147 lines
4.9 KiB
PHP
147 lines
4.9 KiB
PHP
<?php
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/**
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* This file was originally part of brick/math
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*
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* Copyright (c) 2013-present Benjamin Morel
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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* @link https://github.com/brick/math brick/math at GitHub
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*/
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declare(strict_types=1);
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namespace Ramsey\Uuid\Math;
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/**
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* Specifies a rounding behavior for numerical operations capable of discarding
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* precision.
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*
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* Each rounding mode indicates how the least significant returned digit of a
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* rounded result is to be calculated. If fewer digits are returned than the
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* digits needed to represent the exact numerical result, the discarded digits
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* will be referred to as the discarded fraction regardless the digits'
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* contribution to the value of the number. In other words, considered as a
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* numerical value, the discarded fraction could have an absolute value greater
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* than one.
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*/
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final class RoundingMode
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{
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/**
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* Private constructor. This class is not instantiable.
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*
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* @codeCoverageIgnore
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*/
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private function __construct()
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{
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}
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/**
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* Asserts that the requested operation has an exact result, hence no
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* rounding is necessary.
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*/
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public const UNNECESSARY = 0;
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/**
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* Rounds away from zero.
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*
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* Always increments the digit prior to a nonzero discarded fraction.
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* Note that this rounding mode never decreases the magnitude of the
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* calculated value.
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*/
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public const UP = 1;
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/**
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* Rounds towards zero.
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*
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* Never increments the digit prior to a discarded fraction (i.e.,
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* truncates). Note that this rounding mode never increases the magnitude of
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* the calculated value.
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*/
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public const DOWN = 2;
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/**
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* Rounds towards positive infinity.
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*
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* If the result is positive, behaves as for UP; if negative, behaves as for
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* DOWN. Note that this rounding mode never decreases the calculated value.
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*/
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public const CEILING = 3;
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/**
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* Rounds towards negative infinity.
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*
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* If the result is positive, behave as for DOWN; if negative, behave as for
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* UP. Note that this rounding mode never increases the calculated value.
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*/
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public const FLOOR = 4;
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/**
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* Rounds towards "nearest neighbor" unless both neighbors are equidistant,
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* in which case round up.
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*
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* Behaves as for UP if the discarded fraction is >= 0.5; otherwise, behaves
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* as for DOWN. Note that this is the rounding mode commonly taught at
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* school.
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*/
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public const HALF_UP = 5;
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/**
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* Rounds towards "nearest neighbor" unless both neighbors are equidistant,
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* in which case round down.
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*
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* Behaves as for UP if the discarded fraction is > 0.5; otherwise, behaves
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* as for DOWN.
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*/
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public const HALF_DOWN = 6;
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/**
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* Rounds towards "nearest neighbor" unless both neighbors are equidistant,
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* in which case round towards positive infinity.
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*
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* If the result is positive, behaves as for HALF_UP; if negative, behaves
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* as for HALF_DOWN.
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*/
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public const HALF_CEILING = 7;
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/**
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* Rounds towards "nearest neighbor" unless both neighbors are equidistant,
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* in which case round towards negative infinity.
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*
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* If the result is positive, behaves as for HALF_DOWN; if negative, behaves
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* as for HALF_UP.
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*/
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public const HALF_FLOOR = 8;
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/**
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* Rounds towards the "nearest neighbor" unless both neighbors are
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* equidistant, in which case rounds towards the even neighbor.
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*
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* Behaves as for HALF_UP if the digit to the left of the discarded fraction
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* is odd; behaves as for HALF_DOWN if it's even.
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*
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* Note that this is the rounding mode that statistically minimizes
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* cumulative error when applied repeatedly over a sequence of calculations.
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* It is sometimes known as "Banker's rounding", and is chiefly used in the
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* USA.
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*/
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public const HALF_EVEN = 9;
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}
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