On 2015-08-03 at 04:43, Phil Ruffwind <[email protected]> wrote: > I think the error message could be made clearer simply by emphasizing the fact > that type ambiguity over the lack of instances. > > Ambiguous type variable 't0' arising from a use of > elem :: a -> t0 a -> Bool > caused by the lack of an instance 'Data.String.IsString (t0 Char)' > Either add a type annotation to dictate what 't0' should be > based on one of the potential instances: > instance Foldable (Either a) -- Defined in ‘Data.Foldable’ > instance Foldable Data.Proxy.Proxy -- Defined in ‘Data.Foldable’ > instance GHC.Arr.Ix i => Foldable (GHC.Arr.Array i) > -- Defined in ‘Data.Foldable’ > ...plus three others) > or define the required instance 'Data.String.IsString (t0 Char)'.
Yes, I think that message would be fine. _______________________________________________ ghc-devs mailing list [email protected] http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
