content: /*
   * 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.calcite.adapter.enumerable;
  
  import org.apache.calcite.linq4j.function.Function2;
  
  /**
   * Performs accumulation against a pre-collected list of input sources,
   * used with {@link LazyAggregateLambdaFactory}.
   *
   * @param <TAccumulate> Type of the accumulator
   * @param <TSource>     Type of the enumerable input source
   */
  public class BasicLazyAccumulator<TAccumulate, TSource>
      implements LazyAggregateLambdaFactory.LazyAccumulator<TAccumulate, TSource> {
  
    private final Function2<TAccumulate, TSource, TAccumulate> accumulatorAdder;
  
    public BasicLazyAccumulator(Function2<TAccumulate, TSource, TAccumulate> accumulatorAdder) {
      this.accumulatorAdder = accumulatorAdder;
    }
  
    @Override public void accumulate(Iterable<TSource> sourceIterable, TAccumulate accumulator) {
      TAccumulate accumulator1 = accumulator;
      for (TSource tSource : sourceIterable) {
        accumulator1 = accumulatorAdder.apply(accumulator1, tSource);
      }
    }
  }
  