43 lines
1.1 KiB
TypeScript
43 lines
1.1 KiB
TypeScript
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// Copyright 2021 Signal Messenger, LLC
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// SPDX-License-Identifier: AGPL-3.0-only
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/* eslint-disable max-classes-per-file */
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/* eslint-disable no-await-in-loop */
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/* eslint-disable no-restricted-syntax */
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export type MaybeAsyncIterable<T> = Iterable<T> | AsyncIterable<T>;
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export function concat<T>(
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iterables: Iterable<MaybeAsyncIterable<T>>
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): AsyncIterable<T> {
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return new ConcatAsyncIterable(iterables);
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}
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class ConcatAsyncIterable<T> implements AsyncIterable<T> {
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constructor(private readonly iterables: Iterable<MaybeAsyncIterable<T>>) {}
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async *[Symbol.asyncIterator](): AsyncIterator<T> {
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for (const iterable of this.iterables) {
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for await (const value of iterable) {
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yield value;
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}
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}
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}
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}
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export function wrapPromise<T>(
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promise: Promise<MaybeAsyncIterable<T>>
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): AsyncIterable<T> {
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return new WrapPromiseAsyncIterable(promise);
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}
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class WrapPromiseAsyncIterable<T> implements AsyncIterable<T> {
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constructor(private readonly promise: Promise<MaybeAsyncIterable<T>>) {}
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async *[Symbol.asyncIterator](): AsyncIterator<T> {
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for await (const value of await this.promise) {
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yield value;
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}
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}
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}
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