[whatwg] Steps for finding one or two numbers in a string

[Henri Sivonen]

The part of the spec about numbers at
http://whatwg.org/specs/web-apps/current-work/#numbers
talks about skipping characters in the class Zs. Also, it talks about  
characters like U+066A ARABIC PERCENT SIGN, U+FE6A SMALL PERCENT SIGN  
and U+FF05 FULLWIDTH PERCENT SIGN.

On the other hand, when the spec talks about digits, it talks about "U 
+0030 DIGIT ZERO to U+0039 DIGIT NINE" and not about character class Nd.

Referring to character classes instead of particular characters is  
problematic, because what constitutes a conforming number changes  
when Unicode introduces ANCIENT BRUTOPIAN QUARTER CUBIT SPACE or  
SYLDAVIAN VULGAR DIGIT FIVE.

I think i18n political correctness has no place in attributes. I  
think they should be ASCII only with the XML notion of whitespace.  
However, the human-readable fallback content of the progress and  
meter elements is not so clear-cut. Still, I doubt whether it is  
worthwhile to have an unstable but universal number format for  
content that is displayed to end users only as fallback.

-- 
Henri Sivonen
hsivonen at iki.fi
http://hsivonen.iki.fi/