1 /* Copyright (C) 1995,1996,1997,1998, 2000 Free Software Foundation, Inc.
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2, or (at your option)
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this software; see the file COPYING. If not, write to
15 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
16 * Boston, MA 02111-1307 USA
18 * As a special exception, the Free Software Foundation gives permission
19 * for additional uses of the text contained in its release of GUILE.
21 * The exception is that, if you link the GUILE library with other files
22 * to produce an executable, this does not by itself cause the
23 * resulting executable to be covered by the GNU General Public License.
24 * Your use of that executable is in no way restricted on account of
25 * linking the GUILE library code into it.
27 * This exception does not however invalidate any other reasons why
28 * the executable file might be covered by the GNU General Public License.
30 * This exception applies only to the code released by the
31 * Free Software Foundation under the name GUILE. If you copy
32 * code from other Free Software Foundation releases into a copy of
33 * GUILE, as the General Public License permits, the exception does
34 * not apply to the code that you add in this way. To avoid misleading
35 * anyone as to the status of such modified files, you must delete
36 * this exception notice from them.
38 * If you write modifications of your own for GUILE, it is your choice
39 * whether to permit this exception to apply to your modifications.
40 * If you do not wish that, delete this exception notice. */
42 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
43 gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
48 #include "libguile/_scm.h"
49 #include "libguile/chars.h"
50 #include "libguile/eval.h"
51 #include "libguile/smob.h"
52 #include "libguile/variable.h"
53 #include "libguile/alist.h"
54 #include "libguile/fluids.h"
55 #include "libguile/strings.h"
56 #include "libguile/vectors.h"
57 #include "libguile/weaks.h"
58 #include "libguile/modules.h"
60 #include "libguile/validate.h"
61 #include "libguile/symbols.h"
69 /* NUM_HASH_BUCKETS is the number of symbol scm_hash table buckets.
71 #define NUM_HASH_BUCKETS 137
76 duplicate_string (const char * src
, unsigned long length
)
78 char * dst
= scm_must_malloc (length
+ 1, "duplicate_string");
79 memcpy (dst
, src
, length
);
91 scm_string_hash (const unsigned char *str
, scm_sizet len
)
96 unsigned long h
= 264;
98 h
= (h
<< 8) + ((unsigned) (scm_downcase (str
[h
% len
])));
106 h
= (h
<< 8) + ((unsigned) (scm_downcase (str
[--i
])));
112 int scm_symhash_dim
= NUM_HASH_BUCKETS
;
116 * looks up the symbol in the symhash table.
120 scm_sym2vcell (SCM sym
, SCM thunk
, SCM definep
)
122 if (SCM_NIMP (thunk
))
126 if (SCM_EVAL_CLOSURE_P (thunk
))
127 /* Bypass evaluator in the standard case. */
128 var
= scm_eval_closure_lookup (thunk
, sym
, definep
);
130 var
= scm_apply (thunk
, sym
, scm_cons (definep
, scm_listofnull
));
132 if (SCM_FALSEP (var
))
136 if (SCM_IMP(var
) || !SCM_VARIABLEP (var
))
137 scm_wta (sym
, "strangely interned symbol? ", "");
138 return SCM_VARVCELL (var
);
147 = scm_string_hash (SCM_SYMBOL_UCHARS (sym
), SCM_LENGTH (sym
)) % scm_symhash_dim
;
150 for (lsym
= SCM_VELTS (scm_symhash
)[hash
]; SCM_NIMP (lsym
); lsym
= SCM_CDR (lsym
))
153 if (SCM_EQ_P (SCM_CAR (z
), sym
))
160 for (lsym
= *(lsymp
= &SCM_VELTS (scm_weak_symhash
)[hash
]);
162 lsym
= *(lsymp
= SCM_CDRLOC (lsym
)))
165 if (SCM_EQ_P (SCM_CAR (z
), sym
))
167 if (SCM_NFALSEP (definep
))
169 /* Move handle from scm_weak_symhash to scm_symhash. */
170 *lsymp
= SCM_CDR (lsym
);
171 SCM_SETCDR (lsym
, SCM_VELTS(scm_symhash
)[hash
]);
172 SCM_VELTS(scm_symhash
)[hash
] = lsym
;
179 return scm_wta (sym
, "uninterned symbol? ", "");
184 * looks up the symbol in an arbitrary obarray.
188 scm_sym2ovcell_soft (SCM sym
, SCM obarray
)
192 = scm_string_hash (SCM_SYMBOL_UCHARS (sym
), SCM_LENGTH (sym
)) % SCM_LENGTH (obarray
);
194 for (lsym
= SCM_VELTS (obarray
)[hash
];
196 lsym
= SCM_CDR (lsym
))
199 if (SCM_EQ_P (SCM_CAR (z
), sym
))
211 scm_sym2ovcell (SCM sym
, SCM obarray
)
214 answer
= scm_sym2ovcell_soft (sym
, obarray
);
215 if (!SCM_FALSEP (answer
))
217 scm_wta (sym
, "uninterned symbol? ", "");
218 return SCM_UNSPECIFIED
; /* not reached */
221 /* Intern a symbol whose name is the LEN characters at NAME in OBARRAY.
223 OBARRAY should be a vector of lists, indexed by the name's hash
224 value, modulo OBARRAY's length. Each list has the form
225 ((SYMBOL . VALUE) ...), where SYMBOL is a symbol, and VALUE is the
226 value associated with that symbol (in the current module? in the
229 To "intern" a symbol means: if OBARRAY already contains a symbol by
230 that name, return its (SYMBOL . VALUE) pair; otherwise, create a
231 new symbol, add the pair (SYMBOL . SCM_UNDEFINED) to the
232 appropriate list of the OBARRAY, and return the pair.
234 If softness is non-zero, don't create a symbol if it isn't already
235 in OBARRAY; instead, just return #f.
237 If OBARRAY is SCM_BOOL_F, create a symbol listed in no obarray and
238 return (SYMBOL . SCM_UNDEFINED).
240 If OBARRAY is scm_symhash, and that doesn't contain the symbol,
241 check scm_weak_symhash instead. */
245 scm_intern_obarray_soft (const char *name
,scm_sizet len
,SCM obarray
,unsigned int softness
)
247 scm_sizet raw_hash
= scm_string_hash ((unsigned char *) name
, len
);
253 if (SCM_FALSEP (obarray
))
255 hash
= raw_hash
% 1019;
256 goto uninterned_symbol
;
259 hash
= raw_hash
% SCM_LENGTH (obarray
);
262 for (lsym
= SCM_VELTS (obarray
)[hash
]; SCM_NIMP (lsym
); lsym
= SCM_CDR (lsym
))
265 SCM a
= SCM_CAR (lsym
);
267 unsigned char *tmp
= SCM_SYMBOL_UCHARS (z
);
268 if (SCM_LENGTH (z
) != len
)
271 if (((unsigned char *) name
)[i
] != tmp
[i
])
280 if (SCM_EQ_P (obarray
, scm_symhash
))
282 obarray
= scm_weak_symhash
;
283 goto retry_new_obarray
;
294 SCM_SETCHARS (lsym
, duplicate_string (name
, len
));
295 SCM_SET_SYMBOL_HASH (lsym
, raw_hash
);
296 SCM_SET_PROP_SLOTS (lsym
, scm_cons (SCM_BOOL_F
, SCM_EOL
));
297 SCM_SETLENGTH (lsym
, (long) len
, scm_tc7_symbol
);
299 if (SCM_FALSEP (obarray
))
303 SCM_NEWCELL (answer
);
305 SCM_SETCAR (answer
, lsym
);
306 SCM_SETCDR (answer
, SCM_UNDEFINED
);
317 SCM_SETCAR (a
, lsym
);
318 SCM_SETCDR (a
, SCM_UNDEFINED
);
320 SCM_SETCDR (b
, SCM_VELTS(obarray
)[hash
]);
321 SCM_VELTS(obarray
)[hash
] = b
;
329 scm_intern_obarray (const char *name
,scm_sizet len
,SCM obarray
)
331 return scm_intern_obarray_soft (name
, len
, obarray
, 0);
336 scm_intern (const char *name
,scm_sizet len
)
338 return scm_intern_obarray (name
, len
, scm_symhash
);
343 scm_intern0 (const char * name
)
345 return scm_intern (name
, strlen (name
));
349 /* Intern the symbol named NAME in scm_symhash, NAME is null-terminated. */
