How to setup Emacs ReasonML development environment in Ubuntu 16
** Update on 27.04.2018. These instructions work for the previous releases of ReasonML (Reason CLI 3.0.4). They might not work with the newest releases**
Emacs has a great support for ReasonML via reason-mode.
But installing reason-mode is not enough. Other tools must be installed and configured to open all possibilities.
Following steps were performed on DigitalOcean’s $20 instance (with 3Gb of RAM). If you want to use cheaper instances, then you will not be able to install bs-platform, as it’s compilation process eats a lot of RAM and will fail for you.
1. Install Reason toolchain: https://github.com/reasonml/reason-cli:
npm install -g https://github.com/reasonml/reason-cli/archive/3.0.4-bin-linux.tar.gz
This command installs different tools, which are later used by Emacs’s reason-mode.
2. Install a package manager for OCaml: https://opam.ocaml.org/doc/Install.html.
3. Install merlin: https://github.com/ocaml/merlin. This is an IDE plugin for Emacs/Vim.
opam install merlin
opam user-setup install
Follow all the instructions, provided by installer. You have to update .emacs file with the commands, provided by the installer (it updates file automatically).
4. Install BuckleScript Platform:
npm install -g bs-platform
5. Install auto-complete, company, merlin-mode, reason-mode in Emacs.
To install reason-mode via Emacs package manager, you have to add MELPA repository to your Emacs. Instructions are provided here: https://melpa.org/#/getting-started
6. Setup reason-mode for Emacs with these instructions:
Pay attention, that you need to update .emacs file again with reason/merlin setup. Copy and paste that whole section with Reason Setup instructions into your .emacs file.
BUT, for Ubuntu 16.04 there was such issue: “refmt — — where” could not be executed by Emacs, and setup process failed. I had to remove (shell-cmd “refmt — — where”) and (shell-cmd “camlmerlin — — where”) expressions from .emacs file.
After this, I finally could use all the possibilities of merlin and reason modes in Emacs :-)
I ended with such .emacs file:
