values produces multiple return values. It can only be used in
a binding or returning position.
values is also a pattern in let
Syntax
;; produce multiple values
(values ⟨expr⟩ ...)
;; destructure multiple values into variable bindings
(let (values ⟨var⟩...) = ⟨expr⟩)
;; or
(let (((values ⟨var⟩...) ⟨expr⟩)
...)
...)
Semantics
- The number and types of returned values must match the surrounding expected type.
- Multiple values can be destructured with
let (values ...) = .... - In a
forallbinder,Valuesinstead annotates a type variable representing an entire result sequence:(forall ((:r Values)) (Void -> :r) -> :r).
Example
(define (sum-and-product x y)
(values (+ x y) (* x y)))