1 /* Copyright (C) 1995,1996,1997,1998,2000,2001, 2003, 2004, 2006, 2009 Free Software Foundation, Inc.
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public License
5 * as published by the Free Software Foundation; either version 3 of
6 * the License, or (at your option) any later version.
8 * This library is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
25 #include "libguile/_scm.h"
26 #include "libguile/chars.h"
27 #include "libguile/eval.h"
28 #include "libguile/hash.h"
29 #include "libguile/smob.h"
30 #include "libguile/variable.h"
31 #include "libguile/alist.h"
32 #include "libguile/fluids.h"
33 #include "libguile/strings.h"
34 #include "libguile/vectors.h"
35 #include "libguile/hashtab.h"
36 #include "libguile/weaks.h"
37 #include "libguile/modules.h"
38 #include "libguile/read.h"
39 #include "libguile/srfi-13.h"
41 #include "libguile/validate.h"
42 #include "libguile/symbols.h"
44 #include "libguile/private-options.h"
56 SCM_DEFINE (scm_sys_symbols
, "%symbols", 0, 0, 0,
58 "Return the system symbol obarray.")
59 #define FUNC_NAME s_scm_sys_symbols
71 /* In order to optimize reading speed, this function breaks part of
72 * the hashtable abstraction. The optimizations are:
74 * 1. The argument string can be compared directly to symbol objects
75 * without first creating an SCM string object. (This would have
76 * been necessary if we had used the hashtable API in hashtab.h.)
78 * 2. We can use the raw hash value stored in scm_i_symbol_hash (sym)
81 * Both optimizations might be possible without breaking the
82 * abstraction if the API in hashtab.c is improved.
86 scm_i_hash_symbol (SCM obj
, unsigned long n
, void *closure
)
88 return scm_i_symbol_hash (obj
) % n
;
92 lookup_interned_symbol (SCM name
, unsigned long raw_hash
)
94 /* Try to find the symbol in the symbols table */
96 size_t len
= scm_i_string_length (name
);
97 unsigned long hash
= raw_hash
% SCM_HASHTABLE_N_BUCKETS (symbols
);
99 for (l
= SCM_HASHTABLE_BUCKET (symbols
, hash
);
103 SCM sym
= SCM_CAAR (l
);
104 if (scm_i_symbol_hash (sym
) == raw_hash
105 && scm_i_symbol_length (sym
) == len
)
109 /* Slightly faster path for comparing narrow to narrow. */
110 if (scm_i_is_narrow_string (name
) && scm_i_is_narrow_symbol (sym
))
112 const char *chrs
= scm_i_symbol_chars (sym
);
113 const char *str
= scm_i_string_chars (name
);
118 if (str
[i
] != chrs
[i
])
124 /* Somewhat slower path for comparing narrow to wide or
129 if (scm_i_string_ref (name
, i
) != scm_i_symbol_ref (sym
, i
))
143 /* Intern SYMBOL, an uninterned symbol. */
145 intern_symbol (SCM symbol
)
150 hash
= scm_i_symbol_hash (symbol
) % SCM_HASHTABLE_N_BUCKETS (symbols
);
151 slot
= SCM_HASHTABLE_BUCKET (symbols
, hash
);
152 cell
= scm_cons (symbol
, SCM_UNDEFINED
);
154 SCM_SET_HASHTABLE_BUCKET (symbols
, hash
, scm_cons (cell
, slot
));
155 SCM_HASHTABLE_INCREMENT (symbols
);
157 if (SCM_HASHTABLE_N_ITEMS (symbols
) > SCM_HASHTABLE_UPPER (symbols
))
158 scm_i_rehash (symbols
, scm_i_hash_symbol
, 0, "intern_symbol");
162 scm_i_str2symbol (SCM str
)
165 size_t raw_hash
= scm_i_string_hash (str
);
167 symbol
= lookup_interned_symbol (str
, raw_hash
);
168 if (scm_is_false (symbol
))
170 /* The symbol was not found, create it. */
171 symbol
= scm_i_make_symbol (str
, 0, raw_hash
,
172 scm_cons (SCM_BOOL_F
, SCM_EOL
));
173 intern_symbol (symbol
);
181 scm_i_str2uninterned_symbol (SCM str
)
183 size_t raw_hash
= scm_i_string_hash (str
);
185 return scm_i_make_symbol (str
, SCM_I_F_SYMBOL_UNINTERNED
,
186 raw_hash
, scm_cons (SCM_BOOL_F
, SCM_EOL
));
189 SCM_DEFINE (scm_symbol_p
, "symbol?", 1, 0, 0,
191 "Return @code{#t} if @var{obj} is a symbol, otherwise return\n"
193 #define FUNC_NAME s_scm_symbol_p
195 return scm_from_bool (scm_is_symbol (obj
));
199 SCM_DEFINE (scm_symbol_interned_p
, "symbol-interned?", 1, 0, 0,
201 "Return @code{#t} if @var{symbol} is interned, otherwise return\n"
203 #define FUNC_NAME s_scm_symbol_interned_p
205 SCM_VALIDATE_SYMBOL (1, symbol
);
206 return scm_from_bool (scm_i_symbol_is_interned (symbol
));
210 SCM_DEFINE (scm_make_symbol
, "make-symbol", 1, 0, 0,
212 "Return a new uninterned symbol with the name @var{name}. "
213 "The returned symbol is guaranteed to be unique and future "
214 "calls to @code{string->symbol} will not return it.")
215 #define FUNC_NAME s_scm_make_symbol
217 SCM_VALIDATE_STRING (1, name
);
218 return scm_i_str2uninterned_symbol (name
);
222 SCM_DEFINE (scm_symbol_to_string
, "symbol->string", 1, 0, 0,
224 "Return the name of @var{symbol} as a string. If the symbol was\n"
225 "part of an object returned as the value of a literal expression\n"
226 "(section @pxref{Literal expressions,,,r5rs, The Revised^5\n"
227 "Report on Scheme}) or by a call to the @code{read} procedure,\n"
228 "and its name contains alphabetic characters, then the string\n"
229 "returned will contain characters in the implementation's\n"
230 "preferred standard case---some implementations will prefer\n"
231 "upper case, others lower case. If the symbol was returned by\n"
232 "@code{string->symbol}, the case of characters in the string\n"
233 "returned will be the same as the case in the string that was\n"
234 "passed to @code{string->symbol}. It is an error to apply\n"
235 "mutation procedures like @code{string-set!} to strings returned\n"
236 "by this procedure.\n"
238 "The following examples assume that the implementation's\n"
239 "standard case is lower case:\n"
242 "(symbol->string 'flying-fish) @result{} \"flying-fish\"\n"
243 "(symbol->string 'Martin) @result{} \"martin\"\n"
245 " (string->symbol \"Malvina\")) @result{} \"Malvina\"\n"
247 #define FUNC_NAME s_scm_symbol_to_string
249 SCM_VALIDATE_SYMBOL (1, s
);
250 return scm_i_symbol_substring (s
, 0, scm_i_symbol_length (s
));
255 SCM_DEFINE (scm_string_to_symbol
, "string->symbol", 1, 0, 0,
257 "Return the symbol whose name is @var{string}. This procedure\n"
258 "can create symbols with names containing special characters or\n"
259 "letters in the non-standard case, but it is usually a bad idea\n"
260 "to create such symbols because in some implementations of\n"
261 "Scheme they cannot be read as themselves. See\n"
262 "@code{symbol->string}.\n"
264 "The following examples assume that the implementation's\n"
265 "standard case is lower case:\n"
268 "(eq? 'mISSISSIppi 'mississippi) @result{} #t\n"
269 "(string->symbol \"mISSISSIppi\") @result{} @r{the symbol with name \"mISSISSIppi\"}\n"
270 "(eq? 'bitBlt (string->symbol \"bitBlt\")) @result{} #f\n"
272 " (string->symbol (symbol->string 'JollyWog))) @result{} #t\n"
273 "(string=? \"K. Harper, M.D.\"\n"
275 " (string->symbol \"K. Harper, M.D.\"))) @result{}#t\n"
277 #define FUNC_NAME s_scm_string_to_symbol
279 SCM_VALIDATE_STRING (1, string
);
280 return scm_i_str2symbol (string
);
284 SCM_DEFINE (scm_string_ci_to_symbol
, "string-ci->symbol", 1, 0, 0,
286 "Return the symbol whose name is @var{str}. @var{str} is\n"
287 "converted to lowercase before the conversion is done, if Guile\n"
288 "is currently reading symbols case-insensitively.")
289 #define FUNC_NAME s_scm_string_ci_to_symbol
291 return scm_string_to_symbol (SCM_CASE_INSENSITIVE_P
292 ? scm_string_downcase(str
)
297 #define MAX_PREFIX_LENGTH 30
299 SCM_DEFINE (scm_gensym
, "gensym", 0, 1, 0,
301 "Create a new symbol with a name constructed from a prefix and\n"
302 "a counter value. The string @var{prefix} can be specified as\n"
303 "an optional argument. Default prefix is @code{ g}. The counter\n"
304 "is increased by 1 at each call. There is no provision for\n"
305 "resetting the counter.")
306 #define FUNC_NAME s_scm_gensym
308 static int gensym_counter
= 0;
312 char buf
[SCM_INTBUFLEN
];
314 if (SCM_UNBNDP (prefix
))
315 prefix
= scm_from_locale_string (" g");
317 /* mutex in case another thread looks and incs at the exact same moment */
318 scm_i_scm_pthread_mutex_lock (&scm_i_misc_mutex
);
319 n
= gensym_counter
++;
320 scm_i_pthread_mutex_unlock (&scm_i_misc_mutex
);
322 n_digits
= scm_iint2str (n
, 10, buf
);
323 suffix
= scm_from_locale_stringn (buf
, n_digits
);
324 name
= scm_string_append (scm_list_2 (prefix
, suffix
));
325 return scm_string_to_symbol (name
);
329 SCM_DEFINE (scm_symbol_hash
, "symbol-hash", 1, 0, 0,
331 "Return a hash value for @var{symbol}.")
332 #define FUNC_NAME s_scm_symbol_hash
334 SCM_VALIDATE_SYMBOL (1, symbol
);
335 return scm_from_ulong (scm_i_symbol_hash (symbol
));
339 SCM_DEFINE (scm_symbol_fref
, "symbol-fref", 1, 0, 0,
341 "Return the contents of @var{symbol}'s @dfn{function slot}.")
342 #define FUNC_NAME s_scm_symbol_fref
344 SCM_VALIDATE_SYMBOL (1, s
);
345 return SCM_CAR (SCM_CELL_OBJECT_3 (s
));
350 SCM_DEFINE (scm_symbol_pref
, "symbol-pref", 1, 0, 0,
352 "Return the @dfn{property list} currently associated with @var{symbol}.")
353 #define FUNC_NAME s_scm_symbol_pref
355 SCM_VALIDATE_SYMBOL (1, s
);
356 return SCM_CDR (SCM_CELL_OBJECT_3 (s
));
361 SCM_DEFINE (scm_symbol_fset_x
, "symbol-fset!", 2, 0, 0,
363 "Change the binding of @var{symbol}'s function slot.")
364 #define FUNC_NAME s_scm_symbol_fset_x
366 SCM_VALIDATE_SYMBOL (1, s
);
367 SCM_SETCAR (SCM_CELL_OBJECT_3 (s
), val
);
368 return SCM_UNSPECIFIED
;
373 SCM_DEFINE (scm_symbol_pset_x
, "symbol-pset!", 2, 0, 0,
375 "Change the binding of @var{symbol}'s property slot.")
376 #define FUNC_NAME s_scm_symbol_pset_x
378 SCM_VALIDATE_SYMBOL (1, s
);
379 SCM_SETCDR (SCM_CELL_OBJECT_3 (s
), val
);
380 return SCM_UNSPECIFIED
;
385 scm_from_locale_symbol (const char *sym
)
387 return scm_from_locale_symboln (sym
, -1);
391 scm_from_locale_symboln (const char *sym
, size_t len
)
393 SCM str
= scm_from_locale_stringn (sym
, len
);
394 return scm_i_str2symbol (str
);
398 scm_take_locale_symboln (char *sym
, size_t len
)
402 str
= scm_take_locale_stringn (sym
, len
);
403 return scm_i_str2symbol (str
);
407 scm_take_locale_symbol (char *sym
)
409 return scm_take_locale_symboln (sym
, (size_t)-1);
413 scm_symbols_prehistory ()
415 symbols
= scm_make_weak_key_hash_table (scm_from_int (2139));
416 scm_permanent_object (symbols
);
423 #include "libguile/symbols.x"