(values . values)
Returns multiple values.
(call-with-values producer ... consumer)
Invoke the producers and pass all values returned by them in order to consumer. This extends R5RS by allowing more than one producer. Equivalent to Common Lisp's multiple-value-call. See #87.
(let-values ((lambda-list expression) ...) body)
Each lambda-list should be a formal arguments list as for a lambda expression, cf. section 4.1.4 of the R5RS.
The expressions are evaluated in the current environment, the variables of the lambda-list are bound to fresh locations, the return values of the expressions are stored in the variables, the body is evaluated in the extended environment, and the values of the last expression of body are returned. The body is a tail body, cf. section 3.5 of the R5RS.
The matching of each lambda-list to values is done in the same way as in a lambda expression, and it is an error for an expression to return a number of values that does not match its corresponding lambda-list. (From SRFI 11.)
(let-values (((a b . c) (values 1 2 3 4))) (list a b c)) --> (1 2 (3 4)) (let ((a 'a) (b 'b) (x 'x) (y 'y)) (let-values (((a b) (values x y)) ((x y) (values a b))) (list a b x y))) --> (x y a b)(let*-values ((lambda-list expression) ...) body)
let*-values is similar to let-values, but the bindings are performed sequentially from left to right, and the region of a binding indicated by (<formals> <expression>) is the part of the let*-values expression to the right of the binding. Thus the second binding is done in an environment in which the first binding is visible, and so on. (From SRFI 11.)
(let ((a 'a) (b 'b) (x 'x) (y 'y)) (let*-values (((a b) (values x y)) ((x y) (values a b))) (list a b x y))) --> (x y x y)(set!-values (lambda-list) expression)
Assigns the values returned by expression to the variables in lambda-list. Returns undefined values. Equivalent to Common Lisp's multiple-variable-setq.
(define-values (var ...) expr)
Defines the vars and binds them to the values of expr.