is a lexical environment
5804 structure as used by the actual tree code evaluator. When ENV is
5805 a top-level environment, then changes to the current module are
5806 tracked by updating ENV so that it continues to be in sync with
5809 - scm_primitive_eval (exp)
5811 evaluates EXP in the top-level environment as determined by the
5812 current module. This is done by constructing a suitable
5813 environment and calling scm_i_eval. Thus, changes to the
5814 top-level module are tracked normally.
5816 - scm_eval (exp, mod)
5818 evaluates EXP while MOD is the current module. This is done by
5819 setting the current module to MOD, invoking scm_primitive_eval on
5820 EXP, and then restoring the current module to the value it had
5821 previously. That is, while EXP is evaluated, changes to the
5822 current module are tracked, but these changes do not persist when
5825 For each level of evals, there are two variants, distinguished by a
5826 _x suffix: the ordinary variant does not modify EXP while the _x
5827 variant can destructively modify EXP into something completely
5828 unintelligible. A Scheme data structure passed as EXP to one of the
5829 _x variants should not ever be used again for anything. So when in
5830 doubt, use the ordinary variant.
5835 scm_i_eval_x (SCM exp
, SCM env
)
5837 if (scm_is_symbol (exp
))
5838 return *scm_lookupcar (scm_cons (exp
, SCM_UNDEFINED
), env
, 1);
5840 return SCM_I_XEVAL (exp
, env
);
5844 scm_i_eval (SCM exp
, SCM env
)
5846 exp
= scm_copy_tree (exp
);
5847 if (scm_is_symbol (exp
))
5848 return *scm_lookupcar (scm_cons (exp
, SCM_UNDEFINED
), env
, 1);
5850 return SCM_I_XEVAL (exp
, env
);
5854 scm_primitive_eval_x (SCM exp
)
5857 SCM transformer
= scm_current_module_transformer ();
5858 if (SCM_NIMP (transformer
))
5859 exp
= scm_call_1 (transformer
, exp
);
5860 env
= scm_top_level_env (scm_current_module_lookup_closure ());
5861 return scm_i_eval_x (exp
, env
);
5864 SCM_DEFINE (scm_primitive_eval
, "primitive-eval", 1, 0, 0,
5866 "Evaluate @var{exp} in the top-level environment specified by\n"
5867 "the current module.")
5868 #define FUNC_NAME s_scm_primitive_eval
5871 SCM transformer
= scm_current_module_transformer ();
5872 if (scm_is_true (transformer
))
5873 exp
= scm_call_1 (transformer
, exp
);
5874 env
= scm_top_level_env (scm_current_module_lookup_closure ());
5875 return scm_i_eval (exp
, env
);
5880 /* Eval does not take the second arg optionally. This is intentional
5881 * in order to be R5RS compatible, and to prepare for the new module
5882 * system, where we would like to make the choice of evaluation
5883 * environment explicit. */
5886 change_environment (void *data
)
5888 SCM pair
= SCM_PACK (data
);
5889 SCM new_module
= SCM_CAR (pair
);
5890 SCM old_module
= scm_current_module ();
5891 SCM_SETCDR (pair
, old_module
);
5892 scm_set_current_module (new_module
);
5896 restore_environment (void *data
)
5898 SCM pair
= SCM_PACK (data
);
5899 SCM old_module
= SCM_CDR (pair
);
5900 SCM new_module
= scm_current_module ();
5901 SCM_SETCAR (pair
, new_module
);
5902 scm_set_current_module (old_module
);
5906 inner_eval_x (void *data
)
5908 return scm_primitive_eval_x (SCM_PACK(data
));
5912 scm_eval_x (SCM exp
, SCM module
)
5913 #define FUNC_NAME "eval!"
5915 SCM_VALIDATE_MODULE (2, module
);
5917 return scm_internal_dynamic_wind
5918 (change_environment
, inner_eval_x
, restore_environment
,
5919 (void *) SCM_UNPACK (exp
),
5920 (void *) SCM_UNPACK (scm_cons (module
, SCM_BOOL_F
)));
5925 inner_eval (void *data
)
5927 return scm_primitive_eval (SCM_PACK(data
));
5930 SCM_DEFINE (scm_eval
, "eval", 2, 0, 0,
5931 (SCM exp
, SCM module
),
5932 "Evaluate @var{exp}, a list representing a Scheme expression,\n"
5933 "in the top-level environment specified by @var{module}.\n"
5934 "While @var{exp} is evaluated (using @code{primitive-eval}),\n"
5935 "@var{module} is made the current module. The current module\n"
5936 "is reset to its previous value when @var{eval} returns.\n"
5937 "Example: (eval '(+ 1 2) (interaction-environment))")
5938 #define FUNC_NAME s_scm_eval
5940 SCM_VALIDATE_MODULE (2, module
);
5942 return scm_internal_dynamic_wind
5943 (change_environment
, inner_eval
, restore_environment
,
5944 (void *) SCM_UNPACK (exp
),
5945 (void *) SCM_UNPACK (scm_cons (module
, SCM_BOOL_F
)));
5950 /* At this point, deval and scm_dapply are generated.
5957 #if (SCM_ENABLE_DEPRECATED == 1)
5959 /* Deprecated in guile 1.7.0 on 2004-03-29. */
5960 SCM
scm_ceval (SCM x
, SCM env
)
5962 if (scm_is_pair (x
))
5963 return ceval (x
, env
);
5964 else if (scm_is_symbol (x
))
5965 return *scm_lookupcar (scm_cons (x
, SCM_UNDEFINED
), env
, 1);
5967 return SCM_I_XEVAL (x
, env
);
5970 /* Deprecated in guile 1.7.0 on 2004-03-29. */
5971 SCM
scm_deval (SCM x
, SCM env
)
5973 if (scm_is_pair (x
))
5974 return deval (x
, env
);
5975 else if (scm_is_symbol (x
))
5976 return *scm_lookupcar (scm_cons (x
, SCM_UNDEFINED
), env
, 1);
5978 return SCM_I_XEVAL (x
, env
);
5982 dispatching_eval (SCM x
, SCM env
)
5984 if (scm_debug_mode_p
)
5985 return scm_deval (x
, env
);
5987 return scm_ceval (x
, env
);
5990 /* Deprecated in guile 1.7.0 on 2004-03-29. */
5991 SCM (*scm_ceval_ptr
) (SCM x
, SCM env
) = dispatching_eval
;
5999 scm_init_opts (scm_evaluator_traps
,
6000 scm_evaluator_trap_table
,
6001 SCM_N_EVALUATOR_TRAPS
);
6002 scm_init_opts (scm_eval_options_interface
,
6004 SCM_N_EVAL_OPTIONS
);
6006 scm_tc16_promise
= scm_make_smob_type ("promise", 0);
6007 scm_set_smob_mark (scm_tc16_promise
, scm_markcdr
);
6008 scm_set_smob_free (scm_tc16_promise
, promise_free
);
6009 scm_set_smob_print (scm_tc16_promise
, promise_print
);
6011 undefineds
= scm_list_1 (SCM_UNDEFINED
);
6012 SCM_SETCDR (undefineds
, undefineds
);
6013 scm_permanent_object (undefineds
);
6015 scm_listofnull
= scm_list_1 (SCM_EOL
);
6017 f_apply
= scm_c_define_subr ("apply", scm_tc7_lsubr_2
, scm_apply
);
6018 scm_permanent_object (f_apply
);
6020 #include "libguile/eval.x"
6022 scm_add_feature ("delay");