gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/util/ConnectiveP.java

/*
 * 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.tinkerpop.gremlin.process.traversal.util;

import org.apache.tinkerpop.gremlin.process.traversal.P;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.function.Predicate;
import java.util.stream.Stream;

/**
 * @author Marko A. Rodriguez (http://markorodriguez.com)
 */
public abstract class ConnectiveP<V> extends P<V> {

    protected List<P<V>> predicates;

    public ConnectiveP(final P<V>... predicates) {
        super(null, null);
        if (predicates.length < 2)
            throw new IllegalArgumentException("The provided " + this.getClass().getSimpleName() + " array must have at least two arguments: " + predicates.length);
        this.predicates = new ArrayList<>();
        Stream.of(predicates).forEach(this.predicates::add);
    }

    public List<P<V>> getPredicates() {
        return Collections.unmodifiableList(this.predicates);
    }

    @Override
    public P<V> negate() {
        final List<P<V>> negated = new ArrayList<>();
        for (final P<V> predicate : this.predicates) {
            negated.add(predicate.negate());
        }
        this.predicates = negated;
        return this;
    }

    protected P<V> negate(final ConnectiveP<V> p) {
        final List<P<V>> negated = new ArrayList<>();
        for (final P<V> predicate : this.predicates) {
            negated.add(predicate.negate());
        }
        p.predicates = negated;
        return p;
    }

    @Override
    public int hashCode() {
        int result = 0, i = 0;
        for (final P p : this.predicates) {
            result ^= Integer.rotateLeft(p.hashCode(), i++);
        }
        return result;
    }

    @Override
    public boolean equals(final Object other) {
        if (other != null && other.getClass().equals(this.getClass())) {
            final List<P<V>> otherPredicates = ((ConnectiveP<V>) other).predicates;
            if (this.predicates.size() == otherPredicates.size()) {
                for (int i = 0; i < this.predicates.size(); i++) {
                    if (!this.predicates.get(i).equals(otherPredicates.get(i))) {
                        return false;
                    }
                }
                return true;
            }
        }
        return false;
    }

    @Override
    public ConnectiveP<V> clone() {
        final ConnectiveP<V> clone = (ConnectiveP<V>) super.clone();
        clone.predicates = new ArrayList<>();
        for (final P<V> p : this.predicates) {
            clone.predicates.add(p.clone());
        }
        return clone;
    }

    @Override
    public P<V> and(final Predicate<? super V> predicate) {
        if (!(predicate instanceof P))
            throw new IllegalArgumentException("Only P predicates can be and'd together");
        return new AndP<>(this, (P) predicate);
    }

    @Override
    public P<V> or(final Predicate<? super V> predicate) {
        if (!(predicate instanceof P))
            throw new IllegalArgumentException("Only P predicates can be or'd together");
        return new OrP<>(this, (P) predicate);
    }
}