uses

There are just too many use cases, when you might find that methods exposed by built-ins is not enough. Also, different libraries try to fix in a different ways:

1. Libraries like sugarjs extend built-ins with a collection of helpful methods, that provide natural and concise API, which still may or may not fit your use case (if not, you're back to the original problem).

2. Libraries like underscore provide handful utility functions. Unfortunately those are not as chaining friendly (degrade code readability when chaining multiple actions) and have different signature from built-ins.

var sum = _.reduce(_.map(_.filter(numbers, function(n) {
  return n % 2
}), function(num) {
  return num * 3
}), function(memo, n) {
  return memo + n
}, 0)

This library tryes to provide a natural, chainable API that is not limited to any collection of heldful methods, in fact it does not comes with thouse and encourages to build / reuse use case specific methods and collections.

Examples

Any funcitons with generic DSL

var uses = require('uses'), use = uses.use, Target = uses.Target
 
function merge() {
  var sources = Array.prototype.slice.call(arguments)
  var target = sources.pop()
  var whitelist = {}
  sources.forEach(function(source) {
    var properties = descriptor(source)
    Object.keys(properties).forEach(function(name) {
      whitelist[name] = properties[name]
    })
  })
  return Object.defineProperties(target, whitelist)
}
 
function filter() {
  var names = Array.prototype.slice.call(arguments)
  var source = names.pop()
  var properties = descriptor(source)
  var whitelist = {}
  names.forEach(function(name) {
    whitelist[name] = properties[name]
  })
  return Object.create(Object.getPrototypeOf(source), whitelist)
}
 
var actual = use({ a: 1, b: 2, c: 3, d: 4 }).as(Target).
  run(merge, { x: 12, y: 13 }).
  run(filter, 'a', 'b', 'x').
  run()
  // => { x: 12, a: 1, b: 2 }

Define custom DSL

var uses = require('uses'), use = uses.use, DSL = uses.DSL
 
// Define methods useful for working with objects like hashes.
var Hash = DSL.extend({
  merge: function merge(properties) {
    return Object.defineProperties(this, descriptor(properties))
  },
  filter: function filter() {
    var properties = descriptor(this)
    var whitelist = {}
    Array.prototype.slice.call(arguments).forEach(function(name) {
      whitelist[name] = properties[name]
    })
    return Object.create(Object.getPrototypeOf(this), whitelist)
  }
})
 
var hash = use({ a: 1, b: 2, c: 3, d: 4 }).as(Hash).
  merge({ x: 12, y: 13 }).
  filter('a', 'b', 'x').
  run()
  // => { x: 12, a: 1, b: 2 }

Go crazy with fab inspired DSL

 
var uses = require('uses'), use = uses.use, fab = uses.fab
// Same map / filter as in first example
var hash = use({ a: 1, b: 2, c: 3, d: 4 }).as(fab)
  (merge, { x: 12, y: 13 })
  (filter, 'a', 'b', 'x')
  (fab.run)
  // => { x: 12, a: 1, b: 2 }
 

Install

npm install uses