ical_buider.js

// Post parser
// COMPONENT OR STRING

//SAX?

var builder = ICAL.Builder({ /* options */ });

builder.onitem = function() {
  
};

builder.oncomlete = function() {
  
};

builder.process(vcalendar);

// NEXT ?

while((item = builder.next())) {
  
  if (item instanceof ICAL.Event) {
    if (item.isRecurring) {
      // do stuff
      item.exceptions;
      // start/end window, count
      items.nextOccurances(new Date(2011, 1, 1), new Date(2012, 1, 5), 10);
    }
  }
  
}

// Some event
var component;
var event = new ICAL.Event(component);

event.DTSTART?
event.start?
event.endDate?

builder.next will only return full events (not exceptions). The api may not be obvious here but I don't think we should block the whole iteration if we don't have all the exceptions. After the loop all the exceptions should be present.