theta-idl VS WebKit

I've found it comes up pretty often. Sometimes because the logic I'm writing demands it—traversing over some kind of nested recursive structure, for example—but more often because it makes the code easier to read. A real-world example: I have a little interface description language which can generate code in a few different target languages. I want to factor out some of the more complex logic (eg dealing with record types) into self-contained, testable functions, which means that my top-level toDefinition function needs to call toRecord, which needs to call toDefinition for each of the record's fields[1].

(Sorry if it's hard to follow the code without context, but that's the problem with examples—either they're too trivial to be interesting, or they're complex enough to be a bit confusing!)

Additionally—and maybe even more importantly—tail call elimination also makes code written in continuation-passing style (CPS) more efficient. While CPS isn't something we usually want to write by hand, a lot of common abstractions (async libraries, promises, monads) map to CPS under the hood.

[1]: https://github.com/target/theta-idl/blob/stage/theta/src/The...

Multiple engineers are working on adding it back: https://github.com/WebKit/WebKit/pulls?q=is%3Apr+is%3Aclosed...

Since 2023 Chrome announced the View Transition API, and it looks like Safari is also going to support it soon.

One heap per type.

Here’s an allocator optimized for that use case.

https://github.com/WebKit/WebKit/blob/main/Source/bmalloc/li...

To use this in Bun, you’d have to start Bun with the environment variable “BUN_JSC_useDollarVM=1” and then $vm.createBuiltin(mySourceCodeString)

When using this intrinsic, if any of the arguments are incorrect or it cannot otherwise enable it, the entire process will probably crash. In debug builds of JSC it will have a nicer assertion failure but that is not enabled in release builds

Example code: https://github.com/WebKit/WebKit/blob/17351231b4dedb62d81721...

also happy to answer any questions about Bun

Ah, good, let me introduce you to the wonderful world of the Chrome Devtools Protocol! (fka Chrome Remote Debugging Protocol)

I love this API for almost everything browser related. I built my RBI product atop this (BrowserBox: https://dosyago.com), and I think it's a drastically underrated API.

Also, it works out of the box in Edge, Brave, Chromium, and many parts of CRDP are supported by Firefox and Safari^1

1: See for example: https://github.com/WebKit/webkit/tree/main/Source/JavaScript...

No, it's unrelated.

https://github.com/WebKit/WebKit/commit/064df1a9f395f8c6e32c...

It's being worked on now: https://github.com/WebKit/WebKit/pull/17320

It is different. The cross-site navigation flag is a couple of years old. It was enabled by default for iOS in November 2018 for example https://github.com/WebKit/WebKit/commit/e191fc8c412850cb9fd0...