Question

I have a function parent, that calls child, and then does other stuff inside otherStuff:

function parent() {
    child();

    otherStuff();
}

Is it possible to modify child (and leave parent as is) so that the child call forces parent to return right after child returns? Will this be possible in EcmaScript 6?

Answer 1

Bad way to do this is to throw an exception in child, which will bubble up to parent and then to the original caller. This approach makes an expectation for the original caller of parent to catch the exception.

function originalCaller() {
  try {
    parent();
  }
  catch(e) {}
}

function parent() {
  child();
  otherStuff();
}

function child() {
  throw 0;
}

function otherStuff() {
  // other stuff
}

You want to leave parent as is, right?
So, the ugly way is to let child temporarily modify otherStuff:

function child() {
  _otherStuff = otherStuff;
 otherStuff = function() { otherStuff = _otherStuff; }
}

This way otherStuff does nothing once and then goes back to the original state. Again, not only is it totally ugly, but makes an assumption about parent‘s structure.