[luatex] Vital RTL issues in LuaTeX

[Khaled Hosny]

On Fri, Apr 10, 2009 at 12:21:49PM +0200, luigi scarso wrote:
> >>
> >>
> >> I am most certainly not going to implement anything in C until there
> >> is a fully working version implemented in pure lua or as otp(s).
> >>
> >
> >
> > From the very beginning, I knew you would say because you were pretending
> > like there is no issue at all. But please in future say this at the very
> > beginning so people do not waste their time.
> hmm, I disagree.
> Coding in C is hard: you must ensure portability, you must ensure
> correctness, you must ensure best solution , you must...
> 
> But you have speed , speed, and speed .
> 
> So a fully working version implemented in pure lua  is really a good
> point to start to coding in C .

I, personally, don't think we need to code any thing at the engine
level, this just make things more complex and less flexible, lets take
the example Taco pointed out, if we applied bidi algorithm on 3.5
(chapter 3, section 5) it'll stay 3.5 regardless of text direction,
however it should be 5.3 in RTL, and some people might disagree and say
it should be 3.5 in all cases. If BiDi was hard coded in th engine, it'll
just make things more complex, and one will need to put a Unicode 'right
to left mark' before the dot. The same can be said for numbered lists
etc.

Regards,
 Khaled

-- 
 Khaled Hosny
 Arabic localiser and member of Arabeyes.org team
 Free font developer
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