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Hi! Is it possible to enable the various ghc-extensions one-by-one via a compilerflag (sth. like --ffi or --namespaces). The advantage i see is being able to develop with ghc and use only those extensions hugs or nhc provide (and not exclusively in -glasgow-extensions). Thanks & bye, Axel
About GHCi I find that Haskell interpreter is rather difficult to use: 1."f=3" is a legal statement in Haskell, i.e. define "f" as a constant function, but a parse error occurs. "let f=3" is illegal, "let" and "in" are used together, but it works in GHCi. 2. if I happen to print out an infinite list, I don't know how to interrupt it, when press Ctrl+C, GHCi just quit. 3. I can't use "import" to import modules. There are many sub directories in the imports directory, but I don't know how to import libraries in concurrent, win32, util, lang and objectio
|#179||fixed||Instance match failure on openTypeKind||simonpj||simonpj|
Consider instance Show (a->b) where ... foo x = show (\ _ -> True) This fails with: No instance for (Show (t -> Bool)) arising from use of `show' at Foo.hs:5 Reason: the type of (\_ -> True) is (t -> Bool) where t has an "openTypeKind". It's possible that the function will be applied to say an Int#, and the openTypeKind records that this is OK. BUT, the instance decl Show (a->b) has a::liftedTypeKind, and that doesn't match an openTypeKind type variable. This bug relates to GHC's unsatisfactory treatment of the variants of kind "type", for which there are at least 2 other SourceForge bugs registered (753780 and 753777). It's very obscure, so I'm not going to fix it today.
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