doc-src/Codegen/Thy/examples/Codegen.hs
author huffman
Thu, 17 Nov 2011 15:07:46 +0100
changeset 45547 94c37f3df10f
parent 30226 2f4684e2ea95
permissions -rw-r--r--
HOL-Word: removed more duplicate theorems

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];

}