#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 nfrisby): That way of saying it clarifies the expectations for me. And doesn't seem too burdensome for the plugin author. Thus I think this ticket could be resolved by updating the documentation. (Though I still would like for a plugin to be able to request the flattened Wanteds. Separate ticket?) In particular this sentence in the User Guide "[The plugin] will be invoked at two points in the constraint solving process: after simplification of given constraints, and after unflattening of wanted constraints." would benefit from some elaboration. Specifically, "unflattening of wanted constraints" is somewhat ambiguous: until you spelled it out, I was thinking that if a constraint is flattened, it doesn't have any flattening variables in it. However, I'm inferring here that the jargon is used to mean that "unflattening a wanted constraint" only eliminates fmvs, possibly leaving fsks behind? That's what I've been confused about (until now, I think). Thanks. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15147#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler