#4485: Unexplained change in type-inference + OverlappingInstances in ---------------------------------+------------------------------------------ Reporter: JeremyShaw | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.0.1 RC1 Keywords: | Testcase: Blockedby: | Difficulty: Os: Unknown/Multiple | Blocking: Architecture: Unknown/Multiple | Failure: GHC rejects valid program ---------------------------------+------------------------------------------
Comment(by simonpj): Right. I think you need !IncoherentInstances. With this flag, and the new typechecker patches, your module compiles ok. Currently GHC crashes without !IncoherentInstances, for a tiresome reason; Dimitrios is fixing that. To make !IncoherentInstances behave as well as possible, we should really wait until all ''other'' equalities are solved, to minimise the chance of a bogus choice (as you say). We'll do that in due course. Simon -- Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4485#comment:4> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler _______________________________________________ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs