diff options
Diffstat (limited to 'gmp-6.3.0/demos/expr/exprfa.c')
| -rw-r--r-- | gmp-6.3.0/demos/expr/exprfa.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/gmp-6.3.0/demos/expr/exprfa.c b/gmp-6.3.0/demos/expr/exprfa.c new file mode 100644 index 0000000..1918cb5 --- /dev/null +++ b/gmp-6.3.0/demos/expr/exprfa.c @@ -0,0 +1,191 @@ +/* mpf expression evaluation + +Copyright 2000-2002, 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 either: + + * 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. + +or + + * the GNU General Public License as published by the Free Software + Foundation; either version 2 of the License, or (at your option) any + later version. + +or both in parallel, as here. + +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 General Public License +for more details. + +You should have received copies of the GNU General Public License and the +GNU Lesser General Public License along with the GNU MP Library. If not, +see https://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, 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] = '\0'; + + 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 (const struct mpexpr_operator_t *table, + mpf_ptr res, int base, unsigned long prec, + 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); +} |