diff options
Diffstat (limited to 'Objects')
| -rw-r--r-- | Objects/object.c | 37 | ||||
| -rw-r--r-- | Objects/typeobject.c | 13 |
2 files changed, 18 insertions, 32 deletions
diff --git a/Objects/object.c b/Objects/object.c index 85dbd28..49c9852 100644 --- a/Objects/object.c +++ b/Objects/object.c @@ -500,35 +500,19 @@ PyObject_Bytes(PyObject *v) return PyBytes_FromObject(v); } -/* The new comparison philosophy is: we completely separate three-way - comparison from rich comparison. That is, PyObject_Compare() and - PyObject_Cmp() *just* use the tp_compare slot. And PyObject_RichCompare() - and PyObject_RichCompareBool() *just* use the tp_richcompare slot. +/* For Python 3.0.1 and later, the old three-way comparison has been + completely removed in favour of rich comparisons. PyObject_Compare() and + PyObject_Cmp() are gone, and the builtin cmp function no longer exists. + The old tp_compare slot will be renamed to tp_reserved, and should no + longer be used. Use tp_richcompare instead. See (*) below for practical amendments. - IOW, only cmp() uses tp_compare; the comparison operators (==, !=, <=, <, - >=, >) only use tp_richcompare. Note that list.sort() only uses <. + tp_richcompare gets called with a first argument of the appropriate type + and a second object of an arbitrary type. We never do any kind of + coercion. - (And yes, eventually we'll rip out cmp() and tp_compare.) - - The calling conventions are different: tp_compare only gets called with two - objects of the appropriate type; tp_richcompare gets called with a first - argument of the appropriate type and a second object of an arbitrary type. - We never do any kind of coercion. - - The return conventions are also different. - - The tp_compare slot should return a C int, as follows: - - -1 if a < b or if an exception occurred - 0 if a == b - +1 if a > b - - No other return values are allowed. PyObject_Compare() has the same - calling convention. - - The tp_richcompare slot should return an object, as follows: + The tp_richcompare slot should return an object, as follows: NULL if an exception occurred NotImplemented if the requested comparison is not implemented @@ -544,9 +528,6 @@ PyObject_Bytes(PyObject *v) comparing the object pointer (i.e. falling back to the base object implementation). - - If three-way comparison is not implemented, it falls back on rich - comparison (but not the other way around!). - */ /* Map rich comparison operators to their swapped version, e.g. LT <--> GT */ diff --git a/Objects/typeobject.c b/Objects/typeobject.c index 3f1df8d..c6d6fc8 100644 --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -3662,7 +3662,7 @@ inherit_slots(PyTypeObject *type, PyTypeObject *base) type->tp_setattr = base->tp_setattr; type->tp_setattro = base->tp_setattro; } - /* tp_compare see tp_richcompare */ + /* tp_compare is ignored, see tp_richcompare */ COPYSLOT(tp_repr); /* tp_hash see tp_richcompare */ COPYSLOT(tp_call); @@ -3670,12 +3670,10 @@ inherit_slots(PyTypeObject *type, PyTypeObject *base) { /* Copy comparison-related slots only when not overriding them anywhere */ - if (type->tp_compare == NULL && - type->tp_richcompare == NULL && + if (type->tp_richcompare == NULL && type->tp_hash == NULL && !overrides_hash(type)) { - type->tp_compare = base->tp_compare; type->tp_richcompare = base->tp_richcompare; type->tp_hash = base->tp_hash; } @@ -3888,6 +3886,13 @@ PyType_Ready(PyTypeObject *type) goto error; } + /* Check reserved slots */ + if (type->tp_compare) { + PyErr_Format(PyExc_TypeError, + "type %s has tp_compare", + type->tp_name); + } + /* All done -- set the ready flag */ assert(type->tp_dict != NULL); type->tp_flags = |