#8555: Simplify given `Coercible` constraints -------------------------------------+------------------------------------- Reporter: nomeata | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 7.7 checker) | Operating System: Unknown/Multiple Keywords: | Type of failure: GHC rejects Architecture: Unknown/Multiple | valid program Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: #8503 | -------------------------------------+------------------------------------- It would be feasible and possibly useful if {{{ foo :: Coercible [a] [b] => a -> b foo = coerce }}} would work. This involve simplifying `CtGiven`s similar to how given (nominal) equalities are simplified. I’ll defer working on this, as it is not strictly required, it seems. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8555 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler