libguile/eq.c

   1 /*      Copyright (C) 1995,1996,1997,1998, 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
  45 \f
  46 #include <stdio.h>
  47 #include "_scm.h"
  48 #include "ramap.h"
  49 #include "stackchk.h"
  50 #include "strorder.h"
  51 #include "async.h"
  52 #include "root.h"
  53 #include "smob.h"
  54 #include "unif.h"
  55 #include "vectors.h"
  56
  57 #include "validate.h"
  58 #include "eq.h"
  59 \f
  60 SCM_DEFINE1 (scm_eq_p, "eq?", scm_tc7_rpsubr,
  61              (SCM x, SCM y),
  62              "Return #t iff X references the same object as Y.\n"
  63              "`eq?' is similar to `eqv?' except that in some cases\n"
  64              "it is capable of discerning distinctions finer than\n"
  65              "those detectable by `eqv?'.\n")
  66 #define FUNC_NAME s_scm_eq_p
  67 {
  68   return SCM_BOOL(x==y);
  69 }
  70 #undef FUNC_NAME
  71
  72
  73 SCM_DEFINE1 (scm_eqv_p, "eqv?", scm_tc7_rpsubr,
  74              (SCM x, SCM y),
  75              "The `eqv?' procedure defines a useful equivalence relation on objects.\n"
  76              "Briefly, it returns #t if X and Y should normally be\n"
  77              "regarded as the same object.  This relation is left\n"
  78              "slightly open to interpretation, but works for comparing\n"
  79              "immediate integers, characters, and inexact numbers.\n")
  80 #define FUNC_NAME s_scm_eqv_p
  81 {
  82   if (x == y)
  83     return SCM_BOOL_T;
  84   if (SCM_IMP (x))
  85     return SCM_BOOL_F;
  86   if (SCM_IMP (y))
  87     return SCM_BOOL_F;
  88   /* this ensures that types and scm_length are the same. */
  89   if (SCM_CAR (x) != SCM_CAR (y))
  90     {
  91       /* treat mixes of real and complex types specially */
  92       if (SCM_SLOPPY_INEXACTP (x))
  93         {
  94           if (SCM_SLOPPY_REALP (x))
  95             return SCM_BOOL (SCM_SLOPPY_COMPLEXP (y)
  96                              && SCM_REAL_VALUE (x) == SCM_COMPLEX_REAL (y)
  97                              && 0.0 == SCM_COMPLEX_IMAG (y));
  98           else
  99             return SCM_BOOL (SCM_SLOPPY_REALP (y)
 100                              && SCM_COMPLEX_REAL (x) == SCM_REAL_VALUE (y)
 101                              && SCM_COMPLEX_IMAG (x) == 0.0);
 102         }
 103       return SCM_BOOL_F;
 104     }
 105   if (SCM_NUMP (x))
 106     {
 107 # ifdef SCM_BIGDIG
 108       if (SCM_BIGP (x))
 109         return SCM_BOOL (0 == scm_bigcomp (x, y));
 110 # endif
 111       if (SCM_REALPART (x) != SCM_REALPART(y)) return SCM_BOOL_F;
 112       if (SCM_CPLXP(x) && (SCM_IMAG(x) != SCM_IMAG(y))) return SCM_BOOL_F;
 113       return SCM_BOOL_T;
 114     }
 115   return SCM_BOOL_F;
 116 }
 117 #undef FUNC_NAME
 118
 119
 120 SCM_DEFINE1 (scm_equal_p, "equal?", scm_tc7_rpsubr,
 121              (SCM x, SCM y),
 122              "Return #t iff X and Y are recursively `eqv?' equivalent.\n"
 123              "`equal?' recursively compares the contents of pairs, vectors, and\n"
 124              "strings, applying `eqv?' on other objects such as numbers and\n"
 125              "symbols.  A rule of thumb is that objects are generally `equal?'\n"
 126              "if they print the same.  `Equal?' may fail to terminate if its\n"
 127              "arguments are circular data structures.\n")
 128 #define FUNC_NAME s_scm_equal_p
 129 {
 130   SCM_CHECK_STACK;
 131  tailrecurse:
 132   SCM_TICK;
 133   if (x == y)
 134     return SCM_BOOL_T;
 135   if (SCM_IMP (x))
 136     return SCM_BOOL_F;
 137   if (SCM_IMP (y))
 138     return SCM_BOOL_F;
 139   if (SCM_SLOPPY_CONSP (x) && SCM_SLOPPY_CONSP (y))
 140     {
 141       if (SCM_FALSEP (scm_equal_p (SCM_CAR (x), SCM_CAR (y))))
 142         return SCM_BOOL_F;
 143       x = SCM_CDR(x);
 144       y = SCM_CDR(y);
 145       goto tailrecurse;
 146     }
 147   if (SCM_TYP7S (x) == scm_tc7_string && SCM_TYP7S (y) == scm_tc7_string)
 148     return scm_string_equal_p (x, y);
 149   /* This ensures that types and scm_length are the same.  */
 150   if (SCM_CAR (x) != SCM_CAR (y))
 151     {
 152       /* treat mixes of real and complex types specially */
 153       if (SCM_SLOPPY_INEXACTP (x))
 154         {
 155           if (SCM_SLOPPY_REALP (x))
 156             return SCM_BOOL (SCM_SLOPPY_COMPLEXP (y)
 157                              && SCM_REAL_VALUE (x) == SCM_COMPLEX_REAL (y)
 158                              && 0.0 == SCM_COMPLEX_IMAG (y));
 159           else
 160             return SCM_BOOL (SCM_SLOPPY_REALP (y)
 161                              && SCM_COMPLEX_REAL (x) == SCM_REAL_VALUE (y)
 162                              && SCM_COMPLEX_IMAG (x) == 0.0);
 163         }
 164       return SCM_BOOL_F;
 165     }
 166   switch (SCM_TYP7 (x))
 167     {
 168     default:
 169       return SCM_BOOL_F;
 170     case scm_tc7_vector:
 171     case scm_tc7_wvect:
 172       return scm_vector_equal_p (x, y);
 173     case scm_tc7_smob:
 174       {
 175         int i = SCM_SMOBNUM (x);
 176         if (!(i < scm_numsmob))
 177           return SCM_BOOL_F;
 178         if (scm_smobs[i].equalp)
 179           return (scm_smobs[i].equalp) (x, y);
 180         else
 181           return SCM_BOOL_F;
 182       }
 183 #ifdef HAVE_ARRAYS
 184     case scm_tc7_bvect: case scm_tc7_uvect: case scm_tc7_ivect:
 185     case scm_tc7_fvect: case scm_tc7_cvect: case scm_tc7_dvect:
 186     case scm_tc7_svect:
 187 #ifdef HAVE_LONG_LONGS
 188     case scm_tc7_llvect:
 189 #endif
 190     case scm_tc7_byvect:
 191       if (scm_tc16_array && scm_smobs[0x0ff & (scm_tc16_array >> 8)].equalp)
 192         return scm_array_equal_p (x, y);
 193 #endif
 194     }
 195   return SCM_BOOL_F;
 196 }
 197 #undef FUNC_NAME
 198
 199
 200 \f
 201
 202
 203
 204 void
 205 scm_init_eq ()
 206 {
 207 #include "eq.x"
 208 }
 209
 210
 211 /*
 212   Local Variables:
 213   c-file-style: "gnu"
 214   End:
 215 */