Re: [csswg-drafts] [css-text] Use the Unicode East Asian Auto Spacing for `text-autospace` (#11013)

To be more precise, the proposal is to change the "[8.5.2. Text Spacing Character Classes](https://drafts.csswg.org/css-text-4/#text-spacing-classes)" to:

**ideogrpahs**:
* All characters where the Unicode East Asian Auto Spacing property [UTR#number-TBD, [L2-24-057R](https://www.unicode.org/L2/L2024/24057r-auto-spacing-prop.pdf)]] is W.

**non-ideographic letters or numerals**
* If the content language is Chinese or its micro-languages, all characters where the Unicode East Asian Auto Spacing property is N or C.
* Otherwise, if the content language is Japanese or Korean, all characters where the Unicode East Asian Auto Spacing property is N.
* Otherwise no characters in this class.

**non-ideographic letters**
* All **non-ideographic letters or numerals** characters that don't belong to the Unicode Decimal Digit Number [Nd] [general category](https://drafts.csswg.org/css-text-4/#unicode-general-category).

**non-ideographic numerals**
* All **non-ideographic letters or numerals** characters that belong to the Unicode Decimal Digit Number [Nd] [general category](https://drafts.csswg.org/css-text-4/#unicode-general-category).

Notes on the content language:
* Does the CSS have a definition for "Chinese or its micro-languages" somewhere? If not, we might need a list here.
* The last "otherwise" is for the performance reasons. The current definitions allows implementers to optimize the performance by using script boundaries, but using the Unicode property will make it more difficult. From our prototype, this feature will impact the line breaking performance by a few percent if without the script boundary optimization. The last "otherwise" helps not applying the algorithm for non-CJK content.

-- 
GitHub Notification of comment by kojiishi
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/11013#issuecomment-2404509319 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Thursday, 10 October 2024 08:58:09 UTC