Would someone feel able to open a Trac ticket summarising this thread (as well as pointing to it), and making a proposal?
Thanks Simon | -----Original Message----- | From: ghc-devs [mailto:ghc-devs-boun...@haskell.org] On Behalf Of Daniel | Bergey | Sent: 03 August 2015 17:47 | To: Phil Ruffwind; Reid Barton | Cc: ghc-devs | Subject: Re: Typechecker / OverloadedStrings question 7.8 vs. 7.10 | | On 2015-08-03 at 04:43, Phil Ruffwind <r...@rufflewind.com> 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 | ghc-devs@haskell.org | http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs