David Mandelin's blog

I waited a couple weeks after the last update to accumulate more cool stuff to talk about, and then I ended up having to wait a few more to get sick, get better, travel, give a talk, and then (partially) dig out from the backlog. Turns out there’s a ton of updates by now: GC [...]

I was holding off on updates around the holidays, when things were kind of quiet, but lots of stuff is happening again: ECMAScript 6 Jason landed Simple Maps and Sets per the draft specification. Yay! Speaking of which, Chris Leary blogged yesterday about how you can increase your badassery, stop him from harassing motorists on [...]

This will be a short one: it’s been a fairly quiet week, with mostly fixes for crashes and other small bugs. The one big landing was ObjShrink, by Brian Hackett, which took the size of a JS object down from about 48 bytes (on 32-bit platforms) to 16 bytes. ObjShrink also made shapes (an auxiliary [...]

Help Firefox get incremental GC Bill McCloskey has incremental GC working as a prototype in the larch branch. The current version is probably pretty crashy but does show the pause time improvements on some sites. It would help Bill a lot to get a list of sites that have big GC pauses now in Firefox. [...]

Update since last time (11/1): Stuff that might affect you We are moving to a model where JSRuntimes are single-threaded. That means if you want to use multiple threads, you’ll create separate runtimes. (Web workers do this in Firefox now.) This is going to help us make a lot of simplifications to the engine, and [...]

For a while, I was pretty swamped, with not enough time to do a regular team newsletter. And then, I figured I’d have to go back over the past 2 months of activity to sort out everything that happened so I could write a proper giant update. But, I realize that’s way too hard and [...]

I’ve been swamped the past few weeks, so this is a bigger catch-up newsletter. I’ll just give the big news because there’s plenty of it. New Hire Nicolas Pierron has joined the JS team to work on IonMonkey. He has done a lot of work on the NixOS package system as well as a few [...]

New Hire Sean Stangl has joined the JS team. He worked on JägerMonkey last year as an intern, and now he’s here full-time, initially working on IonMonkey. Welcome, Sean! Project Status Updates Type Inference: Brian Hackett is fixing regressions and getting ready to “land” type inference. Landing is tricky because the complexity of the project [...]