Python-like range implementation, using JS generators for lazy evaulation.

range.js

function* range(...args) {
  var start = 0;
  var stop  = 0;
  var step  = 1;

  if(args.length == 1)
    stop = args[0];
  else if(args.length == 2) {
    start = args[0];
    stop  = args[1];
  }
  else if(args.length != 0) {
    start = args[0];
    stop  = args[1];
    step  = args[2];
  }
    
  while(start < stop) {
    yield start;
    start += step;
  }
  yield stop;
}