#8034: Missing ambiguity test for class methods ---------------------------------+------------------------------------------ Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.7 Keywords: | Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: | Blocking: Related: | ---------------------------------+------------------------------------------ If you write {{{ type family F a foo :: F a -> F a foo = ... }}} then `foo` is rejected as having an ambiguous type. But if instead you write {{{ class C a where type F a foo :: F a -> F a }}} no such test is made. That's inconsistent, and leads to downstream errors (see #8030 for example). Better to do an ambiguity test. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/8034 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler