#10087: DefaultSignatures: error message mentions internal name -------------------------------------+------------------------------------- Reporter: andreas.abel | Owner: Type: feature request | Status: infoneeded Priority: normal | Milestone: Component: Compiler (Type | Version: 7.8.4 checker) | Resolution: | Keywords: Generics Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Other | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by RyanGlScott): * status: new => infoneeded Comment: I'm a bit confused about the state of affairs for this ticket. Pedro, I don't really understand what you mean when you say "So perhaps that's what we should do in this case, too." After all, this code: {{{#!hs {-# LANGUAGE DefaultSignatures #-} class C a where reflexive :: a -> Bool default reflexive :: Eq a => a -> Bool reflexive x = x == x data D instance C D where }}} and this code: {{{#!hs class C a where reflexive :: Eq a => a -> Bool reflexive x = x == x data D instance C D }}} appear to be fundamentally different. In the former, `reflexive` defines a function that //requires// an `Eq a` constraint when the user doesn't implement it. In the latter, `reflexive` defines a function that //presupposes// that `a` is an instance of `Eq`. When viewed in this light, shouldn't the former code error and the latter code be OK? Simon, what are `GenDefMeth` and `NoDefMeth`? I can't find anything in the source about them (save for one possibly outdated comment on `NoDefMeth`). Were they replaced by `DefMethSpec` (i.e, [http://git.haskell.org/ghc.git/blob/93d85af9fec968b43452891ec7b10382a4a99a38... this]) at some point? If so, are your comments about a proposed refactoring still relevant? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10087#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler