+(define* (make-time-segment time #:optional (queue (make-q)))
+ (make-time-segment-intern time queue))
+
+(define (time-< time1 time2)
+ (cond ((< (car time1)
+ (car time2))
+ #t)
+ ((and (= (car time1)
+ (car time2))
+ (< (cdr time1)
+ (cdr time2)))
+ #t)
+ (else #f)))
+
+(define (time-= time1 time2)
+ (and (= (car time1) (car time2))
+ (= (cdr time1) (cdr time2))))
+
+(define (make-schedule)
+ '())
+
+(define (schedule-add! time proc schedule)
+ (let ((time (time-segment-right-format time)))
+ (define (belongs-before? segments)
+ (or (null? segments)
+ (error))
+ )
+
+ ;; Find and add a schedule segment
+ (error)))
+
+(define (schedule-empty? schedule)
+ (eq? schedule '()))
+
+
+\f
+;;; Port handling
+;;; =============
+
+(define (make-port-mapping)
+ (make-hash-table))
+
+(define* (port-mapping-set! port-mapping port #:optional read write except)
+ "Sets port-mapping for reader / writer / exception handlers"
+ (if (not (or read write except))
+ (throw 'no-handlers-given "No handlers given for port" port))
+ (hashq-set! port-mapping port
+ `#(,read ,write ,except)))
+
+(define (port-mapping-remove! port-mapping port)
+ (hashq-remove! port-mapping port))
+
+;; TODO: This is O(n), I'm pretty sure :\
+;; ... it might be worthwhile for us to have a
+;; port-mapping record that keeps a count of how many
+;; handlers (maybe via a promise?)
+(define (port-mapping-empty? port-mapping)
+ "Is this port mapping empty?"
+ (eq? (hash-count (const #t) port-mapping) 0))
+
+(define (port-mapping-non-empty? port-mapping)
+ "Whether this port-mapping contains any elements"
+ (not (port-mapping-empty? port-mapping)))
+
+
+\f
+;;; Execution of agenda, and current agenda
+;;; =======================================