create NameConstant AST class for None, True, and False literals (closes #16619)
diff --git a/Parser/Python.asdl b/Parser/Python.asdl
index c24d840..0d373b0 100644
--- a/Parser/Python.asdl
+++ b/Parser/Python.asdl
@@ -1,4 +1,4 @@
--- ASDL's five builtin types are identifier, int, string, bytes, object
+-- ASDL's six builtin types are identifier, int, string, bytes, object, singleton
module Python
{
@@ -69,8 +69,8 @@
| Num(object n) -- a number as a PyObject.
| Str(string s) -- need to specify raw, unicode, etc?
| Bytes(bytes s)
+ | NameConstant(singleton value)
| Ellipsis
- -- other literals? bools?
-- the following expression can appear in assignment context
| Attribute(expr value, identifier attr, expr_context ctx)
diff --git a/Parser/asdl.py b/Parser/asdl.py
index 08aa05b..1f98ada 100644
--- a/Parser/asdl.py
+++ b/Parser/asdl.py
@@ -222,7 +222,7 @@
" field ::= Id ? "
return Field(type[0], opt=True)
-builtin_types = ("identifier", "string", "bytes", "int", "object")
+builtin_types = ("identifier", "string", "bytes", "int", "object", "singleton")
# below is a collection of classes to capture the AST of an AST :-)
# not sure if any of the methods are useful yet, but I'm adding them
diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py
index a9e6626..9557ba0 100755
--- a/Parser/asdl_c.py
+++ b/Parser/asdl_c.py
@@ -820,6 +820,7 @@
Py_INCREF((PyObject*)o);
return (PyObject*)o;
}
+#define ast2obj_singleton ast2obj_object
#define ast2obj_identifier ast2obj_object
#define ast2obj_string ast2obj_object
#define ast2obj_bytes ast2obj_object
@@ -831,6 +832,17 @@
/* Conversion Python -> AST */
+static int obj2ast_singleton(PyObject *obj, PyObject** out, PyArena* arena)
+{
+ if (obj != Py_None && obj != Py_True && obj != Py_False) {
+ PyErr_SetString(PyExc_ValueError,
+ "AST singleton must be True, False, or None");
+ return 1;
+ }
+ *out = obj;
+ return 0;
+}
+
static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena)
{
if (obj == Py_None)