libguile/strorder.c

   1 /*      Copyright (C) 1995, 1996, 1999, 2000 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 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
  43    gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
  44 \f
  45
  46 #include <stdio.h>
  47 #include "libguile/_scm.h"
  48 #include "libguile/chars.h"
  49 #include "libguile/strings.h"
  50 #include "libguile/symbols.h"
  51
  52 #include "libguile/validate.h"
  53 #include "libguile/strorder.h"
  54 \f
  55
  56 SCM_DEFINE1 (scm_string_equal_p, "string=?", scm_tc7_rpsubr,
  57              (SCM s1, SCM s2),
  58              "Lexicographic equality predicate; \n"
  59              "Returns @t{#t} if the two strings are the same length and contain the same\n"
  60              "characters in the same positions, otherwise returns @t{#f}. (r5rs)\n\n"
  61              "@samp{String-ci=?} treats\n"
  62              "upper and lower case letters as though they were the same character, but\n"
  63              "@samp{string=?} treats upper and lower case as distinct characters.")
  64 #define FUNC_NAME s_scm_string_equal_p
  65 {
  66   scm_sizet length;
  67
  68   SCM_VALIDATE_STRING (1, s1);
  69   SCM_VALIDATE_STRING (2, s2);
  70
  71   length = SCM_STRING_LENGTH (s2);
  72   if (SCM_STRING_LENGTH (s1) == length)
  73     {
  74       unsigned char *c1 = SCM_ROUCHARS (s1) + length - 1;
  75       unsigned char *c2 = SCM_ROUCHARS (s2) + length - 1;
  76       scm_sizet i;
  77
  78       /* comparing from back to front typically finds mismatches faster */
  79       for (i = 0; i != length; ++i, --c1, --c2)
  80         if (*c1 != *c2)
  81           return SCM_BOOL_F;
  82
  83       return SCM_BOOL_T;
  84     }
  85   else
  86     {
  87       return SCM_BOOL_F;
  88     }
  89 }
  90 #undef FUNC_NAME
  91
  92
  93 SCM_DEFINE1 (scm_string_ci_equal_p, "string-ci=?", scm_tc7_rpsubr,
  94              (SCM s1, SCM s2),
  95              "Case-insensitive string equality predicate; returns @t{#t} if\n"
  96              "the two strings are the same length and their component characters\n"
  97              "match (ignoring case) at each position; otherwise returns @t{#f}. (r5rs)")
  98 #define FUNC_NAME s_scm_string_ci_equal_p
  99 {
 100   scm_sizet length;
 101
 102   SCM_VALIDATE_STRING (1, s1);
 103   SCM_VALIDATE_STRING (2, s2);
 104
 105   length = SCM_STRING_LENGTH (s2);
 106   if (SCM_STRING_LENGTH (s1) == length)
 107     {
 108       unsigned char *c1 = SCM_ROUCHARS (s1) + length - 1;
 109       unsigned char *c2 = SCM_ROUCHARS (s2) + length - 1;
 110       scm_sizet i;
 111
 112       /* comparing from back to front typically finds mismatches faster */
 113       for (i = 0; i != length; ++i, --c1, --c2)
 114         if (scm_upcase (*c1) != scm_upcase (*c2))
 115           return SCM_BOOL_F;
 116
 117       return SCM_BOOL_T;
 118     }
 119   else
 120     {
 121       return SCM_BOOL_F;
 122     }
 123 }
 124 #undef FUNC_NAME
 125
 126
 127 SCM_DEFINE1 (scm_string_less_p, "string<?", scm_tc7_rpsubr,
 128              (SCM s1, SCM s2),
 129              "Lexicographic ordering predicate; returns @t{#t} if @var{s1}\n"
 130              "is lexicographically less than @var{s2}.  (r5rs)")
 131 #define FUNC_NAME s_scm_string_less_p
 132 {
 133   scm_sizet i, length1, length2, lengthm;
 134   unsigned char *c1, *c2;
 135
 136   SCM_VALIDATE_STRING (1, s1);
 137   SCM_VALIDATE_STRING (2, s2);
 138
 139   length1 = SCM_STRING_LENGTH (s1);
 140   length2 = SCM_STRING_LENGTH (s2);
 141   lengthm = min (length1, length2);
 142   c1 = SCM_ROUCHARS (s1);
 143   c2 = SCM_ROUCHARS (s2);
 144
 145   for (i = 0; i != lengthm; ++i, ++c1, ++c2) {
 146     int c = *c1 - *c2;
 147     if (c < 0) return SCM_BOOL_T;
 148     if (c > 0) return SCM_BOOL_F;
 149   }
 150
 151   return SCM_BOOL (length1 < length2);
 152 }
 153 #undef FUNC_NAME
 154
 155
 156 SCM_DEFINE1 (scm_string_leq_p, "string<=?", scm_tc7_rpsubr,
 157              (SCM s1, SCM s2),
 158              "Lexicographic ordering predicate; returns @t{#t} if @var{s1}\n"
 159              "is lexicographically less than or equal to @var{s2}.  (r5rs)")
 160 #define FUNC_NAME s_scm_string_leq_p
 161 {
 162   return SCM_BOOL_NOT (scm_string_less_p (s2, s1));
 163 }
 164 #undef FUNC_NAME
 165
 166
 167 SCM_DEFINE1 (scm_string_gr_p, "string>?", scm_tc7_rpsubr,
 168              (SCM s1, SCM s2),
 169              "Lexicographic ordering predicate; returns @t{#t} if @var{s1}\n"
 170              "is lexicographically greater than @var{s2}.  (r5rs)")
 171 #define FUNC_NAME s_scm_string_gr_p
 172 {
 173   return scm_string_less_p (s2, s1);
 174 }
 175 #undef FUNC_NAME
 176
 177
 178 SCM_DEFINE1 (scm_string_geq_p, "string>=?", scm_tc7_rpsubr,
 179              (SCM s1, SCM s2),
 180              "Lexicographic ordering predicate; returns @t{#t} if @var{s1}\n"
 181              "is lexicographically greater than or equal to @var{s2}.  (r5rs)")
 182 #define FUNC_NAME s_scm_string_geq_p
 183 {
 184   return SCM_BOOL_NOT (scm_string_less_p (s1, s2));
 185 }
 186 #undef FUNC_NAME
 187
 188
 189 SCM_DEFINE1 (scm_string_ci_less_p, "string-ci<?", scm_tc7_rpsubr,
 190              (SCM s1, SCM s2),
 191              "Case insensitive lexicographic ordering predicate; \n"
 192              "returns @t{#t} if @var{s1} is lexicographically less than\n"
 193              "@var{s2} regardless of case.  (r5rs)")
 194 #define FUNC_NAME s_scm_string_ci_less_p
 195 {
 196   scm_sizet i, length1, length2, lengthm;
 197   unsigned char *c1, *c2;
 198
 199   SCM_VALIDATE_STRING (1, s1);
 200   SCM_VALIDATE_STRING (2, s2);
 201
 202   length1 = SCM_STRING_LENGTH (s1);
 203   length2 = SCM_STRING_LENGTH (s2);
 204   lengthm = min (length1, length2);
 205   c1 = SCM_ROUCHARS (s1);
 206   c2 = SCM_ROUCHARS (s2);
 207
 208   for (i = 0; i != lengthm; ++i, ++c1, ++c2) {
 209     int c = scm_upcase (*c1) - scm_upcase (*c2);
 210     if (c < 0) return SCM_BOOL_T;
 211     if (c > 0) return SCM_BOOL_F;
 212   }
 213
 214   return SCM_BOOL (length1 < length2);
 215 }
 216 #undef FUNC_NAME
 217
 218
 219 SCM_DEFINE1 (scm_string_ci_leq_p, "string-ci<=?", scm_tc7_rpsubr,
 220              (SCM s1, SCM s2),
 221              "Case insensitive lexicographic ordering predicate; \n"
 222              "returns @t{#t} if @var{s1} is lexicographically less than\n"
 223              "or equal to @var{s2} regardless of case.  (r5rs)")
 224 #define FUNC_NAME s_scm_string_ci_leq_p
 225 {
 226   return SCM_BOOL_NOT (scm_string_ci_less_p (s2, s1));
 227 }
 228 #undef FUNC_NAME
 229
 230
 231 SCM_DEFINE1 (scm_string_ci_gr_p, "string-ci>?", scm_tc7_rpsubr,
 232              (SCM s1, SCM s2),
 233              "Case insensitive lexicographic ordering predicate; \n"
 234              "returns @t{#t} if @var{s1} is lexicographically greater than\n"
 235              "@var{s2} regardless of case.  (r5rs)")
 236 #define FUNC_NAME s_scm_string_ci_gr_p
 237 {
 238   return scm_string_ci_less_p (s2, s1);
 239 }
 240 #undef FUNC_NAME
 241
 242
 243 SCM_DEFINE1 (scm_string_ci_geq_p, "string-ci>=?", scm_tc7_rpsubr,
 244              (SCM s1, SCM s2),
 245              "Case insensitive lexicographic ordering predicate; \n"
 246              "returns @t{#t} if @var{s1} is lexicographically greater than\n"
 247              "or equal to @var{s2} regardless of case.  (r5rs)")
 248 #define FUNC_NAME s_scm_string_ci_geq_p
 249 {
 250   return SCM_BOOL_NOT (scm_string_ci_less_p (s1, s2));
 251 }
 252 #undef FUNC_NAME
 253
 254 \f
 255
 256 void
 257 scm_init_strorder ()
 258 {
 259 #include "libguile/strorder.x"
 260 }
 261
 262
 263 /*
 264   Local Variables:
 265   c-file-style: "gnu"
 266   End:
 267 */