-- Source code from
--   Purely Functional Data Structures
     
    Cambridge University Press , 1998
--
  Copyright ( c ) 1998 Cambridge University Press

module Deque (Deque(..)) where
  import Prelude hiding (head,tail,last,init)

  class Deque q where
    empty   :: q a
    isEmpty :: q a -> Bool

    cons    :: a -> q a -> q a
    head    :: q a -> a
    tail    :: q a -> q a

    snoc    :: q a -> a -> q a
    last    :: q a -> a
    init    :: q a -> q a

 Source code from
   Purely Functional Data Structures

     
    Cambridge University Press , 1998
  Copyright ( c ) 1998 Cambridge University Press

module Deque (Deque(..)) where
  import Prelude hiding (head,tail,last,init)

  class Deque q where
    empty   :: q a
    isEmpty :: q a -> Bool

    cons    :: a -> q a -> q a
    head    :: q a -> a
    tail    :: q a -> q a

    snoc    :: q a -> a -> q a
    last    :: q a -> a
    init    :: q a -> q a
