[no subject]

"Since saxon:parse() and saxon:serialize() should have been part of
the spec"

Why?
They are unnecessary.
Serialization can be achieved with
http://www.fgeorges.org/xslt/serial/ - an pure XSLT 2.0 solution.

Saxon:parse has always been unnecessary.
Parsing can be done with the fn:doc() function - just pass a data: URI
(RFC 2397).
If Saxon still doesn't support this 9-year-old standard, then you can
resort to writing a my:doc () xsl:function using use-when to test the
xsl:vendor system-property to identify saxon, and use saxon:parse in
that case, and use fn:doc() for other cases.

Then you will be able to add the word pure to the subject line.
-- 
Colin Adams
Preston Lancashire