mirror of
https://git.savannah.gnu.org/git/guile.git
synced 2025-04-29 19:30:36 +02:00
7c53325c31
* libguile/integers.c (scm_integer_to_double_z): Doubles that can't be exactly represented as integers should round. (bignum_frexp_z): New helper. (scm_integer_from_mpz, scm_integer_from_double): New internal functions. * libguile/numbers.h: * libguile/numbers.c (scm_i_bigcmp, scm_i_dbl2big, scm_i_dbl2num): Remove unused internal functions. (scm_inexact_to_exact): Rework to avoid scm_i_dbl2big. (scm_bigequal): Move here, from eq.c. (scm_integer_to_double_z): Use the new helper. (scm_i_big2dbl): Use scm_integer_to_double_z.
411 lines
12 KiB
C
411 lines
12 KiB
C
/* Copyright 1995-1998,2000-2001,2003-2004,2006,2009-2011,2017-2018,2022
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Free Software Foundation, Inc.
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This file is part of Guile.
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Guile is free software: you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published
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by the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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Guile is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with Guile. If not, see
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<https://www.gnu.org/licenses/>. */
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <math.h>
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#include <string.h>
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#include "array-map.h"
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#include "async.h"
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#include "bitvectors.h"
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#include "boolean.h"
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#include "bytevectors.h"
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#include "eval.h"
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#include "foreign.h"
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#include "arrays.h"
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#include "goops.h"
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#include "gsubr.h"
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#include "hashtab.h"
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#include "pairs.h"
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#include "private-options.h"
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#include "smob.h"
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#include "stackchk.h"
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#include "strorder.h"
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#include "struct.h"
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#include "syntax.h"
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#include "vectors.h"
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#include "eq.h"
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static SCM scm_i_eq_p (SCM x, SCM y, SCM rest);
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SCM_DEFINE (scm_i_eq_p, "eq?", 0, 2, 1,
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(SCM x, SCM y, SCM rest),
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"Return @code{#t} if @var{x} and @var{y} are the same object,\n"
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"except for numbers and characters. For example,\n"
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"\n"
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"@example\n"
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"(define x (vector 1 2 3))\n"
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"(define y (vector 1 2 3))\n"
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"\n"
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"(eq? x x) @result{} #t\n"
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"(eq? x y) @result{} #f\n"
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"@end example\n"
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"\n"
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"Numbers and characters are not equal to any other object, but\n"
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"the problem is they're not necessarily @code{eq?} to themselves\n"
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"either. This is even so when the number comes directly from a\n"
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"variable,\n"
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"\n"
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"@example\n"
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"(let ((n (+ 2 3)))\n"
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" (eq? n n)) @result{} *unspecified*\n"
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"@end example\n"
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"\n"
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"Generally @code{eqv?} should be used when comparing numbers or\n"
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"characters. @code{=} or @code{char=?} can be used too.\n"
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"\n"
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"It's worth noting that end-of-list @code{()}, @code{#t},\n"
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"@code{#f}, a symbol of a given name, and a keyword of a given\n"
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"name, are unique objects. There's just one of each, so for\n"
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"instance no matter how @code{()} arises in a program, it's the\n"
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"same object and can be compared with @code{eq?},\n"
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"\n"
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"@example\n"
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"(define x (cdr '(123)))\n"
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"(define y (cdr '(456)))\n"
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"(eq? x y) @result{} #t\n"
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"\n"
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"(define x (string->symbol \"foo\"))\n"
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"(eq? x 'foo) @result{} #t\n"
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"@end example")
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#define FUNC_NAME s_scm_i_eq_p
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{
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if (SCM_UNBNDP (x) || SCM_UNBNDP (y))
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return SCM_BOOL_T;
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while (scm_is_pair (rest))
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{
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if (!scm_is_eq (x, y))
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return SCM_BOOL_F;
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x = y;
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y = scm_car (rest);
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rest = scm_cdr (rest);
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}
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return scm_from_bool (scm_is_eq (x, y));
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}
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#undef FUNC_NAME
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SCM
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scm_eq_p (SCM x, SCM y)
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{
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return scm_from_bool (scm_is_eq (x, y));
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}
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/* We compare doubles in a special way for 'eqv?' to be able to
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distinguish plus and minus zero and to identify NaNs.
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*/
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static int
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real_eqv (double x, double y)
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{
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return !memcmp (&x, &y, sizeof(double))
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|| (SCM_UNLIKELY (isnan (x)) && SCM_UNLIKELY (isnan (y)));
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}
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SCM
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scm_real_equalp (SCM x, SCM y)
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{
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return scm_from_bool (real_eqv (SCM_REAL_VALUE (x),
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SCM_REAL_VALUE (y)));
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}
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SCM
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scm_complex_equalp (SCM x, SCM y)
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{
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return scm_from_bool (real_eqv (SCM_COMPLEX_REAL (x),
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SCM_COMPLEX_REAL (y))
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&& real_eqv (SCM_COMPLEX_IMAG (x),
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SCM_COMPLEX_IMAG (y)));
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}
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SCM
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scm_i_fraction_equalp (SCM x, SCM y)
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{
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return scm_from_bool
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(scm_is_true (scm_equal_p (SCM_FRACTION_NUMERATOR (x),
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SCM_FRACTION_NUMERATOR (y)))
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&& scm_is_true (scm_equal_p (SCM_FRACTION_DENOMINATOR (x),
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SCM_FRACTION_DENOMINATOR (y))));
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}
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int
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scm_i_heap_numbers_equal_p (SCM x, SCM y)
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{
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// Precondition: both X and Y are heap numbers.
