Use case 5.11 - Possible?

Henry's use case for making absolute URIs (5.11 [1]) relies on the base URI
and schema type information residing in the "infoset" as properties.  I
don't think we can do this today without saying that we have the XDM and
ensuring that the information from both xml:base processing and validation
is preserved by XProc.  Certainly, xml:base should be fine based on what
our 1.0 specification says but the type information that allows inspection
of each attribute isn't.

Thoughts?

I think this needs to be marked as a possibility for V.next.

[1] http://www.w3.org/TR/xproc-requirements/#use-case-make-absolute-urls

-- 
--Alex Milowski
"The excellence of grammar as a guide is proportional to the paucity of the
inflexions, i.e. to the degree of analysis effected by the language
considered."

Bertrand Russell in a footnote of Principles of Mathematics