_links.md

Read Me

• Partials & Currying
• ES6 Classes
• Why do we have an IMG tag
• Exploring ES6
• JResig's Simple Class
• Why Prototypal Inheritance Matters

Talks to Watch (Seriously, Do It!)

• WAT
• The Birth & Death of JavaScript

_solution.js

Function.prototype.partial = function() {
  var fn = this, args = Array.prototype.slice.call(arguments)
  args = [].concat.apply([], args) // flatten the args array

  return function() {
    var args2 = Array.prototype.slice.call(arguments)
    args2 = [].concat.apply([], args2) // flatten the args array
    return fn.apply(fn, args.concat(args2))
  }
}

Function.prototype.curry = function() {
  var fn = this, args = Array.prototype.slice.call(arguments)
  args = [].concat.apply([], args) // flatten the args array
  var argsLeft = fn.length - args.length

  if (argsLeft == 1) {
    return fn.partial(args)
  } else {
    return function() {
      var args2 = Array.prototype.slice.call(arguments)
      return fn.curry.apply(fn, args.concat(args2))
    }
  }
}

function converter(symbol, factor, input) {
  return input * factor + symbol
}

var milesToKM = converter.curry('km')(1.609)
var lbToKG    = converter.curry('kg', 0.453)
var usdToEuro = converter.curry(['€', 0.90])

console.log(milesToKM(500))
console.log(lbToKG(200))
console.log(usdToEuro(20))

currying.js

function converter(symbol, factor, input) {
  return input * factor + symbol
}

// km = miles * 1.609
// kg = lb * 0.453
// euro = USD * 0.90

/*
Challenge: Implement Function.prototype.partial 
  and/or Function.prototype.curry so that we 
  can do things like:
  
  milesToKm = converter.partial('km', 1.609)
  lbsToKg   = converter.curry('kg')(0.453)
*/

es5.js

// Actual JS (< ES6)
function Person(first, last) {
  if (this instanceof Person) {
    this.first = first
    this.last = last
  } else {
    return new Person(first, last)
  }
}
Person.prototype.name = function() {
  return this.first + " " + this.last
}

joshua = new Person('Joshua', 'Wehner')
joshua.name()

es6.js

// ES6
class Person {
  constructor(first, last) {
    this.first = first
    this.last = last
    Person.count++
  }
  
  get name() {
    return this.first + " " + this.last
  }
  
  static get count() {
    return !this._count ? 0 : this._count
  }
  
  static set count(n) {
    this._count = n
  }
}

class FancyDiv {
  constructor(id) {
    this.id = id
    FancyDiv.myDivs = this
  }
  
  static get myDivs() {
    return !this._myDivs ? [] : this._myDivs
  }
  
  static set myDivs(div) {
    this._myDivs = this.myDivs
    this._myDivs = this._myDivs.concat(div)
  }
  
  static find(id) {
    for (var div of this.myDivs) {
      if (div.id === id) {
        return div
      }
    }
  }
}