#| -*-Scheme-*-

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This file is part of MIT/GNU Scheme.

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|#

;;;; Multiple Value Support

(declare (usual-integrations))

(define (transmit-values transmitter receiver)
  (transmitter receiver))

(define (multiple-value-list transmitter)
  (transmitter list))

(define (return . values)
  (lambda (receiver)
    (apply receiver values)))

;;; For efficiency:

(define (return-2 v0 v1)
  (lambda (receiver)
    (receiver v0 v1)))

(define (return-3 v0 v1 v2)
  (lambda (receiver)
    (receiver v0 v1 v2)))

(define (return-4 v0 v1 v2 v3)
  (lambda (receiver)
    (receiver v0 v1 v2 v3)))

(define (return-5 v0 v1 v2 v3 v4)
  (lambda (receiver)
    (receiver v0 v1 v2 v3 v4)))

(define (return-6 v0 v1 v2 v3 v4 v5)
  (lambda (receiver)
    (receiver v0 v1 v2 v3 v4 v5)))

(define (list-multiple first . rest)
  (apply call-multiple list first rest))

(define (cons-multiple cars cdrs)
  (call-multiple cons cars cdrs))

(define (call-multiple procedure . transmitters)
  (apply return
	 (apply map
		procedure
		(map multiple-value-list transmitters))))