dotfiles/emacs-lisp/lsp.org

:PROPERTIES:
:ID:       cc668372-8d95-461b-a7c6-3e2b51de3f40
:END:
#+title: LSP
#+filetags: emacs-load

# SPDX-FileCopyrightText: 2022 Richard Brežák <richard@brezak.sk>
#
# SPDX-License-Identifier: LGPL-3.0-or-later

* Python

Using the Microsoft language server as it's the best afaik. It's weird because it doesn't lookup the path to itself via PATH but has to be statically set.

#+BEGIN_SRC emacs-lisp
  (use-package lsp-python-ms
    :straight t
    :hook (python-mode . (lambda ()
                           (require 'lsp-python-ms)
                           (envrc-mode)
                           (setq-local lsp-python-ms-executable (executable-find "python-language-server"))
                           (lsp)))
    :config
    (defvar-local lsp-python-ms-executable ""))
#+END_SRC

* C/C++

This just requires hooking lsp onto ~c-mode~ and ~c++-mode~.

#+BEGIN_SRC emacs-lisp
  (with-eval-after-load 'lsp
    (add-hook c-mode-hook #'lsp)
    (add-hook c++-mode-hook #'lsp))
#+END_SRC

* Haskell

Enable ~haskell-mode~, and ~lsp-haskell~

#+BEGIN_SRC emacs-lisp
  (use-package haskell-mode
    :straight t
    :hook ((haskell-mode haskell-literate-mode) . interactive-haskell-mode)
    :config
    (setq lsp-haskell-plugin-ghcide-type-lenses-global-on nil
          lsp-haskell-plugin-import-lens-code-lens-on nil))
  (use-package lsp-haskell
    :straight t
    :after lsp-mode
    :hook ((haskell-mode haskell-literate-mode) . #'lsp))
#+END_SRC

Disable the ~haskell-stack-ghc~ flycheck checker, it's not used when lsp starts, but it does get loaded just before it. Loading and unloading it is slow and causes Emacs to freeze for a few seconds, so just disable it.

#+BEGIN_SRC emacs-lisp
  (with-eval-after-load "flycheck"
    (add-to-list 'flycheck-disabled-checkers 'haskell-stack-ghc))
#+END_SRC