regex match

[rebornix]

Use regex to match brackets instead of iterating all characters one by one. Fix performance issues of inserting brackets in a large file.

cc @xconverge @johnfn

[johnfn]

Haha okay this is really interesting. I don't doubt that it's faster, but I have no idea why. A regex would certainly be slower than a handrolled checking function...

My best guess is that Position.IterateDocument was SUPER slow? That's kind of weird though.

[rebornix]

@johnfn it's very likely Generators, which might not be optimized enough by V8.

[rebornix]

	function norm() { 
		for (var i = 0; i < 10000000; i++);
		return 42;
	} 
	function *g() {
		for (var i = 0; i < 10000000; i++) {
			yield i;
		}
	}
	function gen() {
		for(const i of g());
		return 42;
	}
	console.time('normal');
	console.log(norm()); 
	console.timeEnd('normal');
	console.time('generator');
	console.log(gen());
	console.timeEnd('generator');

Result

generators.html:21 normal: 6.246ms
generators.html:24 generator: 578.637ms

[johnfn]

Holy smokes. Yeah, that will do it!