Marco,
> Why do you say that these are not round-trip compatible?
The point I was trying to make is conversion of INV->ZWJ can be thought as
being kind of fallback, you might be able to roundtrip in most cases but
not all. I do agree the conversions you pointed out can be roundtripped. But
does it mean that if I have an ISCII stream, converted it to Unicode would I
be able to render the stream correctly? I think no.
> Does ISCII have
> VOWEL SIGN VOCALLIC L, VOWEL SIGN VOCALLIC RR, VOWEL SIGN VOCALLIC LL?
Yes it does in combination with NUKTA.
0xAA, 0xE9,/* RI + NUKTA => 0x0960 Vocallic RR*/
0xDF, 0xE9,/* Vowel sign RI + NUKTA => 0x0944 Vowel Sign Vocallic
RR*/
0xa6, 0xE9,/* Vowel I + NUKTA => 0x090C Vowel Vocallic L*/
0xdb, 0xE9,/* Vowel sign I + Nukta => 0x0962 Vowel Sign Vocallic L*/
0xa7, 0xE9,/* Vowel II + NUKTA => 0x0961 Vowel Vocallic LL*/
0xdc, 0xE9,/* Vowel sign II + Nukta => 0x0963 Vowel Sign Vocallic
LL*/
0xa1, 0xE9,/* chandrabindu + Nukta => 0x0950 Om*/
0xEA, 0xE9, /* Danda + Nukta => 0x093D Avagraha*/
> > 4) INV+HALANT+RA => RAsub
>
> I think that there is no reason why ZWJ+HALANT+RA alone shouldn't
represent
> RAsub in Unicode as well.
> Actually, I think that also HALANT+RA alone should be enough to represent
> RAsub (in Unicode, at least). But ZWJ should not harm, so one may retain
it
> for round-trip compatibility with ISCII's INV.
You are correct if ZWJ is treated like any other consonant, which is unclear
from rendering rules, so
applications have a choice to try and do the right thing or do nothing.
I tried to see how the combinations below are rendered in Notepad on Win2000
and our Layout demo, and they
donot render HALANT+RA as RAsub
ISCII Rendered
==== =======
KA+INV+HALANT+RA KA |RAsub| /*RAsub does not combine with
KA */
INV+HALANT+RA RAsub
Converted to Unicode:
Unicode Rendered
====== =======
KA+ZWJ+HALANT+RA KA |HALANT| RA
ZWJ+HALANT+RA |HALANT|RA
/* Or even */
HALANT+RA |HALANT|RA
Regards,
Ram
---------------------------------------------------
Ram Viswanadha
International Components For Unicode
GCoC San Jose
IBM
