#10339: PatternSynonyms confuse exhaustiveness check -------------------------------------+------------------------------------- Reporter: hvr | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by wrl314): Another example showing same problem with simple unidirectional pattern synonym: {{{ data Foo2 = Foo2 Int String pattern F a <- Foo2 a _ blah :: Foo2 -> Int blah (F a) = a + 1 }}} Result: {{{ Warning: Pattern match(es) are non-exhaustive In an equation for ‘blah’: Patterns not matched: _ }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10339#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler