{-# LANGUAGE Arrows, NoMonomorphismRestriction #-} module T5333 where import Prelude hiding ( id, (.) ) import Control.Arrow cc1 :: a e b -> a e b -> a e b cc1 = undefined -- With GHC < 7.10.1, the following compile failures occured: -- -- ghc: panic! (the 'impossible' happened) -- (GHC version 7.8.4 for x86_64-unknown-linux): -- mkCmdEnv Not found: base:GHC.Desugar.>>>{v 02V} -- 'g' fails to compile. g = proc (x, y, z) -> ((returnA -< x) &&& (returnA -< y) &&& (returnA -< z)) -- 'f' compiles: -- - without an infix declaration -- - with the infixl declaration -- and fails with the infixr declaration infixr 6 `cc1` -- infixl 6 `cc1` f = proc (x, y, z) -> ((returnA -< x) `cc1` (returnA -< y) `cc1` (returnA -< z))