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| -rw-r--r-- | 2d/time.scm | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/2d/time.scm b/2d/time.scm new file mode 100644 index 0000000..b4c8c07 --- /dev/null +++ b/2d/time.scm @@ -0,0 +1,49 @@ +;;; guile-2d +;;; Copyright (C) 2013 David Thompson <dthompson2@worcester.edu> +;;; +;;; Guile-2d is free software: you can redistribute it and/or modify it +;;; under the terms of the GNU Lesser General Public License as +;;; published by the Free Software Foundation, either version 3 of the +;;; License, or (at your option) any later version. +;;; +;;; Guile-2d is distributed in the hope that it will be useful, but +;;; WITHOUT ANY WARRANTY; without even the implied warranty of +;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +;;; Lesser General Public License for more details. +;;; +;;; You should have received a copy of the GNU Lesser General Public +;;; License along with this program. If not, see +;;; <http://www.gnu.org/licenses/>. + +;;; Commentary: +;; +;; Time-based signals. +;; +;;; Code: + +(define-module (2d time) + #:use-module (2d agenda) + #:use-module (2d signals) + #:export (time-every + time-interval + time-delay)) + +(define (time-interval ticks) + "Create a new signal that sets its value to #t every TICKS agenda +updates." + (let ((signal (make-signal #:init #t))) + (agenda-schedule-interval + (lambda () + (signal-set! signal #t)) ticks) + signal)) + +(define (time-every) + "Create a new signal that sets its value to #t every agenda update." + (time-interval 1)) + +(define (time-delay ticks signal) + (make-signal + #:filter (lambda (value old from) + (wait ticks) + #t) + #:connectors (list signal))) |