I spoke too soon. This is a real bug, and I'm fixing it. Thanks for the report
S | -----Original Message----- | From: Hal Daume III [mailto:[EMAIL PROTECTED]] | Sent: 01 September 2002 14:27 | To: Simon Peyton-Jones | Cc: [EMAIL PROTECTED] | Subject: RE: bug with rank n polymorphism in classes | | | 5.04 for solaris (but it doesn't seem to work in the linux | version, either). | | -- | Hal Daume III | | "Computer science is no more about computers | [EMAIL PROTECTED] | than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume | | On Wed, 28 Aug 2002, Simon Peyton-Jones wrote: | | > Please say which version of GHC you are using. | > | > This program works fine with GHC 5.02.2 | > | > Simon | > | > | -----Original Message----- | > | From: Hal Daume III [mailto:[EMAIL PROTECTED]] | > | Sent: 22 August 2002 20:47 | > | To: [EMAIL PROTECTED] | > | Subject: bug with rank n polymorphism in classes | > | | > | | > | consider: | > | | > | module Foo where | > | | > | class Foo p where | > | foo :: p -> (forall q . Foo q => q -> a) -> a | > | | > | instance Foo Int where | > | | > | | > | if you load this in to ghci, it complains: | > | | > | /home/hdaume/projects/NLP/Foo.hs:6: | > | Ambiguous type variable(s) `q' in the constraint `Foo q' | > | arising from a function with an overloaded argument type | > | at /home/hdaume/projects/NLP/Foo.hs:6 | > | Expected type: Int -> (forall q1. (Foo q1) => q1 -> a) -> a | > | Inferred type: Int -> (q -> a) -> a | > | In the application `GHC.Err.noMethodBindingError | > | "/home/hdaume/projects/NLP/Foo.hs:6|Foo.foo"#' | > | | > | which is a reasonable complaint, but is emiited in a rather | > | bizzare way. | > | | > | -- | > | Hal Daume III | > | | > | "Computer science is no more about computers | [EMAIL PROTECTED] | > | than astronomy is about telescopes." -Dijkstra | | > | www.isi.edu/~hdaume | > | | > | _______________________________________________ | > | Glasgow-haskell-bugs mailing list | > | [EMAIL PROTECTED] | > | http://www.haskell.org/mailman/listinfo/glasgow-| haskell-bugs | > | | > | | _______________________________________________ Glasgow-haskell-bugs mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
