Support more collection data types in v-for

At some situations, plain object isn’t the best choise. I tried to render a Map object by v-for, but seems Vue does not support it currently. (Here’s a post I created in the Help thread on the forum.)

Hope Vue can provide the for ... of syntax in v-for to iterate over data types like Map and Set.

For example:

const map = new Map();
map.set('key1', 'val1');
map.set('key2', 'val2');

and we can render map in this way:

<ul>
    <li v-for="[key, val] of map">{{key}} - {{val}}</li>
</ul>

[catsclaw]

It’s important to be able to iterate over iterators in loops. That seems plainly obvious. It’s a fundamental feature of the language.

The reasons for supporting it are:

1. Iterators, Maps, and Sets are all valid ES6. Refusing to support them means limiting yourself to ES5, which is a decision becoming less and less justified over time.
2. I’m building an application that has internal data stored in Maps and Sets. Instead of making them available to the UI, I now need to keep the data synced between the two manually, or write boilerplate and import it into my templates to do the conversion whenever the data is needed. This is exactly what Vue is intended to avoid.

[posva]

People wanting to use a feature is not, only by itself, an argument that can justify the need of having such feature, it’s necessary to weigh the cost and benefits (what problem is being solved) of adding such feature