emacs-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RLM and LRM are composed?


From: Eli Zaretskii
Subject: RLM and LRM are composed?
Date: Mon, 29 Mar 2010 19:06:32 +0300

Evaluate this form:

  (aset standard-display-table ?‎ (vconcat "->"))

and then visit a file with this single line:

    Hebrew ‏(עברית)     שלום

The character being set up in the standard-display-table is RLM,
RIGHT-TO-LEFT MARK.  If you are reading this in a GUI session, chances
are it will be displayed as whitespace.  The same character is before
the left paren after "Hebrew".  However, Emacs does not display "->"
instead of it, as I'd expect.  It thinks it does (try "C-u C-x =" on
that character), but it doesn't.

If I step with a debugger through produce_glyphs (in the TTY case) or
through x_produce_glyphs (in the GUI case), I see that the glyph we
produce for displaying this character is not IT_CHARACTER, but
IT_COMPOSITION.

Questions:

1. Why do we display this character as composition?  It is not
   supposed to be composed with anything, AFAIK.

2. Is it a bug or a feature that composed characters don't go through
   the display table?  If it's a feature, what is its purpose?

TIA





reply via email to

[Prev in Thread] Current Thread [Next in Thread]