-- Uncommenting the line below causes the typechecker to loop (GHC 6.10.1, Windows) --test = f Zero
Is this expected behavior or a bug?
The call f Zero requires a co-inductive proof of the type class constraint (F Nat): F Nat <=> Vieweable Nat /\ F' (View Nat) <=> True /\ F' (Unit :+: Nat) <=> True /\ F Unit /\ F Nat <=> True /\ True /\ F Nat The type checker does have functionality for such co-inductive proof (generating co-inductive dictionaries), but apparently it's not kicking in here. Probably because of the separate fixedpoint loops for type classes and type families in the checker. -- Tom Schrijvers Department of Computer Science K.U. Leuven Celestijnenlaan 200A B-3001 Heverlee Belgium tel: +32 16 327544 e-mail: tom.schrijvers@cs.kuleuven.be url: http://www.cs.kuleuven.be/~toms/