[XeTeX] Reducing ligatures in arabxetex

[Khaled Hosny]

On Sat, Feb 18, 2012 at 06:12:52PM +0000, Juan Acevedo wrote:
> If I untick Contextual Alternates within Character Alternates, then
> presto, I obtain the desired effect: to use only mandatory ligatures.
> To give a visual reference, I am attaching a screen picture where the
> first line has full ligatures (=Contextual Alternates), and the second
> only mandatory ligatures.

IMO, this will give you really poor result as many of the “ligature¹”
are really required and should not be turned off. At one point I'll try
to split them into ‘rlig’ for forms that I consider a must, ‘liga’ for
good to have but OK to turn off (though still on by default), and ‘dlig’
for exotic ones that are off by default (though I don't consider any of
the existing forms to belong to this category). Though this wouldn't
help you, because XeTeX does not allow controlling feature for complex
scripts, as Jonathan states elsewhere in this thread.

¹ technically speaking, the font has no ligatures at all, but contextual
  alternates.

Regards,
 Khaled