From: John Hudson (firstname.lastname@example.org)
Date: Thu Jul 12 2007 - 16:53:48 CDT
Philippe Verdy wrote:
> If you just consider the case of the cross base used in Lao, or the
> underline base used in Lao, they are indeed easily confusable in
> Latin/Greek/Cyrillic for the former (with letter x), and in Arabic (with the
Yes, so document creators would be ill-advised to use those particular characters as
generic bases in the context of those languages (note, however, not shaddah, tatweel
(kashida), which is, by the way, sometimes used as a generic base for Arabic marks).
The point is that the layout engine shouldn't be deciding which generic bases to allow for
particular scripts or languages. It should allow all of them for any script, just as it
allows the dotted circle. At the next level, font developers might decide not to support a
particular generic base if it happens to be confuseable in the scripts and languages
supported by the font, but even he might decide to leave the decision to the document creator.
> We can't safely assume that generic bases will work in all scripts and all
> languages, including those that are still unencoded but will use combining
Work in what sense? The sense that matters to me is that layout engines should include the
characters that may be used as generic bases in the same text runs as following combining
marks, regardless of script or language. That's why the bases are *generic*. So what is
the easiest way to implement this? Define a set of characters that may be used as generic
bases, based on documentation of existing conventions, and specify that these should all
be treated in the same way as the dotted circle base.
If the UTC are interested in this idea, I can start defining such a set and gather
feedback and requested additions from publishers, lexicographers, scholars, etc.
-- Tiro Typeworks www.tiro.com Gulf Islands, BC email@example.com We say our understanding measures how things are, and likewise our perception, since that is how we find our way around, but in fact these do not measure. They are measured. -- Aristotle, Metaphysics
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