Invalid type class instance passes typechecker #224

paf31 opened this Issue Feb 22, 2014 · 0 comments


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paf31 commented Feb 22, 2014

This obviously shouldn't work:

class OverlappingVars a where
  f :: a -> a

data Foo a b = Foo a b

instance OverlappingVars (Foo a a) where
  f a = a

test = f (Foo "" 0)
@paf31 paf31 added this to the 0.5.0 milestone Feb 22, 2014
@paf31 paf31 closed this in 9420ad3 Feb 22, 2014
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