#8806: Invalid constraints should fail to type check -------------------------------------------+------------------------------- Reporter: erikd | Owner: erikd Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type checker) | Version: 7.6.3 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: -------------------------------------------+------------------------------- With ghc-7.6.3 the following code: {{{ f :: Int => Int f x = x + 1 }}} should fail to type check, but instead compiles and runs as if it was: {{{ f :: Int -> Int f x = x + 1 }}} With 7.8rc1 and git HEAD this results in an error: {{{ Expected a constraint, but ‛Int’ has kind ‛*’ In the type signature for ‛f’: f :: Int => Int }}} We should add a "shouldn't type check" test to avoid the possibilty of a regression. Also: {{{ g :: (Int => Show a) => Int g = undefined }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8806 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler