Step by step instructions to setup doom emacs for Haskell + Haskell Language Server (LSP)

doom_emacs_for_haskell.md

Install doom emacs

git clone --depth 1 https://github.com/hlissner/doom-emacs ~/.emacs.d
cd ~/.emacs.d
bin/doom install

Optional

You can backup your existing ~/.emacs.d, if you have one. If you want to revert back to your older emacs setup, just copy the backup back into ~/.emacs.d and restart emacs

Setup for Haskell dev

Install HLS

Install haskell-language-server, which is the lsp implementation for haskell, using ghcup.

ghcup install hls 0.8.0

Add config to enable Haskell + LSP

To enable haskell, in ~/.doom.d/packages.el add these line:

(package! haskell-mode)
(package! lsp-haskell)

And then in ~/.doom.d/init.el,

• under :tools, add lsp
• under :lang, add (haskell +lsp)

Then run:

cd ~/.emacs.d
bin/doom sync

Optional stylish-haskell

To configure to run stylish-haskell on save, add this to ~/.doom.d/config.el -

(setq haskell-stylish-on-save t)

Finally, restart your emacs for the changes to be applied.

Are these really needed?

(package! haskell-mode)
(package! lsp-haskell)

I thought it was implied by

under :tools, add lsp
under :lang, add (haskell +lsp)

@anka-213 IIRC, yes. But I might be completely wrong. I don't remember if I faced any other issues, that I included those packages explicitly. But I guess you can try out without including the packages and see if it works.

I did have issues when just doing the later part. After doing both and running doom upgrade it magically worked despite nothing else we tried working, so you are probably right.

The instructions on the hls README might need to be updated to include this as well.

Me after doing all of these ran into Command "haskell-language-server-wrapper --lsp -d -l /tmp/hls.log" is not present on the path. in lsp-log.

add the exec path to emacs by adding

(setenv "PATH" (concat (getenv "PATH") ":/path/to/hls/containing/bin"))
(setq exec-path (append exec-path '("/path/to/hls/containing/bin")))

to config.el