Re: [emacs-bidi] bidi categories

[Ehud Karni]

On Sun, 11 Nov 2001 05:57:25 +0100, Alex Schroeder <address@hidden> wrote:
> 
> Hm, I think I must have missed something.  Are you saying that in
> order to get one of the possible logical representations of a visual
> order string, I could just have added lots of explicit ordering codes?

I said 2 things:
  1. Some visual text can not be put into logical order without
     formatting characters.
  2. The adding of formatting characters makes it easier to convert
     visual text to logical order.
                                           
Try for example (capital means strong R [Hebrew] as usual) the
following visual text "ABCD 1234 abcde 5678 EFGH".
With LRM (symbolized by ^) it is represented logically by:
In right-to-left reading direction - "HGFE^ 1234 abcde 5678 ^DCBA"              
            
In left-to-right reading direction - "DCBA^ 1234 abcde 5678 ^HGFE"   
without formatting characters it is impossible.

There are also problems with digits and punctuation (depends on the 
specific order). For example try to represent logically the following
visual text:
    ABCDE .50$ FGHIJ 
    ABCDE .50% FGHIJ 
    ABCDE .$50 FGHIJ       
    ABCDE .%50 FGHIJ 

Each of the above will be easily represented with formatting LRM.
In right-to-left reading direction:
    JIHGF^ <any-digits-and-punctuations-as-in-visual> ^EDCBA
In left-to-right reading direction:
    EDCBA^ <any-digits-and-punctuations-as-in-visual> ^JIHGF

Ehud.


-- 
 Ehud Karni     Mivtach - Simon  Insurance   /"\
 Tel: +972-3-7966-561 Fax: +972-3-7966-667   \ /  ASCII Ribbon Campaign
 (USA) Fax and  voice  mail: 1-815-5509341    X   Against  HTML  Mail
     Better     Safe     Than     Sorry      / \
     mailto:address@hidden    http://www.simonwiesel.co.il