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.
  
  import pynini
  from nemo_text_processing.text_normalization.en.graph_utils import NEMO_NOT_SPACE, GraphFst
  from pynini.lib import pynutil
  
  
  class WordFst(GraphFst):
      """
      Finite state transducer for classifying plain tokens, that do not belong to any special class. This can be considered as the default class.
          e.g. sleep -> tokens { name: "sleep" }
      """
  
      def __init__(self):
          super().__init__(name="word", kind="classify")
          word = pynutil.insert("name: \"") + pynini.closure(NEMO_NOT_SPACE, 1) + pynutil.insert("\"")
          self.fst = word.optimize()
  