{-# LANGUAGE EmptyDataDecls, RankNTypes, ScopedTypeVariables #-}
module Example where {
import Prelude ((==), (/=), (<), (<=), (>=), (>), (+), (-), (*), (/),
(**), (>>=), (>>), (=<<), (&&), (||), (^), (^^), (.), ($), ($!), (++),
(!!), Eq, error, id, return, not, fst, snd, map, filter, concat,
concatMap, reverse, zip, null, takeWhile, dropWhile, all, any, Integer,
negate, abs, divMod, String, Bool(True, False), Maybe(Nothing, Just));
import qualified Prelude;
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;
}