/// <reference lib="es2015.symbol" />

/// <reference lib="es2015.iterable" />

interface SymbolConstructor {

/**

* A method that returns the default async iterator for an object. Called by the semantics of

* the for-await-of statement.

*/

readonly asyncIterator: unique symbol;

}

interface AsyncIterator<T, TReturn = any, TNext = undefined> {

// NOTE: 'next' is defined using a tuple to ensure we report the correct assignability errors in all places.

next(...args: [] | [TNext]): Promise<IteratorResult<T, TReturn>>;

return?(value?: TReturn | PromiseLike<TReturn>): Promise<IteratorResult<T, TReturn>>;

throw?(e?: any): Promise<IteratorResult<T, TReturn>>;

}

interface AsyncIterable<T> {

[Symbol.asyncIterator](): AsyncIterator<T>;

}

interface AsyncIterableIterator<T> extends AsyncIterator<T> {

[Symbol.asyncIterator](): AsyncIterableIterator<T>;

}