[harryposner]

> But I haven't had a need to add any kind of plugin, and it's easy enough to fork a shell for an external process if needed.

For me, coming from writing Clojure with Neovim + vim-sexp + vim-fireplace, I would need Paredit and REPL integration.

Paredit is doable with Treesitter, and I'm actually really excited about Helix's Treesitter integration--- every time I write a non-Lisp language, I miss structural editing, so it'll be nice for other languages catch up to Lisp on that front. It doesn't really look like it's quite there yet, though. The built-operations that use Treesitter are spare [0], and while you could implement operations like promote, slurp, and barf with them, you'd have to clobber some register. I don't see at all how you could implement splice without an actual language, since you would need a way to select all siblings of the current node.

REPL integration absolutely needs a plugin language. Unlike the LSP, there isn't a standard protocol for communicating with a REPL, so each language requires its own REPL client. Unless they want to ship a REPL client for every language under the sun, they'll have to provide some way for users to implement their own clients. That said, every time I look at Conjure, they've added REPL clients for more and more languages [1], so maybe it is feasible to have it built into the editor.

[0] https://docs.helix-editor.com/keymap.html

[1] https://github.com/Olical/conjure/

[exDM69]

> Paredit is doable with Treesitter

Yes, indeed.

Helix has built-in paredit-like navigation using tree-sitter, the default keybindings are alt-i, alt-o, alt-n and alt-p.

Maybe the Debug Adapter Protocol (DAP) used by vscode will solve the REPL issue in the future. Helix has experimental DAP support but it's still quite rough (but no Clojure DAP server yet).