libguile/strings.c

   1 /* Copyright (C) 1995,1996,1998,2000,2001 Free Software Foundation, Inc.
   2  *
   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)
   6  * any later version.
   7  *
   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.
  12  *
  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
  17  *
  18  * As a special exception, the Free Software Foundation gives permission
  19  * for additional uses of the text contained in its release of GUILE.
  20  *
  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.
  26  *
  27  * This exception does not however invalidate any other reasons why
  28  * the executable file might be covered by the GNU General Public License.
  29  *
  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.
  37  *
  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.  */
  41
  42
  43 \f
  44
  45 #include <string.h>
  46
  47 #include "libguile/_scm.h"
  48 #include "libguile/chars.h"
  49 #include "libguile/root.h"
  50 #include "libguile/strings.h"
  51 #include "libguile/deprecation.h"
  52 #include "libguile/validate.h"
  53
  54 \f
  55
  56 /* {Strings}
  57  */
  58
  59 SCM_DEFINE (scm_string_p, "string?", 1, 0, 0,
  60             (SCM obj),
  61             "Return @code{#t} iff @var{obj} is a string, else @code{#f}.")
  62 #define FUNC_NAME s_scm_string_p
  63 {
  64   return SCM_BOOL (SCM_STRINGP (obj));
  65 }
  66 #undef FUNC_NAME
  67
  68
  69 SCM_REGISTER_PROC (s_scm_list_to_string, "list->string", 1, 0, 0, scm_string);
  70
  71 SCM_DEFINE (scm_string, "string", 0, 0, 1,
  72             (SCM chrs),
  73             "@deffnx {Scheme Procedure} list->string chrs\n"
  74             "Return a newly allocated string composed of the arguments,\n"
  75             "@var{chrs}.")
  76 #define FUNC_NAME s_scm_string
  77 {
  78   SCM result;
  79
  80   {
  81     long i = scm_ilength (chrs);
  82
  83     SCM_ASSERT (i >= 0, chrs, SCM_ARG1, FUNC_NAME);
  84     result = scm_allocate_string (i);
  85   }
  86
  87   {
  88     unsigned char *data = SCM_STRING_UCHARS (result);
  89
  90     while (!SCM_NULLP (chrs))
  91       {
  92         SCM elt = SCM_CAR (chrs);
  93
  94         SCM_VALIDATE_CHAR (SCM_ARGn, elt);
  95         *data++ = SCM_CHAR (elt);
  96         chrs = SCM_CDR (chrs);
  97       }
  98   }
  99   return result;
 100 }
 101 #undef FUNC_NAME
 102
 103
 104 /* converts C scm_array of strings to SCM scm_list of strings. */
 105 /* If argc < 0, a null terminated scm_array is assumed. */
 106 SCM
 107 scm_makfromstrs (int argc, char **argv)
 108 {
 109   int i = argc;
 110   SCM lst = SCM_EOL;
 111   if (0 > i)
 112     for (i = 0; argv[i]; i++);
 113   while (i--)
 114     lst = scm_cons (scm_mem2string (argv[i], strlen (argv[i])), lst);
 115   return lst;
 116 }
 117
 118
 119 /* This function must only be applied to memory obtained via malloc,
 120    since the GC is going to apply `free' to it when the string is
 121    dropped.
