[XeTeX] List of ligatures in a font

[mskala at ansuz.sooke.bc.ca]

On Wed, 14 Mar 2012, d fulano wrote:
> how do I determine what are the "standard ligatures" in a font?It is not
> obvious (especially for non-English languages), and they can also vary
> in each font.  Basically what I want to do is this:I can very quicky

It will be tricky with OpenType fonts that have context-sensitive
ligatures, because there may be many different sequences of input glyphs
that activate a given output glyph, and the input sequences can be
described in the font file in terms of matching patterns rather than a
(potentially prohibitively long) explicit list of input sequences.  If you
think you can guess the input sequence by looking at the output glyph (as
will be possible in many cases for Latin script), then you could simply
list the output glyphs and not worry about reverse-engineering the tables
to find the inputs; but that won't be a good assumption in the case of,
for instance, jamo layout changes in Korean.  Stuff like arbitrary-length
fractions implemented by ligature-like substitution will give you a hard
time as well.
-- 
Matthew Skala
mskala at ansuz.sooke.bc.ca                 People before principles.
http://ansuz.sooke.bc.ca/