-- Queues with constant time operations, from
-- /Simple and efficient purely functional queues and deques/,
-- by Chris Okasaki, /JFP/ 5(4):583-592, October 1995.
-- Queues with constant time operations, from
-- /Simple and efficient purely functional queues and deques/,
-- by Chris Okasaki, /JFP/ 5(4):583-592, October 1995.