I've got a macro that extends function definition by letting the user rebind
some identifiers with different values, which are then only available in a
certain context. For the sake of simplicity suppose it looks like this:
(define/foo (func v ...)
#:bind [helper1 expr]
#:bind [helper2 other-expr]
(helper1 v ...)
(helper2 v ...))
I would like helper1 and helper2 to have their normal meaning unless I'm inside
a special `with-foo` form like so:
(helper1 'a) ; normal behavior
(with-foo func
; in here, helper1 and helper2 are bound to expr and other-expr instead
(helper1 'a))
I'd also like `with-foo` to be the only way to access the versions of helper1
and helper2 that have this alternate behavior. I'm attempting to do this with
some submodule hackery, essentially I'm expanding the above to this:
(define (func v ...)
(helper1 v ...)
(helper2 v ...))
(module foo racket/base
(module+ func
(define helper1 expr)
(define helper2 other-expr)
(provide (all-defined-out))))
(begin
(require (submod ".." foo func))
(helper 1))
My reasoning is that by letting "func" double as a submodule identifier, I can
easily bring all the specially-bound identifiers associated with func into
scope, and by putting that submodule in a "foo" submodule I can hide the
existence of the foo submodule so only `with-foo` knows how to require the
correct "func" module. But I'm hitting scope issues - I'm not sure hot to make
the redefinitions of func available in (body ...) in a (with-foo func body ...)
use, naively adding the require imports fails to bring them into scope. Various
combinations of using syntax/loc and datum->syntax on the require statement,
the require submod path, and/or the body are all failing to do what I want.
How can I achieve this? Is there a better way to try and do this?
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