--- /dev/null
+/* 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
+ */
+
+\f
+#ifdef 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"
+\f
+
+#ifdef HAVE_STRING_H
+#include <string.h>
+#endif
+\f
+
+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
+
+
+\f
+
+
+
+void
+scm_init_eq ()
+{
+#include "libguile/eq.x"
+}
+
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/
projects / lilypond.git / blobdiff