Improve error messages around kind mismatches.
[ghc.git] / testsuite / tests / typecheck / should_fail / T8142.hs
1 {-# LANGUAGE TypeFamilies #-}
2
3 module T8142 where
4
5 tracer :: (Functor f, Coinductive f) => (c -> f c) -> (c -> f c)
6 tracer = h where h = (\(_, b) -> ((outI . fmap h) b)) . out
7
8 class Functor g => Coinductive g where
9 type Nu g :: *
10 out :: Nu g -> g (Nu g)
11 outI :: g (Nu g) -> Nu g