001/* 002 * The MIT License (MIT) 003 * 004 * Copyright (c) 2015-2023 decimal4j (tools4j), Marco Terzer 005 * 006 * Permission is hereby granted, free of charge, to any person obtaining a copy 007 * of this software and associated documentation files (the "Software"), to deal 008 * in the Software without restriction, including without limitation the rights 009 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 010 * copies of the Software, and to permit persons to whom the Software is 011 * furnished to do so, subject to the following conditions: 012 * 013 * The above copyright notice and this permission notice shall be included in all 014 * copies or substantial portions of the Software. 015 * 016 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 017 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 018 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 019 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 020 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 021 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 022 * SOFTWARE. 023 */ 024package org.decimal4j.truncate; 025 026import java.math.RoundingMode; 027import java.util.Collections; 028import java.util.LinkedHashSet; 029import java.util.Set; 030 031/** 032 * Policy defining how to handle truncation due to overflow or rounding. A 033 * {@code TruncationPolicy} is uniquely defined by the two elements 034 * {@link #getOverflowMode overflow mode} and {@link #getRoundingMode() rounding 035 * mode}. 036 * <p> 037 * Truncation policies are are defined by {@link UncheckedRounding} and {@link CheckedRounding}. 038 * Some special truncation policies are also defined by 039 * <ul> 040 * <li>{@link #DEFAULT}</li> 041 * <li>{@link #VALUES}</li> 042 * <li>{@link UncheckedRounding#VALUES}</li> 043 * <li>{@link CheckedRounding#VALUES}</li> 044 * </ul> 045 */ 046public interface TruncationPolicy { 047 /** 048 * Default truncation policy: {@link UncheckedRounding#HALF_UP}. 049 */ 050 TruncationPolicy DEFAULT = UncheckedRounding.HALF_UP; 051 052 /** 053 * Unmodifiable set with all possible truncation policies. 054 */ 055 Set<TruncationPolicy> VALUES = Collections.unmodifiableSet(new LinkedHashSet<TruncationPolicy>(UncheckedRounding.VALUES.size(), 2f) { 056 private static final long serialVersionUID = 1L; 057 { 058 addAll(UncheckedRounding.VALUES); 059 addAll(CheckedRounding.VALUES); 060 } 061 }); 062 063 /** 064 * Returns the overflow mode which defines how to deal the situation when an 065 * operation that causes an overflow. 066 * 067 * @return the mode to apply if an arithmetic operation causes an overflow 068 */ 069 OverflowMode getOverflowMode(); 070 071 /** 072 * Returns the rounding mode which defines how to deal the situation when an 073 * operation leads to truncation or rounding. 074 * 075 * @return the rounding mode indicating how the least significant returned 076 * digit of a rounded result is to be calculated 077 */ 078 RoundingMode getRoundingMode(); 079}