#15753: Inconsistent pattern-match warnings when using guards versus case expressions -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: 8.8.1 Component: Compiler | Version: 8.6.1 Resolution: | Keywords: | PatternMatchWarnings Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple error/warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by RyanGlScott): A workaround is to bind the result of `id g` to some auxiliary variable. For instance, both of the following variants of `ex1` are deemed to be exhaustive: {{{#!hs ex1a, ex1b :: a :~: Int -> G a -> () ex1a Refl g | let g' = id g , GInt <- g' = () ex1b Refl g | g' <- id g , GInt <- g' = () }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15753#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler