async.scm

(use gauche.threads)
(use data.queue)

(define *queue* (make-mtqueue))

(define (query)
  (let ((th (make-thread
             (^[]
               (let loop ((n 5))
                 (if (> n 0)
                     (begin
                       (thread-sleep! 1)
                       (enqueue/wait! *queue* (^[] (on-data n)))
                       (loop (- n 1)))
                     (begin
                       (enqueue/wait! *queue* on-end)
                       (enqueue/wait! *queue* 'done))))))))
    (thread-start! th)
    th))

(define *sum* 0)

(define (on-data x)
  (set! *sum* (+ *sum* x))
  (print #"Data received ~x"))

(define (on-end)
  (print (* *sum* *sum*))
  (print "End"))

(query)

(let loop ((task (dequeue/wait! *queue*)))
  (unless (eq? task 'done)
    (task)
    (loop (dequeue/wait! *queue*))))

docker-compose.yml

version: '3'
services:
  gosh:
    image: practicalscheme/gauche
    volumes:
      - .:/work
    working_dir: /work

https://gist.github.com/torus/8ce22c67e6ae93286d92a742f481afba/90f62668e5d99bd33794bc5b182de816827883de
オリジナルのコード。

query は非同期に応答を返す何かのシミュレーション。
on-data と on-end はデータを受け取った時に呼び出されるハンドラ。

query-cont が継続を使ったラッパー。