Mercurial > cpython-lru_cache-weakref
view Python/atof.c @ 48345:cb871f736be0
merge error: test.test_support is now test.support
| author | Amaury Forgeot d'Arc <amauryfa@gmail.com> |
|---|---|
| date | Thu, 19 Jun 2008 22:03:50 +0000 |
| parents | 2dea40e40d9d |
| children | fd25030223b0 |
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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 "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; }
