text: # Copyright (c) 2021, NVIDIA CORPORATION & AFFILIATES.  All rights reserved.
  #
  # 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,
  # 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.
  
  from nemo_text_processing.text_normalization.en.graph_utils import NEMO_NOT_QUOTE, GraphFst
  
  try:
      import pynini
      from pynini.lib import pynutil
  
      PYNINI_AVAILABLE = True
  except (ModuleNotFoundError, ImportError):
      PYNINI_AVAILABLE = False
  
  
  class CardinalFst(GraphFst):
      """
      Finite state transducer for verbalizing cardinals
          e.g. cardinal { integer: "zwei" } -> "zwei"
  
      Args:
          deterministic: if True will provide a single transduction option,
              for False multiple transduction are generated (used for audio-based normalization)
      """
  
      def __init__(self, deterministic: bool = True):
          super().__init__(name="cardinal", kind="verbalize", deterministic=deterministic)
          optional_sign = pynini.closure(pynini.cross("negative: \"true\" ", "minus "), 0, 1)
          self.optional_sign = optional_sign
          if deterministic:
              integer = pynini.closure(NEMO_NOT_QUOTE, 1)
          else:
              integer = (
                  pynini.closure(NEMO_NOT_QUOTE)
                  + pynini.closure(pynini.cross("hundert ", "hundert und "), 0, 1)
                  + pynini.closure(NEMO_NOT_QUOTE)
              )
  
          self.integer = pynutil.delete(" \"") + integer + pynutil.delete("\"")
  
          integer = pynutil.delete("integer:") + self.integer
          self.numbers = integer
          graph = optional_sign + self.numbers
          delete_tokens = self.delete_tokens(graph)
          self.fst = delete_tokens.optimize()
  