[R6RS] modules?

[Matthew Flatt]

At Sat, 22 May 2004 17:32:40 +0200, Michael Sperber wrote:
> Matthew> I remain convinced that MzScheme's `module' is compatible with a
> Matthew> low-overhead component system, but I can't point to an implementation.
> 
> Could you provide just the barest hint on how this would look like?
> (Just enough for me to be confident it's possible.)

I imagine a language that turns the body of a module into a unit, and
automatic linking of units when there's no ambiguity.

Something like this:

  (module foo (lib "unit.ss")
    (import "baz-sig.ss")
    (export "foo-sig.ss")

    (define make-foo ...)
    ...)

  ;; A compound unit:
  (module foo+baz (lib "unit.ss")
     (import ...)
     (link "baz.ss")
     (link "foo.ss")
     ;; because baz.ss provides the only local implementation of
     ;;  "baz-sig.ss", ad imported by "foo.ss", then it's automatically
     ;; linked with "foo.ss"
  
     ;; Actually, I imagine getting rid of the "atomic" and
     ;;  "compound" distinction. So you can add more defns here.
     (define more ...)

     (export ...) )


  ;; An alternate linking
  (module foo+baz-alt (lib "unit.ss")
     (link "baz.ss")
     (link "baz-wrapper.ss" to "baz.ss")
     (link "foo.ss" to "baz-wrapper.ss")
     ;; Since there's more than one implementation of
     ;;  "baz-sig.ss", not we have to be more explicit
     ;;  about the linking. Maybe a lot of other links are
     ;;  still implicit.

     ...)

Matthew