Quantify the performance improvement

[gsathya]

The README claims:

String.prototype[Symbol.iterator] which allows a hassle-free iteration over string codepoints, but yields their string values, which are inefficient to work with in performance-critical lexers, and still lack position information.

I would expect the iteration protocol to dominate baseline performance, which is still true for this proposal. I'm curious about the performance gains with this proposal. Is there a benchmark for this claim?

[littledan]

I guess part of the motivation for this proposal is performance and part is ergonomics. Maybe this proposal would be justified if there were only an ergonomics benefit. To assess that, it would be good to understand how these divide up in practice as far as what users' needs are. I've heard that some amount of manual UTF-16 decoding in JavaScript is more for performance than ergonomics reasons.