beatrichartz/parallel_stream

A parallelized stream implementation for Elixir

Source code at GitHub https://github.com/beatrichartz/parallel_stream

{
  "createdAt": "2015-10-17T19:48:04Z",
  "defaultBranch": "main",
  "description": "A parallelized stream implementation for Elixir",
  "fullName": "beatrichartz/parallel_stream",
  "homepage": "",
  "language": "Elixir",
  "name": "parallel_stream",
  "pushedAt": "2022-09-17T04:31:11Z",
  "stargazersCount": 103,
  "topics": [
    "elixir",
    "parallelism",
    "parallelize",
    "stream"
  ],
  "updatedAt": "2025-09-26T21:31:04Z",
  "url": "https://github.com/beatrichartz/parallel_stream"
}

ParallelStream

Parallelized stream implementation for elixir

What does it do?

Parallelize some stream operations in Elixir whilst keeping your stream in order. Operates with a worker pool.

How do I get it?

Add

{:parallel_stream, "~> 1.1.0"}

to your deps in mix.exs like so:

defp deps do
  [
    {:parallel_stream, "~> 1.1.0"}
  ]
end

Note: Elixir 1.5.0 is required

How to use

Do this to parallelize a map:

stream = 1..10 |> ParallelStream.map(fn i -> i * 2 end)
stream |> Enum.into([])
[2,4,6,8,10,12,14,16,18,20]

The generated stream is sorted the same as the input stream.

More supported functions are each (to produce side-effects):

1..100 |> ParallelStream.each(&IO.inspect/1)

filter:

stream = 1..20 |> ParallelStream.filter(fn i -> i |> rem(2) == 0 end)
stream |> Enum.into([])
[2,4,6,8,10,12,14,16,18,20]

and filter’s counterpart, reject:

stream = 1..20 |> ParallelStream.reject(fn i -> i |> rem(2) == 0 end)
stream |> Enum.into([])
[1,3,5,7,9,11,13,15,17,19]

License

MIT