demo snippest of js2coffee talk at Berlin Node.js Meetup #3 - 2014-03-12 - try it out on http://js2coffee.org

js2coffee.org.js

// buggy when switch multiple times (js2coffee, coffee2js, js2coffee, ...)
foo = "bar" 
// avoid the bug
main.foo = "bar";

// example for variable shadowing
var x = 0;
main.f = function(err, res) {
  var x = 1;
};

// existence operator
if (main.foo != null) {
  qux();
}

// inversible operators
if (foo && bar !== true || anything()) {
  qux();
} else {
  baz();
}

// show later in the slides (ternary operator) how this would be converted with js2coffee
main.foo = boolVal ? "yes" : "no";

// pretty print for complex object structures
main.x = {
  foo: 1,
  bar: 2,
  nested: {
    foo: 3,
    bar: 4
  },
  array: [
    1, 2, {
      foo: 1
    }, {
      bar: 2
    }
  ]
};