What is the time frame for USE shapers to provide support for CV+C ?

[Richard Wordingham via Unicode]

On Tue, 14 May 2019 03:08:04 +0100
Richard Wordingham via Unicode <unicode at unicode.org> wrote:

> On Tue, 14 May 2019 00:58:07 +0000
> Andrew Glass via Unicode <unicode at unicode.org> wrote:
> 
> > Here is the essence of the initial changes needed to support CV+C.
> > Open to feedback.
> > 
> > 
> >   *   Create new SAKOT class
> > SAKOT (Sk) based on UISC = Invisible_Stacker
> >   *   Reduced HALANT class
> > Now only HALANT (H) based on UISC = Virama
> >   *   Updated Standard cluster mode
> > 
> > [< R | CS >] < B | GB > [VS] (CMAbv)* (CMBlw)* (< < H | Sk > B |
> > SUB  
> > > [VS] (CMAbv)* (CMBlw)*)* [MPre] [MAbv] [MBlw] [MPst] (VPre)*
> > > (VAbv)* (VBlw)* (VPst)* (VMPre)* (VMAbv)* (VMBlw)* (VMPst)* (Sk
> > > B)* (FAbv)* (FBlw)* (FPst)* [FM]  

> This next question does not, I believe, affect HarfBuzz.  Will NFC
> code render as well as unnormalised code?  In the first example above,
> <TONE-2, SAKOT, LOW YA> normalises to <SAKOT, TONE-2, LOW YA>, which
> does not match any portion of the regular expression.

Could someone answer this question, please?  The USE documentation
("CGJ handling will need to be updated if USE is modified to support
normalization") still implies that the USE does not respect canonical
equivalence.

Richard.