1 /* Copyright (C) 1995,1996,1997,1998,2000,2001,2003, 2004, 2006 Free Software Foundation, Inc.
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Lesser General Public
5 * License as published by the Free Software Foundation; either
6 * version 2.1 of the License, or (at your option) any later version.
8 * This library 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 GNU
11 * Lesser General Public License for more details.
13 * You should have received a copy of the GNU Lesser General Public
14 * License along with this library; if not, write to the Free Software
15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 #include "libguile/_scm.h"
24 #include "libguile/ramap.h"
25 #include "libguile/stackchk.h"
26 #include "libguile/strorder.h"
27 #include "libguile/async.h"
28 #include "libguile/root.h"
29 #include "libguile/smob.h"
30 #include "libguile/unif.h"
31 #include "libguile/vectors.h"
33 #include "libguile/struct.h"
34 #include "libguile/goops.h"
35 #include "libguile/objects.h"
37 #include "libguile/validate.h"
38 #include "libguile/eq.h"
46 SCM_DEFINE1 (scm_eq_p, "eq?", scm_tc7_rpsubr,
48 "Return @code{#t} if @var{x} and @var{y} are the same object,\n"
49 "except for numbers and characters. For example,\n"
52 "(define x (vector 1 2 3))\n"
53 "(define y (vector 1 2 3))\n"
55 "(eq? x x) @result{} #t\n"
56 "(eq? x y) @result{} #f\n"
59 "Numbers and characters are not equal to any other object, but\n"
60 "the problem is they're not necessarily @code{eq?} to themselves\n"
61 "either. This is even so when the number comes directly from a\n"
65 "(let ((n (+ 2 3)))\n"
66 " (eq? n n)) @result{} *unspecified*\n"
69 "Generally @code{eqv?} should be used when comparing numbers or\n"
70 "characters. @code{=} or @code{char=?} can be used too.\n"
72 "It's worth noting that end-of-list @code{()}, @code{#t},\n"
73 "@code{#f}, a symbol of a given name, and a keyword of a given\n"
74 "name, are unique objects. There's just one of each, so for\n"
75 "instance no matter how @code{()} arises in a program, it's the\n"
76 "same object and can be compared with @code{eq?},\n"
79 "(define x (cdr '(123)))\n"
80 "(define y (cdr '(456)))\n"
81 "(eq? x y) @result{} #t\n"
83 "(define x (string->symbol \"foo\"))\n"
84 "(eq? x 'foo) @result{} #t\n"
86 #define FUNC_NAME s_scm_eq_p
88 return scm_from_bool (scm_is_eq (x, y));
92 /* We compare doubles in a special way for 'eqv?' to be able to
93 distinguish plus and minus zero and to identify NaNs.
97 real_eqv (double x, double y)
99 return !memcmp (&x, &y, sizeof(double)) || (x != x && y != y);
103 SCM_PRIMITIVE_GENERIC_1 (scm_eqv_p, "eqv?", scm_tc7_rpsubr,
105 "Return @code{#t} if @var{x} and @var{y} are the same object, or\n"
106 "for characters and numbers the same value.\n"
108 "On objects except characters and numbers, @code{eqv?} is the\n"
109 "same as @code{eq?}, it's true if @var{x} and @var{y} are the\n"
112 "If @var{x} and @var{y} are numbers or characters, @code{eqv?}\n"
113 "compares their type and value. An exact number is not\n"
114 "@code{eqv?} to an inexact number (even if their value is the\n"
118 "(eqv? 3 (+ 1 2)) @result{} #t\n"
119 "(eqv? 1 1.0) @result{} #f\n"
121 #define FUNC_NAME s_scm_eqv_p
123 if (scm_is_eq (x, y))
129 /* this ensures that types and scm_length are the same. */
131 if (SCM_CELL_TYPE (x) != SCM_CELL_TYPE (y))
133 /* fractions use 0x10000 as a flag (at the suggestion of Marius Vollmer),
134 but this checks the entire type word, so fractions may be accidentally
135 flagged here as unequal. Perhaps I should use the 4th double_cell word?
