Not sure I understand what you are doing here. Care to satify my curiosity? :-)

The spec requires that you return a wrapped iterator and I accomplish that by basically doing:

var inner = /* ... */
var outer = { __proto__: Iterator.prototype, next: inner.next.bind(inner) }
return outer

The responsible-adult solution would probably involve an additional class with internal fields for inner and inner.next, custom mark and finalize functions, etc. This was less work :-)

Got it, thanks!