salespaulo / flow

Computational parallel flows on top of GenStage

Flow

Flow allows developers to express computations on collections, similar to the Enum and Stream modules, although computations will be executed in parallel using multiple GenStages.

Here is a quick example on how to count words in a document in parallel with Flow:

File.stream!("path/to/some/file")
|> Flow.from_enumerable()
|> Flow.flat_map(&String.split(&1, " "))
|> Flow.partition()
|> Flow.reduce(fn -> %{} end, fn word, acc ->
  Map.update(acc, word, 1, & &1 + 1)
end)
|> Enum.to_list()

See documentation for Flow or José Valim's keynote at ElixirConf 2016 introducing the main concepts behind GenStage and Flow.

Installation

Flow requires Elixir v1.5 and Erlang/OTP 19+. Add :flow to your list of dependencies in mix.exs:

def deps do
  [{:flow, "~> 1.0"}]
end

License

Copyright 2017 Plataformatec
Copyright 2020 Dashbit

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.