Yes, I know what `String#at` is supposed to do. I was pointing out that `String#at` makes it easy to do the wrong thing. If you do `Array.from(str)` then you suddenly have a complete random-access data structure where you can find out the number of code points in the String, iterate it in reverse from the end to the start, slice it, find the midpoint, etc. `Array.from` looks like an O(n) operation, and it is -- so it encourages developers to cache the value and reuse it.
That said, I can see where a lexer might want to use `String#at`, being careful to do the correct index bump based on `result.length`. However, the fastest JS lexers don't create String objects, they operate directly on the code point (see http://marijnhaverbeke.nl/acorn/#section-58). So I'm -0, mostly because the name isn't great. But I have exactly zero say in the matter anyway. So I'll shut up now. --scott _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
