org.apache.jena.atlas.lib.SetUtils Maven / Gradle / Ivy

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/*
 * 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.HashSet ;
import java.util.Set ;
import java.util.concurrent.ConcurrentHashMap ;

/** Set specific operations */
public class SetUtils
{
    private SetUtils() {}
    
    /** "ConcurrentHashSet" */
    public static final  Set concurrentHashSet() {
        return ConcurrentHashMap.newKeySet() ;
    }
    
    public static  Set setOfOne(X element) { return DS.setOfOne(element) ; }
    
    public static  Set intersection(Set setLeft, Set setRight) {
        Set results = new HashSet<>(setLeft) ;
        results.retainAll(setRight) ;
        return results ;
    }

    public static  boolean intersectionP(Set s1, Set s2) {
        return s1.stream().anyMatch(s2::contains) ;
    }

    public static  Set union(Set s1, Set s2) {
        Set s3 = new HashSet<>(s1) ;
        s3.addAll(s2) ;
        return s3 ;
    }

    /** union difference intersection : those elements in s1 or s2 but not both. */
    public static  Set symmetricDifference(Set s1, Set s2) {
        Set s3 = new HashSet<>() ;
        s1.forEach(x -> {
            if ( !s2.contains(x) )
                s3.add(x) ;
        }) ;
        s2.forEach(x -> {
            if ( !s1.contains(x) )
                s3.add(x) ;
        }) ;
        return s3 ;
    }

    /** Return is s1 \ s2 */

    public static  Set difference(Set s1, Set s2) {
        Set s3 = new HashSet<>(s1) ;
        s3.removeAll(s2) ;
        return s3 ;
    }

    public static  boolean disjoint(Set set1, Set set2) {
        return CollectionUtils.disjoint(set1, set2) ;
    }
}