Support NamedExpr

Fix #58
serge-sans-paille · Jul 23, 2021 · 3cc9b4d · 3cc9b4d
1 parent 2271bc2
commit 3cc9b4d
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diff --git a/README.rst b/README.rst
@@ -186,6 +186,7 @@ ASDL
 
               -- BoolOp() can use left & right?
         expr = BoolOp(boolop op, expr* values)
+             | NamedExpr(expr target, expr value)
              | BinOp(expr left, operator op, expr right)
              | UnaryOp(unaryop op, expr operand)
              | Lambda(arguments args, expr body)

diff --git a/gast/gast.py b/gast/gast.py
@@ -133,6 +133,9 @@ def create_node(self, *args, **kwargs):
     ('BoolOp', (('op', 'values',),
                 ('lineno', 'col_offset', 'end_lineno', 'end_col_offset',),
                 (expr,))),
+    ('NamedExpr', (('target', 'value',),
+                ('lineno', 'col_offset', 'end_lineno', 'end_col_offset',),
+                (expr,))),
     ('BinOp', (('left', 'op', 'right',),
                ('lineno', 'col_offset', 'end_lineno', 'end_col_offset',),
                (expr,))),

diff --git a/tests/test_compat.py b/tests/test_compat.py
@@ -112,6 +112,16 @@ def test_PosonlyArgs(self):
                         "], type_ignores=[])")
                 self.assertEqual(gast.dump(tree), norm)
 
+            def test_NamedExpr(self):
+                code = '(x := 1) '
+                tree = gast.parse(code)
+                compile(gast.gast_to_ast(tree), '<test>', 'exec')
+                norm = ("Module(body=[Expr(value=NamedExpr(target=Name(id='x',"
+                        " ctx=Store(), annotation=None, type_comment=None), "
+                        "value=Constant(value=1, kind=None)))], type_ignores="
+                        "[])")
+                self.assertEqual(gast.dump(tree), norm)
+
         else:
 
             def test_Bytes(self):