num2str.c

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/* num2str.c: bcmath library file. */
/*
    Copyright (C) 1991, 1992, 1993, 1994, 1997 Free Software Foundation, Inc.
    Copyright (C) 2000 Philip A. Nelson
 
    This 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 2 of the License, or (at your option) any later version.
 
    This 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.  (LICENSE)
 
    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to:
 
      The Free Software Foundation, Inc.
      59 Temple Place, Suite 330
      Boston, MA 02111-1307 USA.
 
    You may contact the author by:
       e-mail:  philnelson@acm.org
      us-mail:  Philip A. Nelson
                Computer Science Department, 9062
                Western Washington University
                Bellingham, WA 98226-9062
 
*************************************************************************/
 
#include "bcmath.h"
#include "convert.h"
#include "zend_string.h"
 
/* Convert a numbers to a string.  Base 10 only.*/
zend_string *bc_num2str_ex(bc_num num, size_t scale)
{
    zend_string *str;
    char *sptr;
    size_t index;
    bool signch;
    size_t min_scale = MIN(num->n_scale, scale);
 
    /* Number of sign chars. */
    signch = num->n_sign != PLUS && !bc_is_zero_for_scale(num, min_scale);
    /* Allocate the string memory. */
    if (scale > 0) {
        str = zend_string_alloc(num->n_len + scale + signch + 1, 0);
    } else {
        str = zend_string_alloc(num->n_len + signch, 0);
    }
 
    /* The negative sign if needed. */
    sptr = ZSTR_VAL(str);
    if (signch) *sptr++ = '-';
 
    /* Load the whole number. */
    const char *nptr = num->n_value;
    sptr = bc_copy_and_toggle_bcd(sptr, nptr, nptr + num->n_len);
    nptr += num->n_len;
 
    /* Now the fraction. */
    if (scale > 0) {
        *sptr++ = '.';
        sptr = bc_copy_and_toggle_bcd(sptr, nptr, nptr + min_scale);
        for (index = num->n_scale; index < scale; index++) {
            *sptr++ = BCD_CHAR(0);
        }
    }
 
    /* Terminate the string and return it! */
    *sptr = '\0';
    ZSTR_LEN(str) = sptr - (char *)ZSTR_VAL(str);
    return str;
}