First commit.

Signed-off-by: Chen Xiao <abigwc@gmail.com>

client/node_modules/langium/lib/utils/promise-utils.d.ts

@@ -0,0 +1,54 @@
+/******************************************************************************
+ * Copyright 2021 TypeFox GmbH
+ * This program and the accompanying materials are made available under the
+ * terms of the MIT License, which is available in the project root.
+ ******************************************************************************/
+import { CancellationToken, type AbstractCancellationTokenSource } from '../utils/cancellation.js';
+export type MaybePromise<T> = T | Promise<T>;
+/**
+ * Delays the execution of the current code to the next tick of the event loop.
+ * Don't call this method directly in a tight loop to prevent too many promises from being created.
+ */
+export declare function delayNextTick(): Promise<void>;
+/**
+ * Reset the global interruption period and create a cancellation token source.
+ */
+export declare function startCancelableOperation(): AbstractCancellationTokenSource;
+/**
+ * Change the period duration for `interruptAndCheck` to the given number of milliseconds.
+ * The default value is 10ms.
+ */
+export declare function setInterruptionPeriod(period: number): void;
+/**
+ * This symbol may be thrown in an asynchronous context by any Langium service that receives
+ * a `CancellationToken`. This means that the promise returned by such a service is rejected with
+ * this symbol as rejection reason.
+ */
+export declare const OperationCancelled: unique symbol;
+/**
+ * Use this in a `catch` block to check whether the thrown object indicates that the operation
+ * has been cancelled.
+ */
+export declare function isOperationCancelled(err: unknown): err is typeof OperationCancelled;
+/**
+ * This function does two things:
+ *  1. Check the elapsed time since the last call to this function or to `startCancelableOperation`. If the predefined
+ *     period (configured with `setInterruptionPeriod`) is exceeded, execution is delayed with `delayNextTick`.
+ *  2. If the predefined period is not met yet or execution is resumed after an interruption, the given cancellation
+ *     token is checked, and if cancellation is requested, `OperationCanceled` is thrown.
+ *
+ * All services in Langium that receive a `CancellationToken` may potentially call this function, so the
+ * `CancellationToken` must be caught (with an `async` try-catch block or a `catch` callback attached to
+ * the promise) to avoid that event being exposed as an error.
+ */
+export declare function interruptAndCheck(token: CancellationToken): Promise<void>;
+/**
+ * Simple implementation of the deferred pattern.
+ * An object that exposes a promise and functions to resolve and reject it.
+ */
+export declare class Deferred<T = void> {
+    resolve: (value: T) => this;
+    reject: (err?: unknown) => this;
+    promise: Promise<T>;
+}
+//# sourceMappingURL=promise-utils.d.ts.map