Representation of First-In, First-Out(FIFO) data structure.

Returns empty queue.

   head empty == Nothing

Create queue from list. The newest element comes head of the queue.

    ["H","e","l","l","o"]
        |> fromListLIFO
        |> head
    --> Just "H"

Create queue from list. The oldest element of the list comes head of the queue.

    ["H"]
        |> (::) "e"
        |> (::) "l"
        |> (::) "l"
        |> (::) "o"
        |> fromListFIFO
        |> head
    --> Just "H"

Returns True if the argument has no element.

    empty
        |> enqueue "a"
        |> isEmpty
    --> False


    empty
        |> enqueue "a"
        |> dequeue
        |> isEmpty
    --> True

Returns the oldest element injected in the queue wrapped in Maybe.

    empty
        |> head
    --> Nothing


    empty
        |> enqueue "e"
        |> enqueue "l"
        |> enqueue "m"
        |> head
    --> Just "e"

Returns the queue as second argument with the element as the first argument injected into the rear side.

    empty
        |> enqueue 100
        |> enqueue 200
        |> head
    --> Just 100

Returns queue without the oldest element of the given queue.

    empty
        |> enqueue "e"
        |> enqueue "l"
        |> enqueue "m"
        |> enqueue "i"
        |> enqueue "s"
        |> enqueue "h"
        |> dequeue
        |> head
    --> Just "l"

Convert a queue to List. The last element in the queue will become the head of the returned list.

    empty
        |> enqueue 100
        |> enqueue 200
        |> enqueue 300
        |> toListLIFO
    --> [300,200,100]

Convert a queue to List. The first element in the queue will become the head of the returned list.

    empty
        |> enqueue 100
        |> enqueue 200
        |> enqueue 300
        |> toListFIFO
    --> [100,200,300]