[3.10] bpo-44490: Add __parameters__ and __getitem__ to types.Union (GH-26980) (GH-27207)

Co-authored-by: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Co-authored-by: Guido van Rossum <gvanrossum@gmail.com>.
(cherry picked from commit c45fa1a5d9)

Co-authored-by: Yurii Karabas <1998uriyyo@gmail.com>
Co-authored-by: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
This commit is contained in:
Serhiy Storchaka 2021-07-17 22:14:57 +03:00 committed by GitHub
parent e22e8641dd
commit 2d055ce132
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GPG key ID: 4AEE18F83AFDEB23
5 changed files with 102 additions and 19 deletions

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@ -8,6 +8,7 @@
typedef struct {
PyObject_HEAD
PyObject *args;
PyObject *parameters;
} unionobject;
static void
@ -18,6 +19,7 @@ unionobject_dealloc(PyObject *self)
_PyObject_GC_UNTRACK(self);
Py_XDECREF(alias->args);
Py_XDECREF(alias->parameters);
Py_TYPE(self)->tp_free(self);
}
@ -26,6 +28,7 @@ union_traverse(PyObject *self, visitproc visit, void *arg)
{
unionobject *alias = (unionobject *)self;
Py_VISIT(alias->args);
Py_VISIT(alias->parameters);
return 0;
}
@ -450,6 +453,53 @@ static PyMethodDef union_methods[] = {
{"__subclasscheck__", union_subclasscheck, METH_O},
{0}};
static PyObject *
union_getitem(PyObject *self, PyObject *item)
{
unionobject *alias = (unionobject *)self;
// Populate __parameters__ if needed.
if (alias->parameters == NULL) {
alias->parameters = _Py_make_parameters(alias->args);
if (alias->parameters == NULL) {
return NULL;
}
}
PyObject *newargs = _Py_subs_parameters(self, alias->args, alias->parameters, item);
if (newargs == NULL) {
return NULL;
}
PyObject *res = _Py_Union(newargs);
Py_DECREF(newargs);
return res;
}
static PyMappingMethods union_as_mapping = {
.mp_subscript = union_getitem,
};
static PyObject *
union_parameters(PyObject *self, void *Py_UNUSED(unused))
{
unionobject *alias = (unionobject *)self;
if (alias->parameters == NULL) {
alias->parameters = _Py_make_parameters(alias->args);
if (alias->parameters == NULL) {
return NULL;
}
}
Py_INCREF(alias->parameters);
return alias->parameters;
}
static PyGetSetDef union_properties[] = {
{"__parameters__", union_parameters, (setter)NULL, "Type variables in the types.Union.", NULL},
{0}
};
static PyNumberMethods union_as_number = {
.nb_or = _Py_union_type_or, // Add __or__ function
};
@ -471,8 +521,10 @@ PyTypeObject _Py_UnionType = {
.tp_members = union_members,
.tp_methods = union_methods,
.tp_richcompare = union_richcompare,
.tp_as_mapping = &union_as_mapping,
.tp_as_number = &union_as_number,
.tp_repr = union_repr,
.tp_getset = union_properties,
};
PyObject *
@ -516,6 +568,7 @@ _Py_Union(PyObject *args)
return NULL;
}
result->parameters = NULL;
result->args = args;
_PyObject_GC_TRACK(result);
return (PyObject*)result;