RQ

Better living through asynchronicity

This is a CommonJS-compatible port of this library for node.js/io.js.

The original source is available at: https://github.com/douglascrockford/RQ

Introduction

Turn based servers are now joining turn based browsers in providing race-free and deadlock-free interactivity. The event-driven model has long been popular in UI systems, but the nature of work in servers presents some new challenges. Functional programming provides solutions, including monads, arrows, promises, and various flavors of FRP. This is another such solution, intended to enhance ease of use for tasks which are common to server applications by providing support of sequences, parallel operations, with timeouts and cancellations.

Installation

$ npm install async-rq

Usage

For complete documentation see help.md.

var RQ = require('async-rq');

RQ.sequence() example

function widget(name, delay) {
  return function requestor(callback, value) {
    setTimeout(function() {
      if(!value) value = '(start)';
      callback(value + ' -> ' + name);
    }, delay);
  };
}

var runner = RQ.sequence([
  widget('Seq A1', 100),
  widget('Seq A2', 10),
  widget('Seq A3', 1),
  function(callback, value) {
    callback(value + ' -> (end)');
  }
]);

runner(function(success, failure) {
  console.log(success);
});

Result:

(start) -> Seq A1 -> Seq A2 -> Seq A3 -> (end)

RQ.race() example

function timer(i, delay) {
  return function requestor(callback, value) {
    setTimeout(function() {
      callback(i);
    }, delay);
  }
}

var racer = RQ.race([
  timer(1, 1000),
  timer(2, 500),
  timer(3, 520),
]);

racer(function(success, failure) {
  console.log(success);
});

Result will be:

2

Author

Douglas Crockford (@douglascrockford)

Licence

?