351 scm_sysintern0_no_module_lookup (const char *name
)
355 easy_answer
= scm_intern_obarray_soft (name
, strlen (name
), scm_symhash
, 1);
356 if (SCM_NIMP (easy_answer
))
364 scm_sizet len
= strlen (name
);
365 scm_sizet raw_hash
= scm_string_hash ((unsigned char *) name
, len
);
366 scm_sizet hash
= raw_hash
% scm_symhash_dim
;
369 SCM_SETCHARS (lsym
, name
);
370 SCM_SET_SYMBOL_HASH (lsym
, raw_hash
);
371 SCM_SET_PROP_SLOTS (lsym
, scm_cons (SCM_BOOL_F
, SCM_EOL
));
372 SCM_SETLENGTH (lsym
, (long) len
, scm_tc7_symbol
);
374 lsym
= scm_cons (lsym
, SCM_UNDEFINED
);
375 SCM_VELTS (scm_symhash
)[hash
] = scm_cons (lsym
, SCM_VELTS (scm_symhash
)[hash
]);
381 /* Intern the symbol named NAME in scm_symhash, and give it the value
382 VAL. NAME is null-terminated. Use the current top_level lookup
383 closure to give NAME its value.
386 scm_sysintern (const char *name
, SCM val
)
388 SCM vcell
= scm_sysintern0 (name
);
389 SCM_SETCDR (vcell
, val
);
394 scm_sysintern0 (const char *name
)
397 if (scm_module_system_booted_p
398 && SCM_NIMP (lookup_proc
= SCM_TOP_LEVEL_LOOKUP_CLOSURE
))
400 SCM sym
= SCM_CAR (scm_intern0 (name
));
401 SCM vcell
= scm_sym2vcell (sym
, lookup_proc
, SCM_BOOL_T
);
402 if (SCM_FALSEP (vcell
))
403 scm_misc_error ("sysintern0", "can't define variable", sym
);
407 return scm_sysintern0_no_module_lookup (name
);
410 /* Lookup the value of the symbol named by the nul-terminated string
411 NAME in the current module. */
413 scm_symbol_value0 (const char *name
)
415 /* This looks silly - we look up the symbol twice. But it is in
416 fact necessary given the current module system because the module
417 lookup closures are written in scheme which needs real symbols. */
418 SCM symbol
= scm_intern_obarray_soft (name
, strlen (name
), scm_symhash
, 0);
419 SCM vcell
= scm_sym2vcell (SCM_CAR (symbol
),
420 SCM_TOP_LEVEL_LOOKUP_CLOSURE
,
422 if (SCM_FALSEP (vcell
))
423 return SCM_UNDEFINED
;
424 return SCM_CDR (vcell
);
427 SCM_DEFINE (scm_symbol_p
, "symbol?", 1, 0, 0,
429 "Returns @t{#t} if @var{obj} is a symbol, otherwise returns @t{#f}. (r5rs)")
430 #define FUNC_NAME s_scm_symbol_p
432 return SCM_BOOL (SCM_SYMBOLP (obj
));
436 SCM_DEFINE (scm_symbol_to_string
, "symbol->string", 1, 0, 0,
438 "Returns the name of @var{symbol} as a string. If the symbol was part of\n"
439 "an object returned as the value of a literal expression (section\n"
440 "@pxref{Literal expressions,,,r4rs, The Revised^4 Report on Scheme}) or\n"
441 "by a call to the @samp{read} procedure, and its name contains alphabetic\n"
442 "characters, then the string returned will contain characters in the\n"
443 "implementation's preferred standard case---some implementations will\n"
444 "prefer upper case, others lower case. If the symbol was returned by\n"
445 "@samp{string->symbol}, the case of characters in the string returned\n"
446 "will be the same as the case in the string that was passed to\n"
447 "@samp{string->symbol}. It is an error to apply mutation procedures like\n"
