Tamil Brahmi Short Mid Vowels

[Shriramana Sharma via Unicode]

This is a unique problem because this is probably the only case where the
same script produces conjuncts for one language and not for another. I had
asked for a separate Tamil Brahmi virama to be encoded which would obviate
this problem but that was shot down. Maybe that case should be reopened?

On Sat 21 Jul, 2018, 06:33 Richard Wordingham via Unicode, <
unicode at unicode.org> wrote:

> A problem has been spotted with the rendering of Tamil Brahmi vowels -
> in particular the sequence <U+11013 BRAHMI LETTER KA, U+11044 BRAHMI
> VOWEL SIGN O, U+11046 BRAHMI VIRAMA> does not conform to the grammar
> of the Universal Shaping Engine (USE); a dotted circle may be inserted
> between the vowel and the pulli.
>
> When considering font-level remedies, I realised that there may be a
> problem with a following consonant - is <U+11013, U+11044, U+11046,
> U+11022 BRAHMI LETTER TA> a correct encoding of what may be
> transliterated as _kŏta_?
>
> The nearest to a convincing justification I can find for it to require
> U+200C ZWNJ after the virama is the text in TUS Section 12.1 for
> *Explicit Virama*, but that merely says that ZWNJ is required to
> produce explicit virama rather than a _conjunct_.  As I understand
> it, a subscript final consonant would be encoded as consonant+virama
> rather than virama+consonant, so there is no ambiguity in Brahmi text.
> (If we try to make a rule out of two conflicting mechanisms, the
> difference might be that one is used for viramas and the other is used
> for invisible stackers, though that would require changing U+10A3F
> KHAROSHTHI VIRAMA back to being a virama.) The problem is that a font
> that tries to recover the situation might interpret <U+11013,
> U+11044, U+25CC DOTTED CIRCLE, U+11046, U+11022> as having TA
> subscripted to the dotted circle.  If ZWNJ is required for _kŏta_, what
> text if any in TUS requires it?
>
> Richard.
>
>
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