Setup OCaml with Dune in Under a Minute

Install version 1.21.0 or higher of the vscode-ocaml-platform plugin for Visual Studio Code. By default it assumes that you'll be using Opam to install ocamllsp. To configure it to work with the Dune nightly, add the following to your settings.json file:

// settings.json
{
  "ocaml.sandbox": {
    "kind": "custom",
    "template": "$prog $args"
  }
}

The easiest way to configure Neovim for OCaml is by installing the lspconfig package. The default configuration will work with the Dune nightly, so just enable it with:

-- init.lua
require'lspconfig'.ocamllsp.setup{}

Emacs users will need to add the Dune nightly's bin directory to their exec-path and PATH variables. The rest of the configuration is the same as for regular OCaml. Here's a minimal example configuration for Emacs that uses use-package to install packages:

; init.el
; add the dune nightly bin path to exec-path and PATH
(add-to-list 'exec-path "~/.local/bin" t)
(setenv "PATH" (concat (expand-file-name "~/.local/bin") ":" (getenv "PATH")))
 
; mode for editing ocaml files
(use-package tuareg)
 
; lsp client mode
(use-package lsp-mode
  :init
  ; start ocamllsp automatically for ocaml files
  :hook ((tuareg-mode . lsp)))

No manual configuration is necessary! Just install the OCaml extensions for Zed (you should get a pop-up the first time you edit an OCaml file).