[elpa] externals/auctex 08ab3c1 23/78: Allow hiding ^ and _ script signs

[Tassilo Horn]

branch: externals/auctex
commit 08ab3c10d51f0956e8faca2c85f5e0d38bee4303
Author: Tassilo Horn <address@hidden>
Commit: Tassilo Horn <address@hidden>

    Allow hiding ^ and _ script signs
    
    * font-latex.el (font-latex-fontify-script): Add possible value
    `multi-level' to allow raising/lowering scripts of scripts, and
    another value `invisible' which in addition hides the ^ and _
    characters in scripts.
    (font-latex-match-script): Use it.
    (font-latex-make-user-keywords): Add font-lock entry for script
    signs.
    (font-latex-script-invisible): New function.
---
 ChangeLog     |    7 ++++-
 font-latex.el |   90 +++++++++++++++++++++++++++++++++++---------------------
 2 files changed, 62 insertions(+), 35 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 3d698b7..703db99 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,8 +1,13 @@
 2015-09-03  Tassilo Horn  <address@hidden>
 
        * font-latex.el (font-latex-fontify-script): Add possible value
-       `multi-level' to allow raising/lowering scripts of scripts.
+       `multi-level' to allow raising/lowering scripts of scripts, and
+       another value `invisible' which in addition hides the ^ and _
+       characters in scripts.
        (font-latex-match-script): Use it.
+       (font-latex-make-user-keywords): Add font-lock entry for script
+       signs.
+       (font-latex-script-invisible): New function.
 
        * tex.el (TeX-tex-mode): Don't ignore case when matching the
        TeX-format-list regexes.
diff --git a/font-latex.el b/font-latex.el
index 2a9fc26..0df8a96 100644
--- a/font-latex.el
+++ b/font-latex.el
@@ -810,7 +810,7 @@ Generated by `font-latex-make-user-keywords'.")))
     (add-to-list 'font-latex-keywords-1 item)
     (add-to-list 'font-latex-keywords-2 item))
   (dolist (item
-          '((font-latex-match-math-env
+          `((font-latex-match-math-env
              (0 'font-latex-warning-face t t)
              (1 'font-latex-math-face append t))
             (font-latex-match-math-envII
@@ -818,7 +818,8 @@ Generated by `font-latex-make-user-keywords'.")))
             (font-latex-match-simple-command
              (0 'font-latex-sedate-face append))
             (font-latex-match-script
-             (1 (font-latex-script (match-beginning 0)) append))))
+             (1 (font-latex-script (match-beginning 0)) append))
+            ("[_^]" (0 (font-latex-script-invisible (match-beginning 0)) t))))
     (add-to-list 'font-latex-keywords-2 item t)))
 (font-latex-make-user-keywords)
 
@@ -856,17 +857,23 @@ This feature does not work in XEmacs.
 By default, super/subscripts are raised/lowered if this variable
 is non-nil.  This fontification only affects one level of
 scripts, e.g., in x^y^z, the y and the z have the same size and
-are equally raised over x.  If this variable is set to the symbol
-`multi-level', then y is raised above x, and z is raised above y.
-With many script levels, the text might become too small to be
-readable."
+are equally raised over x.
+
+If this variable is set to the symbol `multi-level', then y is
+raised above x, and z is raised above y.  With many script
+levels, the text might become too small to be readable.
+
+If this variable is set to the symbol `invisible', then the
+effect is essentially like `multi-level' but additionally the
+script operators ^ and _ are not displayed."
   :type '(choice (boolean :tag "Enabled")
-                (const :tag "Multiple levels" multi-level))
+                (const :tag "Multiple levels" multi-level)
+                (const :tag "Hide ^ and _" invisible))
   :group 'font-latex)
 (put 'font-latex-fontify-script 'safe-local-variable
      (lambda (val)
        (or (TeX-booleanp val)
-          (eq 'multi-level val))))
+          (memq val '(multi-level invisible)))))
 
