Generate the bindings directly in C
The other options were ot generate scheme code, or use scheme macros to generate it at macro expand time. The latter is not possible in r7rs-small, because syntax-case has been removed. So I will not go down this road. The former is quite awkward, because we constantly need to jump in the XML document in order to get the C type names of things. So for now everything is XSLT+C.