examples/example-0.rkt
#lang racket
;;; Example 0 - Functions as Events

(require (planet williams/simulation/simulation))

;;; (generator n) -> void?
;;;   n : exact-nonnegative-integer?
(define (generator n)
  (for ((i (in-range n)))
    (wait (random-exponential 4.0))
    (schedule #:now (customer i))))

;;; (customer i) -< void?
;;;   i : exact-nonnegative-integer?
(define (customer i)
  (printf "~a: customer ~a enters~n"
          (current-simulation-time) i)
  (work (random-flat 2.0 10.0))
  (printf "~a: customer ~a leaves~n"
          (current-simulation-time) i))

;;; (run-simulation n) -> void?
;;;   n : exact-nonnegative-integer?
(define (run-simulation n)
  (with-new-simulation-environment
   (schedule #:at 0.0 (generator n))
   (start-simulation)))

;;; Run the simulation fot 10 customers.
(run-simulation 10)