tests: remove extra_files.py (#12223)
[ghc.git] / testsuite / tests / typecheck / should_fail / T8428.hs
1 {-# LANGUAGE RankNTypes #-}
2 {-# LANGUAGE ImpredicativeTypes #-}
3
4 module T8428 where
5
6 import Control.Monad.ST
7
8 data IdentityT m a = IdentityT { runIdentityT :: m a }
9
10 runIdST :: IdentityT (forall s. ST s) a -> a
11 runIdST = runST . runIdentityT
12 -- Test formatting in the error message.
13 -- In fact this should be rejected as a kind error (#8388)