libguile/eq.c

   1 /*      Copyright (C) 1995,1996,1997,1998 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
  54 #include "scm_validate.h"
  55 #include "eq.h"
  56 \f
  57 SCM_DEFINE1 (scm_eq_p, "eq?", scm_tc7_rpsubr,
  58              (SCM x, SCM y),
  59              "Return #t iff X references the same object as Y.\n"
  60              "`eq?' is similar to `eqv?' except that in some cases\n"
  61              "it is capable of discerning distinctions finer than\n"
  62              "those detectable by `eqv?'.\n")
  63 #define FUNC_NAME s_scm_eq_p
  64 {
  65   return SCM_BOOL(x==y);
  66 }
  67 #undef FUNC_NAME
  68
  69
  70 SCM_DEFINE1 (scm_eqv_p, "eqv?", scm_tc7_rpsubr,
  71              (SCM x, SCM y),
  72              "The `eqv?' procedure defines a useful equivalence relation on objects.\n"
  73              "Briefly, it returns #t if X and Y should normally be\n"
  74              "regarded as the same object.  This relation is left\n"
  75              "slightly open to interpretation, but works for comparing\n"
  76              "immediate integers, characters, and inexact numbers.\n")
  77 #define FUNC_NAME s_scm_eqv_p
  78 {
  79   if (x==y) return SCM_BOOL_T;
  80   if (SCM_IMP(x)) return SCM_BOOL_F;
  81   if (SCM_IMP(y)) return SCM_BOOL_F;
  82   /* this ensures that types and scm_length are the same. */
  83   if (SCM_CAR(x) != SCM_CAR(y)) return SCM_BOOL_F;
  84   if (SCM_NUMP(x)) {
  85 # ifdef SCM_BIGDIG
  86     if (SCM_BIGP(x)) return SCM_BOOL(0==scm_bigcomp(x, y));
  87 # endif
  88 #ifdef SCM_FLOATS
  89     if (SCM_REALPART(x) != SCM_REALPART(y)) return SCM_BOOL_F;
  90     if (SCM_CPLXP(x) && (SCM_IMAG(x) != SCM_IMAG(y))) return SCM_BOOL_F;
  91 #endif
  92     return SCM_BOOL_T;
  93   }
  94   return SCM_BOOL_F;
  95 }
  96 #undef FUNC_NAME
  97
  98
  99 SCM_DEFINE1 (scm_equal_p, "equal?", scm_tc7_rpsubr,
 100              (SCM x, SCM y),
 101              "Return #t iff X and Y are recursively `eqv?' equivalent.\n"
 102              "`equal?' recursively compares the contents of pairs, vectors, and\n"
 103              "strings, applying `eqv?' on other objects such as numbers and\n"
 104              "symbols.  A rule of thumb is that objects are generally `equal?'\n"
 105              "if they print the same.  `Equal?' may fail to terminate if its\n"
 106              "arguments are circular data structures.\n")
 107 #define FUNC_NAME s_scm_equal_p
 108 {
 109   SCM_CHECK_STACK;
 110  tailrecurse: SCM_TICK;
 111         if (x==y) return SCM_BOOL_T;
 112         if (SCM_IMP(x)) return SCM_BOOL_F;
 113         if (SCM_IMP(y)) return SCM_BOOL_F;
 114         if (SCM_CONSP(x) && SCM_CONSP(y)) {
 115                 if SCM_FALSEP(scm_equal_p(SCM_CAR(x), SCM_CAR(y))) return SCM_BOOL_F;
 116                 x = SCM_CDR(x);
 117                 y = SCM_CDR(y);
 118                 goto tailrecurse;
 119         }
 120         if (SCM_TYP7S (x) == scm_tc7_string
 121             && SCM_TYP7S (y) == scm_tc7_string)
 122           return scm_string_equal_p (x, y);
 123         /* This ensures that types and scm_length are the same.  */
 124         if (SCM_CAR(x) != SCM_CAR(y)) return SCM_BOOL_F;
 125         switch (SCM_TYP7(x)) {
 126         default: return SCM_BOOL_F;
 127         case scm_tc7_vector:
 128         case scm_tc7_wvect:
 129           return scm_vector_equal_p(x, y);
 130         case scm_tc7_smob: {
 131                 int i = SCM_SMOBNUM(x);
 132                 if (!(i < scm_numsmob)) return SCM_BOOL_F;
 133                 if (scm_smobs[i].equalp)
 134                   return (scm_smobs[i].equalp)(x, y);
 135                 else
 136                   return SCM_BOOL_F;
 137               }
 138 #ifdef HAVE_ARRAYS
 139         case scm_tc7_bvect: case scm_tc7_uvect: case scm_tc7_ivect:
 140         case scm_tc7_fvect:     case scm_tc7_cvect: case scm_tc7_dvect:
 141         case scm_tc7_svect:
 142 #ifdef HAVE_LONG_LONGS
 143         case scm_tc7_llvect:
 144 #endif
 145         case scm_tc7_byvect:
 146           if (   scm_tc16_array
 147               && scm_smobs[0x0ff & (scm_tc16_array >> 8)].equalp)
 148             return scm_array_equal_p(x, y);
 149 #endif
 150         }
 151         return SCM_BOOL_F;
 152 }
 153 #undef FUNC_NAME
 154
 155
 156 \f
 157
 158
 159
 160 void
 161 scm_init_eq ()
 162 {
 163 #include "eq.x"
 164 }
 165