'''simple docstring'''

from __future__ import annotations

from collections.abc import Iterator
from typing import Generic, TypeVar

UpperCamelCase__  :						Optional[int]					=      TypeVar('T')


class 					_lowercase						(   Generic[T] ):
      '''simple docstring'''


      def __init__(					self       ,lowerCamelCase_				)      ->      Optional[Any]:



         '''simple docstring'''



         UpperCAmelCase__				:					Optional[int] 					=	data
         UpperCAmelCase__				:					Node[T] | None 					=	None




      def __str__(					self				)      ->      str:



         '''simple docstring'''



         return f'''{self.data}'''




class 					_lowercase						(   Generic[T] ):
      '''simple docstring'''


      def __init__(					self				)      ->      None:



         '''simple docstring'''



         UpperCAmelCase__				:					Node[T] | None 					=	None




      def __iter__(					self				)      ->      Iterator[T]:



         '''simple docstring'''



         UpperCAmelCase__				:					List[Any] 					=	self.top
         while node:
            yield node.data
            UpperCAmelCase__				:					Any 					=	node.next




      def __str__(					self				)      ->      str:



         '''simple docstring'''



         return "->".join([str(lowerCamelCase_				) for item in self]				)




      def __len__(					self				)      ->      int:



         '''simple docstring'''



         return len(tuple(iter(self				)				)				)




      def 		lowerCAmelCase__       (					self				)      ->      bool:



         '''simple docstring'''



         return self.top is None




      def 		lowerCAmelCase__       (					self       ,lowerCamelCase_				)      ->      None:



         '''simple docstring'''



         UpperCAmelCase__				:					List[Any] 					=	Node(lowerCamelCase_				)
         if not self.is_empty():
            UpperCAmelCase__				:					int 					=	self.top
         UpperCAmelCase__				:					Any 					=	node




      def 		lowerCAmelCase__       (					self				)      ->      T:



         '''simple docstring'''



         if self.is_empty():
            raise IndexError('''pop from empty stack'''				)
         assert isinstance(self.top       ,lowerCamelCase_				)
         UpperCAmelCase__				:					Any 					=	self.top
         UpperCAmelCase__				:					str 					=	self.top.next
         return pop_node.data




      def 		lowerCAmelCase__       (					self				)      ->      T:



         '''simple docstring'''



         if self.is_empty():
            raise IndexError('''peek from empty stack'''				)

         assert self.top is not None
         return self.top.data




      def 		lowerCAmelCase__       (					self				)      ->      None:



         '''simple docstring'''



         UpperCAmelCase__				:					List[Any] 					=	None


if __name__ == "__main__":
  from doctest import testmod

  testmod()





'''simple docstring'''

from dataclasses import dataclass, field
from typing import ClassVar, Dict

from ..features import Features, Sequence, Value
from .base import TaskTemplate


@dataclass(frozen=lowerCAmelCase )
class 					_lowercase						(   lowerCAmelCase ):
      '''simple docstring'''


      UpperCAmelCase_   :   str   				= field(default='''question-answering-extractive'''		,metadata={'''include_in_asdict_even_if_is_default''': True} )
      UpperCAmelCase_   :   ClassVar[Features]   				= Features({'''question''': Value('''string''' ), '''context''': Value('''string''' )} )
      UpperCAmelCase_   :   ClassVar[Features]   				= Features(
          {
              '''answers''': Sequence(
                  {
                      '''text''': Value('''string''' ),
                      '''answer_start''': Value('''int32''' ),
                  } )
          } )
      UpperCAmelCase_   :   str   				= "question"
      UpperCAmelCase_   :   str   				= "context"
      UpperCAmelCase_   :   str   				= "answers"




      @property
      def 		lowerCAmelCase__       (					self				)      ->      Dict[str, str]:



         '''simple docstring'''



         return {self.question_column: "question", self.context_column: "context", self.answers_column: "answers"}




