Provide basic 'prettify-symbols-alist' in Sweep Prolog mode

* sweeprolog.el (sweeprolog-mode): set a local value for
'prettify-symbols-alist' that renders the neck operator as a unicode
left arrow.

diff --git a/sweeprolog.el b/sweeprolog.el
index 266db397d5b72543872471e2ed102514b6af53f0..3941d816b97aaaa7491c805410f2ec9c65b9785e 100644 (file)
--- a/sweeprolog.el
+++ b/sweeprolog.el
@@ -4688,6 +4688,7 @@ certain contexts to maintain conventional Prolog layout."
   (setq-local comment-multi-line t)
   (setq-local add-log-current-defun-function
               #'sweeprolog-add-log-current-defun)
+  (setq-local prettify-symbols-alist '((":-" . ?←)))
   (setq-local mode-line-process
               '(:eval
                 (when (sweeprolog-buffer-loaded-since-last-modification-p)