1/* mpq expression evaluation
2
3Copyright 2000, 2001, 2004 Free Software Foundation, Inc.
4
5This file is part of the GNU MP Library.
6
7The GNU MP Library is free software; you can redistribute it and/or modify
8it under the terms of the GNU Lesser General Public License as published by
9the Free Software Foundation; either version 3 of the License, or (at your
10option) any later version.
11
12The GNU MP Library is distributed in the hope that it will be useful, but
13WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
15License for more details.
16
17You should have received a copy of the GNU Lesser General Public License
18along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
19
20
21#include <stdio.h>
22#include "gmp.h"
23#include "expr-impl.h"
24
25
26static int
27e_mpq_ulong_p (mpq_srcptr q)
28{
29  return mpz_fits_ulong_p (mpq_numref (q))
30    && mpz_cmp_ui (mpq_denref (q), 1L) == 0;
31}
32
33/* get value as a ui, on the assumption it fits */
34static int
35e_mpq_get_ui_fits (mpq_srcptr q)
36{
37  return mpz_get_ui (mpq_numref (q));
38}
39
40static void
41e_mpq_set_si1 (mpq_ptr q, long num)
42{
43  mpq_set_si (q, num, 1L);
44}
45
46/* The same as mpz, but putting the result in the numerator.  Negatives and
47   fractions aren't parsed here because '-' and '/' are operators. */
48static size_t
49e_mpq_number (mpq_ptr res, __gmp_const char *e, size_t elen, int base)
50{
51  mpz_set_ui (mpq_denref (res), 1L);
52  return mpexpr_mpz_number (mpq_numref (res), e, elen, base);
53}
54
55
56/* ignoring prec */
57static void
58e_mpq_init (mpq_ptr q, unsigned long prec)
59{
60  mpq_init (q);
61}
62
63int
64mpq_expr_a (__gmp_const struct mpexpr_operator_t *table,
65            mpq_ptr res, int base,
66            __gmp_const char *e, size_t elen,
67            mpq_srcptr var[26])
68{
69  struct mpexpr_parse_t  p;
70
71  p.table = table;
72  p.res = (mpX_ptr) res;
73  p.base = base;
74  p.e = e;
75  p.elen = elen;
76  p.var = (mpX_srcptr *) var;
77
78  p.mpX_clear       = (mpexpr_fun_one_t)      mpq_clear;
79  p.mpX_ulong_p     = (mpexpr_fun_i_unary_t)  e_mpq_ulong_p;
80  p.mpX_get_ui      = (mpexpr_fun_get_ui_t)   e_mpq_get_ui_fits;
81  p.mpX_init        = (mpexpr_fun_unary_ui_t) e_mpq_init;
82  p.mpX_number      = (mpexpr_fun_number_t)   e_mpq_number;
83  p.mpX_set         = (mpexpr_fun_unary_t)    mpq_set;
84  p.mpX_set_or_swap = (mpexpr_fun_unary_t)    mpq_swap;
85  p.mpX_set_si      = (mpexpr_fun_set_si_t)   e_mpq_set_si1;
86  p.mpX_swap        = (mpexpr_fun_swap_t)     mpq_swap;
87
88  return mpexpr_evaluate (&p);
89}
90