Re: [Q] units and macros in MzScheme

["Robby Findler" <robby@cs.rice.edu>]

>    Can one define a macro inside a unit and then export/import it to
another
>    unit or into the global namespace?
>
>    thanks,
>    -- Leo
>
> Good question.
>
> Short answer: no.
>

Although Matthias is exactly right about defining the *macro* in a unit, one
can define the *implementation* of the macro in a unit. Perhaps this isn't
what you want, we we do use this pattern fairly often to define macros in
drscheme's source code:

(require-library "invoke.ss")
(define-values/invoke-unit
 (thunk)
 (unit (import)
       (export thunk)

       (define (thunk x) `(lambda () ,x))))

(define-macro thunk thunk)

Hope that helps,
Robby