Method next

tfjs-data/src/iterators/lazy_iterator.ts:544–551

()

  }

  async next(): Promise<IteratorResult<T>> {
    // This sets this.lastRead to a new Promise right away, as opposed to
    // saying `await this.lastRead; this.lastRead = this.serialNext();` which
    // would not work because this.nextRead would be updated only after the
    // promise resolves.
    this.lastRead = this.lastRead.then(() => this.serialNext());
    return this.lastRead;
  }

  private async serialNext(): Promise<IteratorResult<T>> {
    return this.upstream.next();