#11385: Unify named wildcards in different type applications -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.1 checker) | Keywords: Resolution: | NamedWildCards TypeApplications Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Iceland_jack): I disliked the lack of binders in my idea. That would be fixed by Replying to [comment:2 goldfire]:
{{{ asTypeOf = \ @a -> const @a @a }}}
like comment:4:ticket:11350 and comment:1:ticket:11638. Let me see if I understand: {{{#!hs add4 :: (Enum a, Enum b) => a -> b -> Int add4 a b = (fromEnum a + fromEnum b) `mod` 4 }}} if you want `add4 :: Enum a => a -> a -> Int` you write {{{#!hs -- add4 @_a @_a` \ @a -> add4 @a @a :: Enum a => a -> a -> Int }}} {{{#!hs -- Sub @(Ord _a) @(Eq _a) \ @a -> Sub @(Ord a) @(Eq a) :: (Ord a => Dict (Eq a)) -> Ord a :- Eq a }}} {{{#!hs -- map @_a @_a \ @a -> map @a @a :: (a -> a) -> [a] -> [a] }}} LGTM. ---- It may be worth allowing {{{#!hs (\ @a -> map @a @a) @Int :: (Int -> Int) -> [Int] -> [Int] }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11385#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler