Stefan,
amb is a macro that chooses among the results of evaluating the expressions it
is provided, so
(amb *someList*)
evaluates *someList*, resulting in a list, and chooses that. You could define
a function
(define (amb-list list)
(if (null? list)
(amb)
(amb (car list)
(amb-list (cdr list)))))
It's also possible that the amb library provides such a function, which may be
implemented more efficiently; I don't know which amb library you're using, so I
can't help you there.
Note that the simple solution of using
(apply amb *someList*)
will fail, since amb is a macro, not an ordinary function. Good luck!
Will
On Sep 12, 2010, at 9:16 AM, Stefan Busch wrote:
> Hello racket community,
>
> though it may be impolite to enter the community with a wish,
> I'd like to ask for help with the following problem:
>
>
> I want a and b to "run through" all elements of two given lists,
> and then to catch the combinations that fullfill a desired condition with
> an "amb-assert" statement.
>
> If I try this in the following way
>
> (amb-collect
> (let ((a (amb *someList*)
> (b (amb *someDifferentList*))...............
>
> it turns out that not the list elemets are considered possible values for a
> or b,
> but the lists themselves are treated as the only possible value.
>
> In all examples I could find for the uage of "amb-collect" the values to run
> through were
> recited, but in my case these are quite many, so would be grateful for a
> handier solution.
>
> thanks,
> Stefan
>
>
>
>
>
>
>
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