#11390: GHC does not warn about redundant patterns -------------------------------------+------------------------------------- Reporter: Iceland_jack | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.1 Resolution: | Keywords: warnings, | PatternMatchWarnings 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 goldfire): I agree with George (gkaracha). `sillyId x = x` can't be called on a value, but Haskell isn't call-by-value. I will use `Void` instead of `F1 Char`, because the type family bit isn't the interesting part here. {{{ silly1 :: Void -> Void silly1 x = x silly2 :: Void -> Void silly2 x = error "urk" }}} `silly1 undefined` and `silly2 undefined` have different runtime behavior; the pattern is not redundant. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11390#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler