From ff2f35fc478d0047fef4ae3e0b09f43c37961bec Mon Sep 17 00:00:00 2001
From: Tassilo Horn <tsdh@gnu.org>
Date: Fri, 21 Aug 2015 09:38:01 +0200
Subject: [PATCH] Add TeX defaults for prettify-symbol-mode

* lisp/textmodes/tex-mode.el (tex--prettify-symbols-alist): Rename
from tex-prettify-symbols-alist.
(tex--prettify-symbols-compose-p): New function.
(tex-common-initialization): Use them as prettify-symbols-alist
and prettify-symbols-compose-predicate.
---
 lisp/textmodes/tex-mode.el | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/lisp/textmodes/tex-mode.el b/lisp/textmodes/tex-mode.el
index 54783869403..8f68c71fd17 100644
--- a/lisp/textmodes/tex-mode.el
+++ b/lisp/textmodes/tex-mode.el
@@ -1205,6 +1205,7 @@ Entering SliTeX mode runs the hook `text-mode-hook', then the hook
 
 (defvar tildify-space-string)
 (defvar tildify-foreach-region-function)
+(defvar tex--prettify-symbols-alist)
 
 (defun tex-common-initialization ()
   ;; Regexp isearch should accept newline and formfeed as whitespace.
@@ -1246,7 +1247,7 @@ Entering SliTeX mode runs the hook `text-mode-hook', then the hook
   (setq-local facemenu-remove-face-function t)
   (setq-local font-lock-defaults
 	      '((tex-font-lock-keywords tex-font-lock-keywords-1
-	         tex-font-lock-keywords-2 tex-font-lock-keywords-3)
+                                        tex-font-lock-keywords-2 tex-font-lock-keywords-3)
 		nil nil nil nil
 		;; Who ever uses that anyway ???
 		(font-lock-mark-block-function . mark-paragraph)
@@ -1254,6 +1255,8 @@ Entering SliTeX mode runs the hook `text-mode-hook', then the hook
 		 . tex-font-lock-syntactic-face-function)
 		(font-lock-unfontify-region-function
 		 . tex-font-lock-unfontify-region)))
+  (setq-local prettify-symbols-alist tex--prettify-symbols-alist)
+  (setq-local prettify-symbols-compose-predicate #'tex--prettify-symbols-compose-p)
   (setq-local syntax-propertize-function
 	      (syntax-propertize-rules latex-syntax-propertize-rules))
   ;; TABs in verbatim environments don't do what you think.
@@ -2945,7 +2948,7 @@ There might be text before point."
 
 ;;; Prettify Symbols Support
 
-(defvar tex-prettify-symbols-alist
+(defvar tex--prettify-symbols-alist
   '( ;; Lowercase Greek letters.
     ("\\alpha" . ?α)
     ("\\beta" . ?β)
@@ -3056,6 +3059,8 @@ There might be text before point."
     ("\\centerdot" . ?·)
     ("\\checkmark" . ?✓)
     ("\\chi" . ?χ)
+    ("\\cdot" . ?⋅)
+    ("\\cdots" . ?⋯)
     ("\\circ" . ?∘)
     ("\\circeq" . ?≗)
     ("\\circlearrowleft" . ?↺)
@@ -3398,6 +3403,17 @@ There might be text before point."
     ("\\textreferencemark" . ?※))
   "A `prettify-symbols-alist' usable for (La)TeX modes.")
 
+(defun tex--prettify-symbols-compose-p (start end _match)
+  (let* ((after-char (char-after end))
+         (after-syntax  (char-syntax after-char)))
+    (not (or
+          ;; Don't compose \alpha@foo.
+          (eq after-syntax ?_)
+          ;; The \alpha in \alpha2 may be composed but of course \alphax may not.
+          (and (eq after-syntax ?w)
+               (or (< after-char ?0)
+                   (> after-char ?9)))))))
+
 (run-hooks 'tex-mode-load-hook)
 
 (provide 'tex-mode)
-- 
2.39.2