#8026: DatatypeContexts should be fixed, not deprecated -------------------------------+-------------------------------------------- Reporter: gidyn | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Resolution: | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase: | Blockedby: Blocking: | Related: -------------------------------+-------------------------------------------- Comment(by monoidal): @gidyn: What would the type of `x` be in your example? You probably want `x` to ''introduce'' the validity of constraint `Eq a`. So the type would be somewhat dual to `Eq a => Pair a -> a`: using it would prove the constraint `Eq a`, rather than requiring evidence for the constraint. Something like `Pair a -> (Eq a; a)`. It seems to me this change would complicate the type system a lot, while the benefits are rather doubtful. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/8026#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler