gistfile1.scm

(use gauche.generator)
(use gauche.lazy)

(define-syntax chain
  (syntax-rules ()
    [(_ lis proc ...)
     (let loop ([p (map (lambda (p) 
                          (append `(pa$) p)) 
                        (list `proc ...))]
                [l lis])
       (if (pair? p)
         (loop (cdr p) ((eval (car p) (interaction-environment)) l)) 
         l))]))

(define (tmpgen cnt)
  (generate
    (lambda (yield)
      (let loop ([i 0]) 
        (when (< i cnt)
          (print "Generate: " i)
          (yield i)
          (loop (+ i 1)))))))

(chain (generator->lseq (tmpgen 10))
       (lmap (^x (* x 2))))

(chain '(1 2 3 4 5)
       (map (^x (* x 2)))
       (map (^x (+ x 1))))
;; => (3 5 7 9 11)

(take (chain (lrange 0)
             (lmap (^x (* x 2))))
      10)
;; => (0 2 4 6 8 10 12 14 16 18)