138 /* treat mixes of real and complex types specially */
139 if (SCM_INEXACTP (x))
142 return scm_from_bool (SCM_COMPLEXP (y)
143 && real_eqv (SCM_REAL_VALUE (x),
144 SCM_COMPLEX_REAL (y))
145 && SCM_COMPLEX_IMAG (y) == 0.0);
147 return scm_from_bool (SCM_REALP (y)
148 && real_eqv (SCM_COMPLEX_REAL (x),
150 && SCM_COMPLEX_IMAG (x) == 0.0);
153 if (SCM_FRACTIONP (x) && SCM_FRACTIONP (y))
154 return scm_i_fraction_equalp (x, y);
160 return scm_from_bool (scm_i_bigcmp (x, y) == 0);
161 } else if (SCM_REALP (x)) {
162 return scm_from_bool (real_eqv (SCM_REAL_VALUE (x), SCM_REAL_VALUE (y)));
163 } else if (SCM_FRACTIONP (x)) {
164 return scm_i_fraction_equalp (x, y);
165 } else { /* complex */
166 return scm_from_bool (real_eqv (SCM_COMPLEX_REAL (x),
167 SCM_COMPLEX_REAL (y))
168 && real_eqv (SCM_COMPLEX_IMAG (x),
169 SCM_COMPLEX_IMAG (y)));
172 if (SCM_UNPACK (g_scm_eqv_p))
173 return scm_call_generic_2 (g_scm_eqv_p, x, y);
180 SCM_PRIMITIVE_GENERIC_1 (scm_equal_p, "equal?", scm_tc7_rpsubr,
182 "Return @code{#t} if @var{x} and @var{y} are the same type, and\n"
183 "their contents or value are equal.\n"
185 "For a pair, string, vector or array, @code{equal?} compares the\n"
186 "contents, and does so using using the same @code{equal?}\n"
187 "recursively, so a deep structure can be traversed.\n"
190 "(equal? (list 1 2 3) (list 1 2 3)) @result{} #t\n"
191 "(equal? (list 1 2 3) (vector 1 2 3)) @result{} #f\n"
194 "For other objects, @code{equal?} compares as per @code{eqv?},\n"
195 "which means characters and numbers are compared by type and\n"
196 "value (and like @code{eqv?}, exact and inexact numbers are not\n"
197 "@code{equal?}, even if their value is the same).\n"
200 "(equal? 3 (+ 1 2)) @result{} #t\n"
201 "(equal? 1 1.0) @result{} #f\n"
204 "Hash tables are currently only compared as per @code{eq?}, so\n"
205 "two different tables are not @code{equal?}, even if their\n"
206 "contents are the same.\n"
208 "@code{equal?} does not support circular data structures, it may\n"
209 "go into an infinite loop if asked to compare two circular lists\n"
212 "New application-defined object types (Smobs) have an\n"
213 "@code{equalp} handler which is called by @code{equal?}. This\n"
214 "lets an application traverse the contents or control what is\n"
215 "considered @code{equal?} for two such objects. If there's no\n"
216 "handler, the default is to just compare as per @code{eq?}.")
217 #define FUNC_NAME s_scm_equal_p
222 if (scm_is_eq (x, y))
228 if (scm_is_pair (x) && scm_is_pair (y))
230 if (scm_is_false (scm_equal_p (SCM_CAR (x), SCM_CAR (y))))
236 if (SCM_TYP7 (x) == scm_tc7_string && SCM_TYP7 (y) == scm_tc7_string)
237 return scm_string_equal_p (x, y);
238 if (SCM_TYP7 (x) == scm_tc7_smob && SCM_TYP16 (x) == SCM_TYP16 (y))
240 int i = SCM_SMOBNUM (x);
241 if (!(i < scm_numsmob))
243 if (scm_smobs[i].equalp)
244 return (scm_smobs[i].equalp) (x, y);
248 /* This ensures that types and scm_length are the same. */
249 if (SCM_CELL_TYPE (x) != SCM_CELL_TYPE (y))
251 /* treat mixes of real and complex types specially */
252 if (SCM_INEXACTP (x) && SCM_INEXACTP (y))
255 return scm_from_bool (SCM_COMPLEXP (y)
256 && SCM_REAL_VALUE (x) == SCM_COMPLEX_REAL (y)
257 && SCM_COMPLEX_IMAG (y) == 0.0);
259 return scm_from_bool (SCM_REALP (y)
260 && SCM_COMPLEX_REAL (x) == SCM_REAL_VALUE (y)
261 && SCM_COMPLEX_IMAG (x) == 0.0);
264 /* Vectors can be equal to one-dimensional arrays.
266 if (SCM_I_ARRAYP (x) || SCM_I_ARRAYP (y))
267 return scm_array_equal_p (x, y);
271 switch (SCM_TYP7 (x))
279 return scm_bigequal (x, y);
281 return scm_real_equalp (x, y);
282 case scm_tc16_complex:
283 return scm_complex_equalp (x, y);
284 case scm_tc16_fraction:
285 return scm_i_fraction_equalp (x, y);
289 return scm_i_vector_equal_p (x, y);
292 /* Check equality between structs of equal type (see cell-type test above)
293 that are not GOOPS instances. GOOPS instances are treated via the
295 if ((SCM_STRUCTP (x)) && (!SCM_INSTANCEP (x)))
296 return scm_i_struct_equalp (x, y);
299 if (SCM_UNPACK (g_scm_equal_p))
300 return scm_call_generic_2 (g_scm_equal_p, x, y);
314 #include "libguile/eq.x"