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| {- errors: | |
| common/src/Common/WrappedShow1.hs:42:43: error: | |
| • Couldn't match expected type ‘[a] -> ShowS’ with actual type ‘a’ | |
| ‘a’ is a rigid type variable bound by | |
| the type signature for: | |
| reifyShow :: forall a t. | |
| (a -> a -> a) | |
| -> a | |
| -> (forall s. Reifies s (ReifiedShow a) => t -> ReflectedShow a s) | |
| -> t | |
| -> a | |
| at common/src/Common/WrappedShow1.hs:38:6 | |
| • In the second argument of ‘ReifiedShow’, namely ‘z’ | |
| In the first argument of ‘reify’, namely ‘(ReifiedShow f z)’ | |
| In the expression: reify (ReifiedShow f z) (unreflectedShow (m xs)) | |
| • Relevant bindings include | |
| m :: forall s. Reifies s (ReifiedShow a) => t -> ReflectedShow a s | |
| (bound at common/src/Common/WrappedShow1.hs:42:15) | |
| z :: a (bound at common/src/Common/WrappedShow1.hs:42:13) | |
| f :: a -> a -> a (bound at common/src/Common/WrappedShow1.hs:42:11) | |
| reifyShow :: (a -> a -> a) | |
| -> a | |
| -> (forall s. Reifies s (ReifiedShow a) => t -> ReflectedShow a s) | |
| -> t | |
| -> a | |
| (bound at common/src/Common/WrappedShow1.hs:42:1) | |
| -} | |
| {-# LANGUAGE RankNTypes #-} | |
| {-# LANGUAGE FlexibleInstances #-} | |
| {-# LANGUAGE FlexibleContexts #-} | |
| {-# LANGUAGE KindSignatures #-} | |
| {-# LANGUAGE UndecidableInstances #-} | |
| module Common.WrappedShow1 where | |
| import Data.Functor.Classes | |
| import Data.Reflection | |
| import Data.Coerce | |
| newtype WrappedShow1 f a = WrappedShow1 (f a) | |
| instance Show1 (WrappedShow1 f) | |
| instance (Show1 f, Show a) => Show (WrappedShow1 f a) where | |
| showsPrec x = liftShowsPrec showsPrec showList x | |
| showList x = liftShowList showsPrec showList x | |
| data ReifiedShow a = ReifiedShow | |
| { reifiedShowsPrec :: Int -> a -> ShowS | |
| , reifiedShowList :: [a] -> ShowS | |
| } | |
| instance Reifies s (ReifiedShow a) => Show (ReflectedShow a s) where | |
| showsPrec prec p@(ReflectedShow x) = reifiedShowsPrec (reflect p) prec x | |
| showList xs = reifiedShowList (reflect (head xs)) (coerce xs) | |
| newtype ReflectedShow a s = ReflectedShow a | |
| unreflectedShow :: ReflectedShow a s -> proxy s -> a | |
| unreflectedShow (ReflectedShow a) _ = a | |
| reifyShow | |
| :: (a -> a -> a) | |
| -> a | |
| -> (forall (s :: *). Reifies s (ReifiedShow a) => t -> ReflectedShow a s) | |
| -> t -> a | |
| reifyShow f z m xs = reify (ReifiedShow f z) (unreflectedShow (m xs)) |
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