[ievans]

Absolutely agreed, and copying from a comment I wrote last year: I think the fact that tree-sitter is dependency-free is worth highlighting. For context, some of my teammates maintain the OCaml tree-sitter bindings and often contribute to grammars as part of our work on Semgrep (Semgrep uses tree-sitter for searching code and parsing queries that are code snippets themselves into AST matchers).

Often when writing a linter, you need to bring along the runtime of the language you're targeting. E.g., in python if you're writing a parser using the builtin `ast` module, you need to match the language version & features. So you can't parse Python 3 code with Pylint running on Python 2.7, for instance. This ends up being more obnoxious than you'd think at first, especially if you're targeting multiple languages.

Before tree-sitter, using a language's built-in AST tooling was often the best approach because it is guaranteed to keep up with the latest syntax. IMO the genius of tree-sitter is that it's made it way easier than with traditional grammars to keep the language parsers updated. Highly recommend Max Brunsfield's strange loop talk if you want to learn more about the design choices behind tree-sitter: https://www.youtube.com/watch?v=Jes3bD6P0To

And this has resulted in a bunch of new tools built off on tree-sitter, off the top of my head in addition to difftastic: neovim, Zed, Semgrep, and Github code search!

[drcongo]

Don't forget Zed! https://zed.dev

[fransje26]

> Don't forget Zed!

Mac only, for now.

[germandiago]

Looks great! It has lsp support for code completion? Supports C++?

[TeMPOraL]

Okay, but how does that work with language versions? Like, if I get a "C++ parser" for tree-sitter, how do I know if it's C++03, C++17, C++21 or what? Last time I checked (which was months ago, to be fair), this wasn't documented anywhere, nor were there apparent any mechanisms to support langauge versions and variants.

[MathMonkeyMan]

You can probably rely on backward compatibility of the language and use the "latest." The question is, which version is the grammar written against?

[pfdietz]

And then there's all the variants of SQL...

[Arech]

That's what I was looking at in the very beginning. Here's how it unfolds: Grammar page (https://github.com/tree-sitter/tree-sitter-cpp) reference two documents at the very end:

- Hyperlinked C++ BNF Grammar (https://alx71hub.github.io/hcb/)

- EBNF Syntax: C++ (ISO/IEC 14882:1998(E)) https://www.externsoft.ch/download/cpp-iso.html

The second doc has a year in the title, so it's ancient af. The first one has multiple `C++0x` red marks (whatever that mean, afair that's how C++11 was named before standardization). It mentions `constexpr`, but doesn't know `consteval`, for example. And doesn't even mention any of C++11 attributes, such as [[noreturn]], so despite the "Last updated: 10-Aug-2021", it's likely pre-C++11 and is also ancient af and have no use in a real world.

Who might have thought. /s

[ossusermivami]

don't forget old man emacs is now using tree sitter

[jrave]

helix (https://helix-editor.com/) is using treesitter and LSP as well