Node.js - A Giant Step Backwards(fenn.posterous.com)

    d = asynchronousCache.get("id:3244"); // returns a Deferred
    d.addCallback(function (result) {
	if (result == null) {
	    return asynchronousDB.query("SELECT * from something WHERE id = 3244");
	} else {
	    return result;
	}
    });
    d.addCallback(function (result) {
	// Do various stuff with myThing here
    });

   getSomething("id", function(thething) { 
       // one true code path
   });

   function getSomething(id, callback) {
     var myThing = synchronousCache.get("id:3244");
     if(myThing) { 
         callback(null, myThing);
     } else { 
         async(id, callback);
     }
   }

    async.waterfall([
      function(callback) {
        asynchronousCache.get("id:3244", callback);
      },
      function(myThing, callback) {
        if (myThing == null) {
          asynchronousDB.query("SELECT * from something WHERE id = 3244", callback)
        } else {
          callback(myThing)
        }
      },
      function(myThing, callback) {
        // We now have a thing from the DB or cache, do something with result
        // ...
      }
    ]);

    x = db.getFutureResult("x");
    y = db.getFutureResult("y");
    whenFuturesReady([x,y], callback(x, y) {
        useResults(x,y);
    });

    x = db.getResult("x")
    y = db.getResult("y")
    useResults(x,y)

  function handler(yes, no) {
      return function (err, data) {
          if (data) {
              yes(err, data);
          }
          else {
              no(err, data);
          }
      }
  }

  function get() {
      function done(err, data) {
  
          // do something with data
  
      }
      function db() {
          asynchronousDb.query("SELECT * fomr something where id = 3244", done);
      }
      asynchronousCache.get("id:3244", handler(done, db));
  }