[AUCTeX] Re: TeX-insert-dollar

[Ralf Angeli]

* Ralf Angeli (2006-07-03) writes:

> * David Kastrup (2006-07-03) writes:
>
>> We might leave the current behavior as an option, but for keeping it
>> as a default, I want to hear more than theoretic rationalizations
>> (without them, the feature wouldn't even be there).  I want to hear
>> someone actually speaking up for (or against) it who is affected.
>
> Let's deactivate it.  I doubt we will get much feedback on this list.

How about the following patch?

--- tex.el      07 Jul 2006 21:06:48 +0200      5.581
+++ tex.el      07 Jul 2006 22:30:20 +0200      
@@ -4446,6 +4446,11 @@
   (concat "^" (regexp-quote TeX-dollar-string) "\\|[^" TeX-esc "]"
          (regexp-quote TeX-dollar-string)))
 
+(defcustom TeX-math-insert-double-dollar nil
+  "If non-nil close double dollar math by typing a single `$'."
+  :group 'TeX-macro
+  :type 'boolean)
+
 (defcustom TeX-math-toggle-off-input-method t
   "*If non-nil, auto toggle off CJK input methods when entering math mode."
   :group 'TeX-macro
@@ -4478,14 +4483,18 @@
             (string-equal (substring (car texmathp-why) 0 1) "\$"))
        ;; Math mode was turned on with $ or $$ - so finish it accordingly.
        (progn
-         (insert (car texmathp-why))
-         (save-excursion
-           (goto-char (cdr texmathp-why))
-           (if (pos-visible-in-window-p)
-               (sit-for 1)
-             (message "Matches %s"
-                      (buffer-substring (point)
-                                        (progn (end-of-line) (point)))))))
+         (if TeX-math-insert-double-dollar
+             (insert (car texmathp-why))
+           (insert "$"))
+         (when (or (string= (car texmathp-why) "$")
+                   (zerop (mod (save-excursion (skip-chars-backward "$")) 2)))
+           (save-excursion
+             (goto-char (cdr texmathp-why))
+             (if (pos-visible-in-window-p)
+                 (sit-for 1)
+               (message "Matches %s"
+                        (buffer-substring
+                         (point) (progn (end-of-line) (point))))))))
       ;; Math mode was not entered with dollar - we cannot finish it with one.
       (message "Math mode started with `%s' cannot be closed with dollar"
               (car texmathp-why))

-- 
Ralf