Re: Bidirectional Bugs in hebrew

[Pablo Saratxaga <pablo mandrakesoft com>]

Kaixo!

On Fri, Oct 27, 2000 at 10:38:23AM -0700, Chookij Vanatham wrote:

>] Problem: when writing in hebrew (and RTL direction) a letter and then "-"
>] and a number
> This is because of Bidirection algorithm which doesn't define "minus sign"
> as the R type (Right to Left)

All mathematical signs aren't supposed to be strong LTR ?
(But I agree it isn't a "minus sign", but it seems however to be treated
as a "minus sign" when it is followed by a number).

> which is a strong type. This is because "minus
> sign" in hebrew will have different direction than Left-to-Right script,

You mean the opposite I suppose...

> The bidirection algorihm is used with multi-scripts and not just
> specific to hebrew.

Even with multi-scripts that are all LTR ? That would be a pure waste.
I know of only three RTL scripts in unicode: Arabic (including all the chars
used for non Arabic languages), Hebrew (including all the dots and Yiddish
letters), and Syriac.
Are there others ?

> ] And if we use soft hyphen (0xad, available in iso-8859-6 (Arabic),
> ] iso-8859-8 (Hebrew), cp1255 (Hebrew + Yiddish), cp1256 (Arabic+Farsi+Urdu))
> ] would it produce a rtl string ?
>
> I haven't tried this but I think, you should get the same result because
> "soft hyphen" would not be the R type like hebrew alphabet.

but shouldn't a neutral char inherit the "default" direction (in this case
being RTL if you write in Hebrew.

Well, I'll try it...
It works!:

chanae:~$ echo AA-123BB | fribidi
BB-123AA
chanae:~$ echo AA­123BB | fribidi
BB123­AA

Now that should be put somewhere in a FAQ.

> Because you are using this in unicode locale, so, you can try typing
> RLO or RLE before typing "minus sign" to force the direction to be Right to
> left,

Of course; but that isn't very userfriendly.
Having the keyboard map send a soft hyphen (0x00ad) when in Hebrew/Arabic mode
instead of a "minus" (0x002d) (the numeric keypad should always send
a 0x002d however, IMHO).
That would allow much easier typing.

A real life example: "8-bit" in Hebrew: "8-á" gives "á8-" which is wrong;
and "8­á" gives the right "á­8".
When people are typing text they want the hyphen to follow the direction
of writting; so having the kbd send a soft hyphen seems a good solution.
What do you think about that ?

And are there any implications in using 0x00ad instead of 0x002d for 
"hyphen" meaning in Hebrew/Arabic strings ?

> I haven't tried it but I think fribidi should work with RLO,RLE,PDF as well.
> For the keyboard input, not too sure if gtk+1.3 is enabled to allow users
> to input those RLO, RLE, PDF codes.

AFAIK Gtk+ doesn't handle the keyboard; X11 does.

-- 
Ki ça vos våye bén,
Pablo Saratxaga

http://www.srtxg.easynet.be/		PGP Key available, key ID: 0x8F0E4975