#9497: Silent typed holes -------------------------------------+------------------------------------- Reporter: merijn | Owner: Type: feature | Status: new request | Milestone: Priority: normal | Version: 7.8.3 Component: Compiler | Keywords: typed holes, Resolution: | warnings Operating System: | Architecture: Unknown/Multiple Unknown/Multiple | Difficulty: Unknown Type of failure: | Blocked By: None/Unknown | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by simonpj): Crumbs, you are right. I'd forgotten that we'd decided ''not'' to make typed holes into a language extension (see [http://www.haskell.org/pipermail/ghc-devs/2014-January/003758.html this email]), but rather controlled by `-fwarn-typed-holes` which is on by default. I agree with Richard that this is jolly confusing. Two issues with Richard's proposals: * There is no way to switch off typed holes altogether, and revert to {{{ Hole.hs:1:7: Pattern syntax in expression context: _ }}} Maybe that is OK. * What does `-fno-warn-typed-holes` do in the absence of `-fdefer-typed- holes`? No-op with a warning? * What does `-fwarn-typed-holes` do? Perhaps just re-enable the warning after switching off all warnings with `-w`. Modulo just specifying (and documenting) this behaviour, I'd be content with the above. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9497#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler