edgedb.NamedTuple is now a subclass of tuple

edgedb.NamedTuple will now create a heap type for the names.
weakref.ref() will stop working on edgedb.NamedTuple objects.

edgedb/datatypes/datatypes.h

@@ -93,18 +93,9 @@ PyObject * EdgeRecordDesc_GetDataclassFields(PyObject *);
 
 extern PyTypeObject EdgeNamedTuple_Type;
 
-#define EdgeNamedTuple_Check(d) (Py_TYPE(d) == &EdgeNamedTuple_Type)
-
-typedef struct {
-    PyObject_VAR_HEAD
-    PyObject *desc;
-    PyObject *weakreflist;
-    PyObject *ob_item[1];
-} EdgeNamedTupleObject;
-
 PyObject * EdgeNamedTuple_InitType(void);
+PyObject * EdgeNamedTuple_Type_New(PyObject *);
 PyObject * EdgeNamedTuple_New(PyObject *);
-int EdgeNamedTuple_SetItem(PyObject *, Py_ssize_t, PyObject *);
 
 
 /* === edgedb.Object ======================================== */

edgedb/datatypes/datatypes.pxd

@@ -49,7 +49,7 @@ cdef extern from "datatypes.h":
 
     object EdgeNamedTuple_InitType()
     object EdgeNamedTuple_New(object)
-    int EdgeNamedTuple_SetItem(object, Py_ssize_t, object) except -1
+    object EdgeNamedTuple_Type_New(object)
 
     object EdgeObject_InitType()
     object EdgeObject_New(object);
@@ -75,7 +75,7 @@ cdef record_desc_new(object names, object flags, object cards)
 cdef record_desc_pointer_name(object desc, Py_ssize_t pos)
 cdef record_desc_pointer_card(object desc, Py_ssize_t pos)
 cdef namedtuple_new(object desc)
-cdef namedtuple_set(object tuple, Py_ssize_t pos, object elem)
+cdef namedtuple_type_new(object desc)
 cdef object_new(object desc)
 cdef object_set(object tuple, Py_ssize_t pos, object elem)
 cdef bint set_check(object set)

edgedb/datatypes/datatypes.pyx

@@ -101,8 +101,8 @@ cdef namedtuple_new(object desc):
     return EdgeNamedTuple_New(desc)
 
 
-cdef namedtuple_set(object tuple, Py_ssize_t pos, object elem):
-    EdgeNamedTuple_SetItem(tuple, pos, elem)
+cdef namedtuple_type_new(object desc):
+    return EdgeNamedTuple_Type_New(desc)
 
 
 cdef object_new(object desc):

edgedb/datatypes/internal.h

@@ -29,8 +29,7 @@
 
 
 #define _Edge_IsContainer(o)                                \
-    (PyTuple_CheckExact(o) ||                               \
-     EdgeNamedTuple_Check(o) ||                             \
+    (PyTuple_Check(o) ||                               \
      EdgeObject_Check(o) ||                                 \
      EdgeSet_Check(o) ||                                    \
      EdgeArray_Check(o))