Hi Sam,
I'm a little unclear on your intended use case since (begin ...) does
splice defines, for instance:
(define (add-something x)
(begin
(define one 1)
(define two 2))
(+ x one two))
;;;;;;
Welcome to DrRacket, version 6.9 [3m].
Language: racket/base, with debugging; memory limit: 2048 MB.
> (add-something 5)
8
Can you be more clear on what's going wrong?
Deren
On Thu, Jun 22, 2017 at 3:40 PM, Sam Waxman <samwax...@gmail.com> wrote:
> Hello,
>
> It's simple enough to write a macro that defines something.
>
> (define-syntax-rule (my-define name binding)
> (define name binding))
>
> But what if I would like to define multiple things? I.e.
>
> (define-syntax-rule (my-multiple-define name ... binding ...)
> (define name binding) ...)
>
> The above is no good, because define-syntax-rule expects only one body to
> be returned, not multiple. Wrapping the defines in begin wouldn't work,
> because then they'd only be able to be accessed in the scope of that begin
> (when, in actuality, I want the rest of the code to access them, like they
> would be able to in the first example).
>
> Similarly, if I "upgrade" the syntax-rule to define-syntax, we run into
> the same problems. I thought that the following would work,
>
> (define-syntax (my-multiple-define stx)
> (syntax-case stx ()
> [(_ name1 name2 binding1 binding2)
> #'(define name1 binding1)
> #'(define name2 binding2)]))
>
> but it looks like this only returns the last syntax object, not both of
> them.
>
> (Note, my actual goal here is to define something, then define a syntax
> rule afterwards like
>
> (define-syntax (my-multiple-define stx)
> (syntax-case stx ()
> [(_ x y z)
> #'(define x y)
> #'(define-syntax-rule (z *stuff*)
> *some random body to the syntax-rule*)]))
>
> , so the solution of using define-values to do all the defines in one step
> won't work for me.)
>
> I'd be satisfied either with knowing how to make a macro expand into
> multiple syntax objects (so that one macro can expand into both defines),
> or with someone letting me know how to define something, then define a
> syntax rule afterwards using only one syntax object (like wrapping them in
> a begin but that bumps the definitions inside to the outer scope).
>
> Many thanks in advance!
>
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