org.jhotdraw8.icollection.impl.redblack.Empty Maven / Gradle / Ivy

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/*
 * @(#)Empty.java
 * Copyright © 2023 The authors and contributors of JHotDraw. MIT License.
 */
package org.jhotdraw8.icollection.impl.redblack;

import org.jspecify.annotations.Nullable;

import java.util.Comparator;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.function.BiFunction;

/**
 * The empty tree node.
 * 
 * This class has been derived from 'vavr' RedBlackTree.java.
 * 

 *     RedBlackTree.java. Copyright 2023 (c) vavr. MIT License.
 *     github.com
 * 
 *
 * @param  Component type
 */
public final class Empty implements RedBlackTree {
    public final static Empty EMPTY = new Empty<>();

    @SuppressWarnings("unchecked")
    public static  Empty empty() {
        return (Empty) EMPTY;
    }

    private Empty() {
    }

    @Override
    public boolean color() {
        return Color.BLACK;
    }

    @Override
    public boolean contains(K key, Comparator comparator) {
        return false;
    }


    @Override
    public RedBlackTree find(K key, Comparator comparator) {
        return this;
    }

    @Override
    public RedBlackTree ceiling(K e, Comparator comparator) {
        return this;
    }

    @Override
    public RedBlackTree floor(K e, Comparator comparator) {
        return this;
    }

    @Override
    public RedBlackTree higher(K e, Comparator comparator) {
        return this;
    }

    @Override
    public RedBlackTree orElse(RedBlackTree other) {
        return other;
    }

    @Override
    public RedBlackTree lower(K e, Comparator comparator) {
        return this;
    }

    @Override
    public boolean isEmpty() {
        return true;
    }

    @Override
    public RedBlackTree left() {
        throw new UnsupportedOperationException("left on empty");
    }

    @Override
    public RedBlackTree right() {
        throw new UnsupportedOperationException("right on empty");
    }

    @Override
    public int size() {
        return 0;
    }

    @Override
    public K getKey() {
        throw new NoSuchElementException("key on empty");
    }

    @Override
    public V getValue() {
        throw new NoSuchElementException("value on empty");
    }

    @Override
    public @Nullable K keyOrNull() {
        return null;
    }

    @Override
    public @Nullable V valueOrNull() {
        return null;
    }

    @Override
    public  @Nullable E mapOrNull(BiFunction f) {
        return null;
    }

    @Override
    public Map.@Nullable Entry entryOrNull() {
        return null;
    }

    @Override
    public boolean isRed() {
        return false;
    }

    @Override
    public String toString() {
        return "()";
    }

    @Override
    public String toLispString() {
        return "()";
    }
}