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if (!(SCM_HEAP_OBJECT_P (x) && SCM_HEAP_OBJECT_P (y)))
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abort();
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// eqv? already checks that the heap tags are the same, but we are
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// also called by the VM, which only ensures that both values are
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// numbers. So check tags here too.
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if (SCM_CELL_TYPE (x) != SCM_CELL_TYPE (y))
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return 0;
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switch (SCM_TYP16 (x))
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{
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case scm_tc16_big:
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return scm_is_true (scm_bigequal (x, y));
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case scm_tc16_real:
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return scm_is_true (scm_real_equalp (x, y));
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case scm_tc16_complex:
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return scm_is_true (scm_complex_equalp (x, y));
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case scm_tc16_fraction:
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return scm_is_true (scm_i_fraction_equalp (x, y));
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default:
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abort ();
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}
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}
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static SCM scm_i_eqv_p (SCM x, SCM y, SCM rest);
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#include <stdio.h>
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SCM_DEFINE (scm_i_eqv_p, "eqv?", 0, 2, 1,
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(SCM x, SCM y, SCM rest),
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"Return @code{#t} if @var{x} and @var{y} are the same object, or\n"
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"for characters and numbers the same value.\n"
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"\n"
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"On objects except characters and numbers, @code{eqv?} is the\n"
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"same as @code{eq?}, it's true if @var{x} and @var{y} are the\n"
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"same object.\n"
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"\n"
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"If @var{x} and @var{y} are numbers or characters, @code{eqv?}\n"
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"compares their type and value. An exact number is not\n"
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"@code{eqv?} to an inexact number (even if their value is the\n"
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"same).\n"
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"\n"
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"@example\n"
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"(eqv? 3 (+ 1 2)) @result{} #t\n"
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"(eqv? 1 1.0) @result{} #f\n"
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"@end example")
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#define FUNC_NAME s_scm_i_eqv_p
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{
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if (SCM_UNBNDP (x) || SCM_UNBNDP (y))
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return SCM_BOOL_T;
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while (!scm_is_null (rest))
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{
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if (!scm_is_true (scm_eqv_p (x, y)))
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return SCM_BOOL_F;
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x = y;
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y = scm_car (rest);
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rest = scm_cdr (rest);
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}
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return scm_eqv_p (x, y);
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}
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#undef FUNC_NAME
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SCM scm_eqv_p (SCM x, SCM y)
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#define FUNC_NAME s_scm_i_eqv_p
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{
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if (scm_is_eq (x, y))
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return SCM_BOOL_T;
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if (SCM_IMP (x))
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return SCM_BOOL_F;
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if (SCM_IMP (y))
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return SCM_BOOL_F;
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/* this ensures that types and scm_length are the same. */
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if (SCM_CELL_TYPE (x) != SCM_CELL_TYPE (y))
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return SCM_BOOL_F;
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switch (SCM_TYP7 (x))
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{
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default:
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break;
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case scm_tc7_number:
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return scm_from_bool (scm_i_heap_numbers_equal_p (x, y));
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}
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return SCM_BOOL_F;
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}
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#undef FUNC_NAME
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static SCM scm_i_equal_p (SCM, SCM, SCM);
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SCM_PRIMITIVE_GENERIC (scm_i_equal_p, "equal?", 0, 2, 1,
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(SCM x, SCM y, SCM rest),
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"Return @code{#t} if @var{x} and @var{y} are the same type, and\n"
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"their contents or value are equal.\n"
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"\n"
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"For a pair, string, vector or array, @code{equal?} compares the\n"
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"contents, and does so using using the same @code{equal?}\n"
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"recursively, so a deep structure can be traversed.\n"
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"\n"
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"@example\n"
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"(equal? (list 1 2 3) (list 1 2 3)) @result{} #t\n"
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"(equal? (list 1 2 3) (vector 1 2 3)) @result{} #f\n"
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"@end example\n"
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"\n"
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"For other objects, @code{equal?} compares as per @code{eqv?},\n"
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"which means characters and numbers are compared by type and\n"
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"value (and like @code{eqv?}, exact and inexact numbers are not\n"
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"@code{equal?}, even if their value is the same).\n"
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"\n"
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"@example\n"
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"(equal? 3 (+ 1 2)) @result{} #t\n"
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"(equal? 1 1.0) @result{} #f\n"
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"@end example\n"
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"\n"
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"Hash tables are currently only compared as per @code{eq?}, so\n"
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"two different tables are not @code{equal?}, even if their\n"
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"contents are the same.\n"
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"\n"
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"@code{equal?} does not support circular data structures, it may\n"
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"go into an infinite loop if asked to compare two circular lists\n"
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"or similar.\n"
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"\n"
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"New application-defined object types (Smobs) have an\n"
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"@code{equalp} handler which is called by @code{equal?}. This\n"
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"lets an application traverse the contents or control what is\n"
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"considered @code{equal?} for two such objects. If there's no\n"
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"handler, the default is to just compare as per @code{eq?}.")
