#8851: Standalone deriving and GND behave differently --------------------------------------------+------------------------------ Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.8.1-rc1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Test Case: | Difficulty: Unknown Blocking: | Blocked By: | Related Tickets: --------------------------------------------+------------------------------ Comment (by nomeata): That’s my gut feeling as well. But what if the type checker resolves the constraints in `forall a. (Monad IdrisInnerParser, Show a) => IdrisInnerParser a -> IdrisInnerParser ()’` before coerce is being called, so that it would only have to coerce `forall a. (Show a) => IdrisInnerParser a -> IdrisInnerParser ()’, and that would be fine. This is probably what is happening in case (A) (otherwise the result would not role-type-check). -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8851#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler