Support for ES6 Sets

[chandmk]

Binding repeat.for over a set does nothing

export class Test{
  constructor(){
    this.list = new Set(["foo", "bar", "foo"]);
  }
}

<template>
  <section>
    <ul>
      <li repeat.for="l of list">${l}</li>
    </ul>
</section>
</template>

Following works fine

this.list = Array.from(new Set(["foo", "bar", "foo"]))

[EisenbergEffect]

@jdanyow @martingust How hard would it be to add this do you think?

[martingust]

@jdanyow @EisenbergEffect We will need to patch a Set observer and update the repeater to handle Set object, I think the current for syntax should be good already . A lot of work we could grab from the Map implementation or maybe even refactor some stuff to handle both Map and Set objects. It would be nice to have this in place for beta. Maybe we could split up some work, what you guys think?

[jdanyow]

:+1: looks like a lot of the work you've done for Map can be used for Set. Do you guys think it's worth making the repeat pluggable so users can add implementations for other collection implementations or is it better to handle the core ES6 cases as we have been and use converters for other cases?

[EisenbergEffect]

@jdanyow If you don't think that would be too hard, I think that's a great idea.

[martingust]

@jdanyow @EisenbergEffect That would be pretty cool. Another idea since its all just an array in the end, maybe we could handle everything, Map, Set etc, only in bindingand always provide the repeater with arrays no matter of underlying type. haven't really thought it through or tested anything but it would remove a lot of duplicate logic in the repeater.