#11105: Put the generic-default type in the Class -------------------------------------+------------------------------------- Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- This is an internal GHC refactoring ticket. Consider {{{ {-# LANGUAGE DefaultSignatures #-} class C a where op :: a -> a -> Bool default op :: Ord a => a -> a -> Bool op x y = x < y }}} The `Class` object for `C` has a `ClassOpItem` that specifies * the name `op` * the type of the method `a -> a -> Bool` * that `op` has a generic-default signature BUT it does not contain the actual signature `Ord a => a -> a -> Bool`. That's really wrong; it is certainly part of the definition of the class, and we should print it out when we say `:info C` in ghci. Instead this type is kept solely in the top-level generic-default Id binding. But that means that default-method Ids and generic-default method Ids are treated differently; see `gen_dm_ids` in `tcTyClDecl1` in `TcTyClsDecls`, and `mkDefaultMethodIds` in `TcTyDecls`. We should treat them uniformly. I know how but have too much in flight to do it immediately. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11105 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler