#9108: GADTs and pattern type annotations? -------------------------------------+------------------------------------ Reporter: edsko | Owner: Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Resolution: invalid | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -------------------------------------+------------------------------------ Comment (by edsko): Hmmmm, nasty :( I worked out in a different way, and Andres suggested yet another way (using a type family), but it seems me me that this evaluated- before-pattern-match behaviour is unfortunate behaviour; mightn't have made a difference before GADTs but with GADTs is just seems the wrong way around? Are there reasons ''not'' to evaluate the pattern match before the type annotation? (It's a tricky thing, type checking for GADTs, I realize that :) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9108#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler