Hello, I tried to compile HAppS using the latest GHC snapshot (in compiles fine with 6.41). I for example get the error /home/rene/repos/HAppS/src/HAppS/MACID/Var.hs:23:0: Illegal polymorphic or qualified type: forall state event. Ev state event (ref t) In the type signature for `newEmptyRef': newEmptyRef :: (Monoid t, Ref ref) => AnyEv (ref t) Note that AnyEv is defined as type AnyEv a = forall state event. Ev state event a This should be OK shouldn't it? At least in works in 6.41 and everythis is quantified. Exactly what does the error message Illegal polymorphic or qualified type mean? Rene.
Hello Here is a short example of the GHC 6.5 problem: type AnyE a = forall err. Either err a foo :: Monad m => AnyE (m t) foo = undefined Works with older versions of GHC 6.5, but newer versions fail with the: Illegal polymorphic or qualified type: forall err. Either err (m t) In the type signature for `foo': foo :: (Monad m) => AnyE (m t) - Einar Karttunen
This is a bug. I'm committing a fix as I type. Thanks for boiling it down. Simon | -----Original Message----- | From: glasgow-haskell-users-bounces@haskell.org [mailto:glasgow-haskell-users- | bounces@haskell.org] On Behalf Of Einar Karttunen | Sent: 16 April 2006 13:57 | To: Rene de Visser | Cc: glasgow-haskell-users@haskell.org | Subject: Re: GHC 6.5 error? Illegal polymorphic or qualified type | | Hello | | Here is a short example of the GHC 6.5 problem: | | type AnyE a = forall err. Either err a | foo :: Monad m => AnyE (m t) | foo = undefined | | Works with older versions of GHC 6.5, but newer versions | fail with the: | | Illegal polymorphic or qualified type: forall err. Either err (m t) | In the type signature for `foo': | foo :: (Monad m) => AnyE (m t) | | | - Einar Karttunen | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users@haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
participants (3)
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Einar Karttunen -
Rene de Visser -
Simon Peyton-Jones