Fortunately, with a bit of hacking, this style of syntax is possible without generators :) (I'm hoping to open source a library I wrote that works all the way back to IE6)

Here's your example rewritten in the 'monads' library (I probably need a better name):

monads(function() { var ra = opA.defer(); var rb = opB.defer(); var result = opC(ra(), rb()); });