xref: /netbsd-src/external/lgpl3/gmp/dist/demos/expr/exprq.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /* mpq expression evaluation
2 
3 Copyright 2000, 2001, 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 the GNU Lesser General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or (at your
10 option) any later version.
11 
12 The GNU MP Library is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
15 License for more details.
16 
17 You should have received a copy of the GNU Lesser General Public License
18 along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
19 
20 #include <stdio.h>
21 #include <string.h>
22 #include "gmp.h"
23 #include "expr-impl.h"
24 
25 
26 /* Change this to "#define TRACE(x) x" to get some traces. */
27 #define TRACE(x)
28 
29 
30 static void
31 e_mpq_pow_ui (mpq_ptr r, mpq_srcptr b, unsigned long e)
32 {
33   mpz_pow_ui (mpq_numref(r), mpq_numref(b), e);
34   mpz_pow_ui (mpq_denref(r), mpq_denref(b), e);
35 }
36 
37 /* Wrapped because mpq_sgn is a macro. */
38 static int
39 e_mpq_sgn (mpq_srcptr x)
40 {
41   return mpq_sgn (x);
42 }
43 
44 /* Wrapped because mpq_equal only guarantees a non-zero return, whereas we
45    want 1 or 0 for == and !=. */
46 static int
47 e_mpq_equal (mpq_srcptr x, mpq_srcptr y)
48 {
49   return mpq_equal (x, y) != 0;
50 }
51 static int
52 e_mpq_notequal (mpq_srcptr x, mpq_srcptr y)
53 {
54   return ! mpq_equal (x, y);
55 }
56 
57 static void
58 e_mpq_num (mpq_ptr w, mpq_srcptr x)
59 {
60   if (w != x)
61     mpz_set (mpq_numref(w), mpq_numref(x));
62   mpz_set_ui (mpq_denref(w), 1L);
63 }
64 static void
65 e_mpq_den (mpq_ptr w, mpq_srcptr x)
66 {
67   if (w == x)
68     mpz_swap (mpq_numref(w), mpq_denref(w));
69   else
70     mpz_set (mpq_numref(w), mpq_denref(x));
71   mpz_set_ui (mpq_denref(w), 1L);
72 }
73 
74 
75 static const struct mpexpr_operator_t  _mpq_expr_standard_table[] = {
76 
77   { "**",  (mpexpr_fun_t) e_mpq_pow_ui,
78     MPEXPR_TYPE_BINARY_UI | MPEXPR_TYPE_RIGHTASSOC,                   220 },
79 
80   { "!",   (mpexpr_fun_t) e_mpq_sgn,
81     MPEXPR_TYPE_LOGICAL_NOT | MPEXPR_TYPE_PREFIX,                     210 },
82   { "-",   (mpexpr_fun_t) mpq_neg,
83     MPEXPR_TYPE_UNARY | MPEXPR_TYPE_PREFIX,                           210 },
84 
85   { "*",   (mpexpr_fun_t) mpq_mul,           MPEXPR_TYPE_BINARY,      200 },
86   { "/",   (mpexpr_fun_t) mpq_div,           MPEXPR_TYPE_BINARY,      200 },
87 
88   { "+",   (mpexpr_fun_t) mpq_add,           MPEXPR_TYPE_BINARY,      190 },
89   { "-",   (mpexpr_fun_t) mpq_sub,           MPEXPR_TYPE_BINARY,      190 },
90 
91   { "<<",  (mpexpr_fun_t) mpq_mul_2exp,      MPEXPR_TYPE_BINARY_UI,   180 },
92   { ">>",  (mpexpr_fun_t) mpq_div_2exp,      MPEXPR_TYPE_BINARY_UI,   180 },
93 
94   { "<=",  (mpexpr_fun_t) mpq_cmp,           MPEXPR_TYPE_CMP_LE,      170 },
95   { "<",   (mpexpr_fun_t) mpq_cmp,           MPEXPR_TYPE_CMP_LT,      170 },
96   { ">=",  (mpexpr_fun_t) mpq_cmp,           MPEXPR_TYPE_CMP_GE,      170 },
97   { ">",   (mpexpr_fun_t) mpq_cmp,           MPEXPR_TYPE_CMP_GT,      170 },
98 
99   { "==",  (mpexpr_fun_t) e_mpq_equal,       MPEXPR_TYPE_I_BINARY,    160 },
100   { "!=",  (mpexpr_fun_t) e_mpq_notequal,    MPEXPR_TYPE_I_BINARY,    160 },
101 
102   { "&&",  (mpexpr_fun_t) e_mpq_sgn,         MPEXPR_TYPE_LOGICAL_AND, 120 },
103   { "||",  (mpexpr_fun_t) e_mpq_sgn,         MPEXPR_TYPE_LOGICAL_OR,  110 },
104 
105   { ":",   NULL,                             MPEXPR_TYPE_COLON,       101 },
106   { "?",   (mpexpr_fun_t) e_mpq_sgn,         MPEXPR_TYPE_QUESTION,    100 },
107 
108   { ")",   (mpexpr_fun_t) e_mpq_sgn,         MPEXPR_TYPE_CLOSEPAREN,    4 },
109   { "(",   (mpexpr_fun_t) e_mpq_sgn,         MPEXPR_TYPE_OPENPAREN,     3 },
110   { ",",   (mpexpr_fun_t) e_mpq_sgn,         MPEXPR_TYPE_ARGSEP,        2 },
111   { "$",   NULL,                             MPEXPR_TYPE_VARIABLE,      1 },
112 
113   { "abs",  (mpexpr_fun_t) mpq_abs,          MPEXPR_TYPE_UNARY            },
114   { "cmp",  (mpexpr_fun_t) mpq_cmp,          MPEXPR_TYPE_I_BINARY         },
115   { "den",  (mpexpr_fun_t) e_mpq_den,        MPEXPR_TYPE_UNARY            },
116   { "max",  (mpexpr_fun_t) mpq_cmp,  MPEXPR_TYPE_MAX | MPEXPR_TYPE_PAIRWISE },
117   { "min",  (mpexpr_fun_t) mpq_cmp,  MPEXPR_TYPE_MIN | MPEXPR_TYPE_PAIRWISE },
118   { "num",  (mpexpr_fun_t) e_mpq_num,        MPEXPR_TYPE_UNARY            },
119   { "sgn",  (mpexpr_fun_t) e_mpq_sgn,        MPEXPR_TYPE_I_UNARY          },
120 
121   { NULL }
122 };
123 
124 const struct mpexpr_operator_t * const mpq_expr_standard_table
125 = _mpq_expr_standard_table;
126 
127 
128 int
129 #if HAVE_STDARG
130 mpq_expr (mpq_ptr res, int base, const char *e, ...)
131 #else
132 mpq_expr (va_alist)
133      va_dcl
134 #endif
135 {
136   mpq_srcptr  var[MPEXPR_VARIABLES];
137   va_list     ap;
138   int         ret;
139 #if HAVE_STDARG
140   va_start (ap, e);
141 #else
142   mpq_ptr     res;
143   int         base;
144   const char  *e;
145   va_start (ap);
146   res  = va_arg (ap, mpq_ptr);
147   base = va_arg (ap, int);
148   e    = va_arg (ap, const char *);
149 #endif
150 
151   TRACE (printf ("mpq_expr(): base %d, %s\n", base, e));
152   ret = mpexpr_va_to_var ((void **) var, ap);
153   va_end (ap);
154 
155   if (ret != MPEXPR_RESULT_OK)
156     return ret;
157 
158   return mpq_expr_a (mpq_expr_standard_table, res, base, e, strlen(e), var);
159 }
160