Long standing problem with Vedic tone markers and post-base visarga/anusvara

[Richard Wordingham via Unicode]

On Wed, 1 Jan 2020 01:19:02 +0000
James Kass via Unicode <unicode at unicode.org> wrote:

> A workaround until some kind of satisfactory adjustment is made might
> be to simply use COLON for VISARGA.  Or...
> 
>   VISARGA ⇒ U+02F8 MODIFIER LETTER RAISED COLON
> ANUSVARA⇒U+02D9 DOT ABOVE
> 
> ...as long as the font(s) included both those characters.
> 
> य॑ यॆ॑
> 
> य॑ं -- anusvara last
> यॆ॑ं -- "
> 
> य॑: -- colon last
> यॆ॑: -- "
> 
> य॑˸ -- raised colon modifier last
> यॆ॑˸ -- "
> 
> य॑˙ -- spacing dot above last
> यॆ॑˙ -- "
> 

That's exactly the sort of mess that jack-booted renderers are trying
to minimise.  Their principle is that there should be only one encoding
per shape, though to be fair:

1) some renderers accept canonical equivalents.
2) tolerance may be allowed for ligating (ZWJ, ZWNJ, CGJ), collating
(CGJ, SHY) and line-breaking controls (SHY, ZWSP, WJ).
3) Superseded chillu encodings are still supported.

Richard.