how to write a common lisp function that returns multiple values

Question

I'm doing a tut on lisp http://common-lisp.net/language.html#sec-1 and am wondering how would this function be written:

(my-floor 1.3) 
 => 1 0.3

This question appears to be off-topic because it is answered just several paragraphs down in the document linked in the question. — Joshua Taylor
– Joshua Taylor, Commented Jul 18, 2014 at 20:09
I'm a little bit surprised at the downvotes here. its always easy when you have the answer and know where to look. Yes I know its an obvious question but sometimes its the obvious ones that need to be addressed first before any learning can be done. — zcaudate
– zcaudate, Commented Jul 19, 2014 at 4:24

sds · Accepted Answer · 2017-12-19 16:37:22Z

13

(defun foo (x y)
  (values x y (+ x y) (cons x y)))

Try the function:

> (foo 2 pi)
2 ;
3.1415926535897932385L0 ;
5.1415926535897932383L0 ;
(2 . 3.1415926535897932385L0)

Use the returned values with multiple-value-bind:

(multiple-value-bind (a b sum pair) (foo 1 2)
  (list a b sum pair))
==> (1 2 3 (1 . 2))

or (setf values).

answered Jul 18, 2014 at 15:25

sds

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2 Comments

How does one access these values in code? Is that a list of values?

Much appreciated!