[plt-scheme] mutually required modules

David A. Herman wrote:

> In separating modules between interfaces and implementations, I sometimes
> find that I'd like to offer a particular implementation as the default for
> convenience, but the mutual reference between modules causes a cycle in
> the module resolver.

Xavier Leroy has written a proposal for solving this problem in the OCaml
language.

   What this extension provides is a "module rec ... and ..." binding
   that allows the definition of mutually-recursive modules within the
   same compilation units.  Recursion between compilation units is a
   different problem that is not adressed yet.

   http://cristal.inria.fr/~xleroy/publi/recursive-modules-note.pdf

-d