I can probably find time to take a pass at the unparser, if you want. > cls needs to be an expression node to allow for attribute lookups That's why I suggested "identifier*"! Each identifier in the list would be one part of the dotted name, so we wouldn't need to worry about having arbitrary expressions: Foo() -> MatchClass(["Foo"], [], [], []) foo.bar.Baz() -> MatchClass(["foo", "bar", "Baz"], [], [], []) Not a big deal, though.