| author | haftmann | 
| Tue, 10 Aug 2010 13:58:26 +0200 | |
| changeset 38306 | a062fdf777df | 
| parent 30226 | 2f4684e2ea95 | 
| permissions | -rw-r--r-- | 
module Codegen where { import qualified Nat; class Null a where { nulla :: a; }; heada :: forall a. (Codegen.Null a) => [a] -> a; heada (x : xs) = x; heada [] = Codegen.nulla; null_option :: forall a. Maybe a; null_option = Nothing; instance Codegen.Null (Maybe a) where { nulla = Codegen.null_option; }; dummy :: Maybe Nat.Nat; dummy = Codegen.heada [Just (Nat.Suc Nat.Zero_nat), Nothing]; }