Re: progv in scheme

[Panicz Maciej Godek <godek.maciek@gmail.com>]

2011/9/13, Andrew Gwozdziewycz <apgwoz@gmail.com>:
>
> Seems likely that you could use `syntax-case' to create a `let` out of
> these:
>
> (define-syntax progv
>   (lambda (stx)
>     (define (create-bindings syms vals)
>       (datum->syntax stx (zip (syntax->datum syms) (syntax->datum vals))))
>     (syntax-case stx ()
>       ((_ symbols values body ...)
>        (with-syntax ((bindings (create-bindings #'symbols #'values)))
>           #'(let bindings
>                (begin body ...)))))))
>
>
>
> ;; usage
> (progv (foo bar baz) (1 2 3)
>    (format (current-output-port) "Values: ~a ~a ~a\n" foo bar baz))
> ;; output: "Values: 1 2 3"

Hey,
thanks for this code, maybe one day I will be able to comprehend it :)
for now, the problem is that I want to bind the variables that are
contained within a list, and that I don't know what's in that list.

So, the following code should work as well:
(let ((s '(foo bar baz))
      (v '(1 2 3)))
  (progv s v
     (+ foo bar baz)))
===> 6

regards
M.