bpo-42233: Add union type expression support for GenericAlias and fix de-duplicating of GenericAlias (GH-23077)

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kj 2020-11-09 12:00:13 +08:00 committed by GitHub
parent 23831a7a90
commit 4eb41d055e
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6 changed files with 51 additions and 17 deletions

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@ -10,6 +10,7 @@ extern "C" {
PyAPI_FUNC(PyObject *) _Py_Union(PyObject *args);
PyAPI_DATA(PyTypeObject) _Py_UnionType;
PyAPI_FUNC(PyObject *) _Py_union_type_or(PyObject* self, PyObject* param);
#ifdef __cplusplus
}

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@ -713,6 +713,28 @@ class TypesTests(unittest.TestCase):
assert repr(int | None) == "int | None"
assert repr(int | typing.GenericAlias(list, int)) == "int | list[int]"
def test_or_type_operator_with_genericalias(self):
a = list[int]
b = list[str]
c = dict[float, str]
# equivalence with typing.Union
self.assertEqual(a | b | c, typing.Union[a, b, c])
# de-duplicate
self.assertEqual(a | c | b | b | a | c, a | b | c)
# order shouldn't matter
self.assertEqual(a | b, b | a)
self.assertEqual(repr(a | b | c),
"list[int] | list[str] | dict[float, str]")
class BadType(type):
def __eq__(self, other):
return 1 / 0
bt = BadType('bt', (), {})
# Comparison should fail and errors should propagate out for bad types.
with self.assertRaises(ZeroDivisionError):
list[int] | list[bt]
def test_ellipsis_type(self):
self.assertIsInstance(Ellipsis, types.EllipsisType)

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@ -0,0 +1,5 @@
Allow ``GenericAlias`` objects to use :ref:`union type expressions <types-union>`.
This allows expressions like ``list[int] | dict[float, str]`` where previously a
``TypeError`` would have been thrown. This also fixes union type expressions
not de-duplicating ``GenericAlias`` objects. (Contributed by Ken Jin in
:issue:`42233`.)

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@ -2,6 +2,7 @@
#include "Python.h"
#include "pycore_object.h"
#include "pycore_unionobject.h" // _Py_union_as_number
#include "structmember.h" // PyMemberDef
typedef struct {
@ -573,6 +574,10 @@ ga_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
return Py_GenericAlias(origin, arguments);
}
static PyNumberMethods ga_as_number = {
.nb_or = (binaryfunc)_Py_union_type_or, // Add __or__ function
};
// TODO:
// - argument clinic?
// - __doc__?
@ -586,6 +591,7 @@ PyTypeObject Py_GenericAliasType = {
.tp_basicsize = sizeof(gaobject),
.tp_dealloc = ga_dealloc,
.tp_repr = ga_repr,
.tp_as_number = &ga_as_number, // allow X | Y of GenericAlias objs
.tp_as_mapping = &ga_as_mapping,
.tp_hash = ga_hash,
.tp_call = ga_call,

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@ -6,7 +6,7 @@
#include "pycore_object.h"
#include "pycore_pyerrors.h"
#include "pycore_pystate.h" // _PyThreadState_GET()
#include "pycore_unionobject.h" // _Py_Union()
#include "pycore_unionobject.h" // _Py_Union(), _Py_union_type_or
#include "frameobject.h"
#include "structmember.h" // PyMemberDef
@ -3789,19 +3789,9 @@ type_is_gc(PyTypeObject *type)
return type->tp_flags & Py_TPFLAGS_HEAPTYPE;
}
static PyObject *
type_or(PyTypeObject* self, PyObject* param) {
PyObject *tuple = PyTuple_Pack(2, self, param);
if (tuple == NULL) {
return NULL;
}
PyObject *new_union = _Py_Union(tuple);
Py_DECREF(tuple);
return new_union;
}
static PyNumberMethods type_as_number = {
.nb_or = (binaryfunc)type_or, // Add __or__ function
.nb_or = _Py_union_type_or, // Add __or__ function
};
PyTypeObject PyType_Type = {

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@ -237,9 +237,19 @@ dedup_and_flatten_args(PyObject* args)
PyObject* i_element = PyTuple_GET_ITEM(args, i);
for (Py_ssize_t j = i + 1; j < arg_length; j++) {
PyObject* j_element = PyTuple_GET_ITEM(args, j);
if (i_element == j_element) {
is_duplicate = 1;
int is_ga = Py_TYPE(i_element) == &Py_GenericAliasType &&
Py_TYPE(j_element) == &Py_GenericAliasType;
// RichCompare to also deduplicate GenericAlias types (slower)
is_duplicate = is_ga ? PyObject_RichCompareBool(i_element, j_element, Py_EQ)
: i_element == j_element;
// Should only happen if RichCompare fails
if (is_duplicate < 0) {
Py_DECREF(args);
Py_DECREF(new_args);
return NULL;
}
if (is_duplicate)
break;
}
if (!is_duplicate) {
Py_INCREF(i_element);
@ -290,8 +300,8 @@ is_unionable(PyObject *obj)
type == &_Py_UnionType);
}
static PyObject *
type_or(PyTypeObject* self, PyObject* param)
PyObject *
_Py_union_type_or(PyObject* self, PyObject* param)
{
PyObject *tuple = PyTuple_Pack(2, self, param);
if (tuple == NULL) {
@ -404,7 +414,7 @@ static PyMethodDef union_methods[] = {
{0}};
static PyNumberMethods union_as_number = {
.nb_or = (binaryfunc)type_or, // Add __or__ function
.nb_or = _Py_union_type_or, // Add __or__ function
};
PyTypeObject _Py_UnionType = {