#12473: Ambiguous type var with DefaultSignatures and FunctionalDependencies -------------------------------------+------------------------------------- Reporter: dylex | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 8.0.1 checker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC rejects | Unknown/Multiple valid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by goldfire): There is a fine workaround: `-XAllowAmbiguousTypes`, as the error message suggests. But I tend to agree that this is incorrect behavior by GHC: should we be doing an ambiguity check on generic-default signatures? I think not. Why not? Because we never call a function with the type given by a generic-default signature. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12473#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler