# -*- coding: utf-8 -*-
"""
Copyright Sylvain Bouveret, Yann Chevaleyre and François Durand
sylvain.bouveret@imag.fr, yann.chevaleyre@dauphine.fr, fradurand@gmail.com
This file is part of Whalrus.
Whalrus is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Whalrus is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Whalrus. If not, see <http://www.gnu.org/licenses/>.
"""
from whalrus.converters_ballot.converter_ballot import ConverterBallot
from whalrus.converters_ballot.converter_ballot_general import ConverterBallotGeneral
from whalrus.ballots.ballot_veto import BallotVeto
from whalrus.ballots.ballot_one_name import BallotOneName
from whalrus.ballots.ballot_plurality import BallotPlurality
from whalrus.ballots.ballot_order import BallotOrder
[docs]class ConverterBallotToOrder(ConverterBallot):
"""
Default converter to a :class:`BallotOrder`.
This is a default converter to a :class:`BallotOrder`. It tries to infer the type of input and converts it to
an ordered ballot (possibly a ballot of a subclass, such as :class:`BallotLevels`).
Examples
--------
>>> converter = ConverterBallotToOrder()
>>> converter('a > b ~ c')
BallotOrder(['a', {'b', 'c'}], candidates={'a', 'b', 'c'})
>>> converter(['a', {'b', 'c'}])
BallotOrder(['a', {'b', 'c'}], candidates={'a', 'b', 'c'})
>>> converter({'a': 10, 'b': 7, 'c': 0})
BallotLevels({'a': 10, 'b': 7, 'c': 0}, candidates={'a', 'b', 'c'}, scale=Scale())
>>> converter(BallotOneName('a', candidates={'a', 'b', 'c'}))
BallotOrder(['a', {'b', 'c'}], candidates={'a', 'b', 'c'})
>>> converter(BallotPlurality('a', candidates={'a', 'b', 'c'}))
BallotOrder(['a', {'b', 'c'}], candidates={'a', 'b', 'c'})
>>> converter(BallotVeto('a', candidates={'a', 'b', 'c'}))
BallotOrder([{'b', 'c'}, 'a'], candidates={'a', 'b', 'c'})
"""
def __call__(self, x: object, candidates: set = None) -> BallotOrder:
x = ConverterBallotGeneral()(x, candidates=None)
if isinstance(x, BallotOrder):
return x.restrict(candidates=candidates)
if isinstance(x, BallotVeto):
return BallotOrder([x.candidates_not_in_b, {x.last()}]).restrict(candidates=candidates)
if isinstance(x, BallotOneName):
return BallotOrder([{x.first()}, x.candidates_not_in_b]).restrict(candidates=candidates)
raise NotImplementedError