feat(emacs): provide an option to disable lean-flycheck

src/emacs/lean-flycheck.el

@@ -4,29 +4,29 @@
 ;; Author: Soonho Kong
 ;;
 
-(require 'flycheck)
-
-(setq-local lean-lmake-name "lmake")
-(setq-local lean-lmake-options "--flycheck")
-(eval
- `(flycheck-define-checker lean-checker-file
-    "A Lean syntax checker (file)."
-    :command (,(lean-get-executable lean-lmake-name) ,lean-lmake-options source-inplace)
-    :error-patterns
-    ((error line-start "FLYCHECK_BEGIN ERROR\n"
-            (file-name) ":" line ":" column  ": error: "
-            (minimal-match
-             (message (one-or-more (one-or-more not-newline) "\n") ))
-            "FLYCHECK_END" line-end)
-     (warning line-start "FLYCHECK_BEGIN WARNING\n"
-              (file-name) ":" line ":" column  ": warning "
+(when lean-use-flycheck
+  (require 'flycheck)
+  (setq-local lean-lmake-name "lmake")
+  (setq-local lean-lmake-options "--flycheck")
+  (eval
+   `(flycheck-define-checker lean-checker-file
+      "A Lean syntax checker (file)."
+      :command (,(lean-get-executable lean-lmake-name) ,lean-lmake-options source-inplace)
+      :error-patterns
+      ((error line-start "FLYCHECK_BEGIN ERROR\n"
+              (file-name) ":" line ":" column  ": error: "
               (minimal-match
                (message (one-or-more (one-or-more not-newline) "\n") ))
-              "FLYCHECK_END" line-end))
-    :modes (lean-mode)
-    :predicate
-    (lambda () (and buffer-file-name
-               (string= "lean" (file-name-extension buffer-file-name))))))
-(add-to-list 'flycheck-checkers 'lean-checker-file)
-(add-hook 'lean-mode-hook '(lambda () (flycheck-mode t)))
+              "FLYCHECK_END" line-end)
+       (warning line-start "FLYCHECK_BEGIN WARNING\n"
+                (file-name) ":" line ":" column  ": warning "
+                (minimal-match
+                 (message (one-or-more (one-or-more not-newline) "\n") ))
+                "FLYCHECK_END" line-end))
+      :modes (lean-mode)
+      :predicate
+      (lambda () (and buffer-file-name
+                 (string= "lean" (file-name-extension buffer-file-name))))))
+  (add-to-list 'flycheck-checkers 'lean-checker-file)
+  (add-hook 'lean-mode-hook '(lambda () (flycheck-mode t))))
 (provide 'lean-flycheck)

src/emacs/lean-settings.el

@@ -30,6 +30,11 @@
   :group 'lean
   :type 'string)
 
+(defcustom lean-use-flycheck t
+  "Use flycheck for lean."
+  :group 'lean
+  :type 'boolean)
+
 (defcustom lean-delete-trailing-whitespace nil
   "Set this variable to true to automatically delete trailing
 whitespace when a buffer is loaded from a file or when it is