448 "@code{string-set!} to strings returned by this procedure. (r5rs)\n\n"
449 "The following examples assume that the implementation's standard case is\n"
452 "@t{(symbol->string 'flying-fish) \n"
453 " ==> \"flying-fish\"\n"
454 "(symbol->string 'Martin) ==> \"martin\"\n"
456 " (string->symbol \"Malvina\")) \n"
460 #define FUNC_NAME s_scm_symbol_to_string
462 SCM_VALIDATE_SYMBOL (1, s
);
463 return scm_makfromstr (SCM_SYMBOL_CHARS (s
), SCM_LENGTH (s
), 0);
468 SCM_DEFINE (scm_string_to_symbol
, "string->symbol", 1, 0, 0,
470 "Returns the symbol whose name is @var{string}. This procedure can\n"
471 "create symbols with names containing special characters or letters in\n"
472 "the non-standard case, but it is usually a bad idea to create such\n"
473 "symbols because in some implementations of Scheme they cannot be read as\n"
474 "themselves. See @samp{symbol->string}.\n\n"
475 "The following examples assume that the implementation's standard case is\n"
478 "@t{(eq? 'mISSISSIppi 'mississippi) \n"
480 "(string->symbol \"mISSISSIppi\") \n"
482 " @r{}the symbol with name \"mISSISSIppi\"\n"
483 "(eq? 'bitBlt (string->symbol \"bitBlt\")) \n"
487 " (symbol->string 'JollyWog))) \n"
489 "(string=? \"K. Harper, M.D.\"\n"
491 " (string->symbol \"K. Harper, M.D.\"))) \n"
495 #define FUNC_NAME s_scm_string_to_symbol
500 SCM_VALIDATE_ROSTRING (1,s
);
501 vcell
= scm_intern(SCM_ROCHARS(s
), (scm_sizet
)SCM_LENGTH(s
));
502 answer
= SCM_CAR (vcell
);
508 SCM_DEFINE (scm_string_to_obarray_symbol
, "string->obarray-symbol", 2, 1, 0,
509 (SCM o
, SCM s
, SCM softp
),
510 "Intern a new symbol in @var{obarray}, a symbol table, with name\n"
512 "If @var{obarray} is @code{#f}, use the default system symbol table. If\n"
513 "@var{obarray} is @code{#t}, the symbol should not be interned in any\n"
514 "symbol table; merely return the pair (@var{symbol}\n"
515 ". @var{#<undefined>}).\n\n"
516 "The @var{soft?} argument determines whether new symbol table entries\n"
517 "should be created when the specified symbol is not already present in\n"
518 "@var{obarray}. If @var{soft?} is specified and is a true value, then\n"
519 "new entries should not be added for symbols not already present in the\n"
520 "table; instead, simply return @code{#f}.")
521 #define FUNC_NAME s_scm_string_to_obarray_symbol
527 SCM_VALIDATE_ROSTRING (2,s
);
528 SCM_ASSERT (SCM_BOOLP (o
) || SCM_VECTORP (o
), o
, SCM_ARG1
, FUNC_NAME
);
530 softness
= (!SCM_UNBNDP (softp
) && !SCM_FALSEP(softp
));
531 /* iron out some screwy calling conventions */
534 else if (SCM_EQ_P (o
, SCM_BOOL_T
))
537 vcell
= scm_intern_obarray_soft (SCM_ROCHARS(s
),
538 (scm_sizet
)SCM_ROLENGTH(s
),
541 if (SCM_FALSEP (vcell
))
543 answer
= SCM_CAR (vcell
);
548 SCM_DEFINE (scm_intern_symbol
, "intern-symbol", 2, 0, 0,
550 "Add a new symbol to @var{obarray} with name @var{string}, bound to an\n"
551 "unspecified initial value. The symbol table is not modified if a symbol\n"
552 "with this name is already present.")
553 #define FUNC_NAME s_scm_intern_symbol
556 SCM_VALIDATE_SYMBOL (2,s
);
559 SCM_VALIDATE_VECTOR (1,o
);
560 hval
= scm_string_hash (SCM_SYMBOL_UCHARS (s
), SCM_LENGTH (s
)) % SCM_LENGTH (o
);
561 /* If the symbol is already interned, simply return. */
566 for (lsym
= SCM_VELTS (o
)[hval
];
568 lsym
= SCM_CDR (lsym
))
570 sym
= SCM_CAR (lsym
);
571 if (SCM_EQ_P (SCM_CAR (sym
), s
))
574 return SCM_UNSPECIFIED
;
577 SCM_VELTS (o
)[hval
] =
578 scm_acons (s
, SCM_UNDEFINED
, SCM_VELTS (o
)[hval
]);
581 return SCM_UNSPECIFIED
;
585 SCM_DEFINE (scm_unintern_symbol
, "unintern-symbol", 2, 0, 0,
587 "Remove the symbol with name @var{string} from @var{obarray}. This\n"
588 "function returns @code{#t} if the symbol was present and @code{#f}\n"
590 #define FUNC_NAME s_scm_unintern_symbol
593 SCM_VALIDATE_SYMBOL (2,s
);
596 SCM_VALIDATE_VECTOR (1,o
);
597 hval
= scm_string_hash (SCM_SYMBOL_UCHARS (s
), SCM_LENGTH (s
)) % SCM_LENGTH (o
);
603 for (lsym
= SCM_VELTS (o
)[hval
], lsym_follow
= SCM_BOOL_F
;
605 lsym_follow
= lsym
, lsym
= SCM_CDR (lsym
))
607 sym
= SCM_CAR (lsym
);
608 if (SCM_EQ_P (SCM_CAR (sym
), s
))
610 /* Found the symbol to unintern. */
611 if (SCM_FALSEP (lsym_follow
))
612 SCM_VELTS(o
)[hval
] = lsym
;
614 SCM_SETCDR (lsym_follow
, SCM_CDR(lsym
));
625 SCM_DEFINE (scm_symbol_binding
, "symbol-binding", 2, 0, 0,
627 "Look up in @var{obarray} the symbol whose name is @var{string}, and\n"
628 "return the value to which it is bound. If @var{obarray} is @code{#f},\n"
629 "use the global symbol table. If @var{string} is not interned in\n"
630 "@var{obarray}, an error is signalled.")
631 #define FUNC_NAME s_scm_symbol_binding
634 SCM_VALIDATE_SYMBOL (2,s
);
637 SCM_VALIDATE_VECTOR (1,o
);
638 vcell
= scm_sym2ovcell (s
, o
);
639 return SCM_CDR(vcell
);
644 SCM_DEFINE (scm_symbol_interned_p
, "symbol-interned?", 2, 0, 0,
646 "Return @var{#t} if @var{obarray} contains a symbol with name\n"
647 "@var{string}, and @var{#f} otherwise.")
648 #define FUNC_NAME s_scm_symbol_interned_p
651 SCM_VALIDATE_SYMBOL (2,s
);
654 SCM_VALIDATE_VECTOR (1,o
);
655 vcell
= scm_sym2ovcell_soft (s
, o
);
656 if (SCM_IMP (vcell
) && SCM_EQ_P (o
, scm_symhash
))
657 vcell
= scm_sym2ovcell_soft (s
, scm_weak_symhash
);
658 return (SCM_NIMP(vcell
)
665 SCM_DEFINE (scm_symbol_bound_p
, "symbol-bound?", 2, 0, 0,
667 "Return @var{#t} if @var{obarray} contains a symbol with name\n"
668 "@var{string} bound to a defined value. This differs from\n"
669 "@var{symbol-bound?} in that the mere mention of a symbol usually causes\n"
670 "it to be interned; @code{symbol-bound?} determines whether a symbol has\n"
671 "been given any meaningful value.")
