From 98d05848517a087728c9257abf1466cfd189e0c4 Mon Sep 17 00:00:00 2001
From: Eshel Yaron <me@eshelyaron.com>
Date: Wed, 9 Nov 2022 22:30:46 +0200
Subject: [PATCH] Recognize backslash as part of an operator in tokenization

---
 sweeprolog-tests.el | 12 ++++++------
 sweeprolog.el       |  8 +++++---
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/sweeprolog-tests.el b/sweeprolog-tests.el
index da66d0a..78924f2 100644
--- a/sweeprolog-tests.el
+++ b/sweeprolog-tests.el
@@ -73,22 +73,22 @@ foo(Foo) :- bar.
     (should (equal (get-text-property (+ (point-min) 3)
                                       'font-lock-face)
                    '(sweeprolog-built-in-default-face
-                     sweeprolog-directive-default-face)))
+                     sweeprolog-body-default-face)))
     (should (equal (get-text-property (+ (point-min) 9)
                                       'font-lock-face)
-                   '(sweeprolog-directive-default-face)))
+                   '(sweeprolog-body-default-face)))
     (should (equal (get-text-property (+ (point-min) 10)
                                       'font-lock-face)
                    '(sweeprolog-identifier-default-face
-                     sweeprolog-directive-default-face)))
+                     sweeprolog-body-default-face)))
     (should (equal (get-text-property (+ (point-min) 13)
                                       'font-lock-face)
-                   '(sweeprolog-directive-default-face)))
+                   '(sweeprolog-body-default-face)))
     (should (equal (get-text-property (+ (point-min) 16)
                                       'font-lock-face)
                    '(sweeprolog-local-default-face
                      sweeprolog-predicate-indicator-default-face
-                     sweeprolog-directive-default-face)))
+                     sweeprolog-body-default-face)))
     (should (equal (get-text-property (+ (point-min) 23)
                                       'font-lock-face)
                    '(sweeprolog-fullstop-default-face)))
@@ -103,7 +103,7 @@ foo(Foo) :- bar.
     (should (equal (get-text-property (+ (point-min) 39)
                                       'font-lock-face)
                    '(sweeprolog-undefined-default-face
-                     sweeprolog-clause-default-face)))))
+                     sweeprolog-body-default-face)))))
 
 
 (ert-deftest complete-variable ()
diff --git a/sweeprolog.el b/sweeprolog.el
index 11f6eef..4b87ee0 100644
--- a/sweeprolog.el
+++ b/sweeprolog.el
@@ -1996,7 +1996,7 @@ modified."
       ((rx bow (group-n 1 "0'" anychar))
        (1 (unless (save-excursion (nth 8 (syntax-ppss (match-beginning 0))))
             (string-to-syntax "w"))))
-      ((rx bow (group-n 1 "!"))
+      ((rx bow (group-n 1 "!") eow)
        (1 (unless (save-excursion (nth 8 (syntax-ppss (match-beginning 0))))
             (string-to-syntax "w")))))
      start end)))
@@ -2629,7 +2629,8 @@ predicate definition at or directly above POINT."
             (while (and (not (eobp)) (nth 3 (syntax-ppss)))
               (forward-char))
             (list 'string beg (point)))
-           ((= syn ?.)
+           ((or (= syn ?.)
+                (= syn ?\\))
             (skip-syntax-forward ".")
             (list 'operator beg (point)))
            ((= syn ?\()
@@ -2666,7 +2667,8 @@ predicate definition at or directly above POINT."
                      (= (char-syntax (char-before)) ?_)))
             (skip-syntax-backward "w_")
             (list 'functor (point) end))
-           ((= syn ?.)
+           ((or (= syn ?.)
+                (= syn ?\\))  ; specifically, the backslash character
             (skip-syntax-backward ".")
             (list 'operator (point) end))
            ((= syn ?\()
-- 
2.39.2