use eventQueue; process Reactions in proper order

2023-05-14 15:39:22 -04:00
parent 26383090ba
commit ad41407ac6
5 changed files with 198 additions and 150 deletions
@@ -3,62 +3,74 @@
  var Machine = function(...states) {
    return { states };
  };
-  var State = function(name, ...ons) {
-    return { name, ons };
+  var State = function(name, ...eventReactionCouplings) {
+    return { name, eventReactionCouplings };
  };
  var On = function(eventName, ...reactions) {
    return { eventName, reactions };
  };
-  var Do = function(fn) {
-    return { type: "Do", fn };
+  var SideEffect = function(fn) {
+    return { type: "SideEffect", fn };
  };
  var Goto = function(targetStateName) {
    return { type: "Goto", targetStateName };
  };
-  var Tick = function(doFunctions) {
-    return { doFunctions };
-  };
  function interpret(machine2, options) {
    let { state, context } = options;
    if (typeof state === "undefined") {
      state = machine2.states[0].name;
    }
-    const interpreter = { machine: machine2, state, context, tickQueues: [] };
-    console.log(interpreter);
+    const interpreter = { machine: machine2, state, context, eventQueue: [], isTransitioning: false };
    send(interpreter, ["entry", null]);
    return interpreter;
  }
  function getState(interpreter) {
    return interpreter.machine.states.find((state) => state.name === interpreter.state);
  }
-  function getOns(state, event) {
-    return state.ons.filter((on) => on.eventName === event[0]);
-  }
-  function noop() {
+  function getMatchingEventReactionCouplings(state, event) {
+    return state.eventReactionCouplings.filter((eventReactionCoupling) => eventReactionCoupling.eventName === event[0]);
  }
  function send(interpreter, event) {
-    const state = getState(interpreter);
-    const onsTree = getOns(state, event);
-    const reactions = onsTree.map((on) => on.reactions).flat();
-    const indexOfFirstGoto = reactions.findIndex((reaction) => reaction.type === "Goto");
-    const indexOfFinalReaction = indexOfFirstGoto === -1 ? reactions.length - 1 : indexOfFirstGoto;
-    const reactionsUntilFirstGoto = reactions.slice(0, indexOfFinalReaction + 1);
-    const functionsToRunInTick = reactionsUntilFirstGoto.map((reaction) => {
-      if (reaction.type === "Do") {
-        return reaction.fn;
+    interpreter.eventQueue.push(event);
+    if (interpreter.isTransitioning === false) {
+      interpreter.isTransitioning = true;
+      while (interpreter.eventQueue.length > 0) {
+        processNextEvent(interpreter);
+      }
+      interpreter.isTransitioning = false;
+    }
+  }
+  function processNextEvent(interpreter) {
+    const nextEvent = interpreter.eventQueue.shift();
+    if (typeof nextEvent !== "undefined") {
+      const state = getState(interpreter);
+      const eventReactionCouplings = getMatchingEventReactionCouplings(state, nextEvent);
+      const reactions = eventReactionCouplings.map((eventReactionCoupling) => eventReactionCoupling.reactions).flat();
+      const { sideEffects, contextMutations, goto_ } = categorizeReactions(reactions);
+      sideEffects.forEach((sideEffect) => {
+        sideEffect.fn(interpreter.context, nextEvent, interpreter);
+      });
+      contextMutations.forEach((contextMutation) => {
+        interpreter.context = contextMutation.fn(interpreter.context, nextEvent, interpreter);
+      });
+      if (goto_ !== null) {
+        interpreter.state = goto_.targetStateName;
+        send(interpreter, ["entry", null]);
+      }
+    }
+  }
+  function categorizeReactions(reactions) {
+    let sideEffects = [], contextMutations = [], goto_ = null;
+    reactions.forEach((reaction) => {
+      if (reaction.type === "SideEffect") {
+        sideEffects.push(reaction);
+      } else if (reaction.type === "ContextMutation") {
+        contextMutations.push(reaction);
      } else if (reaction.type === "Goto") {
-        return (ctx, e, self) => {
-          self.state = reaction.targetStateName;
-          send(self, ["entry", e]);
-        };
-      } else {
-        return noop;
+        goto_ = reaction;
      }
    });
-    const tick = Tick(functionsToRunInTick);
-    tick.doFunctions.forEach((fn) => {
-      fn(interpreter.context, event, interpreter);
-    });
+    return { sideEffects, contextMutations, goto_ };
  }

  // src/tests/00-basic.ts
@@ -75,8 +87,8 @@
      "green",
      On(
        "entry",
-        Do(beginTimer),
-        Do(log)
+        SideEffect(beginTimer),
+        SideEffect(log)
      ),
      On(
        "timer-finished",
@@ -87,8 +99,8 @@
      "yellow",
      On(
        "entry",
-        Do(beginTimer),
-        Do(log)
+        SideEffect(beginTimer),
+        SideEffect(log)
      ),
      On(
        "timer-finished",
@@ -99,8 +111,8 @@
      "red",
      On(
        "entry",
-        Do(beginTimer),
-        Do(log)
+        SideEffect(beginTimer),
+        SideEffect(log)
      ),
      On(
        "timer-finished",
@@ -3,62 +3,74 @@
  var Machine = function(...states) {
    return { states };
  };
-  var State = function(name, ...ons) {
-    return { name, ons };
+  var State = function(name, ...eventReactionCouplings) {
+    return { name, eventReactionCouplings };
  };
  var On = function(eventName, ...reactions) {
    return { eventName, reactions };
  };
-  var Do = function(fn) {
-    return { type: "Do", fn };
+  var SideEffect = function(fn) {
+    return { type: "SideEffect", fn };
  };
  var Goto = function(targetStateName) {
    return { type: "Goto", targetStateName };
  };
-  var Tick = function(doFunctions) {
-    return { doFunctions };
-  };
  function interpret(machine, options) {
    let { state, context } = options;
    if (typeof state === "undefined") {
      state = machine.states[0].name;
    }
-    const interpreter = { machine, state, context, tickQueues: [] };
-    console.log(interpreter);
+    const interpreter = { machine, state, context, eventQueue: [], isTransitioning: false };
    send(interpreter, ["entry", null]);
    return interpreter;
  }
  function getState(interpreter) {
    return interpreter.machine.states.find((state) => state.name === interpreter.state);
  }
-  function getOns(state, event) {
-    return state.ons.filter((on) => on.eventName === event[0]);
-  }
-  function noop() {
+  function getMatchingEventReactionCouplings(state, event) {
+    return state.eventReactionCouplings.filter((eventReactionCoupling) => eventReactionCoupling.eventName === event[0]);
  }
  function send(interpreter, event) {
-    const state = getState(interpreter);
-    const onsTree = getOns(state, event);
-    const reactions = onsTree.map((on) => on.reactions).flat();
-    const indexOfFirstGoto = reactions.findIndex((reaction) => reaction.type === "Goto");
-    const indexOfFinalReaction = indexOfFirstGoto === -1 ? reactions.length - 1 : indexOfFirstGoto;
-    const reactionsUntilFirstGoto = reactions.slice(0, indexOfFinalReaction + 1);
-    const functionsToRunInTick = reactionsUntilFirstGoto.map((reaction) => {
-      if (reaction.type === "Do") {
-        return reaction.fn;
+    interpreter.eventQueue.push(event);
+    if (interpreter.isTransitioning === false) {
+      interpreter.isTransitioning = true;
+      while (interpreter.eventQueue.length > 0) {
+        processNextEvent(interpreter);
+      }
+      interpreter.isTransitioning = false;
+    }
+  }
+  function processNextEvent(interpreter) {
+    const nextEvent = interpreter.eventQueue.shift();
+    if (typeof nextEvent !== "undefined") {
+      const state = getState(interpreter);
+      const eventReactionCouplings = getMatchingEventReactionCouplings(state, nextEvent);
+      const reactions = eventReactionCouplings.map((eventReactionCoupling) => eventReactionCoupling.reactions).flat();
+      const { sideEffects, contextMutations, goto_ } = categorizeReactions(reactions);
+      sideEffects.forEach((sideEffect) => {
+        sideEffect.fn(interpreter.context, nextEvent, interpreter);
+      });
+      contextMutations.forEach((contextMutation) => {
+        interpreter.context = contextMutation.fn(interpreter.context, nextEvent, interpreter);
+      });
+      if (goto_ !== null) {
+        interpreter.state = goto_.targetStateName;
+        send(interpreter, ["entry", null]);
+      }
+    }
+  }
+  function categorizeReactions(reactions) {
+    let sideEffects = [], contextMutations = [], goto_ = null;
+    reactions.forEach((reaction) => {
+      if (reaction.type === "SideEffect") {
+        sideEffects.push(reaction);
+      } else if (reaction.type === "ContextMutation") {
+        contextMutations.push(reaction);
      } else if (reaction.type === "Goto") {
-        return (ctx, e, self) => {
-          self.state = reaction.targetStateName;
-          send(self, ["entry", e]);
-        };
-      } else {
-        return noop;
+        goto_ = reaction;
      }
    });
-    const tick = Tick(functionsToRunInTick);
-    tick.doFunctions.forEach((fn) => {
-      fn(interpreter.context, event, interpreter);
-    });
+    return { sideEffects, contextMutations, goto_ };
  }

  // src/tests/01-ping-pong.ts
@@ -85,11 +97,11 @@
      "idle",
      On(
        "entry",
-        Do(log)
+        SideEffect(log)
      ),
      On(
        "server-created",
-        Do((_ctx, [_eventName, serverActor2], self) => {
+        SideEffect((_ctx, [_eventName, serverActor2], self) => {
          self.context.serverActor = serverActor2;
        }),
        Goto("making-request")
@@ -99,8 +111,8 @@
      "making-request",
      On(
        "entry",
-        Do(log),
-        Do(makeRequest),
+        SideEffect(log),
+        SideEffect(makeRequest),
        Goto("awaiting-response")
      )
    ),
@@ -108,11 +120,11 @@
      "awaiting-response",
      On(
        "entry",
-        Do(log)
+        SideEffect(log)
      ),
      On(
        "received-response",
-        Do(log),
+        SideEffect(log),
        Goto("making-request")
      )
    )
@@ -122,11 +134,11 @@
      "awaiting-request",
      On(
        "entry",
-        Do(log)
+        SideEffect(log)
      ),
      On(
        "received-request",
-        Do((_ctx, [_eventName, clientActor2], self) => {
+        SideEffect((_ctx, [_eventName, clientActor2], self) => {
          self.context.clientActor = clientActor2;
        }),
        Goto("sending-response")
@@ -136,12 +148,12 @@
      "sending-response",
      On(
        "entry",
-        Do(log),
-        Do(startTimer)
+        SideEffect(log),
+        SideEffect(startTimer)
      ),
      On(
        "timer-finished",
-        Do(sendResponse),
+        SideEffect(sendResponse),
        Goto("awaiting-request")
      )
    )