#7614: tc_hs_type: bang : The impossible happened -------------------------------+-------------------------------------------- Reporter: erikd | Owner: Type: bug | Status: new Priority: normal | Component: Compiler Version: 7.6.1 | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: Compile-time crash | Blockedby: Blocking: | Related: -------------------------------+-------------------------------------------- A simple data structure with bang patterns like the following: {{{ data MyType = MyType { a :: !Int , b :: !Maybe Int } }}} results in: {{{ ghc: panic! (the 'impossible' happened) (GHC version 7.6.1 for x86_64-unknown-linux): tc_hs_type: bang }}} Adding parentheses around the "Maybe Int" like this: {{{ data MyType = MyType { a :: !Int , b :: !(Maybe Int) } }}} is accepted, but it would be nice if the former example printed a syntax error or some sort of other warning rather than just a panic. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7614 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler