Optimisations for number handling

DRY number classes
Implement __iadd__, etc. for better performance
This commit is contained in:
RunasSudo 2021-01-03 18:39:32 +11:00
parent 673b531475
commit 8d7a1ea1f9
Signed by: RunasSudo
GPG Key ID: 7234E476BF21C61A
7 changed files with 387 additions and 310 deletions

242
pyRCV2/numbers/base.py Normal file
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@ -0,0 +1,242 @@
# pyRCV2: Preferential vote counting
# Copyright © 2020–2021 Lee Yingtong Li (RunasSudo)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
__pragma__ = lambda x: None
is_py = False
__pragma__('skip')
is_py = True
import functools
import math
__pragma__('noskip')
def compatible_types(f):
if is_py:
__pragma__('skip')
import os
if 'PYTEST_CURRENT_TEST' in os.environ:
@functools.wraps(f)
def wrapper(self, other):
if not isinstance(other, self.__class__):
raise ValueError('Attempt to operate on incompatible types')
return f(self, other)
return wrapper
else:
return f
__pragma__('noskip')
else:
# FIXME: Do we need to perform type checking in JS?
return f
class BaseNum:
__slots__ = ['impl'] # Optimisation to reduce overhead of initialising new object
# These enum values may be overridden in subclasses depending on underlying library
ROUND_DOWN = 0
ROUND_HALF_UP = 1
ROUND_HALF_EVEN = 2
ROUND_UP = 3
def __init__(self, value):
if isinstance(value, self.__class__):
self.impl = value.impl
else:
self.impl = self._to_impl(value)
@classmethod
def _to_impl(cls, value):
"""
Internal use: Convert the given value to an impl
Subclasses must override this method
"""
raise NotImplementedError('Method not implemented')
@classmethod
def _from_impl(cls, impl):
"""Internal use: Return an instance directly from the given impl without performing checks"""
if is_py:
obj = cls.__new__(cls)
else:
# Transcrypt's __new__ (incorrectly) calls the constructor
obj = __pragma__('js', '{}', 'Object.create (cls, {__class__: {value: cls, enumerable: true}})')
obj.impl = impl
return obj
def pp(self, dp):
"""
Pretty print to specified number of decimal places
Subclasses must override this method
"""
raise NotImplementedError('Method not implemented')
# Implementation of arithmetic on impls
# Subclasses must override these functions:
@classmethod
def _add_impl(cls, i1, i2):
raise NotImplementedError('Method not implemented')
@classmethod
def _sub_impl(cls, i1, i2):
raise NotImplementedError('Method not implemented')
@classmethod
def _mul_impl(cls, i1, i2):
raise NotImplementedError('Method not implemented')
@classmethod
def _truediv_impl(cls, i1, i2):
raise NotImplementedError('Method not implemented')
@compatible_types
def __eq__(self, other):
raise NotImplementedError('Method not implemented')
@compatible_types
def __ne__(self, other):
return not (self.__eq__(other))
@compatible_types
def __gt__(self, other):
raise NotImplementedError('Method not implemented')
@compatible_types
def __ge__(self, other):
raise NotImplementedError('Method not implemented')
@compatible_types
def __lt__(self, other):
raise NotImplementedError('Method not implemented')
@compatible_types
def __le__(self, other):
raise NotImplementedError('Method not implemented')
def round(self, dps, mode):
"""
Round to the specified number of decimal places, using the ROUND_* mode specified
Subclasses must override this method
"""
raise NotImplementedError('Method not implemented')
# Implement various data model functions based on _*_impl
@compatible_types
def __add__(self, other):
return self._from_impl(self._add_impl(self.impl, other.impl))
@compatible_types
def __sub__(self, other):
return self._from_impl(self._sub_impl(self.impl, other.impl))
@compatible_types
def __mul__(self, other):
return self._from_impl(self._mul_impl(self.impl, other.impl))
@compatible_types
def __truediv__(self, other):
return self._from_impl(self._truediv_impl(self.impl, other.impl))
@compatible_types
def __iadd__(self, other):
self.impl = self._add_impl(self.impl, other.impl)
return self
@compatible_types
def __isub__(self, other):
self.impl = self._sub_impl(self.impl, other.impl)
return self
@compatible_types
def __imul__(self, other):
self.impl = self._mul_impl(self.impl, other.impl)
return self
@compatible_types
def __itruediv__(self, other):
self.impl = self._truediv_impl(self.impl, other.impl)
return self
def __floor__(self):
return self.round(0, self.ROUND_DOWN)
class BasePyNum(BaseNum):
"""Helper class for Num wrappers of Python objects that already implement overloading"""
_py_class = None # Subclasses must specify
@classmethod
def _to_impl(cls, value):
"""Implements BaseNum._to_impl"""
return cls._py_class(value)
def pp(self, dp):
"""Implements BaseNum.pp"""
return format(self.impl, '.{}f'.format(dp))
@classmethod
def _add_impl(cls, i1, i2):
"""Implements BaseNum._add_impl"""
return i1 + i2
@classmethod
def _sub_impl(cls, i1, i2):
"""Implements BaseNum._sub_impl"""
return i1 - i2
@classmethod
def _mul_impl(cls, i1, i2):
"""Implements BaseNum._mul_impl"""
return i1 * i2
@classmethod
def _truediv_impl(cls, i1, i2):
"""Implements BaseNum._truediv_impl"""
return i1 / i2
@compatible_types
def __eq__(self, other):
"""Implements BaseNum.__eq__"""
return self.impl == other.impl
@compatible_types
def __ne__(self, other):
"""Overrides BaseNum.__ne__"""
return self.impl != other.impl
@compatible_types
def __gt__(self, other):
"""Implements BaseNum.__gt__"""
return self.impl > other.impl
@compatible_types
def __ge__(self, other):
"""Implements BaseNum.__ge__"""
return self.impl >= other.impl
@compatible_types
def __lt__(self, other):
"""Implements BaseNum.__lt__"""
return self.impl < other.impl
@compatible_types
def __le__(self, other):
"""Implements BaseNum.__le__"""
return self.impl <= other.impl
@compatible_types
def __iadd__(self, other):
"""Overrides BaseNum.__iadd__"""
self.impl += other.impl
return self
@compatible_types
def __isub__(self, other):
"""Overrides BaseNum.__isub__"""
self.impl -= other.impl
return self
@compatible_types
def __imul__(self, other):
"""Overrides BaseNum.__imul__"""
self.impl *= other.impl
return self
@compatible_types
def __itruediv__(self, other):
"""Overrides BaseNum.__itruediv__"""
self.impl /= other.impl
return self
def __floor__(self):
return self._from_impl(math.floor(self.impl))
def __repr__(self):
return '<{} {}>'.format(self.__class__.__name__, str(self.impl))

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@ -1,5 +1,5 @@
# pyRCV2: Preferential vote counting
# Copyright © 2020 Lee Yingtong Li (RunasSudo)
# Copyright © 2020–2021 Lee Yingtong Li (RunasSudo)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
@ -14,61 +14,65 @@
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
from pyRCV2.numbers.base import BaseNum, compatible_types
Big.DP = 6
def set_dps(dps):
Big.DP = dps
class Fixed:
class Fixed(BaseNum):
"""
Wrapper for big.js (fixed-point arithmetic)
"""
ROUND_DOWN = 0
ROUND_HALF_UP = 1
ROUND_HALF_EVEN = 2
ROUND_UP = 3
def __init__(self, val):
if isinstance(val, Fixed):
self.impl = val.impl
else:
self.impl = Big(val).round(Big.DP)
@classmethod
def _to_impl(cls, value):
"""Implements BaseNum._to_impl"""
return Big(value).round(Big.DP)
def pp(self, dp):
"""Pretty print to specified number of decimal places"""
"""Implements BaseNum.pp"""
return self.impl.toFixed(dp)
def to_rational(self):
"""Convert to an instance of Rational"""
from pyRCV2.numbers import Rational
return Rational(self.impl.toString())
def __add__(self, other):
return Fixed(self.impl.plus(other.impl))
def __sub__(self, other):
return Fixed(self.impl.minus(other.impl))
def __mul__(self, other):
return Fixed(self.impl.times(other.impl))
def __div__(self, other):
return Fixed(self.impl.div(other.impl))
@classmethod
def _add_impl(cls, i1, i2):
"""Implements BaseNum._add_impl"""
return i1.plus(i2)
@classmethod
def _sub_impl(cls, i1, i2):
"""Implements BaseNum._sub_impl"""
return i1.minus(i2)
@classmethod
def _mul_impl(cls, i1, i2):
"""Implements BaseNum._mul_impl"""
return i1.times(i2)
@classmethod
def _truediv_impl(cls, i1, i2):
"""Implements BaseNum._truediv_impl"""
return i1.div(i2)
@compatible_types
def __eq__(self, other):
"""Implements BaseNum.__eq__"""
return self.impl.eq(other.impl)
def __ne__(self, other):
return not self.impl.eq(other.impl)
@compatible_types
def __gt__(self, other):
"""Implements BaseNum.__gt__"""
return self.impl.gt(other.impl)
@compatible_types
def __ge__(self, other):
"""Implements BaseNum.__ge__"""
return self.impl.gte(other.impl)
@compatible_types
def __lt__(self, other):
"""Implements BaseNum.__lt__"""
return self.impl.lt(other.impl)
@compatible_types
def __le__(self, other):
"""Implements BaseNum.__le__"""
return self.impl.lte(other.impl)
def __floor__(self):
return self.round(0, Fixed.ROUND_DOWN)
def round(self, dps, mode):
"""Round to the specified number of decimal places, using the ROUND_* mode specified"""
"""Implements BaseNum.round"""
return Fixed(self.impl.round(dps, mode))

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@ -1,5 +1,5 @@
# pyRCV2: Preferential vote counting
# Copyright © 2020 Lee Yingtong Li (RunasSudo)
# Copyright © 2020–2021 Lee Yingtong Li (RunasSudo)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
@ -14,9 +14,9 @@
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
from pyRCV2.numbers.base import BasePyNum, compatible_types
import decimal
import functools
import math
_quantize_exp = 6
@ -24,76 +24,23 @@ def set_dps(dps):
global _quantize_exp
_quantize_exp = decimal.Decimal('10') ** -dps
def compatible_types(f):
@functools.wraps(f)
def wrapper(self, other):
if not isinstance(other, Fixed):
raise ValueError('Attempt to operate on incompatible types')
return f(self, other)
return wrapper
class Fixed:
class Fixed(BasePyNum):
"""
Wrapper for Python Decimal (for fixed-point arithmetic)
"""
_py_class = decimal.Decimal # For BasePyNum
ROUND_DOWN = decimal.ROUND_DOWN
ROUND_HALF_UP = decimal.ROUND_HALF_UP
ROUND_HALF_EVEN = decimal.ROUND_HALF_EVEN
ROUND_UP = decimal.ROUND_UP
def __init__(self, val):
if isinstance(val, Fixed):
self.impl = val.impl
else:
self.impl = decimal.Decimal(val).quantize(_quantize_exp)
def __repr__(self):
return '<Fixed {}>'.format(str(self.impl))
def pp(self, dp):
"""Pretty print to specified number of decimal places"""
return format(self.impl, '.{}f'.format(dp))
def to_rational(self):
"""Convert to an instance of Rational"""
from pyRCV2.numbers import Rational
return Rational(self.impl)
@compatible_types
def __add__(self, other):
return Fixed(self.impl + other.impl)
@compatible_types
def __sub__(self, other):
return Fixed(self.impl - other.impl)
@compatible_types
def __mul__(self, other):
return Fixed(self.impl * other.impl)
@compatible_types
def __truediv__(self, other):
return Fixed(self.impl / other.impl)
@compatible_types
def __eq__(self, other):
return self.impl == other.impl
@compatible_types
def __ne__(self, other):
return self.impl != other.impl
@compatible_types
def __gt__(self, other):
return self.impl > other.impl
@compatible_types
def __ge__(self, other):
return self.impl >= other.impl
@compatible_types
def __lt__(self, other):
return self.impl < other.impl
@compatible_types
def __le__(self, other):
return self.impl <= other.impl
def __floor__(self):
return Fixed(math.floor(self.impl))
@classmethod
def _to_impl(cls, value):
"""Overrides BasePyNum._to_impl"""
return decimal.Decimal(value).quantize(_quantize_exp)
def round(self, dps, mode):
"""Round to the specified number of decimal places, using the ROUND_* mode specified"""
"""Implements BaseNum.round"""
return Fixed(self.impl.quantize(decimal.Decimal('10') ** -dps, mode))

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@ -1,5 +1,5 @@
# pyRCV2: Preferential vote counting
# Copyright © 2020 Lee Yingtong Li (RunasSudo)
# Copyright © 2020–2021 Lee Yingtong Li (RunasSudo)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
@ -14,65 +14,77 @@
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
class Native:
from pyRCV2.numbers.base import BaseNum, compatible_types
class Native(BaseNum):