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#define FUNC_NAME s_scm_i_equal_p
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{
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if (SCM_UNBNDP (x) || SCM_UNBNDP (y))
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return SCM_BOOL_T;
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while (!scm_is_null (rest))
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{
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if (!scm_is_true (scm_equal_p (x, y)))
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return SCM_BOOL_F;
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x = y;
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y = scm_car (rest);
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rest = SCM_CDR (rest);
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}
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return scm_equal_p (x, y);
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}
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#undef FUNC_NAME
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SCM
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scm_equal_p (SCM x, SCM y)
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#define FUNC_NAME s_scm_i_equal_p
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{
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SCM_CHECK_STACK;
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tailrecurse:
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SCM_TICK;
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if (scm_is_eq (x, y))
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return SCM_BOOL_T;
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if (SCM_IMP (x))
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return SCM_BOOL_F;
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if (SCM_IMP (y))
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return SCM_BOOL_F;
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if (scm_is_pair (x) && scm_is_pair (y))
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{
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if (scm_is_false (scm_equal_p (SCM_CAR (x), SCM_CAR (y))))
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return SCM_BOOL_F;
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x = SCM_CDR(x);
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y = SCM_CDR(y);
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goto tailrecurse;
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}
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if (SCM_TYP7 (x) == scm_tc7_smob && SCM_TYP16 (x) == SCM_TYP16 (y))
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{
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int i = SCM_SMOBNUM (x);
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if (!(i < scm_numsmob))
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return SCM_BOOL_F;
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if (scm_smobs[i].equalp)
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return (scm_smobs[i].equalp) (x, y);
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else
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goto generic_equal;
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}
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/* This ensures that types and scm_length are the same. */
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if (SCM_CELL_TYPE (x) != SCM_CELL_TYPE (y))
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{
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/* Vectors can be equal to one-dimensional arrays.
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*/
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if (scm_is_array (x) && scm_is_array (y))
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return scm_array_equal_p (x, y);
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return SCM_BOOL_F;
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}
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switch (SCM_TYP7 (x))
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{
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default:
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/* Check equality between structs of equal type (see cell-type test above). */
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if (SCM_STRUCTP (x))
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{
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if (SCM_INSTANCEP (x))
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goto generic_equal;
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else
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return scm_i_struct_equalp (x, y);
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}
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break;
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case scm_tc7_number:
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switch SCM_TYP16 (x)
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{
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case scm_tc16_big:
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return scm_bigequal (x, y);
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case scm_tc16_real:
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return scm_real_equalp (x, y);
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case scm_tc16_complex:
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return scm_complex_equalp (x, y);
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case scm_tc16_fraction:
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return scm_i_fraction_equalp (x, y);
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default:
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/* assert not reached? */
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return SCM_BOOL_F;
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}
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case scm_tc7_pointer:
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return scm_from_bool (SCM_POINTER_VALUE (x) == SCM_POINTER_VALUE (y));
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case scm_tc7_string:
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return scm_string_equal_p (x, y);
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case scm_tc7_bytevector:
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return scm_bytevector_eq_p (x, y);
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case scm_tc7_array:
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return scm_array_equal_p (x, y);
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case scm_tc7_bitvector:
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return scm_i_bitvector_equal_p (x, y);
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case scm_tc7_vector:
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case scm_tc7_wvect:
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return scm_i_vector_equal_p (x, y);
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case scm_tc7_syntax:
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if (scm_is_false (scm_equal_p (scm_syntax_wrap (x),
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scm_syntax_wrap (y))))
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return SCM_BOOL_F;
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if (scm_is_false (scm_equal_p (scm_syntax_module (x),
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scm_syntax_module (y))))
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return SCM_BOOL_F;
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x = scm_syntax_expression (x);
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y = scm_syntax_expression (y);
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goto tailrecurse;
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}
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/* Otherwise just return false. Dispatching to the generic is the wrong thing
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here, as we can hit this case for any two objects of the same type that we
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think are distinct, like different symbols. */
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return SCM_BOOL_F;
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generic_equal:
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if (SCM_UNPACK (g_scm_i_equal_p))
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return scm_call_2 (g_scm_i_equal_p, x, y);
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else
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return SCM_BOOL_F;
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}
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#undef FUNC_NAME
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void
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scm_init_eq ()
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{
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#include "eq.x"
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}
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