[webkit-dev] Fwd: Fwd: HTML5 & MathML3 entities

Alexey Proskuryakov ap at webkit.org
Fri Sep 17 14:57:25 PDT 2010


17.09.2010, в 14:28, David Carlisle написал(а):

> No the code point is in the math symbols block and was always intended
> for math usage. Some time after the code point was added (I think, I
> don't have the data to hand) it got added a canonical mapping to to 3xxx
> block, that was an error that the unicode consortium is now trying to
> correct (or at least back when unicode 3.x added this new character)

I cannot follow this argument. My understanding is that adding a single character canonical decomposition implies deprecation in Unicode, so describing this as a two-step process confuses me.

> > which was not very helpful.&rang used to be a synonym to U+232A, but
> > now the former is a CJK character, and the latter is a math one. I
> > think that consistency with Unicode consortium's choice is an
> > important consideration.
> 
> I think you have "former" and "latter" swapped in the above?

Yes, sorry about that. They used to be synonyms, it hard not to get confused!

> MathML did not violate any specs.


Perhaps there can be different opinions about this :)

At the time I looked at this (and also currently) the deprecated character had a canonical decomposition that made it equivalent to a CJK character. Any software that treats this character as a math one clearly violates many versions of the Unicode specs, including the current one. It might have been conformant to Unicode 2.0 or some earlier version though.

> the lang and rang entity names come from the ISO math entity to denote
> math angle brackets. These sets and these names predate Unicode and predate HTML, it's unfortunate that after the names were mapped to unicode a canonical mapping to a different character was added, but

I don't see how the origins of the debate change the fact that these Unicode fonts you mentioned violated the Unicode spec. They may have been doing "the right thing" or not, but arguing that they didn't violate the letter of the spec seems strange.

Clearly, I have a different perspective, since I don't think that things that pre-date HTML and Unicode should have much weight in today's decisions.

> the only fix the UTC suggest for that is just not using 2329 at all and use 27E8 instead. Which is what the entity spec recommends.


Did they actually suggest to use it for the lang entity in HTML, or did they suggest to use it when a math character is desired?

- WBR, Alexey Proskuryakov



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