testsuite/tests/pmcheck/complete_sigs/T14253.hs

   1 {-# LANGUAGE GADTs #-}
   2 {-# LANGUAGE PatternSynonyms #-}
   3 {-# LANGUAGE TypeOperators #-}
   4 {-# LANGUAGE RankNTypes #-}
   5 {-# LANGUAGE PolyKinds #-}
   6
   7 module T14253 where
   8
   9 import GHC.Exts
  10 import Data.Kind
  11
  12 data TypeRep (a :: k) where
  13     Con :: TypeRep (a :: k)
  14     TrFun   :: forall (r1 :: RuntimeRep) (r2 :: RuntimeRep)
  15                       (a :: TYPE r1) (b :: TYPE r2).
  16                TypeRep a
  17             -> TypeRep b
  18             -> TypeRep (a -> b)
  19
  20 pattern Fun :: forall k (fun :: k). ()
  21             => forall (r1 :: RuntimeRep) (r2 :: RuntimeRep)
  22                       (arg :: TYPE r1) (res :: TYPE r2).
  23                (k ~ Type, fun ~~ (arg -> res))
  24             => TypeRep arg
  25             -> TypeRep res
  26             -> TypeRep fun
  27 pattern Fun arg res <- TrFun arg res
  28
  29 data Dynamic where
  30     Dynamic :: forall a. TypeRep a -> a -> Dynamic
  31
  32 -- Adding this results in failure
  33 {-# COMPLETE Con #-}
  34
  35 dynApply :: Dynamic -> Dynamic -> Maybe Dynamic
  36 -- Changing TrFun to Fun also results in failure
  37 dynApply (Dynamic (Fun ta tr) f) (Dynamic ta' x) = undefined
  38 dynApply _ _ = Nothing
  39