#14968: QuantifiedConstraints: Can't be RHS of type family instances -------------------------------------+------------------------------------- Reporter: josef | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.5 checker) | Keywords: Resolution: | QuantifiedConstraints Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #9269 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): Replying to [comment:6 goldfire]:
This simply doesn't happen with constraints, so we avoid the challenge.
Really? Is there some sort of invariant in GHC that upholds this claim? You can certainly have `x :: ty` where `ty :: Constraint` in Core, so this claim is quite surprising to me. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14968#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler