# Copyright 2017 Neural Networks and Deep Learning lab, MIPT
#
# 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 typing import List, Union
from deeppavlov.core.common.registry import register
from deeppavlov.core.models.component import Component
StrTokenReverserInfo = Union[List[str], List['StrTokenReverserInfo']]
[docs]@register('str_token_reverser')
class StrTokenReverser(Component):
"""Component for converting strings to strings with reversed token positions
Args:
tokenized: The parameter is only needed to reverse tokenized strings.
"""
def __init__(self, tokenized: bool = False, *args, **kwargs) -> None:
self.tokenized = tokenized
@staticmethod
def _reverse_str(raw_string):
splitted = raw_string.split()
splitted.reverse()
string = ' '.join(splitted)
return string
@staticmethod
def _reverse_tokens(raw_tokens):
raw_tokens.reverse()
return raw_tokens
[docs] def __call__(self, batch: Union[str, list, tuple]) -> StrTokenReverserInfo:
"""Recursively search for strings in a list and convert them to strings with reversed token positions
Args:
batch: a string or a list containing strings
Returns:
the same structure where all strings tokens are reversed
"""
if isinstance(batch, (list, tuple)):
batch = batch.copy()
if self.tokenized:
if isinstance(batch, (list, tuple)):
if isinstance(batch[-1], str):
return self._reverse_tokens(batch)
else:
return [self(line) for line in batch]
raise RuntimeError(f'The objects passed to the reverser are not list or tuple! '
f' But they are {type(batch)}.'
f' If you want to passed str type directly use option tokenized = False')
else:
if isinstance(batch, (list, tuple)):
return [self(line) for line in batch]
else:
return self._reverse_str(batch)