
#11245: Non-exhaustive pattern, "Patterns not matched" list is empty -------------------------------------+------------------------------------- Reporter: osa1 | Owner: gkaracha Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Resolution: | Keywords: 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 see your point about this not being a bug, but can't we have a better error message? For example: {{{ Exhaustive.hs:10:7: warning: Pattern match(es) are non-exhaustive In the definition for ‘a’: Cases not matched: (Just i <- x), not (odd i) }}} Maybe it's hard to get that "cases not matched" so exactly, but at least we can say vaguely that the guards are incomplete, instead of the error suggesting that a list follows but then omitting the list. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11245#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler