eschulte/propagator.clj

## 40 changes: 40 additions & 0 deletions propagator.clj
@@ -0,0 +1,40 @@

    (ns
(ns

        #^{:author "Eric Schulte",
    #^{:author "Eric Schulte",

           :license "GPLV3",
       :license "GPLV3",

           :doc "Simple concurrent propagator system."}
       :doc "Simple concurrent propagator system."}

      propagator
  propagator

      (:use clojure.contrib.repl-utils clojure.contrib.math))
  (:use clojure.contrib.repl-utils clojure.contrib.math))


    (defmacro cell "Define a new cell."
(defmacro cell "Define a new cell."

      [name state]
  [name state]

      `(def ~name (agent ~state)))
  `(def ~name (agent ~state)))


    (defn set-cell "Set the value of a cell" [cell value]
(defn set-cell "Set the value of a cell" [cell value]

      (send cell (fn [_] value)))
  (send cell (fn [_] value)))


    (defmacro propagator "Define a new propagator."
(defmacro propagator "Define a new propagator."

      [name in-cells out-cells & body]
  [name in-cells out-cells & body]

      `(do
  `(do

         (defn ~(with-meta name
     (defn ~(with-meta name

                  (assoc (meta name)
              (assoc (meta name)

                    :in-cells in-cells :out-cells out-cells))
                :in-cells in-cells :out-cells out-cells))

           ~in-cells ~@body)
       ~in-cells ~@body)

         (doseq [cell# ~in-cells] (add-neighbor cell# ~name))
     (doseq [cell# ~in-cells] (add-neighbor cell# ~name))

         ~name))
     ~name))


    (defmacro run-propagator
(defmacro run-propagator

      "Run a propagator, first collect the most recent values from all
  "Run a propagator, first collect the most recent values from all

    cells associated with the propagator, then evaluate."
cells associated with the propagator, then evaluate."

      [propagator]
  [propagator]

      `(let [results# (apply ~propagator (map deref (:in-cells ^#'~propagator)))]
  `(let [results# (apply ~propagator (map deref (:in-cells ^#'~propagator)))]

         (doseq [cell# (:out-cells ^#'~propagator)]
     (doseq [cell# (:out-cells ^#'~propagator)]

           (when (not (= @cell# results#))
       (when (not (= @cell# results#))

             (send cell# (fn [_#] results#))))
         (send cell# (fn [_#] results#))))

         results#))
     results#))


    (defmacro add-neighbor "Add a neighbor to the given cell."
(defmacro add-neighbor "Add a neighbor to the given cell."

      [cell neighbor]
  [cell neighbor]

      `(add-watcher
  `(add-watcher

        ~cell :send
    ~cell :send

        (agent nil :validator (fn [_#] (do (future (run-propagator ~neighbor)) true)))
    (agent nil :validator (fn [_#] (do (future (run-propagator ~neighbor)) true)))

        (fn [_# _#])))
    (fn [_# _#])))