[vimscript] Add lsp server support

layers/+lang/vimscript/README.org

@@ -6,14 +6,64 @@
 - [[#description][Description]]
   - [[#features][Features:]]
 - [[#install][Install]]
+- [[#configuration][Configuration]]
+  - [[#choosing-a-backend][Choosing a backend]]
+     - [[#company-vimscript][Company-vimscript]]
+     - [[#lsp][LSP]]
 
 * Description
-This layer adds basic support for vimscript and pentadactyl config files.
+This layer adds support for vimscript and pentadactyl config files.
 
 ** Features:
 - Syntax highlighting
+- Auto-completion (with LSP)
+- Syntax-checking (with LSP)
 
 * Install
 To use this configuration layer, add it to your =~/.spacemacs=. You will need to
 add =vimscript= to the existing =dotspacemacs-configuration-layers= list in this
 file.
+
+* Configuration
+All layer configurations can be done by setting layer variables in your dotfile.
+No custom user config lines are necessary
+
+** Choosing a backend
+This layer provides two alternative backends to choose from.
+
+*** Company-vimscript
+This is the default choice if nothing is set and no lsp layer
+is loaded in your dotfile. This mode only provides very
+limited IDE capabilities. Used best if only small scripts
+are edited. To set explicitly set the following in your
+dotfile:
+
+#+BEGIN_SRC emacs-lisp
+  (vimscript :variables vimscript-backend 'company-vimscript)
+#+END_SRC
+
+*** LSP
+For proper IDE support this backend should be used. It is
+based on an external server which will be started automatically
+by emacs, once a vimscript file is opened. The keybindings are
+the same for all lsp modes so if you are already familiar with
+one you should be able to work the same in all modes.
+
+To set explicitly do the following in your dotfile:
+
+#+BEGIN_SRC emacs-lisp
+  (vimscript :variables
+             vimscript-backend 'lsp)
+#+END_SRC
+
+For this to work you will also need to install
+the latest version of the lsp server with below command:
+
+#+BEGIN_SRC sh
+  npm install -g vim-language-server
+#+END_SRC
+
+NOTE: Keybindings for LSP are defined in the
+LSP layer. Also it is advisable to have a look
+at the autocomplete layer for an optimal
+intellisense config for LSP.

layers/+lang/vimscript/config.el

@@ -1,6 +1,6 @@
 ;;; config.el --- Vimscript Layer packages File for Spacemacs
 ;;
-;; Copyright (c) 2012-2018 Sylvain Benner & Contributors
+;; Copyright (c) 2012-2020 Sylvain Benner & Contributors
 ;;
 ;; Author: Sylvain Benner <sylvain.benner@gmail.com>
 ;; URL: https://github.com/syl20bnr/spacemacs
@@ -12,3 +12,8 @@
 ;; variables
 
 (spacemacs|define-jump-handlers vimrc-mode)
+
+(defvar vimscript-backend nil
+  "The backend to use for IDE features.
+Possible values are `lsp' and `company-vimscript'.
+If `nil' then 'company-vimscript` is the default backend unless `lsp' layer is used")

layers/+lang/vimscript/funcs.el

@@ -0,0 +1,32 @@
+;;; funcs.el --- vimscript Layer functions File for Spacemacs
+;;
+;; Copyright (c) 2012-2020 Sylvain Benner & Contributors
+;;
+;; Author: Maximilian Wolff <smile13241324@gmail.com>
+;; URL: https://github.com/syl20bnr/spacemacs
+;;
+;; This file is not part of GNU Emacs.
+;;
+;;; License: GPLv3
+
+(defun spacemacs//vimscript-backend ()
+  "Returns selected backend."
+  (if vimscript-backend
+      vimscript-backend
+    (cond
+     ((configuration-layer/layer-used-p 'lsp) 'lsp)
+     (t 'company-vimscript))))
+
+(defun spacemacs//vimscript-setup-company ()
+  "Conditionally setup company based on backend."
+  (pcase (spacemacs//vimscript-backend)
+    ;; Activate lsp company explicitly to activate
+    ;; standard backends as well
+    (`lsp (spacemacs|add-company-backends
+            :backends company-capf
+            :modes vimrc-mode))))
+
+(defun spacemacs//vimscript-setup-backend ()
+  "Conditionally setup vimscript backend."
+  (pcase (spacemacs//vimscript-backend)
+    (`lsp (lsp))))

layers/+lang/vimscript/layers.el

@@ -0,0 +1,14 @@
+;;; layers.el --- vimscript Layer layers File for Spacemacs
+;;
+;; Copyright (c) 2012-2020 Sylvain Benner & Contributors
+;;
+;; Author: Maximilian Wolff <smile13241324@gmail.com>
+;; URL: https://github.com/syl20bnr/spacemacs
+;;
+;; This file is not part of GNU Emacs.
+;;
+;;; License: GPLv3
+
+(when (and (boundp 'vimscript-backend)
+           (eq vimscript-backend 'lsp))
+  (configuration-layer/declare-layer-dependencies '(lsp)))

layers/+lang/vimscript/packages.el

@@ -1,6 +1,6 @@
 ;;; packages.el --- vimscript Layer packages File for Spacemacs
 ;;
-;; Copyright (c) 2012-2018 Sylvain Benner & Contributors
+;; Copyright (c) 2012-2020 Sylvain Benner & Contributors
 ;;
 ;; Author: Sylvain Benner <sylvain.benner@gmail.com>
 ;; URL: https://github.com/syl20bnr/spacemacs
@@ -9,14 +9,21 @@
 ;;
 ;;; License: GPLv3
 
-(setq vimscript-packages
-    '(
-      vimrc-mode
-      ggtags
-      counsel-gtags
-      helm-gtags
-      dactyl-mode
-      ))
+(defconst vimscript-packages
+  '(
+    company
+    flycheck
+    vimrc-mode
+    ggtags
+    counsel-gtags
+    helm-gtags
+    dactyl-mode))
+
+(defun vimscript/post-init-company ()
+  (spacemacs//vimscript-setup-company))
+
+(defun vimscript/post-init-flycheck ()
+  (spacemacs/enable-flycheck 'vimrc-mode))
 
 (defun vimscript/init-vimrc-mode ()
   "Initialize vimrc package"
@@ -26,11 +33,12 @@
     :defer t
     :init
     (progn
-    (defun spacemacs//vimrc-mode-hook ()
-      "Hooked function for `vimrc-mode-hook'."
-      (highlight-numbers-mode -1)
-      (rainbow-delimiters-mode-disable))
-    (add-hook 'vimrc-mode-hook 'spacemacs//vimrc-mode-hook))))
+      (defun spacemacs//vimrc-mode-hook ()
+        "Hooked function for `vimrc-mode-hook'."
+        (highlight-numbers-mode -1)
+        (rainbow-delimiters-mode-disable)
+        (spacemacs//vimscript-setup-backend))
+      (add-hook 'vimrc-mode-hook 'spacemacs//vimrc-mode-hook))))
 
 (defun vimscript/init-dactyl-mode ()
   (use-package dactyl-mode