add stream() and parallelStream()

Both methods return an IntStream.

primitiveCollections/src/main/java/org/lucares/collections/IntList.java

@@ -3,6 +3,9 @@ package org.lucares.collections;
 import java.io.Serializable;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Spliterator.OfInt;
+import java.util.stream.IntStream;
+import java.util.stream.StreamSupport;
 
 /**
  * A list for primitive ints.
@@ -15,7 +18,6 @@ public class IntList implements Serializable, Cloneable {
 	// TODO support Iterator
 	// TODO add mod counts
 	// TODO support sublists
-	// TODO support Stream-API
 	// TODO add retainAll
 	// TODO add removeAll
 	// TODO add removeIf
@@ -25,6 +27,7 @@ public class IntList implements Serializable, Cloneable {
 	// TODO add indexOf
 	// TODO add toArray(int[] a)
 	// TODO remove bounds checks that are handled by java, e.g. negative indices
+	// TODO toString
 
 	private static final long serialVersionUID = -6823520157007564746L;
 
@@ -318,6 +321,46 @@ public class IntList implements Serializable, Cloneable {
 		}
 	}
 
+	/**
+	 * Returns a sequential {@link IntStream} with this collection as its source.
+	 *
+	 * @return a sequential {@link IntStream}
+	 */
+	public IntStream stream() {
+
+		return Arrays.stream(data, 0, index);
+	}
+
+	/**
+	 * Returns a parallel {@link IntStream} with this collection as its source.
+	 *
+	 * @return a parallel {@link IntStream}
+	 */
+	public IntStream parallelStream() {
+		final OfInt spliterator = Arrays.spliterator(data, 0, index);
+		return StreamSupport.intStream(spliterator, true);
+	}
+
+	@Override
+	public String toString() {
+
+		if (data == null)
+			return "null";
+		final int iMax = data.length - 1;
+		if (iMax == -1)
+			return "[]";
+
+		final StringBuilder result = new StringBuilder();
+		result.append('[');
+		for (int i = 0; i < index; i++) {
+			if (i > 0) {
+				result.append(", ");
+			}
+			result.append(data[i]);
+		}
+		return result.append(']').toString();
+	}
+
 	@Override
 	public int hashCode() {
 		if (index == 0) {