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
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
8 * This library 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 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 02110-1301 USA
24 #include "libguile/_scm.h"
25 #include "libguile/chars.h"
26 #include "libguile/eval.h"
27 #include "libguile/hash.h"
28 #include "libguile/smob.h"
29 #include "libguile/variable.h"
30 #include "libguile/alist.h"
31 #include "libguile/fluids.h"
32 #include "libguile/strings.h"
33 #include "libguile/vectors.h"
34 #include "libguile/hashtab.h"
35 #include "libguile/weaks.h"
36 #include "libguile/modules.h"
37 #include "libguile/read.h"
38 #include "libguile/srfi-13.h"
40 #include "libguile/validate.h"
41 #include "libguile/symbols.h"
52 SCM_DEFINE (scm_sys_symbols, "%symbols", 0, 0, 0,
54 "Return the system symbol obarray.")
55 #define FUNC_NAME s_scm_sys_symbols
67 /* In order to optimize reading speed, this function breaks part of
68 * the hashtable abstraction. The optimizations are:
70 * 1. The argument string can be compared directly to symbol objects
71 * without first creating an SCM string object. (This would have
72 * been necessary if we had used the hashtable API in hashtab.h.)
74 * 2. We can use the raw hash value stored in scm_i_symbol_hash (sym)
77 * Both optimizations might be possible without breaking the
78 * abstraction if the API in hashtab.c is improved.
82 scm_i_hash_symbol (SCM obj, unsigned long n, void *closure)
84 return scm_i_symbol_hash (obj) % n;
88 lookup_interned_symbol (const char *name, size_t len,
89 unsigned long raw_hash)
91 /* Try to find the symbol in the symbols table */
93 unsigned long hash = raw_hash % SCM_HASHTABLE_N_BUCKETS (symbols);
95 for (l = SCM_HASHTABLE_BUCKET (symbols, hash);
99 SCM sym = SCM_CAAR (l);
100 if (scm_i_symbol_hash (sym) == raw_hash
101 && scm_i_symbol_length (sym) == len)
103 const char *chrs = scm_i_symbol_chars (sym);
109 if (name[i] != chrs[i])
122 /* Intern SYMBOL, an uninterned symbol. */
124 intern_symbol (SCM symbol)
129 hash = scm_i_symbol_hash (symbol) % SCM_HASHTABLE_N_BUCKETS (symbols);
130 slot = SCM_HASHTABLE_BUCKET (symbols, hash);
131 cell = scm_cons (symbol, SCM_UNDEFINED);
133 SCM_SET_HASHTABLE_BUCKET (symbols, hash, scm_cons (cell, slot));
134 SCM_HASHTABLE_INCREMENT (symbols);
136 if (SCM_HASHTABLE_N_ITEMS (symbols) > SCM_HASHTABLE_UPPER (symbols))
137 scm_i_rehash (symbols, scm_i_hash_symbol, 0, "intern_symbol");
141 scm_i_c_mem2symbol (const char *name, size_t len)
144 size_t raw_hash = scm_string_hash ((const unsigned char *) name, len);
146 symbol = lookup_interned_symbol (name, len, raw_hash);
147 if (scm_is_false (symbol))
149 /* The symbol was not found, create it. */
150 symbol = scm_i_c_make_symbol (name, len, 0, raw_hash,
151 scm_cons (SCM_BOOL_F, SCM_EOL));
152 intern_symbol (symbol);
159 scm_i_mem2symbol (SCM str)
162 const char *name = scm_i_string_chars (str);
163 size_t len = scm_i_string_length (str);
164 size_t raw_hash = scm_string_hash ((const unsigned char *) name, len);
166 symbol = lookup_interned_symbol (name, len, raw_hash);
167 if (scm_is_false (symbol))
169 /* The symbol was not found, create it. */
170 symbol = scm_i_make_symbol (str, 0, raw_hash,
171 scm_cons (SCM_BOOL_F, SCM_EOL));
172 intern_symbol (symbol);
180 scm_i_mem2uninterned_symbol (SCM str)
182 const char *name = scm_i_string_chars (str);
183 size_t len = scm_i_string_length (str);
184 size_t raw_hash = scm_string_hash ((const unsigned char *) name, len);
186 return scm_i_make_symbol (str, SCM_I_F_SYMBOL_UNINTERNED,
187 raw_hash, scm_cons (SCM_BOOL_F, SCM_EOL));
190 SCM_DEFINE (scm_symbol_p, "symbol?", 1, 0, 0,
192 "Return @code{#t} if @var{obj} is a symbol, otherwise return\n"
194 #define FUNC_NAME s_scm_symbol_p
196 return scm_from_bool (scm_is_symbol (obj));
200 SCM_DEFINE (scm_symbol_interned_p, "symbol-interned?", 1, 0, 0,
202 "Return @code{#t} if @var{symbol} is interned, otherwise return\n"
204 #define FUNC_NAME s_scm_symbol_interned_p
206 SCM_VALIDATE_SYMBOL (1, symbol);
207 return scm_from_bool (scm_i_symbol_is_interned (symbol));
211 SCM_DEFINE (scm_make_symbol, "make-symbol", 1, 0, 0,
213 "Return a new uninterned symbol with the name @var{name}. "
214 "The returned symbol is guaranteed to be unique and future "
215 "calls to @code{string->symbol} will not return it.")
216 #define FUNC_NAME s_scm_make_symbol
218 SCM_VALIDATE_STRING (1, name);
219 return scm_i_mem2uninterned_symbol (name);
223 SCM_DEFINE (scm_symbol_to_string, "symbol->string", 1, 0, 0,
225 "Return the name of @var{symbol} as a string. If the symbol was\n"
226 "part of an object returned as the value of a literal expression\n"
227 "(section @pxref{Literal expressions,,,r5rs, The Revised^5\n"
228 "Report on Scheme}) or by a call to the @code{read} procedure,\n"
229 "and its name contains alphabetic characters, then the string\n"
230 "returned will contain characters in the implementation's\n"
231 "preferred standard case---some implementations will prefer\n"
232 "upper case, others lower case. If the symbol was returned by\n"
233 "@code{string->symbol}, the case of characters in the string\n"
234 "returned will be the same as the case in the string that was\n"
235 "passed to @code{string->symbol}. It is an error to apply\n"
236 "mutation procedures like @code{string-set!} to strings returned\n"
237 "by this procedure.\n"
239 "The following examples assume that the implementation's\n"
240 "standard case is lower case:\n"
243 "(symbol->string 'flying-fish) @result{} \"flying-fish\"\n"
244 "(symbol->string 'Martin) @result{} \"martin\"\n"
246 " (string->symbol \"Malvina\")) @result{} \"Malvina\"\n"
248 #define FUNC_NAME s_scm_symbol_to_string
250 SCM_VALIDATE_SYMBOL (1, s);
251 return scm_i_symbol_substring (s, 0, scm_i_symbol_length (s));
256 SCM_DEFINE (scm_string_to_symbol, "string->symbol", 1, 0, 0,
258 "Return the symbol whose name is @var{string}. This procedure\n"
259 "can create symbols with names containing special characters or\n"
260 "letters in the non-standard case, but it is usually a bad idea\n"
261 "to create such symbols because in some implementations of\n"
262 "Scheme they cannot be read as themselves. See\n"
263 "@code{symbol->string}.\n"
265 "The following examples assume that the implementation's\n"
266 "standard case is lower case:\n"
269 "(eq? 'mISSISSIppi 'mississippi) @result{} #t\n"
270 "(string->symbol \"mISSISSIppi\") @result{} @r{the symbol with name \"mISSISSIppi\"}\n"
271 "(eq? 'bitBlt (string->symbol \"bitBlt\")) @result{} #f\n"
273 " (string->symbol (symbol->string 'JollyWog))) @result{} #t\n"
274 "(string=? \"K. Harper, M.D.\"\n"
276 " (string->symbol \"K. Harper, M.D.\"))) @result{}#t\n"
278 #define FUNC_NAME s_scm_string_to_symbol
280 SCM_VALIDATE_STRING (1, string);
281 return scm_i_mem2symbol (string);
285 SCM_DEFINE (scm_string_ci_to_symbol, "string-ci->symbol", 1, 0, 0,
287 "Return the symbol whose name is @var{str}. @var{str} is\n"
288 "converted to lowercase before the conversion is done, if Guile\n"
289 "is currently reading symbols case-insensitively.")
