bpo-36144: Dictionary Union (PEP 584) (#12088)

1 files changed, 53 insertions, 18 deletions

diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 86ac4ef..4aa927a 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -2320,6 +2320,25 @@ dict_fromkeys_impl(PyTypeObject *type, PyObject *iterable, PyObject *value)
     return _PyDict_FromKeys((PyObject *)type, iterable, value);
 }
 
+/* Single-arg dict update; used by dict_update_common and operators. */
+static int
+dict_update_arg(PyObject *self, PyObject *arg)
+{
+    if (PyDict_CheckExact(arg)) {
+        return PyDict_Merge(self, arg, 1);
+    }
+    _Py_IDENTIFIER(keys);
+    PyObject *func;
+    if (_PyObject_LookupAttrId(arg, &PyId_keys, &func) < 0) {
+        return -1;
+    }
+    if (func != NULL) {
+        Py_DECREF(func);
+        return PyDict_Merge(self, arg, 1);
+    }
+    return PyDict_MergeFromSeq2(self, arg, 1);
+}
+
 static int
 dict_update_common(PyObject *self, PyObject *args, PyObject *kwds,
                    const char *methname)
@@ -2331,23 +2350,7 @@ dict_update_common(PyObject *self, PyObject *args, PyObject *kwds,
         result = -1;
     }
     else if (arg != NULL) {
-        if (PyDict_CheckExact(arg)) {
-            result = PyDict_Merge(self, arg, 1);
-        }
-        else {
-            _Py_IDENTIFIER(keys);
-            PyObject *func;
-            if (_PyObject_LookupAttrId(arg, &PyId_keys, &func) < 0) {
-                result = -1;
-            }
-            else if (func != NULL) {
-                Py_DECREF(func);
-                result = PyDict_Merge(self, arg, 1);
-            }
-            else {
-                result = PyDict_MergeFromSeq2(self, arg, 1);
-            }
-        }
+        result = dict_update_arg(self, arg);
     }
 
     if (result == 0 && kwds != NULL) {
@@ -3169,6 +3172,33 @@ dict_sizeof(PyDictObject *mp, PyObject *Py_UNUSED(ignored))
     return PyLong_FromSsize_t(_PyDict_SizeOf(mp));
 }
 
+static PyObject *
+dict_or(PyObject *self, PyObject *other)
+{
+    if (!PyDict_Check(self) || !PyDict_Check(other)) {
+        Py_RETURN_NOTIMPLEMENTED;
+    }
+    PyObject *new = PyDict_Copy(self);
+    if (new == NULL) {
+        return NULL;
+    }
+    if (dict_update_arg(new, other)) {
+        Py_DECREF(new);
+        return NULL;
+    }
+    return new;
+}
+
+static PyObject *
+dict_ior(PyObject *self, PyObject *other)
+{
+    if (dict_update_arg(self, other)) {
+        return NULL;
+    }
+    Py_INCREF(self);
+    return self;
+}
+
 PyDoc_STRVAR(getitem__doc__, "x.__getitem__(y) <==> x[y]");
 
 PyDoc_STRVAR(sizeof__doc__,
@@ -3274,6 +3304,11 @@ static PySequenceMethods dict_as_sequence = {
     0,                          /* sq_inplace_repeat */
 };
 
+static PyNumberMethods dict_as_number = {
+    .nb_or = dict_or,
+    .nb_inplace_or = dict_ior,
+};
+
 static PyObject *
 dict_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 {
@@ -3335,7 +3370,7 @@ PyTypeObject PyDict_Type = {
     0,                                          /* tp_setattr */
     0,                                          /* tp_as_async */
     (reprfunc)dict_repr,                        /* tp_repr */
-    0,                                          /* tp_as_number */
+    &dict_as_number,                            /* tp_as_number */
     &dict_as_sequence,                          /* tp_as_sequence */
     &dict_as_mapping,                           /* tp_as_mapping */
     PyObject_HashNotImplemented,                /* tp_hash */