"""
Wrapper for JS numbers (naive floating-point arithmetic)
"""
ROUND_DOWN = 0
ROUND_HALF_UP = 1
ROUND_HALF_EVEN = 2
ROUND_UP = 3
def __init__(self, val):
if isinstance(val, Native):
self.impl = val.impl
else:
self.impl = parseFloat(val)
@classmethod
def _to_impl(cls, value):
"""Implements BaseNum._to_impl"""
return parseFloat(value)
def pp(self, dp):
"""Pretty print to specified number of decimal places"""
"""Implements BaseNum.pp"""
return self.impl.toFixed(dp)
def to_rational(self):
"""Convert to an instance of Rational"""
from pyRCV2.numbers import Rational
return Rational(self.impl)
def __add__(self, other):
return Native(self.impl + other.impl)
def __sub__(self, other):
return Native(self.impl - other.impl)
def __mul__(self, other):
return Native(self.impl * other.impl)
def __div__(self, other):
return Native(self.impl / other.impl)
@classmethod
def _add_impl(cls, i1, i2):
"""Implements BaseNum._add_impl"""
return i1 + i2
@classmethod
def _sub_impl(cls, i1, i2):
"""Implements BaseNum._sub_impl"""
return i1 - i2
@classmethod
def _mul_impl(cls, i1, i2):
"""Implements BaseNum._mul_impl"""
return i1 * i2
@classmethod
def _truediv_impl(cls, i1, i2):
"""Implements BaseNum._truediv_impl"""
return i1 / i2
@compatible_types
def __eq__(self, other):
"""Implements BaseNum.__eq__"""
return self.impl == other.impl
@compatible_types
def __ne__(self, other):
"""Overrides BaseNum.__ne__"""
return self.impl != other.impl
@compatible_types
def __gt__(self, other):
"""Implements BaseNum.__gt__"""
return self.impl > other.impl
@compatible_types
def __ge__(self, other):
"""Implements BaseNum.__ge__"""
return self.impl >= other.impl
@compatible_types
def __lt__(self, other):
"""Implements BaseNum.__lt__"""
return self.impl < other.impl
@compatible_types
def __le__(self, other):
"""Implements BaseNum.__le__"""
return self.impl <= other.impl
def __floor__(self):
"""Overrides BaseNum.__floor__"""
return Native(Math.floor(self.impl))
def round(self, dps, mode):
"""Round to the specified number of decimal places, using the ROUND_* mode specified"""
"""Implements BaseNum.round"""
if mode == Native.ROUND_DOWN:
return Native(Math.floor(self.impl * Math.pow(10, dps)) / Math.pow(10, dps))
elif mode == Native.ROUND_HALF_UP:
return Native(Math.round(self.impl * Math.pow(10, dps)) / Math.pow(10, dps))
elif mode == Native.ROUND_HALF_EVEN:
raise Exception('ROUND_HALF_EVEN is not implemented in JS Native context')
raise NotImplementedError('ROUND_HALF_EVEN is not implemented in JS Native context')
elif mode == Native.ROUND_UP:
return Native(Math.ceil(self.impl * Math.pow(10, dps)) / Math.pow(10, dps))
else:
raise Exception('Invalid rounding mode')
raise ValueError('Invalid rounding mode')

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@ -1,5 +1,5 @@
# pyRCV2: Preferential vote counting
# Copyright © 2020 Lee Yingtong Li (RunasSudo)
# Copyright © 2020–2021 Lee Yingtong Li (RunasSudo)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
@ -14,89 +14,27 @@
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
import functools
from pyRCV2.numbers.base import BasePyNum, compatible_types
import math
def compatible_types(f):
@functools.wraps(f)
def wrapper(self, other):
if not isinstance(other, Native):
raise ValueError('Attempt to operate on incompatible types')
return f(self, other)
return wrapper
class Native:
class Native(BasePyNum):
"""
Wrapper for Python float (naive floating-point arithmetic)
"""
ROUND_DOWN = 0
ROUND_HALF_UP = 1
ROUND_HALF_EVEN = 2
ROUND_UP = 3
def __init__(self, val):
if isinstance(val, Native):
self.impl = val.impl
else:
self.impl = float(val)
def __repr__(self):
return '<Native {}>'.format(str(self.impl))
def pp(self, dp):
"""Pretty print to specified number of decimal places"""
return format(self.impl, '.{}f'.format(dp))
def to_rational(self):
"""Convert to an instance of Rational"""
from pyRCV2.numbers import Rational
return Rational(self.impl)
@compatible_types
def __add__(self, other):
return Native(self.impl + other.impl)
@compatible_types
def __sub__(self, other):
return Native(self.impl - other.impl)
@compatible_types
def __mul__(self, other):
return Native(self.impl * other.impl)
@compatible_types
def __truediv__(self, other):
return Native(self.impl / other.impl)
@compatible_types
def __eq__(self, other):
return self.impl == other.impl
@compatible_types
def __ne__(self, other):
return self.impl != other.impl
@compatible_types
def __gt__(self, other):
return self.impl > other.impl
@compatible_types
def __ge__(self, other):
return self.impl >= other.impl
@compatible_types
def __lt__(self, other):
return self.impl < other.impl
@compatible_types
def __le__(self, other):
return self.impl <= other.impl
def __floor__(self):
return Native(math.floor(self.impl))
_py_class = float # For BasePyNum
def round(self, dps, mode):
"""Round to the specified number of decimal places, using the ROUND_* mode specified"""
"""Implements BaseNum.round"""
factor = 10 ** dps
if mode == Native.ROUND_DOWN:
return Native(math.floor(self.impl * factor) / factor)
elif mode == Native.ROUND_HALF_UP:
raise Exception('ROUND_HALF_UP is not implemented in Python Native context')
raise NotImplementedError('ROUND_HALF_UP is not implemented in Python Native context')
elif mode == Native.ROUND_HALF_EVEN:
return Native(round(self.impl * factor) / factor)
elif mode == Native.ROUND_UP:
return Native(math.ceil(self.impl * factor) / factor)
else:
raise Exception('Invalid rounding mode')
raise ValueError('Invalid rounding mode')

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@ -1,5 +1,5 @@
# pyRCV2: Preferential vote counting
# Copyright © 2020 Lee Yingtong Li (RunasSudo)
# Copyright © 2020–2021 Lee Yingtong Li (RunasSudo)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
@ -14,76 +14,75 @@
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
class Rational:
from pyRCV2.numbers.base import BaseNum, compatible_types
class Rational(BaseNum):
"""
Wrapper for BigRational.js (rational arithmetic)
"""
ROUND_DOWN = 0
ROUND_HALF_UP = 1
ROUND_HALF_EVEN = 2
ROUND_UP = 3
def __init__(self, val):
if isinstance(val, Rational):
self.impl = val.impl
else:
self.impl = bigRat(val)
@classmethod
def _to_impl(cls, value):
"""Implements BaseNum._to_impl"""
return bigRat(value)
def pp(self, dp):
"""
Pretty print to specified number of decimal places
This will fail for numbers which cannot be represented as a JavaScript number
"""
"""Implements BaseNum.pp"""
# FIXME: This will fail for numbers which cannot be represented as a JavaScript number
return self.impl.valueOf().toFixed(dp)
def to_rational(self):
return self
def to_num(self):
"""
Convert to an instance of Num
"""
from pyRCV2.numbers import Num
__pragma__('opov')
return Num(self.impl.numerator.toString()) / Num(self.impl.denominator.toString())
__pragma__('noopov')
def __add__(self, other):
return Rational(self.impl.add(other.impl))
def __sub__(self, other):
return Rational(self.impl.subtract(other.impl))
def __mul__(self, other):
return Rational(self.impl.multiply(other.impl))
def __div__(self, other):
return Rational(self.impl.divide(other.impl))
@classmethod
def _add_impl(cls, i1, i2):
"""Implements BaseNum._add_impl"""
return i1.add(i2)
@classmethod
def _sub_impl(cls, i1, i2):
"""Implements BaseNum._sub_impl"""
return i1.subtract(i2)
@classmethod
def _mul_impl(cls, i1, i2):
"""Implements BaseNum._mul_impl"""
return i1.multiply(i2)
@classmethod
def _truediv_impl(cls, i1, i2):
"""Implements BaseNum._truediv_impl"""
return i1.divide(i2)
@compatible_types
def __eq__(self, other):
"""Implements BaseNum.__eq__"""
return self.impl.equals(other.impl)
def __ne__(self, other):
return not self.impl.equals(other.impl)
@compatible_types
def __gt__(self, other):
"""Implements BaseNum.__gt__"""
return self.impl.greater(other.impl)
@compatible_types
def __ge__(self, other):
"""Implements BaseNum.__ge__"""
return self.impl.greaterOrEquals(other.impl)
@compatible_types
def __lt__(self, other):
"""Implements BaseNum.__lt__"""
return self.impl.lesser(other.impl)
@compatible_types
def __le__(self, other):
"""Implements BaseNum.__le__"""
return self.impl.lesserOrEquals(other.impl)
def __floor__(self):
"""Overrides BaseNum.__floor__"""
return Rational(self.impl.floor())
def round(self, dps, mode):
"""Round to the specified number of decimal places, using the ROUND_* mode specified"""
"""Implements BaseNum.round"""
factor = bigRat(10).pow(dps)
if mode == Rational.ROUND_DOWN:
return Rational(self.impl.multiply(factor).floor().divide(factor))
elif mode == Rational.ROUND_HALF_UP:
return Rational(self.impl.multiply(factor).round().divide(factor))
elif mode == Rational.ROUND_HALF_EVEN:
raise Exception('ROUND_HALF_EVEN is not implemented in JS Native context')
raise NotImplementedError('ROUND_HALF_EVEN is not implemented in JS Native context')
elif mode == Rational.ROUND_UP:
return Rational(self.impl.multiply(factor).ceil().divide(factor))
else:
raise Exception('Invalid rounding mode')
raise ValueError('Invalid rounding mode')

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@ -1,5 +1,5 @@
# pyRCV2: Preferential vote counting
# Copyright © 2020 Lee Yingtong Li (RunasSudo)
# Copyright © 2020–2021 Lee Yingtong Li (RunasSudo)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
@ -14,98 +14,33 @@
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
from pyRCV2.numbers.base import BasePyNum, compatible_types
from fractions import Fraction
import functools
import math
def compatible_types(f):
@functools.wraps(f)
def wrapper(self, other):
if not isinstance(other, Rational):
raise ValueError('Attempt to operate on incompatible types')
return f(self, other)
return wrapper
class Rational:
class Rational(BasePyNum):
"""
Wrapper for Python Fraction (rational arithmetic)
"""
ROUND_DOWN = 0
ROUND_HALF_UP = 1
ROUND_HALF_EVEN = 2
ROUND_UP = 3
_py_class = Fraction # For BasePyNum
def __init__(self, val):
if isinstance(val, Rational):
self.impl = val.impl
else:
self.impl = Fraction(val)
def __repr__(self):
return '<Rational {}>'.format(str(self.impl))
def pp(self, dp):
"""
Pretty print to specified number of decimal places
"""
"""Overrides BasePyNum.pp"""
# TODO: Work out if there is a better way of doing this
return format(float(self.impl), '.{}f'.format(dp))
def to_rational(self):
return self
def to_num(self):
"""
Convert to an instance of Num
"""
from pyRCV2.numbers import Num
return Num(self.impl.numerator) / Num(self.impl.denominator)
@compatible_types
def __add__(self, other):
return Rational(self.impl + other.impl)
@compatible_types
def __sub__(self, other):
return Rational(self.impl - other.impl)
@compatible_types
def __mul__(self, other):
return Rational(self.impl * other.impl)
@compatible_types
def __truediv__(self, other):
return Rational(self.impl / other.impl)
@compatible_types
def __eq__(self, other):
return self.impl == other.impl
@compatible_types
def __ne__(self, other):
return self.impl != other.impl
@compatible_types
def __gt__(self, other):
return self.impl > other.impl
@compatible_types
def __ge__(self, other):
return self.impl >= other.impl
@compatible_types
def __lt__(self, other):
return self.impl < other.impl
@compatible_types
def __le__(self, other):
return self.impl <= other.impl
def __floor__(self):
return Rational(math.floor(self.impl))
def round(self, dps, mode):
"""Round to the specified number of decimal places, using the ROUND_* mode specified"""
"""Implements BaseNum.round"""
factor = Fraction(10) ** dps
if mode == Rational.ROUND_DOWN:
return Rational(math.floor(self.impl * factor) / factor)
elif mode == Rational.ROUND_HALF_UP:
raise Exception('ROUND_HALF_UP is not implemented in Python Rational context')
raise NotImplementedError('ROUND_HALF_UP is not implemented in Python Rational context')
elif mode == Rational.ROUND_HALF_EVEN:
return Rational(round(self.impl * factor) / factor)
elif mode == Rational.ROUND_UP:
return Rational(math.ceil(self.impl * factor) / factor)
else:
raise Exception('Invalid rounding mode')
raise ValueError('Invalid rounding mode')