mariusGundersen

The ES6 Promise specification contains the very useful constructor for creating a promise, like so:

var promise = new Promise(function(resolve, reject){
  resolve("hi");
});

promise.then(function(message){
  console.log(message);
});

mariusGundersen

JavaScript has labels, which can be placed before blocks to create a named section of code, serving almost the same use as an imidiately invoked function expression (IIFE)

(function iife(){
  var scoped = "this is scoped stuff";
})();

iife: {
  let scoped = "this is scoped";
}

mariusGundersen

Currently you can export things from a module in at least six different ways, and import things in at least six different ways, resulting in 36 different combinations, most of which are not semantically valid.

Here is a greatly simplified (and probably naive) suggestion for modules in ES6:

###export You can only export named things, including variables and functions.

let a = "hello";
export a;

mariusGundersen

//The file foobar.js contains these two lines of code
var foo = "foo", bar = "bar";
export default = {foo, bar}; 

//It can now be imported into another module using either of these two lines:
import foobar from "foobar";
module foobar from "foobar";
//But not this line:
import {foo, bar} from "foobar";

mariusGundersen

module _ from "underscore";
import _ from "underscore";
import module _ from "underscore";
import {each, map, find} from "underscore";
import "underscore";
import default _ from "underscore";
const _ = System.import("underscore");
import "underscore" as _;
import {_} from "underscore";
import {each as forEach} from "underscore";

mariusGundersen

var component1 = {

  //this method will receive the event and process it
  handleEvent: function(event){
    
    //this is only for debugging
    console.log("debugging!", event.data);    
    
    //the event causes the state of the component to change

mariusGundersen

define([], function() {
        return function deadWeight() {
                var weight = 1000000;
                var theWeight = new Array(weight);
                for (var i = 0; i < weight; i++)
                        theWeight[i] = i;

                this.getWeight = function() { return theWeight;}
        }
});

mariusGundersen

Programmer Collective Nouns

• An Enumerable of Rubyists @raganwald
• An Indentation of Pythonistas @raganwald
• A fold of Haskellers! @ReinH
• A Din of Twitterers @raganwald
• A callback of JavaScripters @irvingreid
• An NCC-1701 of Java Programmers @raganwald
• A relation of SQLers @raganwald

mariusGundersen

/*
This is how 3 dependencies are defined using AMD.
Notice how when the number of dependencies grows the
distance between the path to the dependency and the
variable it is stored in grows. It quickly becomes
difficult to see which variable corresponds to which
module name.
*/

define(["jQuery", "an/other/module", "knockout"], function($, dep, ko){

mariusGundersen

var a = 5;
function whatIsA() {
  if(a == undefined) {
    var a = 7;
  }
  return a;
}

whatIsA()//is it 5 or 7?