[Exist-development] type-specific parameters in overloaded functions

[Dave F. <dav...@gm...>]

I'd like to define a function (or two) where they can be called one of the
following ways:

*dave-module:my-function ($my-string as xs:string)
dave-module:my-function ($my-integer as xs:integer)*

The problem is that eXist (or perhaps it's the XQuery language in general)
doesn't like this, as it seems unless I define functions based on the
*number* of parameters as opposed to the *type*, I get an error. No matter
how I try, the interpreter seems to want one over the other. My question: Is
there a way to not have to do any obvious workarounds to get this to work?
Right now all I can do is to define the functions as follows, which does
work:

*dave-module:my-function-s ($my-string as xs:string)
dave-module:my-function ($my-integer as xs:integer)*

(note the "-s" at the end of the function name to denote the fact that it is
expecting a string)

I'm using eXist 1.5 trunk (I forget the revision number off the top of my
head). My apologies if this is a neophyte question, but after a day of
rummaging through the documentation, I'm kind of at a loss.
-- 
David Finton