Re: What is the set of allowed characters in identifiers?

Eli Friedman wrote:
> Are the code points from 128 to 160 valid identifier characters?
> 
> The CSS2.1 draft doesn't give a clear answer.  The prose in 4.1.3 says
> that they are not allowed in identifiers, but the definition of the
> IDENT token in 4.1.1 says that they are allowed.

There could be a technical problem in expressing IDENT using the FLEX
notation: it cannot represent characters above 127 (see note at the
beginning of G.2). The correct grammar of on nonascii should be either:

	nonascii 	0xA0 .. 0x10FFFF 	# hexadecimal
	nonascii 	 160 ..  1114111	# decimal
	nonascii 	0240 .. 04177777 	# octal

but none of the above could be expressed using FLEX.

Thus the prose in 4.1.3 is the only normative reference.


-- 
Andrei Polushin

Received on Friday, 24 August 2007 06:40:40 UTC