#11427: TypeSynonyms not deduced -------------------------------------+------------------------------------- Reporter: phadej | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1-rc1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by phadej): goldfire: I can break previous example by adding `MyEq a` constraint to `MyClass`: {{{ {-# LANGUAGE UndecidableInstances #-} {-# LANGUAGE FlexibleInstances #-} class MyEq a where myeq :: a -> a -> Bool class MyEq a => MyOrd a where mycomp :: a -> a -> Ordering class MyEq a => MyClass a where mydef :: a -> Bool instance MyOrd a => MyClass a where mydef x = myeq x x }}} AFAICS, `MyOrd a` in instance declration should provide `MyEq a`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11427#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler