[racket] How to test a function which return multiple values?

On Sun, 6 Oct 2013 18:08:36 +0800
Laurent <laurent.orseau at gmail.com> wrote:

> You can use `call-with-values' and wrap it in a helper:
> 
> #lang racket
> (require rackunit)
> 
> (define (call-with-values->list p . args)
>   (call-with-values (λ()(apply p args)) list))
> 
> (define (some-proc x y)
>   (values y x))
> 
> (check-equal? (call-with-values->list some-proc 2 1)
>               (list 1 2))
> 
> 
> (Usually I abbreviate `call-with-values->list' to `cvl'.)
> I wonder why there is not something similar in the main distribution
> though.
> 

Thanks for your reply. Good to see that my solution wasn't totally
stupid. However, your way is far better.

-- 
Manfred


> Laurent
> 
> 
> On Sun, Oct 6, 2013 at 5:51 PM, Manfred Lotz
> <manfred.lotz at arcor.de> wrote:
> 
> > Hi there,
> > Assume a function which returns values. I couldn't find anything in
> > rackunit to test such a function out of the box.
> >
> > Simple example:
> >
> > (define (mval)
> >   (values 1 2 3))
> >
> >
> > Now I like to test it using rackunit. The only idea I have is:
> >
> >   (let-values ([(x y z) (mval)])
> >     (check-equal? (list x y z) (list 1 2 3)))
> >
> > Works fine. However, I can imagine this could be done better and/or
> > easier.
> >
> >
> > --
> > Manfred
> >
> > ____________________
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> >   http://lists.racket-lang.org/users
> >
>