#15147: Type checker plugin receives Wanteds that are not completely unflattened -------------------------------------+------------------------------------- Reporter: nfrisby | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler (Type | Version: 8.4.1 checker) | Keywords: Resolution: | TypeCheckerPlugins 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 diatchki): I agree with Simon here, I think it'd be more consistent if the plugins were always given the flattened constraints, as it seems simpler and more consistent. Also, is it the case that un-flattening only substitutes in the variables that it introduces by flattening, and not all constraints that are in a similar form? More concretely, if I a programmer wrote `x ~ F a, G x ~ G Int`, then would un-flattening rewrite this to `G (F a) ~ G Int` or would it leave it as is? If the latter, then plugins should already be prepared to deal with this case, as it would be quite odd if the one form worked but the other didn't. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15147#comment:17 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler