#14266: AllowAmbiguousTypes doesn't play well with default class methods -------------------------------------+------------------------------------- Reporter: chris-martin | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 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 chris-martin): Thanks Ryan - yes that's a great description of what I was trying to do. One correction: I'm pretty sure `MultiMonoid` alone ''does'' require `AllowAmbiguousTypes` even before you get to `MultiFoldable`. The "complete" result is now on Hackage https://hackage.haskell.org/package/multi- instance-0.0.0.1/docs/MultiInstance.html although I ended up scrapping the `MultiFoldable` class altogether. It was an extended thought experiment more than anything, probably beyond the bounds of reasonable Haskell. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14266#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler