Re: Whitespace normalization for union types

> The fact that the whitespace-value is at hand when the value was
> already validated against the member-types, seems to contradict with
> [2] Datatype Valid, which mandates the pattern facet to be applied
> first; but without the whitespace-value, normalization is not possible,
> so applying the pattern facet is not possible as well.
> Can someone clarify this?

That rules says that patterns are applied to the lexical values, but  
lexical values only exist *after* white space normalization. 3.1.4 of  
Structures [1] discusses how the "initial value" is turned into a  
"normalized value" using white space processing. (The "initial value"  
space is also called the "pre-lexical" space.) 2.2.1.2 says is it the  
normalized value that is fed into the simple type validation process.

So your example appears valid.

initial value = ' a  '
normalized value (string) = ' a  ' => not valid
normalized value (token) = 'a' => valid

xan

[1]  
http://www.w3.org/TR/2004/REC-xmlschema-1-20041028/ 
structures.html#d0e1654