net.sf.javagimmicks.collections8.MoreCollections Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of gimmicks Show documentation
Utility classes, APIs and tools for Java
There is a newer version: 0.99-alpha1
package net.sf.javagimmicks.collections8;

import java.util.Collection;
import java.util.Collections;
import java.util.function.BiConsumer;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

import net.sf.javagimmicks.util8.Pair;

/**
 * Provides some {@link Collection} helper functions in addition to
 * {@link Collections}.
 */
public class MoreCollections
{
   private MoreCollections()
   {}

   /**
    * Performs a classic "cross-product" (non-parallel)
    * {@link Iterable#forEach(java.util.function.Consumer)} operation on two
    * given {@link Iterable}s invoking the given {@link BiConsumer} for each
    * combination of elements.
    * 
    * @param aElements
    *           the first level {@link Iterable} to iterate over
    * @param bElements
    *           the second level {@link Iterable} to iterate over
    * @param action
    *           the {@link BiConsumer} which will be called with each pair of
    *           elements of the two given {@link Iterable}s
    * @param 
    *           the type of elements of the first level {@link Iterable}
    * @param 
    *           the type of elements of the second level {@link Iterable}
    */
   public static  void crossProductForEach(final Iterable aElements,
         final Iterable bElements,
         final BiConsumer action)
   {
      aElements.forEach(aElement -> //
            bElements.forEach(bElement -> //
                  action.accept(aElement, bElement)));
   }

   /**
    * Creates a sequential {@link Stream} which contains the cross-product of
    * two given {@link Collection}s as {@link Pair} objects.
    * 
    * @param aCollection
    *           the "outer" {@link Collection} for the cross-product
    * @param bCollection
    *           the "inner" {@link Collection} for the cross-product
    * @param 
    *           the type of elements of the "outer" {@link Collection}
    * @param 
    *           the type of elements of the "inner" {@link Collection}
    * @return the resulting {@link Stream} of {@link Pair}s
    */
   public static  Stream> crossProductStream(final Collection aCollection,
         final Collection bCollection)
   {
      return StreamSupport.stream(new CrossProductSpliterator(aCollection, bCollection), false);
   }

   /**
    * Creates a parallel {@link Stream} which contains the cross-product of two
    * given {@link Collection}s as {@link Pair} objects.
    * 
    * @param aCollection
    *           the "outer" {@link Collection} for the cross-product
    * @param bCollection
    *           the "inner" {@link Collection} for the cross-product
    * @param 
    *           the type of elements of the "outer" {@link Collection}
    * @param 
    *           the type of elements of the "inner" {@link Collection}
    * @return the resulting {@link Stream} of {@link Pair}s
    */
   public static  Stream> crossProductParallelStream(final Collection aCollection,
         final Collection bCollection)
   {
      return StreamSupport.stream(new CrossProductSpliterator(aCollection, bCollection), true);
   }
}