Polymer: [Suggestion] for-of instead of for-loop

[zaclummys]

Would it be a good idea if Polymer adopted for-of instead of for-loop to iterate over arrays? Babel offers a plugin to convert it harmoniously without using iterators.

[TimvdLippe]

I am okay with these changes, although I have two comments:

1. Are there any performance characteristics associated with this change? We do not want to regress in terms of performance
2. Rather than doing this all at once, I propose we change these loops whenever we are changing the file anyways, to avoid cluttering our git history

[zaclummys]

for-of brings good features:

• Iteration over array-like (HTMLCollection, NodeList, Arguments), iterators and generators.
• Faster than Array#forEach
• DRY/Readability
• Async iteration
• Can be compiled to for-loop, keeping all theses features and the performance as it is.

[sorvell]

Thanks for the suggestion. We love using for-of in application code, but within the library itself we generally manually iterate lists.

We do this for speed and to avoid the extra compiled code. For example, a simple for-of balloons to 25 lines using babel.

[zaclummys]

@sorvell, as mentioned above:

Babel offers a plugin to convert it harmoniously without using iterators.

Please, check here.