content: package org.apache.solr.search.function;
  /**
   * 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.
   */
  
  import org.apache.lucene.index.IndexReader;
  import org.apache.lucene.search.Searcher;
  
  import java.util.Map;
  import java.util.Arrays;
  import java.io.IOException;
  
  
  /**
   *
   *
   **/ // a simple function of multiple sources
  public abstract class MultiFloatFunction extends ValueSource {
    protected final ValueSource[] sources;
  
    public MultiFloatFunction(ValueSource[] sources) {
      this.sources = sources;
    }
  
    abstract protected String name();
    abstract protected float func(int doc, DocValues[] valsArr);
  
    @Override
    public String description() {
      StringBuilder sb = new StringBuilder();
      sb.append(name()).append('(');
      boolean firstTime=true;
      for (ValueSource source : sources) {
        if (firstTime) {
          firstTime=false;
        } else {
          sb.append(',');
        }
        sb.append(source);
      }
      sb.append(')');
      return sb.toString();
    }
  
    @Override
    public DocValues getValues(Map context, IndexReader reader) throws IOException {
      final DocValues[] valsArr = new DocValues[sources.length];
      for (int i=0; i<sources.length; i++) {
        valsArr[i] = sources[i].getValues(context, reader);
      }
  
      return new DocValues() {
        @Override
        public float floatVal(int doc) {
          return func(doc, valsArr);
        }
        @Override
        public int intVal(int doc) {
          return (int)floatVal(doc);
        }
        @Override
        public long longVal(int doc) {
          return (long)floatVal(doc);
        }
        @Override
        public double doubleVal(int doc) {
          return (double)floatVal(doc);
        }
        @Override
        public String strVal(int doc) {
          return Float.toString(floatVal(doc));
        }
        @Override
        public String toString(int doc) {
          StringBuilder sb = new StringBuilder();
          sb.append(name()).append('(');
          boolean firstTime=true;
          for (DocValues vals : valsArr) {
            if (firstTime) {
              firstTime=false;
            } else {
              sb.append(',');
            }
            sb.append(vals.toString(doc));
          }
          sb.append(')');
          return sb.toString();
        }
      };
    }
  
    @Override
    public void createWeight(Map context, Searcher searcher) throws IOException {
      for (ValueSource source : sources)
        source.createWeight(context, searcher);
    }
  
    @Override
    public int hashCode() {
      return Arrays.hashCode(sources) + name().hashCode();
    }
  
    @Override
    public boolean equals(Object o) {
      if (this.getClass() != o.getClass()) return false;
      MultiFloatFunction other = (MultiFloatFunction)o;
      return this.name().equals(other.name())
              && Arrays.equals(this.sources, other.sources);
    }
  }
  