News for hackers. Stuff that matters.

A comment on Using const/let instead of var can make JavaScript code run 10× slower in Webkit. Parent comment

Re:Using const/let instead of var can make JavaScript code r... by Twirrim on Wednesday October 21, 2020 @01:21AM (#24844968)
From the linked bug:

> I think I can reproduce this behavior on Figma's code base too. I've never noticed because we use Chrome pretty much exclusively for development.

We're already there. Chrome dominates so much of the dev market, so naturally v8 is what people are optimising towards.

[ Parent | on HN ]
Re:Using const/let instead of var can make JavaScript code r... by kjksf on Wednesday October 21, 2020 @01:52AM (#24845117)
In this particular case, they were not optimizing for Chrome. They generated the code that was obvious to generate.

Because of a perf bug in WebKit they added a flag to generate less correct code that is fast in WebKit.

If anything, it's a case of optimizing towards WebKit.

But really, it's a case of performance bug in WebKit and them adding a work-around.

[ Parent | on HN ]
Re:Using const/let instead of var can make JavaScript code r... by thirtyseven on Wednesday October 21, 2020 @01:42AM (#24845074)
Don't worry, everyone still has to test for the captive audience of iOS Webkit users.
[ Parent | on HN ]