Re: Unifying E_Modifier and Extend in UAX 29 (i.e. the necessity of GB10)

We had that originally, but some people objected that some languages
(Arabic, as I recall) can end a string of letters with a ZWJ, and
immediately follow it by an emoji (without an intervening space) without
wanting it to be joined into a grapheme cluster with a following symbol.
While I personally consider that a degenerate case, we tightened the
definition to prevent that.

Mark

Mark

On Tue, Jan 2, 2018 at 10:41 AM, Manish Goregaokar <manish_at_mozilla.com>
wrote:

> In the current draft GB11 mentions Extended_Pictographic Extend* ZWJ x
> Extended_Pictographic.
>
> Can this similarly be distilled to just ZWJ x Extended_Pictographic? This
> does affect cases like <indic letter, virama, ZWJ, emoji> or <arabic
> letter, zwj, emoji> and I'm not certain if that counts as a degenerate
> case. If we do this then all of the rules except the flag emoji one become
> things which can be easily calculated with local information, which is nice
> for implementors.
>
> (Also in the current draft I think GB11 needs a `E_Modifier?` somewhere
> but if we merge that with Extend that's not going to be necessary anyway)
>
> -Manish
>
> On Tue, Jan 2, 2018 at 3:02 PM, Manish Goregaokar <manish_at_mozilla.com>
> wrote:
>
>> > Note: we are already planning to get rid of the GAZ/EBG distinction (
>> http://www.unicode.org/reports/tr29/tr29-32.html#GB10) in any event.
>>
>>
>> This is great! I hadn't noticed this when I last saw that draft (I was
>> focusing on the Virama stuff). Good to know!
>>
>>
>> > Instead, we'd add one line to
>> *Extend <http://www.unicode.org/reports/tr29/tr29-32.html#Extend>:*
>>
>> Yeah, this is essentially what I was hoping we could do.
>>
>> Is there any way to formally propose this? Or is bringing it up here good
>> enough?
>>
>> Thanks,
>>
>> -Manish
>>
>> On Mon, Jan 1, 2018 at 9:17 PM, Mark Davis ☕️ via Unicode <
>> unicode_at_unicode.org> wrote:
>>
>>> This is an interesting suggestion, Manish.
>>>
>>> <non-emoji-base, skin tone modifier> is a degenerate case, so if we
>>> following your suggestion we also could drop E_Base and E_Modifier, and
>>> rule GB10.
>>>
>>> Instead, we'd add one line to *Extend
>>> <http://www.unicode.org/reports/tr29/tr29-32.html#Extend>:*
>>>
>>> OLD
>>> Grapheme_Extend = Yes
>>> *and not* GCB = Virama
>>>
>>> NEW
>>> Grapheme_Extend = Yes, or
>>> Emoji characters listed as Emoji_Modifier=Yes in emoji-data.txt. See [
>>> UTS51 <http://www.unicode.org/reports/tr41/tr41-21.html#UTS51>].
>>> *and not* GCB = Virama
>>>
>>> Note: we are already planning to get rid of the GAZ/EBG distinction (
>>> http://www.unicode.org/reports/tr29/tr29-32.html#GB10) in any event.
>>>
>>> Mark
>>>
>>> On Mon, Jan 1, 2018 at 3:52 PM, Richard Wordingham via Unicode <
>>> unicode_at_unicode.org> wrote:
>>>
>>>> On Mon, 1 Jan 2018 13:24:29 +0530
>>>> Manish Goregaokar via Unicode <unicode_at_unicode.org> wrote:
>>>>
>>>> > <random non-emoji, skin tone modifier> sounds very much like a
>>>> > degenerate case to me.
>>>>
>>>> Generally yes, but I'm not sure that they'd be inappropriate for
>>>> Egyptian hieroglyphs showing human beings. The choice of determinative
>>>> can convey unpronounceable semantic information, though I'm not sure
>>>> that that can be as sensitive as skin colour. However, in such a case
>>>> it would also be appropriate to give a skin tone modifier the property
>>>> Extend.
>>>>
>>>> Richard.
>>>>
>>>
>>>
>>
>
Received on Tue Jan 02 2018 - 04:41:59 CST