Re: Bidirectional text and URLs

[Lars Magne Ingebrigtsen]

Bug fix!  Leading neutralish characters would defeat it.

(defun ensure-left-to-right-string (string)
  (let ((prev (get-char-code-property (aref string 0) 'bidi-class))
        (start 0)
        (pos 0)
        (bits nil))
    (while (< pos (length string))
      (setq current (get-char-code-property (aref string pos) 'bidi-class))
      (when (or (and (eq prev 'L)
                     (memq current '(R AL)))
                (and (memq prev '(R AL))
                     (eq current 'L)))
        (push (substring string start pos) bits)
        (setq start pos))
      (when (memq current '(L R AL))
        (setq prev current))
      (cl-incf pos))
    (push (substring string start pos) bits)
    (mapconcat
     (lambda (bit)
       (if (cl-notany (lambda (char)
                        (memq (get-char-code-property char 'bidi-class) '(R 
AL)))
                      bit)
           ;; Wrap the string in LRO and PDF.
           (concat (string ?\x202d) bit (string ?\x202C))
         ;; And RLO and PDF for the right-to-left bits.
         (concat (string ?\x202e) bit (string ?\x202C))))
     (nreverse bits)
     "")))

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no