 122
 123    Also, s[len] must be `\0', since we promise that strings are
 124    null-terminated.  Perhaps we could handle non-null-terminated
 125    strings by claiming they're shared substrings of a string we just
 126    made up.  */
 127 SCM
 128 scm_take_str (char *s, size_t len)
 129 #define FUNC_NAME "scm_take_str"
 130 {
 131   SCM answer;
 132
 133   SCM_ASSERT_RANGE (2, scm_ulong2num (len), len <= SCM_STRING_MAX_LENGTH);
 134
 135   answer = scm_alloc_cell (SCM_MAKE_STRING_TAG (len), (scm_t_bits) s);
 136   scm_done_malloc (len + 1);
 137
 138   return answer;
 139 }
 140 #undef FUNC_NAME
 141
 142
 143 /* `s' must be a malloc'd string.  See scm_take_str.  */
 144 SCM
 145 scm_take0str (char *s)
 146 {
 147   return scm_take_str (s, strlen (s));
 148 }
 149
 150
 151 SCM
 152 scm_mem2string (const char *src, size_t len)
 153 {
 154   SCM s = scm_allocate_string (len);
 155   char *dst = SCM_STRING_CHARS (s);
 156
 157   while (len--)
 158     *dst++ = *src++;
 159   return s;
 160 }
 161
 162
 163 SCM
 164 scm_str2string (const char *src)
 165 {
 166   return scm_mem2string (src, strlen (src));
 167 }
 168
 169
 170 SCM
 171 scm_makfrom0str (const char *src)
 172 {
 173   if (!src) return SCM_BOOL_F;
 174   return scm_mem2string (src, strlen (src));
 175 }
 176
 177
 178 SCM
 179 scm_makfrom0str_opt (const char *src)
 180 {
 181   return scm_makfrom0str (src);
 182 }
 183
 184
 185 SCM
 186 scm_allocate_string (size_t len)
 187 #define FUNC_NAME "scm_allocate_string"
 188 {
 189   char *mem;
 190   SCM s;
 191
 192   SCM_ASSERT_RANGE (1, scm_long2num (len), len <= SCM_STRING_MAX_LENGTH);
 193
 194   mem = (char *) scm_must_malloc (len + 1, FUNC_NAME);
 195   mem[len] = 0;
 196
 197   s = scm_alloc_cell (SCM_MAKE_STRING_TAG (len), (scm_t_bits) mem);
 198
 199   return s;
 200 }
 201 #undef FUNC_NAME
 202
 203
 204 SCM_DEFINE (scm_make_string, "make-string", 1, 1, 0,
 205             (SCM k, SCM chr),
 206             "Return a newly allocated string of\n"
 207             "length @var{k}.  If @var{chr} is given, then all elements of\n"
 208             "the string are initialized to @var{chr}, otherwise the contents\n"
 209             "of the @var{string} are unspecified.")
 210 #define FUNC_NAME s_scm_make_string
 211 {
 212   if (SCM_INUMP (k))
 213     {
 214       long int i = SCM_INUM (k);
 215       SCM res;
 216
 217       SCM_ASSERT_RANGE (1, k, i >= 0);
 218
 219       res = scm_allocate_string (i);
 220       if (!SCM_UNBNDP (chr))
 221         {
 222           unsigned char *dst;
 223
 224           SCM_VALIDATE_CHAR (2, chr);
 225
 226           dst = SCM_STRING_UCHARS (res);
 227           memset (dst, SCM_CHAR (chr), i);
 228         }
 229
 230       return res;
 231     }
 232   else if (SCM_BIGP (k))
 233     SCM_OUT_OF_RANGE (1, k);
 234   else
 235     SCM_WRONG_TYPE_ARG (1, k);
 236 }
 237 #undef FUNC_NAME
 238
 239
 240 SCM_DEFINE (scm_string_length, "string-length", 1, 0, 0,
 241             (SCM string),
 242             "Return the number of characters in @var{string}.")
 243 #define FUNC_NAME s_scm_string_length
 244 {
 245   SCM_VALIDATE_STRING (1, string);
 246   return SCM_MAKINUM (SCM_STRING_LENGTH (string));
 247 }
 248 #undef FUNC_NAME
 249
 250 SCM_DEFINE (scm_string_ref, "string-ref", 2, 0, 0,
 251             (SCM str, SCM k),
 252             "Return character @var{k} of @var{str} using zero-origin\n"
 253             "indexing. @var{k} must be a valid index of @var{str}.")
