fix for blocks taking a single unpacking argument. (e.g. { |(x, y) })

tests/test_parser.py

@@ -1479,6 +1479,22 @@ def test_block(self, space):
                 )])
             ), 1)),
         ]))
+        assert space.parse("f { |(x, y)| }") == ast.Main(ast.Block([
+            ast.Statement(ast.Send(ast.Self(1), "f", [], ast.SendBlock(
+                [ast.Argument("0")],
+                None,
+                None,
+                ast.Block([
+                    ast.Statement(ast.MultiAssignment(
+                        ast.MultiAssignable([
+                            ast.Variable("x", -1),
+                            ast.Variable("y", -1),
+                        ]),
+                        ast.Variable("0", 1),
+                    ))
+                ]),
+            ), 1))
+        ]))
 
     def test_lambda(self, space):
         assert space.parse("->{}") == ast.Main(ast.Block([

topaz/parser.py

@@ -163,7 +163,7 @@ def append_call_arg(self, box_arg, box):
 
     def new_send_block(self, lineno, params, body):
         stmts = body.getastlist() if body is not None else []
-        args = params.getargs() if params is not None else []
+        args = params.getargs(include_multi=True) if params is not None else []
         splat = params.getsplatarg() if params is not None else None
         block_arg = params.getblockarg() if params is not None else None
 
@@ -2933,8 +2933,8 @@ def __init__(self, args, splat_arg, block_arg):
         self.splat_arg = splat_arg
         self.block_arg = block_arg
 
-    def getargs(self):
-        if self.is_multiassignment():
+    def getargs(self, include_multi=False):
+        if self.is_multiassignment() and not include_multi:
             return []
         else:
             return self.args