blob: bb56d437bfe6f5afbff0d02097d7723db7e90c73 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
|
{-# LANGUAGE GADTs #-}
{-# LANGUAGE PatternSynonyms #-}
{-# LANGUAGE TypeOperators #-}
{-# LANGUAGE RankNTypes #-}
{-# LANGUAGE PolyKinds #-}
module T14253 where
import GHC.Exts
import Data.Kind
data TypeRep (a :: k) where
Con :: TypeRep (a :: k)
TrFun :: forall (r1 :: RuntimeRep) (r2 :: RuntimeRep)
(a :: TYPE r1) (b :: TYPE r2).
TypeRep a
-> TypeRep b
-> TypeRep (a -> b)
pattern Fun :: forall k (fun :: k). ()
=> forall (r1 :: RuntimeRep) (r2 :: RuntimeRep)
(arg :: TYPE r1) (res :: TYPE r2).
(k ~ Type, fun ~~ (arg -> res))
=> TypeRep arg
-> TypeRep res
-> TypeRep fun
pattern Fun arg res <- TrFun arg res
data Dynamic where
Dynamic :: forall a. TypeRep a -> a -> Dynamic
-- Adding this results in failure
{-# COMPLETE Con #-}
dynApply :: Dynamic -> Dynamic -> Maybe Dynamic
-- Changing TrFun to Fun also results in failure
dynApply (Dynamic (Fun ta tr) f) (Dynamic ta' x) = undefined
dynApply _ _ = Nothing
|
