1 85231fd8 2006-05-21 devnull /* Copyright (c) 2002-2006 Lucent Technologies; see LICENSE */
2 91c13e54 2004-02-29 devnull #include <stdarg.h>
3 91c13e54 2004-02-29 devnull #include <string.h>
4 e5aa96ac 2004-12-26 devnull #include "plan9.h"
5 91c13e54 2004-02-29 devnull #include "fmt.h"
6 91c13e54 2004-02-29 devnull #include "fmtdef.h"
9 91c13e54 2004-02-29 devnull * Reads a floating-point number by interpreting successive characters
10 91c13e54 2004-02-29 devnull * returned by (*f)(vp). The last call it makes to f terminates the
11 91c13e54 2004-02-29 devnull * scan, so is not a character in the number. It may therefore be
12 91c13e54 2004-02-29 devnull * necessary to back up the input stream up one byte after calling charstod.
16 91c13e54 2004-02-29 devnull fmtcharstod(int(*f)(void*), void *vp)
18 91c13e54 2004-02-29 devnull double num, dem;
19 91c13e54 2004-02-29 devnull int neg, eneg, dig, exp, c;
25 91c13e54 2004-02-29 devnull eneg = 0;
27 91c13e54 2004-02-29 devnull c = (*f)(vp);
28 91c13e54 2004-02-29 devnull while(c == ' ' || c == '\t')
29 91c13e54 2004-02-29 devnull c = (*f)(vp);
30 91c13e54 2004-02-29 devnull if(c == '-' || c == '+'){
31 91c13e54 2004-02-29 devnull if(c == '-')
33 91c13e54 2004-02-29 devnull c = (*f)(vp);
35 91c13e54 2004-02-29 devnull while(c >= '0' && c <= '9'){
36 91c13e54 2004-02-29 devnull num = num*10 + c-'0';
37 91c13e54 2004-02-29 devnull c = (*f)(vp);
39 91c13e54 2004-02-29 devnull if(c == '.')
40 91c13e54 2004-02-29 devnull c = (*f)(vp);
41 91c13e54 2004-02-29 devnull while(c >= '0' && c <= '9'){
42 91c13e54 2004-02-29 devnull num = num*10 + c-'0';
44 91c13e54 2004-02-29 devnull c = (*f)(vp);
46 91c13e54 2004-02-29 devnull if(c == 'e' || c == 'E'){
47 91c13e54 2004-02-29 devnull c = (*f)(vp);
48 91c13e54 2004-02-29 devnull if(c == '-' || c == '+'){
49 91c13e54 2004-02-29 devnull if(c == '-'){
50 91c13e54 2004-02-29 devnull dig = -dig;
51 91c13e54 2004-02-29 devnull eneg = 1;
53 91c13e54 2004-02-29 devnull c = (*f)(vp);
55 91c13e54 2004-02-29 devnull while(c >= '0' && c <= '9'){
56 91c13e54 2004-02-29 devnull exp = exp*10 + c-'0';
57 91c13e54 2004-02-29 devnull c = (*f)(vp);
60 91c13e54 2004-02-29 devnull exp -= dig;
61 91c13e54 2004-02-29 devnull if(exp < 0){
62 91c13e54 2004-02-29 devnull exp = -exp;
63 91c13e54 2004-02-29 devnull eneg = !eneg;
65 91c13e54 2004-02-29 devnull dem = __fmtpow10(exp);
67 91c13e54 2004-02-29 devnull num /= dem;
69 91c13e54 2004-02-29 devnull num *= dem;
71 91c13e54 2004-02-29 devnull return -num;
72 91c13e54 2004-02-29 devnull return num;