text: # Copyright 2020 The Cirq Developers
  #
  # 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
  #
  #     https://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,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  """Tools and methods for primitives used in quantum information science."""
  
  from cirq.qis.channels import (
      choi_to_kraus,
      choi_to_superoperator,
      kraus_to_choi,
      kraus_to_superoperator,
      operation_to_choi,
      operation_to_superoperator,
      superoperator_to_choi,
      superoperator_to_kraus,
  )
  
  from cirq.qis.clifford_tableau import CliffordTableau
  
  from cirq.qis.measures import (
      entanglement_fidelity,
      fidelity,
      von_neumann_entropy,
  )
  
  from cirq.qis.states import (
      bloch_vector_from_state_vector,
      density_matrix,
      density_matrix_from_state_vector,
      dirac_notation,
      eye_tensor,
      infer_qid_shape,
      one_hot,
      QUANTUM_STATE_LIKE,
      QuantumState,
      quantum_state,
      STATE_VECTOR_LIKE,
      to_valid_density_matrix,
      to_valid_state_vector,
      validate_density_matrix,
      validate_indices,
      validate_qid_shape,
      validate_normalized_state_vector,
  )
  