[Haskell-cafe] Solved but strange error in type inference

Brandon Allbery allbery.b at gmail.com
Tue Jan 3 12:46:12 CET 2012

On Tue, Jan 3, 2012 at 06:35, Yucheng Zhang <yczhang89 at gmail.com> wrote:

> > legSome ((LegGram g)::LegGram nt t s) ntV
> If you compile this without ScopedTypeVariables extension, GHC will
> remind you of it:
> >    Illegal signature in pattern: LegGram nt t s
> >        Use -XScopedTypeVariables to permit it

Right, but I think this is conflating two aspects of ScopedTypeVariables
and may not bring them into scope "fully".  Although, that's a question for
someone who understands ghc's type system far better than I do.

brandon s allbery                                      allbery.b at gmail.com
wandering unix systems administrator (available)     (412) 475-9364 vm/sms
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