Add CellSetFormatter, a couple of implementations, and a few tests.

git-svn-id: https://olap4j.svn.sourceforge.net/svnroot/olap4j/trunk@156 c6a108a4-781c-0410-a6c6-c2d559e19af0

src/org/olap4j/impl/CoordinateIterator.java

@@ -0,0 +1,122 @@
+/*
+// $Id$
+// This software is subject to the terms of the Common Public License
+// Agreement, available at the following URL:
+// http://www.opensource.org/licenses/cpl.html.
+// Copyright (C) 2009-2009 Julian Hyde
+// All Rights Reserved.
+// You must accept the terms of that agreement to use this software.
+*/
+package org.olap4j.impl;
+
+import java.util.Iterator;
+
+/**
+ * Iterator over the coordinates of a hyper-rectangle.
+ *
+ * <p>For example, {@code new CoordinateIterator(new int[] {3, 2})} generates
+ * the pairs {@code {0, 0}, {0, 1}, {1, 0}, {1, 1}, {2, 0}, {2, 1} }.
+ *
+ * @author jhyde
+ * @version $Id$
+ * @since Apr 7, 2009
+ */
+public class CoordinateIterator implements Iterator<int[]> {
+ private final int[] dimensions;
+ private final boolean littleEndian;
+ private final int[] current;
+ private boolean hasNext;
+
+ /**
+ * Creates a big-endian coordinate iterator.
+ *
+ * @param dimensions Array containing the number of elements of each
+ * coordinate axis
+ */
+ public CoordinateIterator(int[] dimensions) {
+ this(dimensions, false);
+ }
+
+ /**
+ * Creates a coordinate iterator.
+ *
+ * @param dimensions Array containing the number of elements of each
+ * @param littleEndian Whether coordinate 0 is the least significant
+ * (and fastest changing) coordinate
+ */
+ public CoordinateIterator(int[] dimensions, boolean littleEndian) {
+ this.dimensions = dimensions;
+ this.littleEndian = littleEndian;
+ this.current = new int[dimensions.length];
+ this.hasNext = true;
+ for (int dimension : dimensions) {
+ if (dimension <= 0) {
+ // an axis is empty. no results will be produced
+ hasNext = false;
+ break;
+ }
+ }
+ }
+
+ /**
+ * Creates an {@link Iterable} that yields a
+ * {@link org.olap4j.impl.CoordinateIterator}.
+ *
+ * <p>Useful in a foreach loop, for example:
+ *
+ * <blockquote>int[] dimensions;
+ * for (int[] coords : CoordinateIterator.iterate(dimensions)) {
+ * foo(coords);
+ * }
+ * </blockquote>
+ *
+ * @param dimensions Array containing the number of elements of each
+ * coordinate axis
+ *
+ * @return Iterable
+ */
+ public static Iterable<int[]> iterate(final int[] dimensions) {
+ return new Iterable<int[]>() {
+ public Iterator<int[]> iterator() {
+ return new CoordinateIterator(dimensions, true);
+ }
+ };
+ }
+
+ public boolean hasNext() {
+ return hasNext;
+ }
+
+ public int[] next() {
+ final int[] result = current.clone();
+ moveToNext();
+ return result;
+ }
+
+ private void moveToNext() {
+ if (littleEndian) {
+ for (int offset = 0; offset < dimensions.length; ++offset) {
+ int k = ++current[offset];
+ if (k < dimensions[offset]) {
+ return;
+ }
+ current[offset] = 0;
+ }
+ } else {
+ for (int offset = dimensions.length - 1; offset >= 0; --offset) {
+ int k = ++current[offset];
+ if (k < dimensions[offset]) {
+ return;
+ }
+ current[offset] = 0;
+ }
+ }
+ hasNext = false;
+ }
+
+ public void remove() {
+ throw new UnsupportedOperationException();
+ }
+}
+
+// End CoordinateIterator.java

src/org/olap4j/query/CellSetFormatter.java

@@ -0,0 +1,38 @@
+/*
+// $Id$
+// This software is subject to the terms of the Common Public License
+// Agreement, available at the following URL:
+// http://www.opensource.org/licenses/cpl.html.
+// Copyright (C) 2009-2009 Julian Hyde
+// All Rights Reserved.
+// You must accept the terms of that agreement to use this software.
+*/
+package org.olap4j.query;
+
+import org.olap4j.CellSet;
+
+import java.io.PrintWriter;
+
+/**
+ * Converts a {@link CellSet} into text.
+ *
+ * <p><b>This interface is experimental. It is not part of the olap4j
+ * specification and is subject to change without notice.</b></p>
+ *
+ * @author jhyde
+ * @version $Id$
+ * @since Apr 15, 2009
+ */
+public interface CellSetFormatter {
+ /**
+ * Formats a CellSet as text to a PrintWriter.
+ *
+ * @param cellSet Cell set
+ * @param pw Print writer
+ */
+ void format(
+ CellSet cellSet,
+ PrintWriter pw);
+}
+
+// End CellSetFormatter.java