Re: [9fans] [RFC] fonts and unicode/utf [TeX]

[tlaronde@polynum.com]

On Sun, Jun 19, 2011 at 06:38:59PM -0400, erik quanstrom wrote:
>
> nobody cares what font encoding tex uses internally.  the
> real issue is the input to tex.  i sure would be very reluctant
> to load anything on my system that will mangle utf-8, especially
> for codepoints <256.  that's the path to wchar_t.

That TeX on Plan9 should accept utf-8 is not a question. But TeX has a
present state, and kerTeX has a present state.

For now, TeX only chews bytes (octets); there is apparently some
acrobatics with a LaTeX macro set trying to accomodate with utf in input
(according to Russ Cox if I understood correctly what he wrote).

One can use TeX with utf as long as one uses only ASCII (by
design/definition of utf). That is one can use TeX in interactive
mode on Plan9 conforming to the TeXbook, since the TeXbook uses
ASCII, even to create non ASCII glyphes (accented with escape
sequences).

TeX will do non desired things if it chews non ASCII encoded in utf
(and this starts even with the Unicode-latin1 range).

BUT, since the "codepoints" described in the latin1 subrange are present
(except for /dcroat and /Dcroat) in the 229 glyphes PostScript Core
fonts, and I can create fonts (tfm) for TeX covering "ASCII/latin1"
characters, this allows people using this more wide (even if limited)
range, to enter the text on Plan9; to use tcs(1) to convert this range
to latin1 i.e. 8 bits encoding, and to feed (not interactive) this file
to TeX. This adds, for now (and for others than Plan9 that still use
chars == octets) some supplementary ability, without removing something.

I have to make a choice. YES, "latin1" too is not less special than not
ASCII in utf; but glyphes are there (in PS core fonts) ; it is in the
same value than Unicode ; so it seems more natural to choose this than
any other _for now_.

Paris has not been built in one day. KerTeX neither.
--
        Thierry Laronde <tlaronde +AT+ polynum +dot+ com>
                      http://www.kergis.com/
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