1/* mpq_get_str -- mpq to string conversion. 2 3Copyright 2001, 2002, 2006 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#include <stdio.h> 21#include <string.h> 22#include "gmp.h" 23#include "gmp-impl.h" 24 25char * 26mpq_get_str (char *str, int base, mpq_srcptr q) 27{ 28 size_t str_alloc, len; 29 30 ASSERT (ABS(base) >= 2); 31 ASSERT (ABS(base) <= 62); 32 33 str_alloc = 0; 34 if (str == NULL) 35 { 36 /* This is an overestimate since we don't bother checking how much of 37 the high limbs of num and den are used. +2 for rounding up the 38 chars per bit of num and den. +3 for sign, slash and '\0'. */ 39 str_alloc = ((size_t) ((ABS (q->_mp_num._mp_size) + q->_mp_den._mp_size) 40 * GMP_LIMB_BITS 41 * mp_bases[ABS(base)].chars_per_bit_exactly)) 42 + 5; 43 str = (char *) (*__gmp_allocate_func) (str_alloc); 44 } 45 46 mpz_get_str (str, base, mpq_numref(q)); 47 len = strlen (str); 48 if (! MPZ_EQUAL_1_P (mpq_denref (q))) 49 { 50 str[len++] = '/'; 51 mpz_get_str (str+len, base, mpq_denref(q)); 52 len += strlen (str+len); 53 } 54 55 ASSERT (len == strlen(str)); 56 ASSERT (str_alloc == 0 || len+1 <= str_alloc); 57 ASSERT (len+1 <= /* size recommended to applications */ 58 mpz_sizeinbase (mpq_numref(q), ABS(base)) + 59 mpz_sizeinbase (mpq_denref(q), ABS(base)) + 3); 60 61 if (str_alloc != 0) 62 __GMP_REALLOCATE_FUNC_MAYBE_TYPE (str, str_alloc, len+1, char); 63 64 return str; 65} 66