macro almost there :-)

given (define-type point x y z)

if at run time, I have the symbol "point", is there anyway that I can make that will return me the name of the fields, i.e. '(x y z)? I'd rather have this than all functions that start with point-* since I also define some of them myself, like point-+ point-scale, ...

Thanks!

On Mon, Jun 1, 2009 at 9:45 PM, David Rush <kumoyuki@gmail.com> wrote:
2009/6/2 lowly coder <lowlycoder@huoyanjinjing.com>:
> are there any amcros that play well with destructuring bind of define-type's
> ? I just want to check to see if there's a pre-existing solution before
> re-inventing my own.
>
> I find myself writing way too much code of the form:
>
> (define-type foo a b)
> (define-type bar c d)
>
> (lambda (x)
>   (let ((c (bar-c x) (d (bar-d x)))
>     (let ((a (foo-a a) (b (foo-b b)) ...

This is the kind of thing where macros get over-used

(define (with-foo f body) (body (foo-a f) (foo-b f)))

david
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