Mercurial > cpython-lru_cache-weakref
view Python/atof.c @ 31965:ef34dec004cd legacy-trunk
Stacks based on lists work better and read more clearly when they
grow and shrink on the right.
| author | Raymond Hettinger <python@rcn.com> |
|---|---|
| date | Tue, 04 May 2004 08:21:52 +0000 |
| parents | 2dea40e40d9d |
| children | fd25030223b0 |
line wrap: on
line source
/* 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 "pyconfig.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; }
