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      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
     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
     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
     58 e_mpq_equal (mpq_srcptr x, mpq_srcptr y)
     59 {
     60   return mpq_equal (x, y) != 0;
     61 }
     62 static int
     63 e_mpq_notequal (mpq_srcptr x, mpq_srcptr y)
     64 {
     65   return ! mpq_equal (x, y);
     66 }
     67 
     68 static void
     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
     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
    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