[css3-text] scoping line break controls, characters that disappear at the end of lines

In 2008 roc outlined some principles for how line breaking controls (i.e. 'white-space',
at the time) are scoped to line-breaking opportunities:

In <http://lists.w3.org/Archives/Public/www-style/2008Dec/0043.html> Robert O'Callahan wrote:
>
> 1) Break opportunities induced by white space are entirely governed by the
>    value of the 'white-space' property on the enclosing element. So, spaces
>    that are white-space:nowrap never create break opportunities.
> 2) When a break opportunity exists between two non-white-space
>    characters, e.g. between two Kanji characters, we consult the value of
>    'white-space' for the nearest common ancestor element of the two characters
>    to decide if the break is allowed.

I'm trying to encode this into the spec. My question is, are spaces (U+0020) the
only characters that fall into category #1? What about the other characters in
General Category Zs?
   http://www.fileformat.info/info/unicode/category/Zs/list.htm

In particular, U+1680 is, like U+0020, expected to disappear at the end of a line.

Which brings up another issue: which characters should disappear at the end of a
line? Right now we keep around all those fixed-width spaces.

~fantasai

Received on Tuesday, 10 January 2012 01:40:17 UTC