#10746: No non-exhaustive pattern match warning given for empty case analysis -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: | PatternMatchWarnings Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: #7669, #11806 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): To summarize, empty case is desugared specially. It therefore needs a special case for coverage checking, but ''not'' the trivial one we currently have. I suspect the right thing is probably to avoid including `_|_` in `mkInitialUncovered` when checking an empty `case`, whatever that involves. You may need to do something else if you want to catch an overlapping trivial pattern in since cases, but even if you miss that it's no big deal. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10746#comment:17 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler