monads.future
The Future(a, b)
monad represents values that depend on time. This allows one
to model time-based effects explicitly, such that one can have full knowledge
of when they're dealing with delayed computations, latency, or anything that
can not be computed immediately.
A common use for this monad is to replace the usual Continuation-Passing Style form of programming, in order to be able to compose and sequence time-dependent effects using the generic and powerful monadic operations.
Example
var Future = require('monads.future')
function get(url) {
return new Future(function(resolve, reject) {
var request = new XMLHttpRequest()
request.onload = function() {
if (!/2\d\d/.test(this.status)) reject(this.responseText)
else resolve(this.responseText)
}
request.open("get", url, true)
request.send()
})
}
var t1 = get('/something')
var t2 = get('/other')
var t3 = t1.map(function(a) {
t2.map(function(b) {
return a + b
})
})
t3.chain(function(a) {
console.log(a)
})
Installing
The easiest way is to grab it from NPM. If you're running in a Browser environment, you can use Browserify
$ npm install monads.future
Using with CommonJS
If you're not using NPM, Download the latest release, and require
the monads.future.umd.js
file:
var Future = require('monads.future')
Using with AMD
Download the latest release, and require the monads.future.umd.js
file:
require(['monads.future'], function(Future) {
( ... )
})
Using without modules
Download the latest release, and load the monads.future.umd.js
file. The properties are exposed in the global Future
object:
<script src="/path/to/monads.future.umd.js"></script>
Compiling from source
If you want to compile this library from the source, you'll need Git, Make, Node.js, and run the following commands:
$ git clone git://github.com/folktale/monads.future.git
$ cd monads.future
$ npm install
$ make bundle
This will generate the dist/monads.future.umd.js
file, which you can load in
any JavaScript environment.
Documentation
You can read the documentation online or build it yourself:
$ git clone git://github.com/folktale/monads.maybe.git
$ cd monads.maybe
$ npm install
$ make documentation
Then open the file docs/literate/index.html
in your browser.
Platform support
This library assumes an ES5 environment, but can be easily supported in ES3 platforms by the use of shims. Just include es5-shim :)
Licence
Copyright (c) 2013 Quildreen Motta.
Released under the MIT licence.