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/*
 * #%L
 * *********************************************************************************************************************
 * 
 * These Foolish Things - Miscellaneous utilities
 * http://thesefoolishthings.tidalwave.it - git clone [email protected]:tidalwave/thesefoolishthings-src.git
 * %%
 * Copyright (C) 2009 - 2016 Tidalwave s.a.s. (http://tidalwave.it)
 * %%
 * *********************************************************************************************************************
 * 
 * Licensed 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.
 * 
 * *********************************************************************************************************************
 * 
 * $Id$
 * 
 * *********************************************************************************************************************
 * #L%
 */
package it.tidalwave.util.spi;

import javax.annotation.Nonnull;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.function.BiConsumer;
import java.util.function.BinaryOperator;
import java.util.function.Supplier;
import java.util.stream.Collector;

/***********************************************************************************************************************
 *
 * A support {@link Collector} which uses an {@link ArrayList} as the accumulator.
 * 
 * @param       the type of collected items
 * @param      the type of collecting item
 * 
 * @author  Fabrizio Giudici
 * @version $Id$
 *
 **********************************************************************************************************************/
public abstract class ArrayListCollectorSupport 
        implements Collector, COLLECTING_TYPE>
  {
    @Override @Nonnull 
    public Supplier> supplier() 
      {
        return ArrayList::new;
      } 

    @Override @Nonnull 
    public BiConsumer, COLLECTED_TYPE> accumulator() 
      {
        return List::add;
      }

    @Override @Nonnull 
    public BinaryOperator> combiner() 
      {
        return (left, right) -> { left.addAll(right); return left; };
      }

    @Override @Nonnull 
    public Set characteristics() 
      {
        // Not CONCURRENT since ArrayList is not thread-safe
        return Collections.emptySet();
      }
  }