#8581: Pattern synonym used in an expression context could have different constraints to pattern used in a pattern context -------------------------------------+------------------------------------- Reporter: cactus | Owner: Type: feature request | Status: new Priority: normal | Milestone: 8.0.1 Component: Compiler | Version: Resolution: | Keywords: | PatternSynonyms 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 mpickering): I've looked a bit now. It seems like the correct thing to do is disassemble the `PatSyns` so that the builder/matcher can be handled separately. The way to do this seems to be to modify `ValBindsOut` to use a new datatype instead of `HsBinds`, split apart the pat syn when calculating sccs and then stitch it back together after typechecking if that is still necessary. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8581#comment:32 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler