Mercurial > cpython-lru_cache-weakref
view Python/atof.c @ 16413:8819867f14ef legacy-trunk
Patch derived from Trent's 101162: a Python/C API testing framework.
STILL NEEDS UNIX BUILD CHANGES.
| author | Tim Peters <tim.peters@gmail.com> |
|---|---|
| date | Fri, 02 Feb 2001 05:57:15 +0000 |
| parents | 6f6f965c5e2d |
| children | 2dea40e40d9d |
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/* Just in case you haven't got an atof() around... This one doesn't check for bad syntax or overflow, and is slow and inaccurate. But it's good enough for the occasional string literal... */ #include "config.h" #include <ctype.h> double atof(char *s) { double a = 0.0; int e = 0; int c; while ((c = *s++) != '\0' && isdigit(c)) { a = a*10.0 + (c - '0'); } if (c == '.') { while ((c = *s++) != '\0' && isdigit(c)) { a = a*10.0 + (c - '0'); e = e-1; } } if (c == 'e' || c == 'E') { int sign = 1; int i = 0; c = *s++; if (c == '+') c = *s++; else if (c == '-') { c = *s++; sign = -1; } while (isdigit(c)) { i = i*10 + (c - '0'); c = *s++; } e += i*sign; } while (e > 0) { a *= 10.0; e--; } while (e < 0) { a *= 0.1; e++; } return a; }
