FIFO

A first-in-first-out queue data structure for Elixir. It wraps Erlang's :queue in a more Elixir-friendly API. It implements the Inspect protocol for pretty printing. It also implements the Enumerable and Collectable protocols for working with collections. Functions take a FIFO as the first argument to allow for piping.

Installation

If available in Hex, the package can be installed by adding fifo to your list of dependencies in mix.exs:

def deps do
  [
    {:fifo, "~> 0.1.0"}
  ]
end

Basic Usage

iex(1)> queue = FIFO.new
#FIFO<[]>
iex(2)> queue = queue |> FIFO.push(1) |> FIFO.push(2)
#FIFO<[1, 2]>
iex(3)> {_, queue} = FIFO.pop(queue)
{{:value, 1}, #FIFO<[2]>}
iex(4)> {_, queue} = FIFO.pop(queue)
{{:value, 2}, #FIFO<[]>}
iex(5)> {_, queue} = FIFO.pop(queue)
{:empty, #FIFO<[]>}

Enumerable and Collectable

iex(37)> queue = FIFO.new([1, 2])
#FIFO<[1, 2]>
iex(38)> queue = Enum.into([3, 4], queue)
#FIFO<[1, 2, 3, 4]>
iex(39)> squared = fn n -> n * n end
#Function<7.126501267/1 in :erl_eval.expr/5>
iex(40)> queue = Enum.map(queue, squared) |> FIFO.new
#FIFO<[1, 4, 9, 16]>

Documentation

Documentation can be generated with ExDoc. Run mix docs to generate documentation locally.

Benchmarks

Where there is more than one way to perform the same operation, I have included benchmarks. These are located in the bench folder. You run them like this:

mix run bench/<filename>.exs