#14385: Clarify error message when missing GADTs extension -------------------------------------+------------------------------------- Reporter: lyxia | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.1 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- If we write a GADT declaration and forget to enable `GADTs` we get the following error message: {{{ ww.hs:1:1: error: • Illegal generalised algebraic data declaration for ‘T’ (Use GADTs to allow GADTs) • In the data declaration for ‘T’ }}} It could be made more explicit for new users that the suggestion is to use the '''extension''' `GADTs`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14385 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler