> On Apr 25, 2016, at 5:05 PM, Matthew Butterick <[email protected]> wrote:
>> I was about to try to apply its awesome power to your example, but I just >> realized that in your new example, the s-expression `(id-maker a ZIM b ZAM >> c)` isn't actually used in a binding position. Instead the individual ids >> within it are used in binding positions. > > Perhaps I'm misusing the term "binding position". I understand it as "the > place where the identifiers sit so they'll get bound". So x and y are in > binding positions here: > > (define x 42) > > (let ([y 42]) > y) Yes, > And in my sample binding macro: > > (define-syntax-rule (binding-form _topid (_id ...)) > (define (_topid) > (let ([_id '_id] ...) > (displayln (format "~a bound ~a" '_topid _id)) ...))) > > whatever `(id ...)`s are in the second argument will be bound (within `let`) > so the second argument position is impliedly a binding position. Wrong? Each `_id` individually is used in the `let`, but the whole thing, `(_id ...)` is not put in any binding position. That's what I meant. The generic-bind package has a notion of a binding position, and macros can expand within them. So if you were using generic-bind, then each `_id` would be expanded individually after being put in its binding position, but the `(_id ...)` itself would not. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
