drewlesueur

this is a title

foo

drewlesueur

How to Generate the Y-Combinator in CoffeeScript

Problem

For fun, let's say you are programming in a language that doesn't allow variable assignments and you still want to make a recursive function. Although you can't assign variables, you can use functions (and enclosed function arguments). Can you make a function recursive without calling it by name?

Lets try implementing the factorial function. First with a function calling itself by name, then with a funtion that never calls itself by name

Here is the implementation of factorial that calls itself by name. It's a simple recursive function

drewlesueur

# normal factorial
factorial = (x) ->
  if x == 1 then return 1
  return x * factorial(x - 1)
console.log factorial(6) #720


# new factorial that doesn't reference itself
factorialGenerator = (fac) ->
  (x) ->

drewlesueur

Sub mycro()
'
' mycro Macro
'
' Keyboard Shortcut: Ctrl+e
'
    ActiveCell.FormulaR1C1 = "yo dawg"
    Range("I9").Select
     
    Dim ws As Worksheet

drewlesueur

var withFakeDate = function (fn) {
  var oldDate = Date;
  var FakeDate = function () {
     var self = new oldDate();
     self.fakeDateWasHere = true;
     return self;
  };
  var oldGetFullYear = Date.prototype.getFullYear;
  Date.prototype.getFullYear = function () {
    return 1996;

drewlesueur

#first generate a key for your domain
openssl genrsa  -out yourdomain.com.key 2048

#then generate the request
openssl req -new -key yourdomain.com.key -out yourdomain.com.csr

#http://mikegrouchy.com/blog/setting-up-nginx-with-ssl-and-godaddy.html

drewlesueur

server.setUpSocket(socket) ->
  socket.on "data", (data) ->
    server.allData.push(data)

#-----------------

server.setUpSocket(socket) ->
  socket.on "data", _.bind(server.onSocketData, null, socket)

drewlesueur

main() {
  var incMaker = () {
    var x = 0;
    var inc = () {
      x += 1;
      return x;
    };
    return inc;
  };
  var inc = incMaker();

drewlesueur

class Point {
  Point(this.x, this.y);
  distanceTo(Point other) {
    var dx = x - other.x;
    var dy = y - other.y;
    return Math.sqrt(dx * dx + dy * dy);
  }
  var x, y;
}

drewlesueur

Presenter = function() {
  this.initialize();
}
Presenter.extend = Backbone.View.extend
_.extend(Presenter.prototype, Backbone.Events, {
  initialize: function () {}
})