Showing the changes to sys/src/cmd/python/Python/atof.c (1 of 3706 files). Show all
Unified · Split
| @@ -0,0 +1,50 @@ | |||
| 1 | |||
| 2 | /* Just in case you haven't got an atof() around... | ||
| 3 | This one doesn't check for bad syntax or overflow, | ||
| 4 | and is slow and inaccurate. | ||
| 5 | But it's good enough for the occasional string literal... */ | ||
| 6 | |||
| 7 | #include "pyconfig.h" | ||
| 8 | |||
| 9 | #include <ctype.h> | ||
| 10 | |||
| 11 | double atof(char *s) | ||
| 12 | { | ||
| 13 | double a = 0.0; | ||
| 14 | int e = 0; | ||
| 15 | int c; | ||
| 16 | while ((c = *s++) != '\0' && isdigit(c)) { | ||
| 17 | a = a*10.0 + (c - '0'); | ||
| 18 | } | ||
| 19 | if (c == '.') { | ||
| 20 | while ((c = *s++) != '\0' && isdigit(c)) { | ||
| 21 | a = a*10.0 + (c - '0'); | ||
| 22 | e = e-1; | ||
| 23 | } | ||
| 24 | } | ||
| 25 | if (c == 'e' || c == 'E') { | ||
| 26 | int sign = 1; | ||
| 27 | int i = 0; | ||
| 28 | c = *s++; | ||
| 29 | if (c == '+') | ||
| 30 | c = *s++; | ||
| 31 | else if (c == '-') { | ||
| 32 | c = *s++; | ||
| 33 | sign = -1; | ||
| 34 | } | ||
| 35 | while (isdigit(c)) { | ||
| 36 | i = i*10 + (c - '0'); | ||
| 37 | c = *s++; | ||
| 38 | } | ||
| 39 | e += i*sign; | ||
| 40 | } | ||
| 41 | while (e > 0) { | ||
| 42 | a *= 10.0; | ||
| 43 | e--; | ||
| 44 | } | ||
| 45 | while (e < 0) { | ||
| 46 | a *= 0.1; | ||
| 47 | e++; | ||
| 48 | } | ||
| 49 | return a; | ||
| 50 | } | ||