Add default values to the iterator factory.

diff --git a/auto_tests/tests/utils_test.js b/auto_tests/tests/utils_test.js
index 05f7169..9c8974c 100644 (file)
--- a/auto_tests/tests/utils_test.js
+++ b/auto_tests/tests/utils_test.js
@@ -156,4 +156,17 @@ UtilsTestCase.prototype.testIterator_whole_array = function() {
   assertEquals('c', iter.next());
   assertFalse(iter.hasNext());
   assertNull(iter.next());
-}
\ No newline at end of file
+}
+
+UtilsTestCase.prototype.testIterator_no_args = function() {
+  var array = ['a', 'b', 'c'];
+  var iter = Dygraph.createIterator(array);
+  assertTrue(iter.hasNext());
+  assertEquals('a', iter.next());
+  assertTrue(iter.hasNext());
+  assertEquals('b', iter.next());
+  assertTrue(iter.hasNext());
+  assertEquals('c', iter.next());
+  assertFalse(iter.hasNext());
+  assertNull(iter.next());
+}

diff --git a/dygraph-utils.js b/dygraph-utils.js
index 907069f..9d599f3 100644 (file)
--- a/dygraph-utils.js
+++ b/dygraph-utils.js
@@ -695,10 +695,10 @@ Dygraph.isAndroid = function() {
  * @param predicate a function that takes parameters array and idx, which
  * returns true when the element should be returned. If omitted, all
  * elements are accepted.
- *
- * TODO(konigsberg): add default vlues to start and length.
  */
 Dygraph.createIterator = function(array, start, length, predicate) {
+  start = start || 0;
+  length = length || array.length;
   var iter = new function() {
     this.end_ = Math.min(array.length, start + length);
     this.nextIdx_ = start - 1; // use -1 so initial call to advance works.