content: /*
   * Copyright © 2018-2025 Commonwealth Scientific and Industrial Research
   * Organisation (CSIRO) ABN 41 687 119 230.
   *
   * 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.
   */
  
  package au.csiro.pathling.terminology.caching;
  
  import au.csiro.pathling.terminology.PropertyOrDesignationList;
  import au.csiro.pathling.terminology.TerminologyService.PropertyOrDesignation;
  import java.util.Collections;
  import java.util.EnumSet;
  import java.util.Set;
  import java.util.function.BiConsumer;
  import java.util.function.BinaryOperator;
  import java.util.function.Function;
  import java.util.function.Supplier;
  import java.util.stream.Collector;
  
  /**
   * A collector that collects a stream of items into a {@link PropertyOrDesignationList}.
   * <p>
   * This is the same as {@link java.util.stream.Collectors#toList()} except that it returns an
   * {@link PropertyOrDesignationList} instead of a generic {@link java.util.List}.
   * <p>
   * We need this because the list implementation needs to be constrained to ensure that it is
   * serializable for persistent caching purposes.
   */
  public class PropertyOrDesignationListCollector implements
      Collector<PropertyOrDesignation, PropertyOrDesignationList, PropertyOrDesignationList> {
  
    @Override
    public Supplier<PropertyOrDesignationList> supplier() {
      return PropertyOrDesignationList::new;
    }
  
    @Override
    public BiConsumer<PropertyOrDesignationList, PropertyOrDesignation> accumulator() {
      return PropertyOrDesignationList::add;
    }
  
    @Override
    public BinaryOperator<PropertyOrDesignationList> combiner() {
      return (left, right) -> {
        left.addAll(right);
        return left;
      };
    }
  
    @Override
    public Function<PropertyOrDesignationList, PropertyOrDesignationList> finisher() {
      return Function.identity();
    }
  
    @Override
    public Set<Characteristics> characteristics() {
      return Collections.unmodifiableSet(EnumSet.of(Characteristics.IDENTITY_FINISH));
    }
  
  }
  