290 #define FUNC_NAME s_scm_string_ci_to_symbol
292 return scm_string_to_symbol (SCM_CASE_INSENSITIVE_P
293 ? scm_string_downcase(str)
298 #define MAX_PREFIX_LENGTH 30
300 SCM_DEFINE (scm_gensym, "gensym", 0, 1, 0,
302 "Create a new symbol with a name constructed from a prefix and\n"
303 "a counter value. The string @var{prefix} can be specified as\n"
304 "an optional argument. Default prefix is @code{ g}. The counter\n"
305 "is increased by 1 at each call. There is no provision for\n"
306 "resetting the counter.")
307 #define FUNC_NAME s_scm_gensym
309 static int gensym_counter = 0;
313 char buf[SCM_INTBUFLEN];
315 if (SCM_UNBNDP (prefix))
316 prefix = scm_from_locale_string (" g");
318 /* mutex in case another thread looks and incs at the exact same moment */
319 scm_i_scm_pthread_mutex_lock (&scm_i_misc_mutex);
320 n = gensym_counter++;
321 scm_i_pthread_mutex_unlock (&scm_i_misc_mutex);
323 n_digits = scm_iint2str (n, 10, buf);
324 suffix = scm_from_locale_stringn (buf, n_digits);
325 name = scm_string_append (scm_list_2 (prefix, suffix));
326 return scm_string_to_symbol (name);
330 SCM_DEFINE (scm_symbol_hash, "symbol-hash", 1, 0, 0,
332 "Return a hash value for @var{symbol}.")
333 #define FUNC_NAME s_scm_symbol_hash
335 SCM_VALIDATE_SYMBOL (1, symbol);
336 return scm_from_ulong (scm_i_symbol_hash (symbol));
340 SCM_DEFINE (scm_symbol_fref, "symbol-fref", 1, 0, 0,
342 "Return the contents of @var{symbol}'s @dfn{function slot}.")
343 #define FUNC_NAME s_scm_symbol_fref
345 SCM_VALIDATE_SYMBOL (1, s);
346 return SCM_CAR (SCM_CELL_OBJECT_3 (s));
351 SCM_DEFINE (scm_symbol_pref, "symbol-pref", 1, 0, 0,
353 "Return the @dfn{property list} currently associated with @var{symbol}.")
354 #define FUNC_NAME s_scm_symbol_pref
356 SCM_VALIDATE_SYMBOL (1, s);
357 return SCM_CDR (SCM_CELL_OBJECT_3 (s));
362 SCM_DEFINE (scm_symbol_fset_x, "symbol-fset!", 2, 0, 0,
364 "Change the binding of @var{symbol}'s function slot.")
365 #define FUNC_NAME s_scm_symbol_fset_x
367 SCM_VALIDATE_SYMBOL (1, s);
368 SCM_SETCAR (SCM_CELL_OBJECT_3 (s), val);
369 return SCM_UNSPECIFIED;
374 SCM_DEFINE (scm_symbol_pset_x, "symbol-pset!", 2, 0, 0,
376 "Change the binding of @var{symbol}'s property slot.")
377 #define FUNC_NAME s_scm_symbol_pset_x
379 SCM_VALIDATE_SYMBOL (1, s);
380 SCM_SETCDR (SCM_CELL_OBJECT_3 (s), val);
381 return SCM_UNSPECIFIED;
386 scm_from_locale_symbol (const char *sym)
388 return scm_i_c_mem2symbol (sym, strlen (sym));
392 scm_from_locale_symboln (const char *sym, size_t len)
394 return scm_i_c_mem2symbol (sym, len);
398 scm_take_locale_symboln (char *sym, size_t len)
401 unsigned long raw_hash;
403 if (len == (size_t)-1)
407 /* Ensure STR is null terminated. A realloc for 1 extra byte should
408 often be satisfied from the alignment padding after the block, with
409 no actual data movement. */
410 sym = scm_realloc (sym, len+1);
414 raw_hash = scm_string_hash ((unsigned char *)sym, len);
415 res = lookup_interned_symbol (sym, len, raw_hash);
416 if (scm_is_false (res))
418 res = scm_i_c_take_symbol (sym, len, 0, raw_hash,
419 scm_cons (SCM_BOOL_F, SCM_EOL));
429 scm_take_locale_symbol (char *sym)
431 return scm_take_locale_symboln (sym, (size_t)-1);
435 scm_symbols_prehistory ()
437 symbols = scm_make_weak_key_hash_table (scm_from_int (2139));
438 scm_permanent_object (symbols);
445 #include "libguile/symbols.x"