Create the a generic fn to let lisp modules override the language server behaviour

nix/modules/language-server/lisp/fg42/language-server.el

@@ -23,7 +23,8 @@
 ;;; Code:
 (eval-when-compile
   (require 'fpkg)
-  (require 'fg42/config))
+  (require 'fg42/config)
+  (require 'cl-lib))
 
 
 ;; Language Servers and friends
@@ -32,6 +33,7 @@
 shipped with Emacs."
   :commands eglot-ensure)
 
+
 (use! eldoc-box
   "View eldoc stuff in a frame."
   :commands eldoc-box-hover-mode
@@ -43,6 +45,20 @@ shipped with Emacs."
   :init (setq markdown-command "multimarkdown"))
 
 
+;;;###autoload
+(cl-defgeneric fg42/setup-lang-server-for (mode)
+  "Setup a language server for the given MODE.
+Other Nix modules can specialize this function to alter
+the default behaviour.  For example for C++:
+
+\(cl-defmethod fg42/setup-lang-server-for ((mode (eql c-ts-mode)))
+   ;; Do whatever you want here
+ )
+
+The default implementation sets up Eglot."
+  (eglot-ensure))
+
+
 ;;;###autoload
 (defun fg42/ensure-lang-server ()
   "Setup the appropriate language server for the current buffer.
@@ -50,16 +66,14 @@ This function is supposed to be run using a hook.
 
 For example:
 
-(add-hook 'foo-mode-hook #'fg42/enruse-lang-server)
+\(add-hook 'foo-mode-hook #'fg42/enruse-lang-server)
 
 or via `use!' `:hook'."
   (interactive)
   ;; TODO: Configure LSP here as an alternative here by looking at
   ;; the configs in `fg42/config'
-
   (add-hook 'eglot-managed-mode-hook #'eldoc-box-hover-mode t)
-  (eglot-ensure))
-
+  (fg42/setup-lang-server-for major-mode))
 
 
 ;;;###autoload