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Accessor VALUES

Syntax

  • values &rest objectobject*
  • (setf (values &rest place) new-values)

Arguments and Values

Description

values returns the objects as multiple values.

setf of values is used to store the multiple values new-values into the places. see section {\secref\SETFofVALUES}.

Examples

(values)

<no values>

(values 1)

1

(values 1 2)

1 2

(values 1 2 3)

1 2 3

(values (values 1 2 3) 4 5)

1 4 5

(defun polar (x y) (values (sqrt (+ (* x x) (* y y))) (atan y x)))

POLAR

(multiple-value-bind (r theta) (polar 3.0 4.0) (vector r theta))

#(5.0 0.927295)

Sometimes it is desirable to indicate explicitly that a function returns exactly one value. For example, the function

(defun foo (x y) (floor (+ x y) y))

FOO

returns two values because floor returns two values. It may be that the second value makes no sense, or that for efficiency reasons it is desired not to compute the second value. values is the standard idiom for indicating that only one value is to be returned:

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

FOO

This works because values returns exactly one value for each of args; as for any function call, if any of args produces more than one value, all but the first are discarded.

Affected By

None.

Exceptional Situations

None.

See Also

Notes

Since values is a function, not a macro or special form, it receives as arguments only the primary values of its argument forms.

\issue{SETF-OF-VALUES:ADD} \issue{SETF-OF-VALUES:ADD} \issue{SETF-OF-VALUES:ADD}