9.1 Multiple Values

See Multiple Return Values for general information about multiple result values. In addition to call-with-values (described in this section), the let-values, let*-values, letrec-values, and define-values forms (among others) create continuations that receive multiple values.

(values v ...) → any

v : any/c

Returns the given vs. That is, values returns as provided arguments.

Examples:
> (values 1)
1
> (values 1 2 3)
1
2
3
> (values)

(call-with-values generator receiver) → any

generator : (-> any)

receiver : procedure?

Calls generator, and passes the values that generator produces as arguments to receiver. Thus, call-with-values creates a continuation that accepts any number of values that receiver can accept. The receiver procedure is called in tail position with respect to the call-with-values call.

Examples:

> (call-with-values (lambda () (values 1 2)) +)

3

> (call-with-values (lambda () 1) (lambda (x y) (+ x y)))

#<procedure>: expects 2 arguments, given 1: 1