1 /* mpq_get_str -- mpq to string conversion. 2 3 Copyright 2001, 2002, 2006, 2011 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 the GNU Lesser General Public License as published by 9 the Free Software Foundation; either version 3 of the License, or (at your 10 option) any later version. 11 12 The GNU MP Library is distributed in the hope that it will be useful, but 13 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 15 License for more details. 16 17 You should have received a copy of the GNU Lesser General Public License 18 along 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 #include "longlong.h" 25 26 char * 27 mpq_get_str (char *str, int base, mpq_srcptr q) 28 { 29 size_t str_alloc, len; 30 31 if (base > 62 || base < -36) 32 return NULL; 33 34 str_alloc = 0; 35 if (str == NULL) 36 { 37 /* This is an overestimate since we don't bother checking how much of 38 the high limbs of num and den are used. +2 for rounding up the 39 chars per bit of num and den. +3 for sign, slash and '\0'. */ 40 DIGITS_IN_BASE_PER_LIMB (str_alloc, ABSIZ(NUM(q)) + SIZ(DEN(q)), ABS(base)); 41 str_alloc += 6; 42 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