loeb.scm

;; will work for any sufficiently lazy functor ;-)
(letrec ((loeb (lambda (stream)
                 (define (%loeb stream)
                   (delay
                     (stream-map (lambda (func)
                                   (func (force (%loeb stream))))
                                 stream)))
                 (force (%loeb stream))))
         (s (stream stream-length
                    stream-car
                    (cut stream-ref <> 3)
                    (cut stream-ref <> 1))))
  (stream->list (loeb s)))