#12708: RFC: Representation polymorphic Num -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Core Libraries | Version: 8.0.1 Resolution: | Keywords: 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 am concerned that it seems the instance resolution defaults to `Type`.. if I remove the instances (and qualify the `fromInteger` views) {{{#!hs -- × × × REMOVED × × × -- instance P.Num a => Num (a :: Type) where -- instance P.Show a => Show (a :: Type) where }}} the types of `show` and `(+)` are (let's give it a module name `UU`) {{{#!hs UU.fromInteger :: UU.Num a => Integer -> a (UU.+) :: UU.Num a => a -> a -> a UU.show :: UU.Show a => a -> String }}} whereas with those instances it seems to default to the `Type`, is this intended! {{{#!hs UU.fromInteger :: Prelude.Num a => Integer -> a (UU.+) :: Prelude.Num a => a -> a -> a (UU.show') :: Prelude.Show a => a -> String }}} ) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12708#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler