exprfa.c
上传用户:qaz666999
上传日期:2022-08-06
资源大小:2570k
文件大小:4k
- /* mpf expression evaluation
- Copyright 2000, 2001, 2002, 2004 Free Software Foundation, Inc.
- This file is part of the GNU MP Library.
- The GNU MP Library is free software; you can redistribute it and/or modify
- it under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 3 of the License, or (at your
- option) any later version.
- The GNU MP Library is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
- License for more details.
- You should have received a copy of the GNU Lesser General Public License
- along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
- /* Future: Bitwise "&", "|" and "&" could be done, if desired. Not sure
- those functions would be much value though. */
- #include <ctype.h>
- #include <stdio.h>
- #include <string.h>
- #include "gmp.h"
- #include "expr-impl.h"
- /* Change this to "#define TRACE(x) x" to get some traces. */
- #define TRACE(x)
- static size_t
- e_mpf_number (mpf_ptr res, __gmp_const char *e, size_t elen, int base)
- {
- char *edup;
- size_t i, ret, extra=0;
- int mant_base, exp_base;
- void *(*allocate_func) (size_t);
- void (*free_func) (void *, size_t);
- TRACE (printf ("mpf_number base=%d "%.*s"n", base, (int) elen, e));
- /* mpf_set_str doesn't currently accept 0x for hex in base==0, so do it
- here instead. FIXME: Would prefer to let mpf_set_str handle this. */
- if (base == 0 && elen >= 2 && e[0] == '0' && (e[1] == 'x' || e[1] == 'X'))
- {
- base = 16;
- extra = 2;
- e += extra;
- elen -= extra;
- }
- if (base == 0)
- mant_base = 10;
- else if (base < 0)
- mant_base = -base;
- else
- mant_base = base;
- /* exponent in decimal if base is negative */
- if (base < 0)
- exp_base = 10;
- else if (base == 0)
- exp_base = 10;
- else
- exp_base = base;
- #define IS_EXPONENT(c)
- (c == '@' || (base <= 10 && base >= -10 && (e[i] == 'e' || e[i] == 'E')))
- i = 0;
- for (;;)
- {
- if (i >= elen)
- goto parsed;
- if (e[i] == '.')
- break;
- if (IS_EXPONENT (e[i]))
- goto exponent;
- if (! isasciidigit_in_base (e[i], mant_base))
- goto parsed;
- i++;
- }
- /* fraction */
- i++;
- for (;;)
- {
- if (i >= elen)
- goto parsed;
- if (IS_EXPONENT (e[i]))
- goto exponent;
- if (! isasciidigit_in_base (e[i], mant_base))
- goto parsed;
- i++;
- }
- exponent:
- i++;
- if (i >= elen)
- goto parsed;
- if (e[i] == '-')
- i++;
- for (;;)
- {
- if (i >= elen)
- goto parsed;
- if (! isasciidigit_in_base (e[i], exp_base))
- break;
- i++;
- }
- parsed:
- TRACE (printf (" parsed i=%u "%.*s"n", i, (int) i, e));
- mp_get_memory_functions (&allocate_func, NULL, &free_func);
- edup = (*allocate_func) (i+1);
- memcpy (edup, e, i);
- edup[i] = ' ';
- if (mpf_set_str (res, edup, base) == 0)
- ret = i + extra;
- else
- ret = 0;
- (*free_func) (edup, i+1);
- return ret;
- }
- static int
- e_mpf_ulong_p (mpf_srcptr f)
- {
- return mpf_integer_p (f) && mpf_fits_ulong_p (f);
- }
- /* Don't want to change the precision of w, can only do an actual swap when
- w and x have the same precision. */
- static void
- e_mpf_set_or_swap (mpf_ptr w, mpf_ptr x)
- {
- if (mpf_get_prec (w) == mpf_get_prec (x))
- mpf_swap (w, x);
- else
- mpf_set (w, x);
- }
- int
- mpf_expr_a (__gmp_const struct mpexpr_operator_t *table,
- mpf_ptr res, int base, unsigned long prec,
- __gmp_const char *e, size_t elen,
- mpf_srcptr var[26])
- {
- struct mpexpr_parse_t p;
- p.table = table;
- p.res = (mpX_ptr) res;
- p.base = base;
- p.prec = prec;
- p.e = e;
- p.elen = elen;
- p.var = (mpX_srcptr *) var;
- p.mpX_clear = (mpexpr_fun_one_t) mpf_clear;
- p.mpX_ulong_p = (mpexpr_fun_i_unary_t) e_mpf_ulong_p;
- p.mpX_get_ui = (mpexpr_fun_get_ui_t) mpf_get_ui;
- p.mpX_init = (mpexpr_fun_unary_ui_t) mpf_init2;
- p.mpX_number = (mpexpr_fun_number_t) e_mpf_number;
- p.mpX_set = (mpexpr_fun_unary_t) mpf_set;
- p.mpX_set_or_swap = (mpexpr_fun_unary_t) e_mpf_set_or_swap;
- p.mpX_set_si = (mpexpr_fun_set_si_t) mpf_set_si;
- p.mpX_swap = (mpexpr_fun_swap_t) mpf_swap;
- return mpexpr_evaluate (&p);
- }