#11503: TypeError woes (incl. pattern match checker) -------------------------------------+------------------------------------- Reporter: goldfire | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.6.1 Component: Compiler | Version: 8.1 Resolution: | Keywords: | PatternMatchWarnings, | CustomTypeErrors Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple error/warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: #14141 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): Simon, I imagine there's a broad reason somewhere for {{{ [G] c ~ fsk, [G] fsk }}} not to be simplified to {{{ [G] c }}} Assuming that's the case I suspect maybe we should track known insoluble constraints the way we track known-bottoming expressions. Since `TypeError ... ~ fsk` and `TypeError ...` is insoluble, we could conclude that `fsk` is insoluble. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11503#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler