X-Git-Url: http://git.hcoop.net/bpt/guile.git/blobdiff_plain/5c11cc9deb3962c0a7b4603327b9414579efe2bf..6774820f1e83a388b3232cd61a66340886b395d8:/libguile/eq.c

diff --git a/libguile/eq.c b/libguile/eq.c
dissimilarity index 91%
index 7e5ee18e1..ebc91c93b 100644
--- a/libguile/eq.c
+++ b/libguile/eq.c
@@ -1,151 +1,325 @@
-/*	Copyright (C) 1995,1996,1997,1998 Free Software Foundation, Inc.
- * 
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- * 
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- * 
- * You should have received a copy of the GNU General Public License
- * along with this software; see the file COPYING.  If not, write to
- * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
- * Boston, MA 02111-1307 USA
- *
- * As a special exception, the Free Software Foundation gives permission
- * for additional uses of the text contained in its release of GUILE.
- *
- * The exception is that, if you link the GUILE library with other files
- * to produce an executable, this does not by itself cause the
- * resulting executable to be covered by the GNU General Public License.
- * Your use of that executable is in no way restricted on account of
- * linking the GUILE library code into it.
- *
- * This exception does not however invalidate any other reasons why
- * the executable file might be covered by the GNU General Public License.
- *
- * This exception applies only to the code released by the
- * Free Software Foundation under the name GUILE.  If you copy
- * code from other Free Software Foundation releases into a copy of
- * GUILE, as the General Public License permits, the exception does
- * not apply to the code that you add in this way.  To avoid misleading
- * anyone as to the status of such modified files, you must delete
- * this exception notice from them.
- *
- * If you write modifications of your own for GUILE, it is your choice
- * whether to permit this exception to apply to your modifications.
- * If you do not wish that, delete this exception notice.  */
-
-#include <stdio.h>
-#include "_scm.h"
-#include "ramap.h"
-#include "stackchk.h"
-#include "strorder.h"
-#include "smob.h"
-#include "unif.h"
-
-#include "eq.h"
-
-SCM_PROC1 (s_eq_p, "eq?", scm_tc7_rpsubr, scm_eq_p);
-
-SCM
-scm_eq_p (x, y)
-     SCM x;
-     SCM y;
-{
-  return ((x==y)
-	  ? SCM_BOOL_T
-	  : SCM_BOOL_F);
-}
-
-
-SCM_PROC1 (s_eqv_p, "eqv?", scm_tc7_rpsubr, scm_eqv_p);
-
-SCM
-scm_eqv_p (x, y)
-     SCM x;
-     SCM y;
-{
-  if (x==y) return SCM_BOOL_T;
-  if (SCM_IMP(x)) return SCM_BOOL_F;
-  if (SCM_IMP(y)) return SCM_BOOL_F;
-  /* this ensures that types and scm_length are the same. */
-  if (SCM_CAR(x) != SCM_CAR(y)) return SCM_BOOL_F;
-  if (SCM_NUMP(x)) {
-# ifdef SCM_BIGDIG
-    if (SCM_BIGP(x)) return (0==scm_bigcomp(x, y)) ? SCM_BOOL_T : SCM_BOOL_F;
-# endif
-#ifdef SCM_FLOATS
-    if (SCM_REALPART(x) != SCM_REALPART(y)) return SCM_BOOL_F;
-    if (SCM_CPLXP(x) && (SCM_IMAG(x) != SCM_IMAG(y))) return SCM_BOOL_F;
-#endif
-    return SCM_BOOL_T;
-  }
-  return SCM_BOOL_F;
-}
-
-
-SCM_PROC1 (s_equal_p, "equal?", scm_tc7_rpsubr, scm_equal_p);
-
-SCM
-scm_equal_p (x, y)
-     SCM x;
-     SCM y;
-{
-  SCM_CHECK_STACK;
- tailrecurse: SCM_TICK;
-	if (x==y) return SCM_BOOL_T;
-	if (SCM_IMP(x)) return SCM_BOOL_F;
-	if (SCM_IMP(y)) return SCM_BOOL_F;
-	if (SCM_CONSP(x) && SCM_CONSP(y)) {
-		if SCM_FALSEP(scm_equal_p(SCM_CAR(x), SCM_CAR(y))) return SCM_BOOL_F;
-		x = SCM_CDR(x);
-		y = SCM_CDR(y);
-		goto tailrecurse;
-	}
-	if (SCM_TYP7S (x) == scm_tc7_string
-	    && SCM_TYP7S (y) == scm_tc7_string)
-	  return scm_string_equal_p (x, y);
-	/* This ensures that types and scm_length are the same.  */
-	if (SCM_CAR(x) != SCM_CAR(y)) return SCM_BOOL_F;
-	switch (SCM_TYP7(x)) {
-        default: return SCM_BOOL_F;
-	case scm_tc7_vector:
-	case scm_tc7_wvect:
-	  return scm_vector_equal_p(x, y);
-	case scm_tc7_smob: {
-	        int i = SCM_SMOBNUM(x);
-	        if (!(i < scm_numsmob)) return SCM_BOOL_F;
-	        if (scm_smobs[i].equalp)
-		  return (scm_smobs[i].equalp)(x, y);
-		else
-		  return SCM_BOOL_F;
-	      }
-	case scm_tc7_bvect: case scm_tc7_uvect: case scm_tc7_ivect:
-	case scm_tc7_fvect:	case scm_tc7_cvect: case scm_tc7_dvect:
-	case scm_tc7_svect:
-#ifdef HAVE_LONG_LONGS
-	case scm_tc7_llvect:
-#endif
-	case scm_tc7_byvect:
-	  if (   scm_tc16_array
-	      && scm_smobs[0x0ff & (scm_tc16_array >> 8)].equalp)
-	    return scm_array_equal_p(x, y);
-	}
-	return SCM_BOOL_F;
-}
-
-
-
-
-
-
-void
-scm_init_eq ()
-{
-#include "eq.x"
-}
-
+/* Copyright (C) 1995,1996,1997,1998,2000,2001,2003, 2004, 2006 Free Software Foundation, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+
+#if HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include "libguile/_scm.h"
+#include "libguile/ramap.h"
+#include "libguile/stackchk.h"
+#include "libguile/strorder.h"
+#include "libguile/async.h"
+#include "libguile/root.h"
+#include "libguile/smob.h"
+#include "libguile/unif.h"
+#include "libguile/vectors.h"
+
+#include "libguile/struct.h"
+#include "libguile/goops.h"
+#include "libguile/objects.h"
+
+#include "libguile/validate.h"
+#include "libguile/eq.h"
+
+#include "libguile/private-options.h"
+
+
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+
+
+SCM_DEFINE1 (scm_eq_p, "eq?", scm_tc7_rpsubr,
+             (SCM x, SCM y),
+	    "Return @code{#t} if @var{x} and @var{y} are the same object,\n"
+	    "except for numbers and characters.  For example,\n"
+	    "\n"
+	    "@example\n"
+	    "(define x (vector 1 2 3))\n"
+	    "(define y (vector 1 2 3))\n"
+	    "\n"
+	    "(eq? x x)  @result{} #t\n"
+	    "(eq? x y)  @result{} #f\n"
+	    "@end example\n"
+	    "\n"
+	    "Numbers and characters are not equal to any other object, but\n"
+	    "the problem is they're not necessarily @code{eq?} to themselves\n"
+	    "either.  This is even so when the number comes directly from a\n"
+	    "variable,\n"
+	    "\n"
+	    "@example\n"
+	    "(let ((n (+ 2 3)))\n"
+	    "  (eq? n n))       @result{} *unspecified*\n"
+	    "@end example\n"
+	    "\n"
+	    "Generally @code{eqv?} should be used when comparing numbers or\n"
+	    "characters.  @code{=} or @code{char=?} can be used too.\n"
+	    "\n"
+	    "It's worth noting that end-of-list @code{()}, @code{#t},\n"
+	    "@code{#f}, a symbol of a given name, and a keyword of a given\n"
+	    "name, are unique objects.  There's just one of each, so for\n"
+	    "instance no matter how @code{()} arises in a program, it's the\n"
+	    "same object and can be compared with @code{eq?},\n"
+	    "\n"
+	    "@example\n"
+	    "(define x (cdr '(123)))\n"
+	    "(define y (cdr '(456)))\n"
+	    "(eq? x y) @result{} #t\n"
+	    "\n"
+	    "(define x (string->symbol \"foo\"))\n"
+	    "(eq? x 'foo) @result{} #t\n"
+	    "@end example")
+#define FUNC_NAME s_scm_eq_p
+{
+  return scm_from_bool (scm_is_eq (x, y));
+}
+#undef FUNC_NAME
+
+/* We compare doubles in a special way for 'eqv?' to be able to
+   distinguish plus and minus zero and to identify NaNs.
