topiary VS scip

You should check out https://github.com/tweag/topiary

Yes, theoretically if you had ~identical grammars you could use it to do a full transpilation. There's a lot of challenges with that though. Writing a correct grammar for 1 language is complicated enough, but writing one for two where all your nodes and fields end up the same is likely insurmountable.

In practice, languages are either:

- Far enough apart that any pure AST transformation is insufficient and you need an AI component to produce usable output

This is something we've discussed[1] in the development of Topiary, deferring the process to the formatter. It's not a priority issue for us right now, but given the lack of universal editor support for elastic tab stops, having the formatter do this seems like a reasonable solution.

[1]: https://github.com/tweag/topiary/issues/170

build on top of https://github.com/tweag/topiary/blob/main/languages/rust.scm

security is up there, but from reading the examples in CodeQL it just seemed like it would be possible to express some truly great versions of "don't do that" rules in it. I am a total JetBrains fanboi, and their introspections are world-class, but getting Qodana to run to completion before the heat death of the universe has proven to require more glucose than I have to offer it. Thus, I'm always interested in alternate implementations, even though I am acutely aware of the computational complexity of what I'm asking

I recalled another link I wish I had included in my question from the SourceGraph folks https://github.com/sourcegraph/scip#scip-code-intelligence-p... which started out life as "Language Server Indexing Protocol" and seems to solve some similar project-wide introspection questions but TBH since their rug pull I've been a lot less willing to hitch my wagon to their train

New standards proliferate all the time and many simply cannot rely solely on a compiler language server but can rely on a custom semantic information protocol - SCIP comes to mind. :)

Over the last ~9 months or so, we've been moving away from LSIF and have been using SCIP instead. https://github.com/sourcegraph/scip (announcement blog post, which covers the reasons for why we stopped using LSIF: https://about.sourcegraph.com/blog/announcing-scip)

This is pretty much exactly what we've built at Sourcegraph. Microsoft had introduced (but pretty much abandoned before it even started) LSIF, a static index format for LSP servers requests/responses.

We took that torch and carried it forward, building the spiritual successor called SCIP[0]. It's language agnostic, we have indexers for quite a few languages already, and we genuinely intend for it to be vendor neutral / a proper OSS project[1].

[0] https://about.sourcegraph.com/blog/announcing-scip

[1] https://github.com/sourcegraph/scip

Created a PR to mention tools using SCIP in the README. https://github.com/sourcegraph/scip/pull/101

I've looked into the pull request that added SCIP support to rust-analyzer, and apparently rust-analyzer uses the scip crate. The linked PR also links to a blog post that explains the motivation for scip. The github repo of the scip crate lives here, it's not linked in Cargo.toml, probably should.