Use lexical-binding in text-mode.el

* lisp/textmodes/text-mode.el: Use lexical-binding.
(text-mode, paragraph-indent-minor-mode, text-mode-hook-identify):
Use setq-local.
(toggle-text-mode-auto-fill): Quote function symbols as such.
(center-line): Minor simplification.
* doc/lispref/modes.texi (Example Major Modes): Update code example
for these changes to text-mode.

1 files changed, 3 insertions, 4 deletions

diff --git a/doc/lispref/modes.texi b/doc/lispref/modes.texi
index 1afbc5a5cee..7b64a56b199 100644
--- a/doc/lispref/modes.texi
+++ b/doc/lispref/modes.texi
@@ -1291,10 +1291,9 @@ You can thus get the full benefit of adaptive filling
 Turning on Text mode runs the normal hook `text-mode-hook'."
 @end group
 @group
-  (set (make-local-variable 'text-mode-variant) t)
-  (set (make-local-variable 'require-final-newline)
-       mode-require-final-newline)
-  (set (make-local-variable 'indent-line-function) 'indent-relative))
+  (setq-local text-mode-variant t)
+  (setq-local require-final-newline mode-require-final-newline)
+  (setq-local indent-line-function #'indent-relative))
 @end group
 @end smallexample