diff options
Diffstat (limited to 'Objects/floatobject.c')
| -rw-r--r-- | Objects/floatobject.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/Objects/floatobject.c b/Objects/floatobject.c index e563583..8533e0e 100644 --- a/Objects/floatobject.c +++ b/Objects/floatobject.c @@ -145,6 +145,38 @@ float_compare(v, w) return (i < j) ? -1 : (i > j) ? 1 : 0; } +static long +float_hash(v) + floatobject *v; +{ + double intpart, fractpart; + int expo; + long x; + /* This is designed so that Python numbers with the same + value hash to the same value, otherwise comparisons + of mapping keys will turn out weird */ + fractpart = modf(v->ob_fval, &intpart); + if (fractpart == 0.0) { + if (intpart > 0x7fffffffL || -intpart > 0x7fffffffL) { + /* Convert to long int and use its hash... */ + object *w = dnewlongobject(v->ob_fval); + if (w == NULL) + return -1; + x = hashobject(w); + DECREF(w); + return x; + } + x = (long)intpart; + } + else { + fractpart = frexp(fractpart, &expo); + x = (long) (intpart + fractpart) ^ expo; /* Rather arbitrary */ + } + if (x == -1) + x = -2; + return x; +} + static object * float_add(v, w) floatobject *v; @@ -378,4 +410,5 @@ typeobject Floattype = { &float_as_number, /*tp_as_number*/ 0, /*tp_as_sequence*/ 0, /*tp_as_mapping*/ + float_hash, /*tp_hash */ }; |