How do I use visitor in oxc-parser using typescript ?

[rizrmd]

Provided example is using rust, how do I do it in typescript/js ?

[overlookmotel]

Currently Oxc is focused on providing JS APIs based on "source text in, source text out". i.e. all AST manipulation occurs on Rust side.

For this reason, the oxc-parser npm package does not currently provide a visitor. It will do in future, but it's going to take a while - it's more complicated than it sounds.

Of course, you can write JS/TS code to traverse/explore the AST in whatever way you would like, but we don't provide an "out of the box" AST visitor (yet).

The JS-side AST almost entirely aligns with ESTree, so you could try using another library which provides an ESTree AST visitor/transformer. However, the AST does not align exactly with ESTree at present - it is our intent that it will (#2854), but we're not there yet. There are also currently no TS type definitions for Oxc's AST (again, more difficult than it sounds - good Rust-JS interop is quite a hard problem).

Sorry that's not the answer that you want, but I hope this info helps somewhat.

[Boshen]

@rizrmd where have you looked and what is lacking from our current documentation?

[rizrmd]

@rizrmd where have you looked and what is lacking from our current documentation?

Mainly here: https://oxc.rs/docs/guide/usage/parser.html
I did search issues, but most of them are discussing rust based visitor.

Also, there are prior works from swc like woodpile and swc-walk.

• Woodpile use wasm-pack to call rust visitor using js.
• swc-walk wraps acorn-walk using js custom visitor that conforms with swc terms.

Both are good enough, the problem is the size in wasm.
swc takes +/- 15-20mb uncompressed, while oxc only 600kb. I am impressed!

I tried to parse oxc result using swc-walk, surprisingly it works for simple code. But there are some differences in node.type, and several node properties. I just add/modify them to works, but I think this is still a hack...

[rizrmd]

Currently Oxc is focused on providing JS APIs based on "source text in, source text out". i.e. all AST manipulation occurs on Rust side.

For this reason, the oxc-parser npm package does not currently provide a visitor. It will do in future, but it's going to take a while - it's more complicated than it sounds.

Of course, you can write JS/TS code to traverse/explore the AST in whatever way you would like, but we don't provide an "out of the box" AST visitor (yet).

The JS-side AST almost entirely aligns with ESTree, so you could try using another library which provides an ESTree AST visitor/transformer. However, the AST does not align exactly with ESTree at present - it is our intent that it will (#2854), but we're not there yet. There are also currently no TS type definitions for Oxc's AST (again, more difficult than it sounds - good Rust-JS interop is quite a hard problem).

Sorry that's not the answer that you want, but I hope this info helps somewhat.

No worries, understandable. Thanks for explaining.

[Boshen]

👍 so the question is regarding visitor in js, and we lack one. We need to document as such. Thank you for the input.