#13021: Inaccessible RHS warning is confusing for users -------------------------------------+------------------------------------- Reporter: mpickering | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.0.1 Keywords: | Operating System: Unknown/Multiple PatternMatchWarnings | Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- The pattern match checker makes the distinction between redundant matches and matches with an inaccessible right hand side. A pattern with an inaccessible RHS, is a redundant pattern which forces the argument so affects strictness. I think this is confusing for users as most of the time you write programs assuming totality but the error message doesn't make it clear why the two warnings are different. I think that instead they should both be called redundant but a note added to the inaccessible case explaining that removing it could affect strictness. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13021 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler