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node_modules/lit-html/development/directives/private-async-helpers.js

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+/**
+ * @license
+ * Copyright 2021 Google LLC
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+// Note, this module is not included in package exports so that it's private to
+// our first-party directives. If it ends up being useful, we can open it up and
+// export it.
+/**
+ * Helper to iterate an AsyncIterable in its own closure.
+ * @param iterable The iterable to iterate
+ * @param callback The callback to call for each value. If the callback returns
+ * `false`, the loop will be broken.
+ */
+export const forAwaitOf = async (iterable, callback) => {
+    for await (const v of iterable) {
+        if ((await callback(v)) === false) {
+            return;
+        }
+    }
+};
+/**
+ * Holds a reference to an instance that can be disconnected and reconnected,
+ * so that a closure over the ref (e.g. in a then function to a promise) does
+ * not strongly hold a ref to the instance. Approximates a WeakRef but must
+ * be manually connected & disconnected to the backing instance.
+ */
+export class PseudoWeakRef {
+    constructor(ref) {
+        this._ref = ref;
+    }
+    /**
+     * Disassociates the ref with the backing instance.
+     */
+    disconnect() {
+        this._ref = undefined;
+    }
+    /**
+     * Reassociates the ref with the backing instance.
+     */
+    reconnect(ref) {
+        this._ref = ref;
+    }
+    /**
+     * Retrieves the backing instance (will be undefined when disconnected)
+     */
+    deref() {
+        return this._ref;
+    }
+}
+/**
+ * A helper to pause and resume waiting on a condition in an async function
+ */
+export class Pauser {
+    constructor() {
+        this._promise = undefined;
+        this._resolve = undefined;
+    }
+    /**
+     * When paused, returns a promise to be awaited; when unpaused, returns
+     * undefined. Note that in the microtask between the pauser being resumed
+     * an an await of this promise resolving, the pauser could be paused again,
+     * hence callers should check the promise in a loop when awaiting.
+     * @returns A promise to be awaited when paused or undefined
+     */
+    get() {
+        return this._promise;
+    }
+    /**
+     * Creates a promise to be awaited
+     */
+    pause() {
+        var _a;
+        (_a = this._promise) !== null && _a !== void 0 ? _a : (this._promise = new Promise((resolve) => (this._resolve = resolve)));
+    }
+    /**
+     * Resolves the promise which may be awaited
+     */
+    resume() {
+        var _a;
+        (_a = this._resolve) === null || _a === void 0 ? void 0 : _a.call(this);
+        this._promise = this._resolve = undefined;
+    }
+}
+//# sourceMappingURL=private-async-helpers.js.map