1 files changed, 79 insertions, 0 deletions
diff --git a/src/main/java/bjc/data/CircularIterator.java b/src/main/java/bjc/data/CircularIterator.java
new file mode 100644
index 0000000..6842b26
--- /dev/null
+++ b/src/main/java/bjc/data/CircularIterator.java
@@ -0,0 +1,79 @@
+package bjc.data;
+
+import java.util.Iterator;
+
+/**
+ * An iterator that repeats elements from a provided iterable.
+ *
+ * @author EVE
+ *
+ * @param <E>
+ *                The type of the iterable.
+ */
+public class CircularIterator<E> implements Iterator<E> {
+	/* The iterable, and our current iterator into it. */
+	private Iterable<E> source;
+	private Iterator<E> curr;
+
+	/* Our current element. */
+	private E curElm;
+
+	/*
+	 * Should we actually get new iterators, or just repeat the last
+	 * element?
+	 */
+	private boolean doCircle;
+
+	/**
+	 * Create a new circular iterator.
+	 *
+	 * @param src
+	 *                The iterable to iterate from.
+	 *
+	 * @param circ
+	 *                Should we actually do circular iteration, or just
+	 *                repeat the terminal element?
+	 */
+	public CircularIterator(final Iterable<E> src, final boolean circ) {
+		source = src;
+		curr = source.iterator();
+
+		doCircle = circ;
+	}
+
+	/**
+	 * Create a new circular iterator that does actual circular iteration.
+	 *
+	 * @param src
+	 *                The iterable to iterate from.
+	 */
+	public CircularIterator(final Iterable<E> src) {
+		this(src, true);
+	}
+
+	@Override
+	public boolean hasNext() {
+		/* We always have something. */
+		return true;
+	}
+
+	@Override
+	public E next() {
+		if (!curr.hasNext()) {
+			if (!doCircle) {
+				return curElm;
+			}
+			
+			curr = source.iterator();
+		}
+
+		curElm = curr.next();
+
+		return curElm;
+	}
+
+	@Override
+	public void remove() {
+		curr.remove();
+	}
+}