+*/
+
+static int
+real_eqv (double x, double y)
+{
+  return !memcmp (&x, &y, sizeof(double)) || (x != x && y != y);
+}
+
+#include <stdio.h>
+SCM_PRIMITIVE_GENERIC_1 (scm_eqv_p, "eqv?", scm_tc7_rpsubr,
+             (SCM x, SCM y),
+	    "Return @code{#t} if @var{x} and @var{y} are the same object, or\n"
+	    "for characters and numbers the same value.\n"
+	    "\n"
+	    "On objects except characters and numbers, @code{eqv?} is the\n"
+	    "same as @code{eq?}, it's true if @var{x} and @var{y} are the\n"
+	    "same object.\n"
+	    "\n"
+	    "If @var{x} and @var{y} are numbers or characters, @code{eqv?}\n"
+	    "compares their type and value.  An exact number is not\n"
+	    "@code{eqv?} to an inexact number (even if their value is the\n"
+	    "same).\n"
+	    "\n"
+	    "@example\n"
+	    "(eqv? 3 (+ 1 2)) @result{} #t\n"
+	    "(eqv? 1 1.0)     @result{} #f\n"
+	    "@end example")
+#define FUNC_NAME s_scm_eqv_p
+{
+  if (scm_is_eq (x, y))
+    return SCM_BOOL_T;
+  if (SCM_IMP (x))
+    return SCM_BOOL_F;
+  if (SCM_IMP (y))
+    return SCM_BOOL_F;
+  /* this ensures that types and scm_length are the same. */
+
+  if (SCM_CELL_TYPE (x) != SCM_CELL_TYPE (y))
+    {
+      /* fractions use 0x10000 as a flag (at the suggestion of Marius Vollmer),
+	 but this checks the entire type word, so fractions may be accidentally
+	 flagged here as unequal.  Perhaps I should use the 4th double_cell word?
+      */
+
+      /* treat mixes of real and complex types specially */
+      if (SCM_INEXACTP (x))
+	{
+	  if (SCM_REALP (x))
+	    return scm_from_bool (SCM_COMPLEXP (y)
+			     && real_eqv (SCM_REAL_VALUE (x),
+					  SCM_COMPLEX_REAL (y))
+			     && SCM_COMPLEX_IMAG (y) == 0.0);
+	  else
+	    return scm_from_bool (SCM_REALP (y)
+			     && real_eqv (SCM_COMPLEX_REAL (x),
+					  SCM_REAL_VALUE (y))
+			     && SCM_COMPLEX_IMAG (x) == 0.0);
+	}
+
+      if (SCM_FRACTIONP (x) && SCM_FRACTIONP (y))
+	return scm_i_fraction_equalp (x, y);
+      return SCM_BOOL_F;
+    }
+  if (SCM_NUMP (x))
+    {
+      if (SCM_BIGP (x)) {
+	return scm_from_bool (scm_i_bigcmp (x, y) == 0);
+      } else if (SCM_REALP (x)) {
+	return scm_from_bool (real_eqv (SCM_REAL_VALUE (x), SCM_REAL_VALUE (y)));
+      } else if (SCM_FRACTIONP (x)) {
+	return scm_i_fraction_equalp (x, y);
+      } else { /* complex */
+	return scm_from_bool (real_eqv (SCM_COMPLEX_REAL (x),
+				   SCM_COMPLEX_REAL (y)) 
+			 && real_eqv (SCM_COMPLEX_IMAG (x),
+				      SCM_COMPLEX_IMAG (y)));
+      }
+    }
+  if (SCM_UNPACK (g_scm_eqv_p))
+    return scm_call_generic_2 (g_scm_eqv_p, x, y);
+  else
+    return SCM_BOOL_F;
+}
+#undef FUNC_NAME
+
+
+SCM_PRIMITIVE_GENERIC_1 (scm_equal_p, "equal?", scm_tc7_rpsubr,
+			 (SCM x, SCM y),
+	    "Return @code{#t} if @var{x} and @var{y} are the same type, and\n"
+	    "their contents or value are equal.\n"
+	    "\n"
+	    "For a pair, string, vector or array, @code{equal?} compares the\n"
+	    "contents, and does so using using the same @code{equal?}\n"
+	    "recursively, so a deep structure can be traversed.\n"
+	    "\n"
+	    "@example\n"
+	    "(equal? (list 1 2 3) (list 1 2 3))   @result{} #t\n"
+	    "(equal? (list 1 2 3) (vector 1 2 3)) @result{} #f\n"
+	    "@end example\n"
+	    "\n"
+	    "For other objects, @code{equal?} compares as per @code{eqv?},\n"
+	    "which means characters and numbers are compared by type and\n"
+	    "value (and like @code{eqv?}, exact and inexact numbers are not\n"
+	    "@code{equal?}, even if their value is the same).\n"
+	    "\n"
+	    "@example\n"
+	    "(equal? 3 (+ 1 2)) @result{} #t\n"
+	    "(equal? 1 1.0)     @result{} #f\n"
+	    "@end example\n"
+	    "\n"
+	    "Hash tables are currently only compared as per @code{eq?}, so\n"
+	    "two different tables are not @code{equal?}, even if their\n"
+	    "contents are the same.\n"
+	    "\n"
+	    "@code{equal?} does not support circular data structures, it may\n"
+	    "go into an infinite loop if asked to compare two circular lists\n"
+	    "or similar.\n"
+	    "\n"
+	    "New application-defined object types (Smobs) have an\n"
+	    "@code{equalp} handler which is called by @code{equal?}.  This\n"
+	    "lets an application traverse the contents or control what is\n"
+	    "considered @code{equal?} for two such objects.  If there's no\n"
+	    "handler, the default is to just compare as per @code{eq?}.")
+#define FUNC_NAME s_scm_equal_p
+{
+  SCM_CHECK_STACK;
+ tailrecurse:
+  SCM_TICK;
+  if (scm_is_eq (x, y))
+    return SCM_BOOL_T;
+  if (SCM_IMP (x))
+    return SCM_BOOL_F;
+  if (SCM_IMP (y))
+    return SCM_BOOL_F;
+  if (scm_is_pair (x) && scm_is_pair (y))
+    {
+      if (scm_is_false (scm_equal_p (SCM_CAR (x), SCM_CAR (y))))
+	return SCM_BOOL_F;
+      x = SCM_CDR(x);
+      y = SCM_CDR(y);
+      goto tailrecurse;
+    }
+  if (SCM_TYP7 (x) == scm_tc7_string && SCM_TYP7 (y) == scm_tc7_string)
+    return scm_string_equal_p (x, y);
+  if (SCM_TYP7 (x) == scm_tc7_smob && SCM_TYP16 (x) == SCM_TYP16 (y))
+    {
+      int i = SCM_SMOBNUM (x);
+      if (!(i < scm_numsmob))
+	return SCM_BOOL_F;
+      if (scm_smobs[i].equalp)
+	return (scm_smobs[i].equalp) (x, y);
+      else
+	goto generic_equal;
+    }
+  /* This ensures that types and scm_length are the same.  */
+  if (SCM_CELL_TYPE (x) != SCM_CELL_TYPE (y))
+    {
+      /* treat mixes of real and complex types specially */
+      if (SCM_INEXACTP (x) && SCM_INEXACTP (y))
+	{
+	  if (SCM_REALP (x))
+	    return scm_from_bool (SCM_COMPLEXP (y)
+			     && SCM_REAL_VALUE (x) == SCM_COMPLEX_REAL (y)
+			     && SCM_COMPLEX_IMAG (y) == 0.0);
+	  else
+	    return scm_from_bool (SCM_REALP (y)
+			     && SCM_COMPLEX_REAL (x) == SCM_REAL_VALUE (y)
+			     && SCM_COMPLEX_IMAG (x) == 0.0);
+	}
+
+      /* Vectors can be equal to one-dimensional arrays.
+       */
+      if (SCM_I_ARRAYP (x) || SCM_I_ARRAYP (y))
+	return scm_array_equal_p (x, y);
+
+      return SCM_BOOL_F;
+    }
+  switch (SCM_TYP7 (x))
+    {
+    default:
+      break;
+    case scm_tc7_number:
+      switch SCM_TYP16 (x)
+        {
+        case scm_tc16_big:
+          return scm_bigequal (x, y);
+        case scm_tc16_real:
+          return scm_real_equalp (x, y);
+        case scm_tc16_complex:
+          return scm_complex_equalp (x, y);
+	case scm_tc16_fraction:
+          return scm_i_fraction_equalp (x, y);
+        }
+    case scm_tc7_vector:
+    case scm_tc7_wvect:
+      return scm_i_vector_equal_p (x, y);
+    }
+
+  /* Check equality between structs of equal type (see cell-type test above)
+     that are not GOOPS instances.  GOOPS instances are treated via the
+     generic function.  */
+  if ((SCM_STRUCTP (x)) && (!SCM_INSTANCEP (x)))
+    return scm_i_struct_equalp (x, y);
+
+ generic_equal:
+  if (SCM_UNPACK (g_scm_equal_p))
+    return scm_call_generic_2 (g_scm_equal_p, x, y);
+  else
+    return SCM_BOOL_F;
+}
+#undef FUNC_NAME
+
+
+
+
+
+
+void
+scm_init_eq ()
+{
+#include "libguile/eq.x"
+}
+
+
+/*
+  Local Variables:
+  c-file-style: "gnu"
+  End:
+*/