 254 #define FUNC_NAME s_scm_string_ref
 255 {
 256   long idx;
 257
 258   SCM_VALIDATE_STRING (1, str);
 259   SCM_VALIDATE_INUM_COPY (2, k, idx);
 260   SCM_ASSERT_RANGE (2, k, idx >= 0 && idx < SCM_STRING_LENGTH (str));
 261   return SCM_MAKE_CHAR (SCM_STRING_UCHARS (str)[idx]);
 262 }
 263 #undef FUNC_NAME
 264
 265
 266 SCM_DEFINE (scm_string_set_x, "string-set!", 3, 0, 0,
 267             (SCM str, SCM k, SCM chr),
 268             "Store @var{chr} in element @var{k} of @var{str} and return\n"
 269             "an unspecified value. @var{k} must be a valid index of\n"
 270             "@var{str}.")
 271 #define FUNC_NAME s_scm_string_set_x
 272 {
 273   SCM_VALIDATE_STRING (1, str);
 274   SCM_VALIDATE_INUM_RANGE (2,k,0,SCM_STRING_LENGTH(str));
 275   SCM_VALIDATE_CHAR (3,chr);
 276   SCM_STRING_UCHARS (str)[SCM_INUM (k)] = SCM_CHAR (chr);
 277   return SCM_UNSPECIFIED;
 278 }
 279 #undef FUNC_NAME
 280
 281
 282 SCM_DEFINE (scm_substring, "substring", 2, 1, 0,
 283             (SCM str, SCM start, SCM end),
 284             "Return a newly allocated string formed from the characters\n"
 285             "of @var{str} beginning with index @var{start} (inclusive) and\n"
 286             "ending with index @var{end} (exclusive).\n"
 287             "@var{str} must be a string, @var{start} and @var{end} must be\n"
 288             "exact integers satisfying:\n\n"
 289             "0 <= @var{start} <= @var{end} <= (string-length @var{str}).")
 290 #define FUNC_NAME s_scm_substring
 291 {
 292   long int from;
 293   long int to;
 294   SCM substr;
 295
 296   SCM_VALIDATE_STRING (1, str);
 297   SCM_VALIDATE_INUM (2, start);
 298   SCM_VALIDATE_INUM_DEF (3, end, SCM_STRING_LENGTH (str));
 299
 300   from = SCM_INUM (start);
 301   SCM_ASSERT_RANGE (2, start, 0 <= from && from <= SCM_STRING_LENGTH (str));
 302   to = SCM_INUM (end);
 303   SCM_ASSERT_RANGE (3, end, from <= to && to <= SCM_STRING_LENGTH (str));
 304
 305   substr = scm_mem2string (&SCM_STRING_CHARS (str)[from], to - from);
 306   scm_remember_upto_here_1 (str);
 307   return substr;
 308 }
 309 #undef FUNC_NAME
 310
 311
 312 SCM_DEFINE (scm_string_append, "string-append", 0, 0, 1,
 313             (SCM args),
 314             "Return a newly allocated string whose characters form the\n"
 315             "concatenation of the given strings, @var{args}.")
 316 #define FUNC_NAME s_scm_string_append
 317 {
 318   SCM res;
 319   size_t i = 0;
 320   register SCM l, s;
 321   register unsigned char *data;
 322
 323   SCM_VALIDATE_REST_ARGUMENT (args);
 324   for (l = args; !SCM_NULLP (l); l = SCM_CDR (l)) {
 325     s = SCM_CAR (l);
 326     SCM_VALIDATE_STRING (SCM_ARGn,s);
 327     i += SCM_STRING_LENGTH (s);
 328   }
 329   res = scm_allocate_string (i);
 330   data = SCM_STRING_UCHARS (res);
 331   for (l = args; !SCM_NULLP (l);l = SCM_CDR (l)) {
 332     s = SCM_CAR (l);
 333     for (i = 0;i<SCM_STRING_LENGTH (s);i++) *data++ = SCM_STRING_UCHARS (s)[i];
 334   }
 335   return res;
 336 }
 337 #undef FUNC_NAME
 338
 339
 340 void
 341 scm_init_strings ()
 342 {
 343   scm_nullstr = scm_allocate_string (0);
 344
 345 #ifndef SCM_MAGIC_SNARFER
 346 #include "libguile/strings.x"
 347 #endif
 348 }
 349
 350
 351 /*
 352   Local Variables:
 353   c-file-style: "gnu"
 354   End:
 355 */