Method next

tfjs-data/src/iterators/lazy_iterator.ts:710–733

()

  }

  async next(): Promise<IteratorResult<O>> {
    const item = await this.upstream.next();
    if (item.done) {
      return {value: null, done: true};
    }
    const inputTensors = tf.tensor_util.getTensorsInContainer(item.value as {});
    // Careful: the transform may mutate the item in place.
    // That's why we have to remember the input Tensors above, and then
    // below dispose only those that were not passed through to the output.
    // Note too that the transform function is responsible for tidying
    // any intermediate Tensors.  Here we are concerned only about the
    // inputs.
    const mapped = this.transform(item.value);
    const outputTensors = tf.tensor_util.getTensorsInContainer(mapped as {});

    // TODO(soergel) faster intersection
    // TODO(soergel) move to tf.disposeExcept(in, out)?
    for (const t of inputTensors) {
      if (!tf.tensor_util.isTensorInList(t, outputTensors)) {
        t.dispose();
      }
    }
    return {value: mapped, done: false};
  }
}

class ErrorHandlingLazyIterator<T> extends LazyIterator<T> {