#2639: Core lint failure with type families, data families, and typeclasses
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Reporter: ryani | Owner:
Type: bug | Status: new
Priority: normal | Component: Compiler
Version: 6.8.3 | Severity: normal
Keywords: | Testcase:
Architecture: Unknown/Multiple | Os: Unknown/Multiple
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I haven't been able to shrink this case smaller and still fail core lint.
{{{
{-# LANGUAGE TypeFamilies, EmptyDataDecls #-}
module CoreLint where
data Eps
data family Work a v
data instance Work Eps v = Eps v
type family Dual a
type instance Dual Eps = Eps
class Connect s where
connect :: (Dual s ~ c, Dual c ~ s) => Work s a -> Work c b -> (a,b)
instance Connect Eps where
connect (Eps a) (Eps b) = (a,b)
}}}
Output from ghc -dcore-lint is attached
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/2639>
GHC <http://www.haskell.org/ghc/>
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