FAQ¶

Which Emacs version should I use?¶

neocaml requires Emacs 29.1+ but Emacs 30+ is recommended. Some features are only available on newer versions:

Emacs 30+: language injection for OCamllex/Menhir, sentence navigation (M-a/M-e), outline-minor-mode integration, tree-sitter-aware list navigation (forward-list, backward-list, down-list)
Emacs 31+: native backward-up-list support via the list thing (on earlier versions, neocaml provides neocaml-backward-up-list as a workaround)

How do I install grammars for dune, opam, OCamllex, or Menhir?¶

M-x neocaml-install-grammars only installs the OCaml and OCaml-interface grammars. The other modes have their own grammar install commands: M-x neocaml-dune-install-grammar, M-x neocaml-opam-install-grammar, M-x neocaml-ocamllex-install-grammar, and M-x neocaml-menhir-install-grammar. Each mode will also prompt you to install its grammar on first use.

Can I use Merlin instead of Eglot?¶

neocaml auto-configures Eglot for ocamllsp, but you can use Merlin instead. Install merlin-mode and enable it via a hook:

(add-hook 'neocaml-base-mode-hook #'merlin-mode)

Merlin provides its own completion, type display, and error checking independently of Eglot.

How do I change the indentation width?¶

Set neocaml-indent-offset (default 2):

(setq neocaml-indent-offset 4)

See Configuration for alternative indentation engines (ocp-indent, tuareg SMIE, indent-relative).

Do I need to remove tuareg or caml-mode?¶

Not strictly, but it's the simplest path. If both are installed, they may fight over .ml/.mli file associations. See Migration for details on running them side by side.

Can I use lsp-mode instead of Eglot?¶

neocaml auto-configures Eglot, but it doesn't depend on it. If you prefer lsp-mode, install it and register neocaml's modes:

(use-package lsp-mode
  :ensure t
  :hook (neocaml-base-mode . lsp))

neocaml's font-lock, indentation, and navigation all work independently of which LSP client (or none) you use.

Why doesn't `(` automatically insert `(* *)` inside comments?¶

neocaml does not implement electric comment delimiters (tuareg does, but the logic is quite complex). Instead, use M-; (comment-dwim) to insert comment delimiters -- it will insert (* *) with point positioned between them, properly indented. This is simpler and more predictable.

Is the name a Matrix reference?¶

Yes. It's also a new Emacs package for OCaml.

What's the relationship between neocaml and tuareg?¶

They're independent projects. tuareg uses a handwritten parser and SMIE for indentation; neocaml uses tree-sitter for everything. You can use tuareg's indentation engine with neocaml if you prefer it (see Configuration). See Migration for a detailed comparison.

Where can I get help?¶

Open an issue on GitHub. You can also run M-x neocaml-bug-report-info to collect debug information for your report.