#13557: error found hole: _ is not appropriate in the following case -------------------------------------+------------------------------------- Reporter: vanto | Owner: (none) Type: feature request | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 8.0.2 Resolution: invalid | Keywords: 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: | -------------------------------------+------------------------------------- Changes (by simonpj): * status: new => closed * resolution: => invalid Comment: Here's a simplified version {{{ f' = [True | s <- [_, _]] }}} Here `_` is not a wildcard pattern, as you say. It's an underscore in an expression, which GHC treats as a wildcard ''expression''. See [http://downloads.haskell.org/~ghc/master/users-guide/glasgow_exts.html #typed-holes Typed Holes] in the user manual. I think this is correct behaviour. Re-open if you disagree. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/13557#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler