From: Philippe de Rochambeau <phiroc@free.fr>
To: kawa mailing list <kawa@sourceware.org>
Subject: Re: values
Date: Sun, 26 Sep 2021 18:19:51 +0200 [thread overview]
Message-ID: <5EC715FC-1C6F-4DF5-9AAB-B7B513E08C2E@free.fr> (raw)
In-Reply-To: <11BE00BD-0D11-4F6A-9314-A7C4FFEF33D6@free.fr>
… and here’s a solution with a local halve procedure:
(let* ((n0 39)
(halve (lambda (n)
(div-and-mod n 2))))
(let-values (((a b) (halve n0)))
(display a)))
>
> I found a solution:
>
> (define (halve n)
> (let-values (((a b) (div-and-mod n 2)))
> a))
>
>>
>>
>> Hi Arvydas,
>> thanks you for your feedback.
>> I’ve managed to retrieve the 19 from div-and-mod using let-values.
>> Now, how do I add a procedure called « (halve n) » which when passed a value such as 39, returns 19?
>> Many thanks.
>> Philippe
>>
>> (display (let-values (((a b) (div-and-mod 39 2)))
>> a))
>>
>>
>>
>>> Le 26 sept. 2021 à 14:33, Arvydas Silanskas <nma.arvydas.silanskas@gmail.com <mailto:nma.arvydas.silanskas@gmail.com>> a écrit :
>>>
>>> Hi
>>>
>>> generally you would use constructs like define-values or let-values to declare multiple variables which will be bound to the received multiple values. There is also a more primitive call-with-values construct for piping those values as arguments to some procedure. To get a list, you could use `(call-with-values (lambda () (values 1 3)) list)`.
>>>
>>> Arvydas
>>>
>>>
>>> Hello,
>>> how do you retrieve the first item returned by the values procedure?
>>> I’ve tried (first (values 1 3)), but to no avail, because values doesn’t return a list.
>>> Many thanks.
>>> Philippe
prev parent reply other threads:[~2021-09-26 16:19 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-26 11:56 values Philippe de Rochambeau
2021-09-26 12:33 ` values Arvydas Silanskas
2021-09-26 13:25 ` values Philippe de Rochambeau
2021-09-26 13:37 ` values Philippe de Rochambeau
2021-09-26 16:19 ` Philippe de Rochambeau [this message]
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