+replicateShape (SumRepr {}) len tag
+ = do
+ rep <- builtin replicatePAIntPrimVar
+ up <- builtin upToPAIntPrimVar
+ return [len, Var rep `mkApps` [len, tag], Var up `App` len]
+replicateShape (IdRepr _) _ _ = return []
+replicateShape (VoidRepr {}) len _ = return [len]