Re: canonical lexical rep

• From: Xan Gregg <xan.gregg@jmp.com>
• Date: Mon, 27 Sep 2004 18:54:34 -0400
• To: xmlschema-dev@w3.org
• Message-Id: <336D3FB4-10D8-11D9-B05F-000A95A7F890@jmp.com>

> Can somebody here explain why exactly we need a canonical lexical rep
> for the various literals of datatypes? What purpose does it solve?

Canonical representation is mainly for non-schema users of the 
datatypes.  There is one place where XML Schema relies on canonical 
representation, though there is a XML Schema 1.1 requirement for that 
dependency to be removed.

The dependency relates to default values, which are stored in the 
component property as values (not lexical representations).  When a 
schema inserts the value into an instance document, it used the 
canonical representation of the value.

Not all datatypes have canonical representations.  xs:QName, at least, 
doesn't.

xan

Received on Monday, 27 September 2004 22:54:45 UTC