mirror of
https://github.com/0intro/wmii
synced 2024-11-30 01:23:12 +03:00
86 lines
2.0 KiB
C
86 lines
2.0 KiB
C
/*
|
|
* The authors of this software are Rob Pike and Ken Thompson.
|
|
* Copyright (c) 2002 by Lucent Technologies.
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
* purpose without fee is hereby granted, provided that this entire notice
|
|
* is included in all copies of any software which is or includes a copy
|
|
* or modification of this software and in all copies of the supporting
|
|
* documentation for such software.
|
|
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
|
|
* WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE
|
|
* ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
|
|
* OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
|
|
*/
|
|
#include <stdarg.h>
|
|
#include <string.h>
|
|
#include "plan9.h"
|
|
#include "fmt.h"
|
|
#include "fmtdef.h"
|
|
|
|
/*
|
|
* Reads a floating-point number by interpreting successive characters
|
|
* returned by (*f)(vp). The last call it makes to f terminates the
|
|
* scan, so is not a character in the number. It may therefore be
|
|
* necessary to back up the input stream up one byte after calling charstod.
|
|
*/
|
|
|
|
double
|
|
fmtcharstod(int(*f)(void*), void *vp)
|
|
{
|
|
double num, dem;
|
|
int neg, eneg, dig, exp, c;
|
|
|
|
num = 0;
|
|
neg = 0;
|
|
dig = 0;
|
|
exp = 0;
|
|
eneg = 0;
|
|
|
|
c = (*f)(vp);
|
|
while(c == ' ' || c == '\t')
|
|
c = (*f)(vp);
|
|
if(c == '-' || c == '+'){
|
|
if(c == '-')
|
|
neg = 1;
|
|
c = (*f)(vp);
|
|
}
|
|
while(c >= '0' && c <= '9'){
|
|
num = num*10 + c-'0';
|
|
c = (*f)(vp);
|
|
}
|
|
if(c == '.')
|
|
c = (*f)(vp);
|
|
while(c >= '0' && c <= '9'){
|
|
num = num*10 + c-'0';
|
|
dig++;
|
|
c = (*f)(vp);
|
|
}
|
|
if(c == 'e' || c == 'E'){
|
|
c = (*f)(vp);
|
|
if(c == '-' || c == '+'){
|
|
if(c == '-'){
|
|
dig = -dig;
|
|
eneg = 1;
|
|
}
|
|
c = (*f)(vp);
|
|
}
|
|
while(c >= '0' && c <= '9'){
|
|
exp = exp*10 + c-'0';
|
|
c = (*f)(vp);
|
|
}
|
|
}
|
|
exp -= dig;
|
|
if(exp < 0){
|
|
exp = -exp;
|
|
eneg = !eneg;
|
|
}
|
|
dem = __fmtpow10(exp);
|
|
if(eneg)
|
|
num /= dem;
|
|
else
|
|
num *= dem;
|
|
if(neg)
|
|
return -num;
|
|
return num;
|
|
}
|