doc-src/Codegen/Thy/examples/Example.hs
author bulwahn
Fri, 21 Oct 2011 11:17:14 +0200
changeset 45231 d85a2fdc586c
parent 44970 52f809bc5402
child 48501 e59778bc71a0
permissions -rw-r--r--
replacing code_inline by code_unfold, removing obsolete code_unfold, code_inline del now that the ancient code generator is removed

{-# LANGUAGE EmptyDataDecls, RankNTypes, ScopedTypeVariables #-}

module Example where {

data Queue a = AQueue [a] [a];

empty :: forall a. Queue a;
empty = AQueue [] [];

dequeue :: forall a. Queue a -> (Maybe a, Queue a);
dequeue (AQueue [] []) = (Nothing, AQueue [] []);
dequeue (AQueue xs (y : ys)) = (Just y, AQueue xs ys);
dequeue (AQueue (v : va) []) =
  let {
    (y : ys) = reverse (v : va);
  } in (Just y, AQueue [] ys);

enqueue :: forall a. a -> Queue a -> Queue a;
enqueue x (AQueue xs ys) = AQueue (x : xs) ys;

}