Add set-lsp-priority! autodef & +lsp/switch-client command

Relevant to #2689

modules/tools/lsp/autoload.el

@@ -1,5 +1,14 @@
 ;;; feature/lsp/autoload.el -*- lexical-binding: t; -*-
 
+;;;###autodef
+(defun set-lsp-priority! (client priority)
+  "Change the PRIORITY of lsp CLIENT."
+  (require 'lsp-mode)
+  (if-let (client (gethash client lsp-clients))
+      (setf (lsp--client-priority (gethash server lsp-clients))
+            priority)
+    (error "No LSP client named %S" client)))
+
 ;;;###autodef
 (defalias 'lsp! #'lsp-deferred)
 
@@ -12,3 +21,33 @@
     (user-error "Couldn't find %S directory" dir))
   (delete-directory dir 'recursive)
   (message "Uninstalled %S" (file-name-nondirectory dir)))
+
+;;;###autoload
+(defun +lsp/switch-client (client)
+  "Switch to another LSP server."
+  (interactive
+   (progn
+     (require 'lsp-mode)
+     (list (completing-read
+            "Select server: "
+            (or (mapcar #'lsp--client-server-id (lsp--find-clients))
+                (user-error "No available LSP clients for %S" major-mode))))))
+  (require 'lsp-mode)
+  (let* ((client (if (symbolp client) client (intern client)))
+         (match (car (lsp--filter-clients (lambda (c) (eq (lsp--client-server-id c) client)))))
+         (workspaces (lsp-workspaces)))
+    (unless match
+      (user-error "Couldn't find an LSP client named %S" client))
+    (let ((old-priority (lsp--client-priority match)))
+      (setf (lsp--client-priority match) 9999)
+      (unwind-protect
+          (if workspaces
+              (lsp-workspace-restart
+               (if (cdr workspaces)
+                   (lsp--completing-read "Select server: "
+                                         workspaces
+                                         'lsp--workspace-print
+                                         nil t)
+                 (car workspaces)))
+            (lsp-mode +1))
+        (setf (lsp--client-priority match) old-priority)))))