qi

A small DSL for async flow control.

Qi

A simple DSL for parallel and sequential processing.

It is simpler and smaller than any other flow control library you will find, and the features are very powerful.

It supports three operations:

  • disperse
  • focus
  • channel
npm install qi

Initialize it on a target function and you will get a callback constructor. You may create as many callbacks as you want and pass them to your subtasks. The target will be called when the subtasks have completed.

It supports the node convention of (err, data). If any of your subtasks return results they will be accumulated in an array. If any return an error, the target will be called immediately with the error, and the results of all further subtasks will be ignored.

should = require 'should'
{focus} = require 'qi'
 
describe 'focus', ->
  it 'should wait for all callbacks to return', (done) ->
    cb = focus done
 
    setTimeout cb(), 1
    setTimeout cb(), 2
    setTimeout cb(), 3
 
  it 'should return all results', (done) ->
    cb = focus (err, results) ->
      should.not.exist err
      results.should.eql [0, 1]
      done()
 
    i = 0
    doStuff = (cb) ->
      -> cb null, i++
 
    setTimeout doStuff(cb()), 1
    setTimeout doStuff(cb()), 2

This creates a function which when called will pass its args on to multiple child functions.

This executes any number of tasks in sequence.

(MIT License)

Copyright (c) 2013 Torchlight Software info@torchlightsoftware.com

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.