HppcExample_005_ForEachValues.java

package com.carrotsearch.hppc.examples;

import org.junit.Test;

import com.carrotsearch.hppc.IntIntHashMap;
import com.carrotsearch.hppc.procedures.IntIntProcedure;

/**
 * An example of plucking a value from an anonymous inner class.
 */
public class HppcExample_005_ForEachValues {
  @Test
  public void forEach_FilteredCounting() {
    // Create a map of key-value pairs.
    final IntIntHashMap map = new IntIntHashMap();
    map.put(1, 2);
    map.put(2, -5);
    map.put(3, 10);
    map.put(4, -1);

    // And count only non-negative values. Note the "counter"
    // is physically part of the anonymous inner class but we can
    // access it because of how forEach is declared (it returns the exact
    // subclass type of the argument).

    int count = map.forEach(new IntIntProcedure() {
      int counter;

      public void apply(int key, int value) {
        if (value >= 0) {
          counter++;
        }
      }
    }).counter;

    System.out.println("There are " + count + " values that are non-negative.");
  }
}