# Copyright 2026 DeepMind Technologies Limited.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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"""Utils."""

import itertools

from kauldron.ktyping import Array
import numpy as np


def count_consecutive(values: Array['L']) -> tuple[tuple[int | bool, int], ...]:  # pyrefly: ignore[unknown-name]
  """Counts consecutive identical elements in a list.

  Useful to debug masks with padding.

  Args:
    values: A list of elements.

  Returns:
    A tuple of tuples, where each inner tuple contains the element
    and its consecutive count.
  """
  return tuple(
      (np.asarray(key).item(), len(list(group)))
      for key, group in itertools.groupby(values)
  )