672 #define FUNC_NAME s_scm_symbol_bound_p
675 SCM_VALIDATE_SYMBOL (2,s
);
678 SCM_VALIDATE_VECTOR (1,o
);
679 vcell
= scm_sym2ovcell_soft (s
, o
);
680 return SCM_BOOL (SCM_NIMP (vcell
) && !SCM_UNBNDP (SCM_CDR (vcell
)));
685 SCM_DEFINE (scm_symbol_set_x
, "symbol-set!", 3, 0, 0,
686 (SCM o
, SCM s
, SCM v
),
687 "Find the symbol in @var{obarray} whose name is @var{string}, and rebind\n"
688 "it to @var{value}. An error is signalled if @var{string} is not present\n"
690 #define FUNC_NAME s_scm_symbol_set_x
693 SCM_VALIDATE_SYMBOL (2,s
);
696 SCM_VALIDATE_VECTOR (1,o
);
697 vcell
= scm_sym2ovcell (s
, o
);
698 SCM_SETCDR (vcell
, v
);
699 return SCM_UNSPECIFIED
;
704 SCM_DEFINE (scm_symbol_fref
, "symbol-fref", 1, 0, 0,
706 "Return the contents of @var{symbol}'s @dfn{function slot}.")
707 #define FUNC_NAME s_scm_symbol_fref
709 SCM_VALIDATE_SYMBOL (1,s
);
710 return SCM_SYMBOL_FUNC (s
);
715 SCM_DEFINE (scm_symbol_pref
, "symbol-pref", 1, 0, 0,
717 "Return the @dfn{property list} currently associated with @var{symbol}.")
718 #define FUNC_NAME s_scm_symbol_pref
720 SCM_VALIDATE_SYMBOL (1,s
);
721 return SCM_SYMBOL_PROPS (s
);
726 SCM_DEFINE (scm_symbol_fset_x
, "symbol-fset!", 2, 0, 0,
728 "Change the binding of @var{symbol}'s function slot.")
729 #define FUNC_NAME s_scm_symbol_fset_x
731 SCM_VALIDATE_SYMBOL (1,s
);
732 SCM_SET_SYMBOL_FUNC (s
, val
);
733 return SCM_UNSPECIFIED
;
738 SCM_DEFINE (scm_symbol_pset_x
, "symbol-pset!", 2, 0, 0,
740 "Change the binding of @var{symbol}'s property slot.")
741 #define FUNC_NAME s_scm_symbol_pset_x
743 SCM_VALIDATE_SYMBOL (1,s
);
745 SCM_SET_SYMBOL_PROPS (s
, val
);
747 return SCM_UNSPECIFIED
;
752 SCM_DEFINE (scm_symbol_hash
, "symbol-hash", 1, 0, 0,
754 "Return a hash value for @var{symbol}.")
