[9fans] Woes of New Language Support

[akumar@mail.nanosouffle.net]

I've been trying to add support for Sanskrit derived
languages, but just rendering the characters has halted
progress.  For the currently supported languages,
such as English, Russian, Greek, French, even Japanese, the
characters are more or less statically mapped to the unicode
(looking at my $font again, I see that Kanji bitmaps are
perhaps mapped to unspecified unicode ranges?).

However, in the class of languages for which I am trying to
provide support, certain characters are meant to be produced
by an ordered combination of other characters.  For example,
the general sequence in Devanagari script (and this extends
to the other scripts as well) is that
consonant+virama+consonant produces
half-consonant+consonant, where the half-consonant has no
other unicode specification.  As a concrete case in
Devanagari, na virama sa (viz., \u0928\u094d\u0938) should
produce the nsa character (this sequence can be seen in any
unicode representation of the word "Sanskrit" in Devanagari
script).

It seems to me that TTF font specifications (i.e., those I
converted to subfonts using Federico's ttf2subf) include
these sequence definitions, which are then processed by each
application providing support for the fonts.  Plan 9
subfonts are much too simple for this.

So, in this case, what are some ideas towards representing
the above?  I've thought about a ktrans-alike that perhaps
filters the data rio gets and processes it for these sort of
things, but it doesn't seem to be the best possible way to
proceed.  If we can even get past this hurdle, I'd be more
than happy to patch ktrans for input support for this class
of languages.


Thanks,
ak