001package conexp.fx.core.collections; 002 003/* 004 * #%L 005 * Concept Explorer FX 006 * %% 007 * Copyright (C) 2010 - 2019 Francesco Kriegel 008 * %% 009 * This program is free software: you can redistribute it and/or modify 010 * it under the terms of the GNU General Public License as 011 * published by the Free Software Foundation, either version 3 of the 012 * License, or (at your option) any later version. 013 * 014 * This program is distributed in the hope that it will be useful, 015 * but WITHOUT ANY WARRANTY; without even the implied warranty of 016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 017 * GNU General Public License for more details. 018 * 019 * You should have received a copy of the GNU General Public 020 * License along with this program. If not, see 021 * <http://www.gnu.org/licenses/gpl-3.0.html>. 022 * #L% 023 */ 024 025import java.util.Optional; 026 027public final class Either<L, R> extends Pair<Optional<L>, Optional<R>> { 028 029 public static final <L, R> Either<L, R> ofLeft(final L left) { 030 if (left == null) 031 throw new NullPointerException(); 032 return new Either<L, R>(left, null); 033 } 034 035 public static final <L, R> Either<L, R> ofRight(final R right) { 036 if (right == null) 037 throw new NullPointerException(); 038 return new Either<L, R>(null, right); 039 } 040 041 private Either(final L left, final R right) { 042 super(Optional.ofNullable(left), Optional.ofNullable(right)); 043 } 044 045}