minimart-2014/minimart/ground.rkt

55 lines
1.7 KiB
Racket

#lang racket/base
(require racket/match)
(require racket/list)
(require "core.rkt")
(provide (struct-out event)
run-ground)
(struct event (descriptor values) #:prefab)
(define (event-handler descriptor)
(handle-evt descriptor (lambda vs (send (event descriptor vs)))))
(define (extract-active-events routes)
(filter-map (lambda (r)
(and (route-subscription? r)
(zero? (route-meta-level r))
(zero? (route-level r))
(match (route-pattern r)
[(event descriptor (? wildcard?)) (event-handler descriptor)]
[_ #f])))
routes))
(define idle-handler
(handle-evt (system-idle-evt) (lambda _ #f)))
(define (run-ground . boot-actions)
(let await-interrupt ((inert? #f) (p (spawn-world boot-actions)) (active-events '()))
(define event-list (if inert?
active-events
(cons idle-handler active-events)))
(if (null? event-list)
(begin (log-info "run-ground: Terminating because inert")
(void))
(let ((e (apply sync event-list)))
(match (deliver-event e -2 p)
[#f ;; inert
(await-interrupt #t p active-events)]
[(transition new-state actions)
(let process-actions ((actions (flatten actions)) (active-events active-events))
(match actions
['()
(await-interrupt #f (struct-copy process p [state new-state]) active-events)]
[(cons a actions)
(match a
[(routing-update routes)
(process-actions actions (extract-active-events routes))]
[(quit)
(log-info "run-ground: Terminating by request")
(void)]
[_
(log-warning "run-ground: ignoring useless meta-action ~v" a)
(process-actions actions active-events)])]))])))))