q9

node_modules/alien-signals/cjs/computed.js

@@ -0,0 +1,61 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.Computed = void 0;
+exports.computed = computed;
+const system_js_1 = require("./system.js");
+function computed(getter) {
+    return new Computed(getter);
+}
+class Computed {
+    constructor(getter) {
+        this.getter = getter;
+        this.cachedValue = undefined;
+        // Dependency
+        this.subs = undefined;
+        this.subsTail = undefined;
+        this.linkedTrackId = -1;
+        // Subscriber
+        this.deps = undefined;
+        this.depsTail = undefined;
+        this.trackId = 0;
+        this.dirtyLevel = 3 /* DirtyLevels.Dirty */;
+        this.canPropagate = false;
+    }
+    get() {
+        const dirtyLevel = this.dirtyLevel;
+        if (dirtyLevel === 2 /* DirtyLevels.MaybeDirty */) {
+            system_js_1.Subscriber.resolveMaybeDirty(this);
+            if (this.dirtyLevel === 3 /* DirtyLevels.Dirty */) {
+                this.update();
+            }
+        }
+        else if (dirtyLevel === 3 /* DirtyLevels.Dirty */ || dirtyLevel === 4 /* DirtyLevels.Released */) {
+            this.update();
+        }
+        const activeTrackId = system_js_1.System.activeTrackId;
+        if (activeTrackId !== 0 && this.linkedTrackId !== activeTrackId) {
+            this.linkedTrackId = activeTrackId;
+            system_js_1.Dependency.linkSubscriber(this, system_js_1.System.activeSub);
+        }
+        return this.cachedValue;
+    }
+    update() {
+        const prevSub = system_js_1.Subscriber.startTrackDependencies(this);
+        const oldValue = this.cachedValue;
+        let newValue;
+        try {
+            newValue = this.getter(oldValue);
+        }
+        finally {
+            system_js_1.Subscriber.endTrackDependencies(this, prevSub);
+        }
+        if (oldValue !== newValue) {
+            this.cachedValue = newValue;
+            const subs = this.subs;
+            if (subs !== undefined) {
+                system_js_1.Dependency.propagate(subs);
+            }
+        }
+    }
+}
+exports.Computed = Computed;