Re: [XeTeX] XeTeX bugs in bidirectional typesetting
Simon Cozens wrote: I would also recommend XeTeX moving to the LuaTeX model I would rather recommend /adding/ the LuaTeX model, and enabling users to select it if they wish; existing documents should not be broken by a change of model. Philip Taylor -- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex
Re: [XeTeX] Σχετ: Re: XeTeX bugs in bidirectional typesetting
Apostolos, I would recommend against following this dangerous path. Once I asked I asked the luaTeX list how to load hyphenation patterns and practically no one knew the answer! So I think your decision is wise. Interesting, because my experience when developing babel is quite the opposite -- loading hyphenations patterns in luatex was trivial, much simpler than with other engines. Anyway, the average user shouldn't be concerned with those issues because a higher level interface is the way to go. PS I think that we should not talk about luaTeX here. Agreed. Cheers Javier -- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex
[XeTeX] Are the new etex changes reflected in XeTeX? (was XeTeX bugs in bidirectional typesetting)
Hi When I discussed the TeX--XeT issues with Peter Breitenlohner, he made few changes in etex. Are these changes applied to XeTeX? The changes were: 1) Fix hyphenation of LR and RL text see http://tug.org/svn/texlive/trunk/Build/source/texk/web2c/etexdir/etex.ch?r1=29312&r2=32197 2) Better handling of right to left text This is quite important since he changed TeX--XeT model into a new version where the order of whatsit nodes is no longer reversed. I believe this fixes many of the TeX--XeT problems if XeTeX applies it. see http://tug.org/svn/texlive/trunk/Build/source/texk/web2c/etexdir/etex.ch?r1=29250&r2=29312 If this is not applied in XeTeX, it is better to apply it and see how things work. -- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex
Re: [XeTeX] XeTeX bugs in bidirectional typesetting
> Well, it's not necessarily useless. If both engines are using the same > model, then you have twice as many communities available to fix bugs. > And it means the bug fixes and bidi expertise can be shared between the > two communities. I would also recommend XeTeX moving to the LuaTeX model > - and then fixing it! Something which did not work for the past 10 years is concrete proof that it is not going to be of any use. > As I understand it, the > problems with bidi were one of the reasons that Khaled stopped working > on XeTeX, which in a sense is a shame - he's exactly the sort of person > you need to get this right... He is by no means an expert in bidi typesetting. I have maintained the bidi package over 10 years and have fixed hundreds of bugs (if not thousands). He has not even written any considerable code for bidi typesetting and he gave up too easily. So your suggestion is simply void which is reasonable since you have no knowledge of the matter. On the other hand, I have both experience and knowledge in both macro level and engine development for bidi typesetting so it is unlikely that I am going to follow anyone. For the past 10 years, I used to be a citizen of a few dictatorship TeX worlds and I along many others were treated like slaves. Now I am announcing my independence, I want to build my own democratic TeX world and free all the slaves so that they can be treated like normal citizens. > If you want an engine with a working bidi model, then you might want to > have a look at SILE. (https://github.com/simoncozens/sile) It uses the > Unicode bidi algorithm and so you get multilevel reordering without any > markup required. (See > https://github.com/simoncozens/sile/blob/master/examples/arabic.pdf) But > of course then you don't get the large set of packages and the mature > community... I do not have time and energy to waste. Please stop advertising. I have no interest in your work. -- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex
Re: [XeTeX] XeTeX bugs in bidirectional typesetting
Hello Vafa, Yes indeed, I thought it was very kind of you to think of me, and I hope you got my reply at that time. If not, you should know that your careful concern was deeply appreciated. I wish you the best in this venture. Pity I haven't got the savvy at this point to help. Happy to help road test though if and when... Best wishes and thanks for the comment. K Sent from my iPhone > On Nov 19, 2016, at 11:33 PM, Simon Cozens wrote: > >> On 20/11/2016 12:35, Vafa Khalighi wrote: >> For the past 10 years I have reported numerous issues to the LuaTeX >> and etex teams without any results but it is more than enough. I am >> not going to waste time and energy doing useless things. > > Well, it's not necessarily useless. If both engines are using the same > model, then you have twice as many communities available to fix bugs. > And it means the bug fixes and bidi expertise can be shared between the > two communities. I would also recommend XeTeX moving to the LuaTeX model > - and then fixing it! > >> I put my time and energy into developing an engine that really has a >> working bidi model. an engine which is developed by a native speaker >> and meets the needs of people with real documents. > > XeTeX has a lot of advantages in terms of opentype support, large set of > packages and mature community. It's a shame the bidi support is not > great; that is a known problem and there are not many people with the > expertise to make it work and do it well. As I understand it, the > problems with bidi were one of the reasons that Khaled stopped working > on XeTeX, which in a sense is a shame - he's exactly the sort of person > you need to get this right... > > If you want an engine with a working bidi model, then you might want to > have a look at SILE. (https://github.com/simoncozens/sile) It uses the > Unicode bidi algorithm and so you get multilevel reordering without any > markup required. (See > https://github.com/simoncozens/sile/blob/master/examples/arabic.pdf) But > of course then you don't get the large set of packages and the mature > community... > > S > > > -- > Subscriptions, Archive, and List information, etc.: > http://tug.org/mailman/listinfo/xetex -- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex
Re: [XeTeX] Are the new etex changes reflected in XeTeX? (was XeTeX bugs in bidirectional typesetting)
On 20/11/2016 03:55, Vafa Khalighi wrote: Hi When I discussed the TeX--XeT issues with Peter Breitenlohner, he made few changes in etex. Are these changes applied to XeTeX? 2) Better handling of right to left text This is quite important since he changed TeX--XeT model into a new version where the order of whatsit nodes is no longer reversed. This is very interesting, I didn't know Peter had done that. I think this is the right way forward (for an etex-based engine such as xetex), and had been hoping to find the time to work on essentially the same idea in xetex, but so far the code exists only in my head. Unfortunately, xetex is no longer built on top of tex.web + etex.ch etc, but has its own separate xetex.web (I think Peter made this change around 2012), and so subsequent improvements in etex won't have automatically become part of the xetex build; they would (I presume) have to be ported over to xetex.web. But that should be relatively straightforward, I hope, and should save me needing to reinvent that particular wheel. JK -- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex
Re: [XeTeX] Are the new etex changes reflected in XeTeX? (was XeTeX bugs in bidirectional typesetting)
On 20 November 2016 at 18:19, Jonathan Kew wrote:
> This is very interesting, I didn't know Peter had done that. I think this is
> the right way forward (for an etex-based engine such as xetex), and had been
> hoping to find the time to work on essentially the same idea in xetex, but
> so far the code exists only in my head.
>
If you do find time to look at this... the other main issue besides \specials
where the current model causes problems is the inability to specify direction
while in vertical mode. The restriction to hmode was probably needed in tex-xet
so the extra nodes got added at safe places but in tex--xet it's less
clearly needed.
The restriction to horizontal mode forces fragile code trying to get
the \beginR into \everypar
at the right time, and with tables there basically is no workaround:
you can not construct the tables in vertical mode while stacking the
columns from the right.
(You can wrap them in a box but then they won't split)
It would be really good if xetex could have commands usable in vmode
that produced the effects of luatex
below (doesn't have to be "\textdir TRT" it could be
"\addBeginRByDefaultInHlists" it doesn't really matter...
Of course it if _was_ "\textdir TRT" that would simplify cross engine
support, but the missing functionality is the main problem, not the
differing syntax.
David
\vsize=5\baselineskip
\topskip=\baselineskip
\ifx\directlua\undefined
\TeXXeTstate=1
%
\else
%
\textdir TRT%columns assembled right to left with RTL text
% \bodydir TRT \pagedir TRT % columns added to right of page
\fi
\halign{&#\quad\hfil\cr
111&222\cr
a&b\cr
aabbcc&bcd\cr
a&b\cr
aabbcc&bcd\cr
a&b\cr
aabbcc&bcd\cr
a&b\cr
}
\bye
--
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Re: [XeTeX] Are the new etex changes reflected in XeTeX? (was XeTeX bugs in bidirectional typesetting)
> If you do find time to look at this... the other main issue besides \specials > where the current model causes problems is the inability to specify direction > while in vertical mode. The restriction to hmode was probably needed in > tex-xet > so the extra nodes got added at safe places but in tex--xet it's less > clearly needed. Do you want to make a bug report for this? It’s good to discuss these issues between us, but when it comes to implementing and distributing changes, it’s best to have a record of them in the bug tracker; XeTeX’s is on Sourceforge as you know: https://sourceforge.net/p/xetex/bugs/. Best, Arthur -- Subscriptions, Archive, and List information, etc.: http://tug.org/mailman/listinfo/xetex
