xref: /PHP-7.0/ext/bcmath/libbcmath/src/str2num.c (revision 9aa6898b)
1 /* str2num.c: bcmath library file. */
2 /*
3     Copyright (C) 1991, 1992, 1993, 1994, 1997 Free Software Foundation, Inc.
4     Copyright (C) 2000 Philip A. Nelson
5 
6     This library is free software; you can redistribute it and/or
7     modify it under the terms of the GNU Lesser General Public
8     License as published by the Free Software Foundation; either
9     version 2 of the License, or (at your option) any later version.
10 
11     This library is distributed in the hope that it will be useful,
12     but WITHOUT ANY WARRANTY; without even the implied warranty of
13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14     Lesser General Public License for more details.  (COPYING.LIB)
15 
16     You should have received a copy of the GNU Lesser General Public
17     License along with this library; if not, write to:
18 
19       The Free Software Foundation, Inc.
20       59 Temple Place, Suite 330
21       Boston, MA 02111-1307 USA.
22 
23     You may contact the author by:
24        e-mail:  philnelson@acm.org
25       us-mail:  Philip A. Nelson
26                 Computer Science Department, 9062
27                 Western Washington University
28                 Bellingham, WA 98226-9062
29 
30 *************************************************************************/
31 
32 #include <config.h>
33 #include <stdio.h>
34 #include <assert.h>
35 #include <stdlib.h>
36 #include <ctype.h>
37 #include <stdarg.h>
38 #include "bcmath.h"
39 #include "private.h"
40 
41 /* Convert strings to bc numbers.  Base 10 only.*/
42 
43 void
bc_str2num(bc_num * num,char * str,int scale)44 bc_str2num (bc_num *num, char *str, int scale)
45 {
46   int digits, strscale;
47   char *ptr, *nptr;
48   char zero_int;
49 
50   /* Prepare num. */
51   bc_free_num (num);
52 
53   /* Check for valid number and count digits. */
54   ptr = str;
55   digits = 0;
56   strscale = 0;
57   zero_int = FALSE;
58   if ( (*ptr == '+') || (*ptr == '-'))  ptr++;  /* Sign */
59   while (*ptr == '0') ptr++;			/* Skip leading zeros. */
60   while (isdigit((int)*ptr)) ptr++, digits++;	/* digits */
61   if (*ptr == '.') ptr++;			/* decimal point */
62   while (isdigit((int)*ptr)) ptr++, strscale++;	/* digits */
63   if ((*ptr != '\0') || (digits+strscale == 0))
64     {
65       *num = bc_copy_num (BCG(_zero_));
66       return;
67     }
68 
69   /* Adjust numbers and allocate storage and initialize fields. */
70   strscale = MIN(strscale, scale);
71   if (digits == 0)
72     {
73       zero_int = TRUE;
74       digits = 1;
75     }
76   *num = bc_new_num (digits, strscale);
77 
78   /* Build the whole number. */
79   ptr = str;
80   if (*ptr == '-')
81     {
82       (*num)->n_sign = MINUS;
83       ptr++;
84     }
85   else
86     {
87       (*num)->n_sign = PLUS;
88       if (*ptr == '+') ptr++;
89     }
90   while (*ptr == '0') ptr++;			/* Skip leading zeros. */
91   nptr = (*num)->n_value;
92   if (zero_int)
93     {
94       *nptr++ = 0;
95       digits = 0;
96     }
97   for (;digits > 0; digits--)
98     *nptr++ = CH_VAL(*ptr++);
99 
100 
101   /* Build the fractional part. */
102   if (strscale > 0)
103     {
104       ptr++;  /* skip the decimal point! */
105       for (;strscale > 0; strscale--)
106 	*nptr++ = CH_VAL(*ptr++);
107     }
108 
109   if (bc_is_zero (*num))
110     (*num)->n_sign = PLUS;
111 }
112 
113