#9587: Type checking with type functions introduces many type variables, which remain ambiguous. The code no longer type checks. -------------------------------------+------------------------------------- Reporter: oleg | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 7.8.3 checker) | Keywords: type Resolution: | family, ambiguity check Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: #9607 | Differential Revisions: -------------------------------------+------------------------------------- Comment (by jstolarek):
one may well define Arr R' a b = String
But the question is whether `Arr R' a b = String` is an acceptable definition? If yes, then of course injectivity is not a solution. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9587#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler