/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.jena.atlas.lib;


import java.util.* ;

public class DS
{
    private DS() {}
 
    public static <X> Set<X> setOfNone()            { return Collections.emptySet()  ; }
    public static <X> Set<X> setOfOne(X element)    { return Collections.singleton(element) ; }
    public static <X> Set<X> set()                  { return new HashSet<>(); }
    public static <X> Set<X> set(int initialSize)   { return new HashSet<>(initialSize); }
    public static <X> Set<X> set(Set<X> other)      { return new HashSet<>(other); }

    public static <K, V> Map<K,V> mapOfNone()       { return Collections.emptyMap() ; }
    public static <K, V> Map<K,V> mapOfOne(K key, V value) { return Collections.singletonMap(key, value) ; }
    public static <K, V> Map<K,V> map()             { return new HashMap<>(); }
    public static <K, V> Map<K,V> map(int initialSize) { return new HashMap<>(initialSize); }
    public static <K, V> Map<K,V> map(Map<K,V> other) { return new HashMap<>(other); }

    public static <T> List<T> listOfNone()          { return Collections.emptyList() ; }
    public static <T> List<T> listOfOne(T element)  { return Collections.singletonList(element) ; }
    public static <T> List<T> list()                { return new ArrayList<>(); }
    public static <T> List<T> list(int initialSize) { return new ArrayList<>(initialSize); }
    public static <T> List<T> list(List<T> other)   { return new ArrayList<>(other); }
}