/*
 * 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.hyracks.algebricks.core.algebra.properties;

import java.util.List;

import org.apache.hyracks.algebricks.core.algebra.base.LogicalVariable;

public final class FunctionalDependency {
    private List<LogicalVariable> head;
    private List<LogicalVariable> tail;

    public FunctionalDependency(List<LogicalVariable> head, List<LogicalVariable> tail) {
        this.head = head;
        this.tail = tail;
    }

    public List<LogicalVariable> getHead() {
        return head;
    }

    public List<LogicalVariable> getTail() {
        return tail;
    }

    @Override
    public String toString() {
        return head + "->" + tail;
    }

    @Override
    public boolean equals(Object obj) {
        if (!(obj instanceof FunctionalDependency)) {
            return false;
        } else {
            FunctionalDependency fd = (FunctionalDependency) obj;
            return fd.getHead().equals(this.head) && fd.getTail().equals(this.tail);
        }
    }

}
