Abstract syntax tree

Rust can go further or the idea of trying to, you know, bolt on ownership and borrowing to, um, your languages.

Like you can probably get pretty decently far with like linters and like, uh, graph traversals and like ASTs and stuff like that.

But at the end of the day, you're not, it's going to be a ceiling and you're not going to be able to get as far as rust has.

And so again, really great bones just by using it, you already get ahead of like a lot of the pat on these like hard to change things.

They had a similar package.

TypeScript AST for syntax tree nodes, those types and the enums such as syntax kind and script target.

And then there's TypeScript slash AST slash is.

And this gives you the type guards for the syntax nodes, not like Node.js, but like the syntax nodes in the tree.

And then they have TypeScript slash AST slash factory, which allows you to create mutable stuff and build the tree.

around that

yeah yeah uh and this is this is big news especially for library maintainers and anyone building tools on top of typescript because we've been waiting for this api and i i believe that this is like not the end all be all like this is the beginning of the compiler api So it's most of the stuff that you would need.

Like the people I speak, like Jeffrey Huntley, the guy who wrote the Ralph Loop thing, and Ryan Lopopolo, who is at OpenAI now at Google, these guys, they're literally, I mean, Jeffrey was talking about, I'm abusing the compiler.

Like I'm getting the compiler to emit an AST, an abstract syntax tree, and then run deterministic checks against that.

The future is going to look much more like people doing like these formal methods.

going to look for correctness much more like formal verification.

An AI agent using this architecture doesn't try to rewrite the whole thing at once.

It makes thousands of tiny edits to what's called the abstract syntax tree, the structural skeleton of the code beneath the surface.

Each micro edit is verified by a compiler.

Each step preserves the functional behavior of the system.

Right, the underlying structure.

Yeah, we have to talk about the abstract syntax tree or the AST.

To me, this feels a bit like...

Well, it's like suddenly seeing the raw green falling code of the Matrix instead of the simulated world, you know? You are finally looking at the DNA of your software.

It does depend on effect as a peer dependency in TypeScript 7.

So recipes use the TypeScript's unstable AST API and effect for APIs.

So yeah, it is pre-alpha.

Hopefully things will look a little bit better in TypeScript 7.1 with the new compiler API.

This, this, this came by my feed.

It's an oldie, but Evangeline Rome posted a link to Desheret's TypeScript factory code generator generator, which is kind of a funny name.

But if you're looking for like a source generator generator, type thing to generate source code from an AST, this might be your thing.

So this will generate TypeScript compiler, excuse me, this will generate code that will generate the TypeScript compiler API factory code which is kind of, it's like meta.

They are vacuuming up the updates the absolute millisecond they hit GitHub or the vendor's repository.

Which feeds directly into the second step, which is semantic AST comparison.

And this, this is the true breakthrough for the adversaries.

Okay, unpack that for me.

AST, AST stands for abstract syntax tree.

This is a radical departure from how traditional code comparison or diffing used to work.

Right, because normally you just look for what changed.

CVE-2026-1731 in Beyond Trust Privileged Remote Access.