Re: [css3-fonts] unicode-range and unicode normalization

fantasai wrote:

>  * The UA must choose a single font for each grapheme cluster. [UAX10]

Did you mean to refer to UAX10?  UAX10 is the Unicode Collation
Algorithm and deals with how to compare two Unicode strings. Matching
character streams to font character maps is a different problem, since
the goal is not to determine equivalence but rather to render a
character sequence correctly.

> A related topic would be what happens when the base character is in
> one element, the combining character in another, and the two are
> assigned different fonts. Do we want different behavior for that
> than for assigning different fonts through unicode-range?

This starts to push into the realm of saving users from themselves. In
general, I don't think we should burden implementations with complex
error handling requirements like this unless it's really a common
occurrence that's hard for the author to work around.  Codepoints
defined in unicode-range descriptors act as a filter on the codepoints
in the cmap of a font, I don't think we should blur that based on
complex conditions.

Cheers,

John