promise.js

// node promise.js
function Promise() {
  this.callbacks = [];
  this.resolved = false;

  this.resolve = function(value) {
    if(this.resolved) {
      throw "Promise already resolved";
    }
    else {
      this.callbacks.forEach(function(cb) {
        cb(value);
      });

      this.resolved = true;
      this.value = value;
    }
  };

  this.success = function(cb) {
    if(this.resolved) {
      cb(this.value);
    }
    else {
      this.callbacks.push(cb);
    }
  };
}

var foo = new Promise();
var bar = new Promise();

foo.resolve('hello');

setTimeout(function(){
  bar.resolve('world');
}, 500);

foo.success(function(result){
  console.log(result);
});

bar.success(function(result){
  console.log(result);
});

rotx.rb

# ruby rotx.rb
def rotx(x, string, encrypt = true)
  x = x - 26 while x > 26
  x = (26 - x).abs unless encrypt

  string.chars.map do |chr|
    x.times do
      next unless chr =~ /[A-Za-z]/
      chr = chr.succ[0]
    end
    chr
  end.join("")
end

raise "wrong!" unless rotx(10, "Hello, World") == "Rovvy, Gybvn"
raise "wrong!" unless rotx(10, "Rovvy, Gybvn", false) == "Hello, World"
raise "wrong!" unless rotx(13, "HELLO") == "URYYB"
raise "wrong!" unless rotx(13, "URYYB", false) == "HELLO"
raise "wrong!" unless rotx(36, "Hello, World") == "Rovvy, Gybvn"
raise "wrong!" unless rotx(36, "Rovvy, Gybvn", false) == "Hello, World"
raise "wrong!" unless rotx(100, "Everlane") == "Aranhwja"
raise "wrong!" unless rotx(100, "Aranhwja", false) == "Everlane"