[plt-scheme] Easy module switching?

On 27/06/07, John Clements <clements at brinckerhoff.org> wrote:
> Units are designed to handle this kind of problem, though in fact
> units give you run-time binding, which might be more flexibility than
> you really want.

I know about units (at least the plt ones), though I admit my
understanding of them is rather primitive. The idea I get is that they
are a tool comparable to, although more flexible and powerful than,
C++ templates. I don't understand how they would help.

Basically I want to be able to swap between different versions of a
module from a central location, preferably without having to actually
rename the module or change the source file(s). The command line would
be a convenient place to be able to set it from. For example, one
solution would be to have all of my files require a new "router"
module which would require one of the alternatives depending on which
I wanted to use. However, to switch between them I would actually have
to change the source of this router module. I want to know if there is
a more convenient alternative.

Good day,
   Henk Boom