#10756: Allow users to indicate inaccessible patterns -------------------------------------+------------------------------------- Reporter: edsko | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by bgamari): Also, kosmikus has suggested that the syntax proposed above looks a bit too similar to a usual RHS. [https://github.com/idris-lang/Idris-dev/wiki /Unofficial-FAQ#where-is-agdas--pattern-and-what-is-impossible Idris], for instance, has a very clearly different syntax for this, {{{ f : Num a => (n : Nat) -> Vect n a -> Nat f Z [] = 0 f Z (_::_) impossible f (S n) (x::xs) = x + f n xs f (S _) [] impossible }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10756#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler