[XeTeX] Traditional TeX ligatures once again

[Jonathan Kew]

On 28 Jun 2007, at 2:21 pm, Evgenie Medvedev wrote:

> The trend around the cyrillic TeX community is to use "<<" and ">>"  
> for
> french-style quotes (\guillemotleft and \guillemotright) which are
> standard typography in Russian, and I would rather keep this  
> convention.
> This is unavoidable, since Russian keyboards don't have these  
> characters
> either.
>
> Unfortunately, while these << and >> sequences translate into  
> ligatures
> in pre-XeTeX fonts,

In the TeX-encoded Cyrillic fonts, to be more exact; not in Computer  
Modern Roman, AFAIK. So this behavior would have been dependent on  
choosing an appropriate font encoding, or something like that (I've  
never really known much about this aspect of LaTeX).

> so it worked before most of the time, they are not
> defined in tex-text font mapping as of version 0.996,

True; that just tries to emulate the behavior found in the default  
CMR fonts (and others that follow the same pattern).

> nor in the
> subversion repository, and as far as I can see, there's no good way to
> fix that with xunicode or using the macros provided by xunicode.

Right; xunicode handles macros, not font-defined ligatures.

> Using
> "< and "> as described in babel docs produces symbols which do not
> translate to U+00AA and U+00AB in the resulting pdf file, and don't  
> look
> right anyway. Maybe it would be a good idea to add these mappings in a
> future version? Meanwhile, how do I define these sequences in the
> document itself, or nearby, without making my TexLive setup  
> incompatible
> with everybody else and without using a preprocessor?

I think you should create a tex-cyrillic mapping, similar to the tex- 
text mapping but containing these replacements and any others that  
are normally expected (at the ligature level; not control sequences)  
by Cyrillic-script users. I'd be happy to include such a mapping in  
future releases, but in the meantime you can add mappings by creating  
the .map file (plain text), compiling it to a .tec file with  
teckit_compile (from the TECkit package, see http://scripts.sil.org/ 
teckit), and placing it somewhere under texmf/fonts/misc/ (look at  
where tex-text.tec is installed). If you put it in a system texmf  
tree, don't forget to run texhash, otherwise it won't be found.

> I've also been struggling with \cyr<letter> not being defined while
> required by babel, (strange, but I got no problems with hypenation  
> which
> have been reported so often, so far) but found the cyrunicode.tex in
> this list's archives, which fixed it -- could it be eventually  
> added to
> xunicode, or something? Or is it a question of testing to see if it's
> complete and correct? Being a native speaker, I could do that.

That would be great. I just put together a minimal list as a test,  
but am not a Russian speaker/reader.

HTH,

JK