matthewmueller

/**
 * Excerpt from: Analysis of generators and other async patterns in node
 * URL: http://spion.github.io/posts/analysis-generators-and-other-async-patterns-node.html#a-gentle-introduction-to-generators
 *
 * When next is invoked, it starts the execution
 * of the generator. The generator runs until it
 * encounters a yield expression. Then it pauses
 * and the execution goes back to the code that
 * called next.

matthewmueller

Flow-based Programming is all about reacting to event sources. Event sources in the browser might be:

• A DOM event
• AJAX call
• Onload initial data passing
• Local DB fetch (local storage, indexdb)

In order to build larger systems, nodes need to be chainable and flows need to be composable. I think the best way to do this in Javascript may look something like this:

matthewmueller

/**
 * Module Dependencies
 */

var debug = require('debug')('lapwing:build');
var relative = require('path').relative;
var resolve = require('path').resolve;
var extname = require('path').extname;
var uglify = require('gulp-uglify');
var Batch = require('better-batch');

matthewmueller

function *something(msg) {
  msg += yield msg; // yields "a", returns "b"
  msg += yield msg; // yields "ab", returns "c"
  msg += yield msg; // yields "abc", returns "d"
  return msg; // returns "abcd"
}

var gen = something('a');
console.log(gen.next().value);    // a
console.log(gen.next('b').value); // ab

matthewmueller

Keybase proof

I hereby claim:

• I am matthewmueller on github.
• I am matthewmueller (https://keybase.io/matthewmueller) on keybase.
• I have a public key whose fingerprint is BFED 49E4 15E0 9C6E C008 3E7F 490F 7168 F0D0 85EB

To claim this, I am signing this object:

matthewmueller

var script = document.currentScript;
var sheet = script.getAttribute('sheet');

var el = document.createElement('div');
el.textContent = 'hi world!';

script.parentNode.replaceChild(el, script);
console.log('lol');

matthewmueller

var a = new Promise(function (resolve, reject) {
  reject(1)
})

function b_success() {
  console.log('b: success', err);
  // not called...

matthewmueller

// Express with Underscore templating
app.register('.html', {
	compile : function(str, options) {
		return function(locals) {
			return _.template(str, locals);
		};
	}
});

matthewmueller

/*
  Step - tiny, but flexible step library
  
  Usage: 
  
    var first = function(next) {
      ...
      return next(null, name, date);
    }
  

matthewmueller

/*
  Counter used for async calls
  
  Example:
    var files = ['a', 'b'];
    finished = after(files.length);
    
    finished() // false
    finished() // true