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
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