Bradley Meck (2015-02-16T14:40:26.000Z)
d at domenic.me (2015-02-21T00:38:42.842Z)
I think it is important to not attempt to pre-optimize and create partial solutions. I is fairly easy for the compiler to understand *when* [Symbol.iterator] is invoked and optimize it at that point, same concept as on the stack replacement. A better question in my book, is there any engine author who is concerned about the difficulty of implementing such an optimization. Having a shared object means much more escape tracking than if the object was not shared.