2012-04-25

Emacs 24: Oddity with Bidirectional Language/Script Support

first, here's my emacs version am testing from. “GNU Emacs 24.0.93.1 (i386-mingw-nt6.1.7601) of 2012-02-15 on MARVIN”

Some facts:

  • Right arrow key is bound to right-char.
  • Ctrl+f】 keys is bound to forward-char.

Now, paste this sentence in emacs “(كتاب ألف ليلة و ليلة)”. Then, hold down right arrow key, then when cursor moves into the Arabic text, it'll suddenly reverse direction, and move right to left, until it reaches the left most arabic char sequence, it'll jump back to the english text and continue move right.

Now, do the same but using forward-charCtrl+f】. Actually, the same behavior is observed visually!

from Eli Zaretskii's post (at Source groups.google.com), it seems to be the expected behavior. But then what's the difference of forward-char and right-char? Am totally confused now.

In emacs 23, holding right arrow (or 【Ctrl+f】) simply move cursor to the right, ALWAYS. I was expecting this from emacs 24's right-char.