[plt-scheme] Brainstorming about how to transform UML XMI into some code

Hi folks,

Most good UML editors support the ability to export to XMI:

http://en.wikipedia.org/wiki/XML_Metadata_Interchange

Regardless of our take on the role of UML and its editors, I've got a question.

We have been looking at a technology called OAW:

http://www.openarchitectureware.org/

It provides a pretty straightforward way to transform XMI into
whatever you feel like generating. Using Eclipse it lets you write
transformations in a little statically typed functional language. For
example:

<<DEFINE Root for data::DataModel>>
    <<EXPAND Entity FOREACH entity>>
<<ENDDEFINE>>

That functions starts processing the model at the highest level and
for each Entity it has inside of it, call the function Entity (for
type Entity).

How would one approach something like this in Scheme?

Would it be obvious to me if I read EOPL or SICP how one may approach
this problem?