Example 4-1. Wrapping a thenable for interoperability

function thenable(value) {
	return {
		then: function (onfulfill, onreject) {
			onfulfill(value);
		}
	};
}

var promise = Promise.resolve(thenable('voila!'));
promise.then(function(result) {
	console.log(result);
});

// Console output:
// voila!