 (defcustom font-latex-script-display '((raise -0.3) . (raise 0.3))
   "Display specification for subscript and superscript content.
@@ -1096,14 +1103,14 @@ have changed."
                  '(:inherit fixed-pitch)
                '(:family "courier"))))
     `((((class grayscale) (background light))
-        (:foreground "DimGray" ,@font))
-       (((class grayscale) (background dark))
-        (:foreground "LightGray" ,@font))
-       (((class color) (background light))
-        (:foreground "SaddleBrown" ,@font))
-       (((class color) (background dark))
-        (:foreground "burlywood" ,@font))
-       (t (,@font))))
+       (:foreground "DimGray" ,@font))
+      (((class grayscale) (background dark))
+       (:foreground "LightGray" ,@font))
+      (((class color) (background light))
+       (:foreground "SaddleBrown" ,@font))
+      (((class color) (background dark))
+       (:foreground "burlywood" ,@font))
+      (t (,@font))))
   "Face used to highlight TeX verbatim environments."
   :group 'font-latex-highlighting-faces)
 
@@ -1209,8 +1216,8 @@ triggers Font Lock to recognize the change."
   ;; `VirTeX-common-initialization' and place it in the different
   ;; `xxx-mode' calls instead, but _after_ `major-mode' is set.
   (let ((defaults
-        `((font-latex-keywords font-latex-keywords-1 font-latex-keywords-2)
-          nil nil ,font-latex-syntax-alist nil))
+         `((font-latex-keywords font-latex-keywords-1 font-latex-keywords-2)
+           nil nil ,font-latex-syntax-alist nil))
        (variables
         '((font-lock-comment-start-regexp . "%")
           (font-lock-mark-block-function . mark-paragraph)
@@ -1251,21 +1258,21 @@ triggers Font Lock to recognize the change."
 
 (defun font-latex-jit-lock-force-redisplay (buf start end)
   "Compatibility for Emacsen not offering `jit-lock-force-redisplay'."
-    ;; The following block is an expansion of `jit-lock-force-redisplay'
-    ;; and involved macros taken from CVS Emacs on 2007-04-28.
-    (with-current-buffer buf
-      (let ((modified (buffer-modified-p)))
-       (unwind-protect
-           (let ((buffer-undo-list t)
-                 (inhibit-read-only t)
-                 (inhibit-point-motion-hooks t)
-                 (inhibit-modification-hooks t)
-                 deactivate-mark
-                 buffer-file-name
-                 buffer-file-truename)
-             (put-text-property start end 'fontified t))
-         (unless modified
-           (restore-buffer-modified-p nil))))))
+  ;; The following block is an expansion of `jit-lock-force-redisplay'
+  ;; and involved macros taken from CVS Emacs on 2007-04-28.
+  (with-current-buffer buf
+    (let ((modified (buffer-modified-p)))
+      (unwind-protect
+         (let ((buffer-undo-list t)
+               (inhibit-read-only t)
+               (inhibit-point-motion-hooks t)
+               (inhibit-modification-hooks t)
+               deactivate-mark
+               buffer-file-name
+               buffer-file-truename)
+           (put-text-property start end 'fontified t))
+       (unless modified
+         (restore-buffer-modified-p nil))))))
 
 (defun font-latex-fontify-region (beg end &optional loudly)
   "Fontify region from BEG to END.
@@ -1864,7 +1871,7 @@ END marks boundaries for searching for quotation ends."
   (when (and font-latex-fontify-script
             (re-search-forward "[_^] *\\([^\n\\{}]\\|\
 \\\\\\(address@hidden|[^ \t\n]\\)\\|\\({\\)\\)" limit t))
-    (if (and (not (eq 'multi-level font-latex-fontify-script))
+    (if (and (not (memq font-latex-fontify-script '(multi-level invisible)))
             (font-latex-faces-present-p '(font-latex-subscript-face
                                           font-latex-superscript-face)))
        ;; Apply subscript and superscript highlighting only once (in case
@@ -1916,6 +1923,21 @@ END marks boundaries for searching for quotation ends."
                   ,(cdr font-latex-script-display))
          'font-latex-superscript-face)))))
 
+(defun font-latex-script-invisible (pos)
+  "Make the super/subscript sign invisible."
+  (when (and (eq font-latex-fontify-script 'invisible)
+            (font-latex-faces-present-p 'font-latex-math-face pos)
+            (not (font-latex-faces-present-p '(font-lock-constant-face
+                                               font-lock-builtin-face
+                                               font-lock-comment-face
+                                               font-latex-verbatim-face) pos))
+            ;; Check for backslash quoting
+            (not (let ((odd nil)
+                       (pos pos))
+                   (while (eq (char-before pos) ?\\)
+                     (setq pos (1- pos) odd (not odd)))
+                   odd)))
+    `(face nil invisible t)))
 
 ;;; docTeX