#393: functions without implementations -------------------------------------+------------------------------------- Reporter: c_maeder | Owner: simonpj Type: feature | Status: new request | Milestone: ⊥ Priority: normal | Version: None Component: Compiler | Keywords: (Type checker) | Architecture: Unknown/Multiple Resolution: None | Difficulty: Moderate (less Operating System: | than a day) Unknown/Multiple | Blocked By: Type of failure: | Related Tickets: None/Unknown | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by simonpj): Actually using this {{{ f :: Int -> Int f = _ -- Note "_" not "undefined" }}} plus compiling with `-fdefer-type-errors`, will give a runtime error when (and only when) `f` is called, giving file and line number. See [http://www.haskell.org/ghc/docs/latest/html/users_guide/typed-holes.html the manual on typed holes]. See #9497 for making this a bit better. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/393#comment:24 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler