xref: /netbsd-src/external/lgpl3/gmp/dist/demos/expr/exprq.c (revision ce54336801cf28877c3414aa2fcb251dddd543a2)
1 /* mpq expression evaluation
2 
3 Copyright 2000-2002 Free Software Foundation, Inc.
4 
5 This file is part of the GNU MP Library.
6 
7 The GNU MP Library is free software; you can redistribute it and/or modify
8 it under the terms of either:
9 
10   * the GNU Lesser General Public License as published by the Free
11     Software Foundation; either version 3 of the License, or (at your
12     option) any later version.
13 
14 or
15 
16   * the GNU General Public License as published by the Free Software
17     Foundation; either version 2 of the License, or (at your option) any
18     later version.
19 
20 or both in parallel, as here.
21 
22 The GNU MP Library is distributed in the hope that it will be useful, but
23 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
24 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
25 for more details.
26 
27 You should have received copies of the GNU General Public License and the
28 GNU Lesser General Public License along with the GNU MP Library.  If not,
29 see https://www.gnu.org/licenses/.  */
30 
31 #include <stdio.h>
32 #include <string.h>
33 #include "gmp.h"
34 #include "expr-impl.h"
35 
36 
37 /* Change this to "#define TRACE(x) x" to get some traces. */
38 #define TRACE(x)
39 
40 
41 static void
e_mpq_pow_ui(mpq_ptr r,mpq_srcptr b,unsigned long e)42 e_mpq_pow_ui (mpq_ptr r, mpq_srcptr b, unsigned long e)
43 {
44   mpz_pow_ui (mpq_numref(r), mpq_numref(b), e);
45   mpz_pow_ui (mpq_denref(r), mpq_denref(b), e);
46 }
47 
48 /* Wrapped because mpq_sgn is a macro. */
49 static int
e_mpq_sgn(mpq_srcptr x)50 e_mpq_sgn (mpq_srcptr x)
51 {
52   return mpq_sgn (x);
53 }
54 
55 /* Wrapped because mpq_equal only guarantees a non-zero return, whereas we
56    want 1 or 0 for == and !=. */
57 static int
e_mpq_equal(mpq_srcptr x,mpq_srcptr y)58 e_mpq_equal (mpq_srcptr x, mpq_srcptr y)
59 {
60   return mpq_equal (x, y) != 0;
61 }
62 static int
e_mpq_notequal(mpq_srcptr x,mpq_srcptr y)63 e_mpq_notequal (mpq_srcptr x, mpq_srcptr y)
64 {
65   return ! mpq_equal (x, y);
66 }
67 
68 static void
e_mpq_num(mpq_ptr w,mpq_srcptr x)69 e_mpq_num (mpq_ptr w, mpq_srcptr x)
70 {
71   if (w != x)
72     mpz_set (mpq_numref(w), mpq_numref(x));
73   mpz_set_ui (mpq_denref(w), 1L);
74 }
75 static void
e_mpq_den(mpq_ptr w,mpq_srcptr x)76 e_mpq_den (mpq_ptr w, mpq_srcptr x)
77 {
78   if (w == x)
79     mpz_swap (mpq_numref(w), mpq_denref(w));
80   else
81     mpz_set (mpq_numref(w), mpq_denref(x));
82   mpz_set_ui (mpq_denref(w), 1L);
83 }
84 
85 
86 static const struct mpexpr_operator_t  _mpq_expr_standard_table[] = {
87 
88   { "**",  (mpexpr_fun_t) e_mpq_pow_ui,
89     MPEXPR_TYPE_BINARY_UI | MPEXPR_TYPE_RIGHTASSOC,                   220 },
90 
91   { "!",   (mpexpr_fun_t) e_mpq_sgn,
92     MPEXPR_TYPE_LOGICAL_NOT | MPEXPR_TYPE_PREFIX,                     210 },
93   { "-",   (mpexpr_fun_t) mpq_neg,
94     MPEXPR_TYPE_UNARY | MPEXPR_TYPE_PREFIX,                           210 },
95 
96   { "*",   (mpexpr_fun_t) mpq_mul,           MPEXPR_TYPE_BINARY,      200 },
97   { "/",   (mpexpr_fun_t) mpq_div,           MPEXPR_TYPE_BINARY,      200 },
98 
99   { "+",   (mpexpr_fun_t) mpq_add,           MPEXPR_TYPE_BINARY,      190 },
100   { "-",   (mpexpr_fun_t) mpq_sub,           MPEXPR_TYPE_BINARY,      190 },
101 
102   { "<<",  (mpexpr_fun_t) mpq_mul_2exp,      MPEXPR_TYPE_BINARY_UI,   180 },
103   { ">>",  (mpexpr_fun_t) mpq_div_2exp,      MPEXPR_TYPE_BINARY_UI,   180 },
104 
105   { "<=",  (mpexpr_fun_t) mpq_cmp,           MPEXPR_TYPE_CMP_LE,      170 },
106   { "<",   (mpexpr_fun_t) mpq_cmp,           MPEXPR_TYPE_CMP_LT,      170 },
107   { ">=",  (mpexpr_fun_t) mpq_cmp,           MPEXPR_TYPE_CMP_GE,      170 },
108   { ">",   (mpexpr_fun_t) mpq_cmp,           MPEXPR_TYPE_CMP_GT,      170 },
109 
110   { "==",  (mpexpr_fun_t) e_mpq_equal,       MPEXPR_TYPE_I_BINARY,    160 },
111   { "!=",  (mpexpr_fun_t) e_mpq_notequal,    MPEXPR_TYPE_I_BINARY,    160 },
112 
113   { "&&",  (mpexpr_fun_t) e_mpq_sgn,         MPEXPR_TYPE_LOGICAL_AND, 120 },
114   { "||",  (mpexpr_fun_t) e_mpq_sgn,         MPEXPR_TYPE_LOGICAL_OR,  110 },
115 
116   { ":",   NULL,                             MPEXPR_TYPE_COLON,       101 },
117   { "?",   (mpexpr_fun_t) e_mpq_sgn,         MPEXPR_TYPE_QUESTION,    100 },
118 
119   { ")",   (mpexpr_fun_t) e_mpq_sgn,         MPEXPR_TYPE_CLOSEPAREN,    4 },
120   { "(",   (mpexpr_fun_t) e_mpq_sgn,         MPEXPR_TYPE_OPENPAREN,     3 },
121   { ",",   (mpexpr_fun_t) e_mpq_sgn,         MPEXPR_TYPE_ARGSEP,        2 },
122   { "$",   NULL,                             MPEXPR_TYPE_VARIABLE,      1 },
123 
124   { "abs",  (mpexpr_fun_t) mpq_abs,          MPEXPR_TYPE_UNARY            },
125   { "cmp",  (mpexpr_fun_t) mpq_cmp,          MPEXPR_TYPE_I_BINARY         },
126   { "den",  (mpexpr_fun_t) e_mpq_den,        MPEXPR_TYPE_UNARY            },
127   { "max",  (mpexpr_fun_t) mpq_cmp,  MPEXPR_TYPE_MAX | MPEXPR_TYPE_PAIRWISE },
128   { "min",  (mpexpr_fun_t) mpq_cmp,  MPEXPR_TYPE_MIN | MPEXPR_TYPE_PAIRWISE },
129   { "num",  (mpexpr_fun_t) e_mpq_num,        MPEXPR_TYPE_UNARY            },
130   { "sgn",  (mpexpr_fun_t) e_mpq_sgn,        MPEXPR_TYPE_I_UNARY          },
131 
132   { NULL }
133 };
134 
135 const struct mpexpr_operator_t * const mpq_expr_standard_table
136 = _mpq_expr_standard_table;
137 
138 
139 int
mpq_expr(mpq_ptr res,int base,const char * e,...)140 mpq_expr (mpq_ptr res, int base, const char *e, ...)
141 {
142   mpq_srcptr  var[MPEXPR_VARIABLES];
143   va_list     ap;
144   int         ret;
145   va_start (ap, e);
146 
147   TRACE (printf ("mpq_expr(): base %d, %s\n", base, e));
148   ret = mpexpr_va_to_var ((void **) var, ap);
149   va_end (ap);
150 
151   if (ret != MPEXPR_RESULT_OK)
152     return ret;
153 
154   return mpq_expr_a (mpq_expr_standard_table, res, base, e, strlen(e), var);
155 }
156