Re: Unicode 3.1: IDS and ZW(N)J

From: Mark Davis (markdavis34@home.com)
Date: Thu Jan 25 2001 - 00:15:25 EST


It doesn't add any value to insert joiners. Just add the IDS itself to the
font table.

Mark

----- Original Message -----
From: "John Cowan" <jcowan@reutershealth.com>
To: "Unicode List" <unicode@unicode.org>
Sent: Wednesday, January 24, 2001 11:21
Subject: Re: Unicode 3.1: IDS and ZW(N)J

> John Jenkins wrote:
>
>
> > [B]ut in
> > any event the basic stance we've taken in the past has consistently been
> > that there is no expectation that IDSs will *ever* be rendered as single
> > glyphs.
>
> That is not what the Unicode Standard 3.0 says. It says that an IDS
> may be rendered either as a sequence of glyphs or as a single glyph.
>
> Allowing ZWNJ will prevent such rendering; allowing ZWJ will encourage
> such rendering in fonts which can do it.
>
> This actually doesn't require any magic processing during rendering,
> except to add IDS sequences with ZWJ in them to font ligaturing tables,
> as Unicode 3.1 now requires in joining scripts (Arabic, etc.)
> It is more a matter of not forcing conformant IDS processors to treat
> a sequence with a joiner in it as two separate sequences.
>
> > Even allowing that smart font technology might make it possible
> > to render them with single glyphs, I think they should be processed in
> > the same fashion as (say) combining character sequences. We don't allow
> > for a joiner between an e and an acute accent. If the system can render
> > that CSS as a single glyph, then it can and that's as much as need be
done.
>
> Granted. But the word "ligature" is not used there, whereas it is
> explicitly so used on page 271.
>
> --
> There is / one art || John Cowan <jcowan@reutershealth.com>
> no more / no less || http://www.reutershealth.com
> to do / all things || http://www.ccil.org/~cowan
> with art- / lessness \\ -- Piet Hein
>
>



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