755 #define FUNC_NAME s_scm_symbol_hash
757 SCM_VALIDATE_SYMBOL (1, symbol
);
758 return SCM_MAKINUM (SCM_SYMBOL_HASH (symbol
));
764 copy_and_prune_obarray (SCM from
, SCM to
)
767 int length
= SCM_LENGTH (from
);
768 for (i
= 0; i
< length
; ++i
)
770 SCM head
= SCM_VELTS (from
)[i
]; /* GC protection */
774 while (SCM_NIMP (ls
))
776 if (!SCM_UNBNDP (SCM_CDAR (ls
)))
778 *lloc
= scm_cons (SCM_CAR (ls
), SCM_EOL
);
779 lloc
= SCM_CDRLOC (*lloc
);
783 SCM_VELTS (to
)[i
] = res
;
788 SCM_DEFINE (scm_builtin_bindings
, "builtin-bindings", 0, 0, 0,
790 "Create and return a copy of the global symbol table, removing all\n"
792 #define FUNC_NAME s_scm_builtin_bindings
794 int length
= SCM_LENGTH (scm_symhash
);
795 SCM obarray
= scm_make_vector (SCM_MAKINUM (length
), SCM_EOL
);
796 copy_and_prune_obarray (scm_symhash
, obarray
);
802 SCM_DEFINE (scm_builtin_weak_bindings
, "builtin-weak-bindings", 0, 0, 0,
805 #define FUNC_NAME s_scm_builtin_weak_bindings
807 int length
= SCM_LENGTH (scm_weak_symhash
);
808 SCM obarray
= scm_make_doubly_weak_hash_table (SCM_MAKINUM (length
));
809 copy_and_prune_obarray (scm_weak_symhash
, obarray
);
814 #define MAX_PREFIX_LENGTH 30
816 static int gensym_counter
;
818 SCM_DEFINE (scm_gensym
, "gensym", 0, 1, 0,
820 "Create a new symbol with name constructed from a prefix and a counter value.\n"
821 "The string PREFIX can be specified as an optional argument.\n"
822 "Default prefix is @code{g}. The counter is increased by 1 at each call.\n"
823 "There is no provision for resetting the counter.")
824 #define FUNC_NAME s_scm_gensym
826 char buf
[MAX_PREFIX_LENGTH
+ SCM_INTBUFLEN
];
829 if (SCM_UNBNDP (prefix
))
836 SCM_VALIDATE_STRINGORSUBSTR (1, prefix
);
837 len
= SCM_ROLENGTH (prefix
);
838 if (len
> MAX_PREFIX_LENGTH
)
839 name
= SCM_MUST_MALLOC (MAX_PREFIX_LENGTH
+ SCM_INTBUFLEN
);
840 strncpy (name
, SCM_ROCHARS (prefix
), len
);
843 int n_digits
= scm_iint2str (gensym_counter
++, 10, &name
[len
]);
844 SCM res
= SCM_CAR (scm_intern (name
, len
+ n_digits
));
846 scm_must_free (name
);
852 static int gentemp_counter
;
854 SCM_DEFINE (scm_gentemp
, "gentemp", 0, 2, 0,
855 (SCM prefix
, SCM obarray
),
856 "Create a new symbol with a name unique in an obarray.\n"
857 "The name is constructed from an optional string PREFIX and a counter\n"
858 "value. The default prefix is @var{t}. The OBARRAY is specified as a\n"
859 "second optional argument. Default is the system obarray where all\n"
860 "normal symbols are interned. The counter is increased by 1 at each\n"
861 "call. There is no provision for resetting the counter.")
862 #define FUNC_NAME s_scm_gentemp
864 char buf
[MAX_PREFIX_LENGTH
+ SCM_INTBUFLEN
];
867 if (SCM_UNBNDP (prefix
))
874 SCM_VALIDATE_STRINGORSUBSTR (1, prefix
);
875 len
= SCM_ROLENGTH (prefix
);
876 if (len
> MAX_PREFIX_LENGTH
)
877 name
= SCM_MUST_MALLOC (MAX_PREFIX_LENGTH
+ SCM_INTBUFLEN
);
878 strncpy (name
, SCM_ROCHARS (prefix
), len
);
881 if (SCM_UNBNDP (obarray
))
882 obarray
= scm_symhash
;
884 SCM_ASSERT ((SCM_VECTORP (obarray
) || SCM_WVECTP (obarray
)),
889 n_digits
= scm_iint2str (gentemp_counter
++, 10, &name
[len
]);
890 while (!SCM_FALSEP (scm_intern_obarray_soft (name
,
895 SCM vcell
= scm_intern_obarray_soft (name
,
900 scm_must_free (name
);
901 return SCM_CAR (vcell
);
911 #include "libguile/symbols.x"