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