Update charted to 0.4.8 and roll

packages/quiver/lib/collection.dart

Index: packages/quiver/lib/collection.dart
diff --git a/packages/quiver/lib/collection.dart b/packages/quiver/lib/collection.dart
index 269aaac27304ea5bcd1bb85efdf9515c52408b22..4e8f3102fa1181f5e67898622316d912c9fcdb94 100644
--- a/packages/quiver/lib/collection.dart
+++ b/packages/quiver/lib/collection.dart
@@ -12,9 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-/**
- * Collection classes and related utilities.
- */
+/// Collection classes and related utilities.
 library quiver.collection;
 
 import 'dart:collection';
@@ -33,13 +31,11 @@ part 'src/collection/delegates/map.dart';
 part 'src/collection/delegates/queue.dart';
 part 'src/collection/delegates/set.dart';
 
-/**
- * Checks [List]s [a] and [b] for equality.
- *
- * Returns `true` if [a] and [b] are both null, or they are the same length and
- * every element of [a] is equal to the corresponding element at the same index
- * in [b].
- */
+/// Checks [List]s [a] and [b] for equality.
+///
+/// Returns `true` if [a] and [b] are both null, or they are the same length
+/// and every element of [a] is equal to the corresponding element at the same
+/// index in [b].
 bool listsEqual(List a, List b) {
   if (a == b) return true;
   if (a == null || b == null) return false;
@@ -52,12 +48,10 @@ bool listsEqual(List a, List b) {
   return true;
 }
 
-/**
- * Checks [Map]s [a] and [b] for equality.
- *
- * Returns `true` if [a] and [b] are both null, or they are the same length and
- * every key `k` in [a] exists in [b] and the values `a[k] == b[k]`.
- */
+/// Checks [Map]s [a] and [b] for equality.
+///
+/// Returns `true` if [a] and [b] are both null, or they are the same length
+/// and every key `k` in [a] exists in [b] and the values `a[k] == b[k]`.
 bool mapsEqual(Map a, Map b) {
   if (a == b) return true;
   if (a == null || b == null) return false;
@@ -72,12 +66,10 @@ bool mapsEqual(Map a, Map b) {
   return true;
 }
 
-/**
- * Checks [Set]s [a] and [b] for equality.
- *
- * Returns `true` if [a] and [b] are both null, or they are the same length and
- * every element in [b] exists in [a].
- */
+/// Checks [Set]s [a] and [b] for equality.
+///
+/// Returns `true` if [a] and [b] are both null, or they are the same length and
+/// every element in [b] exists in [a].
 bool setsEqual(Set a, Set b) {
   if (a == b) return true;
   if (a == null || b == null) return false;
@@ -85,3 +77,23 @@ bool setsEqual(Set a, Set b) {
 
   return a.containsAll(b);
 }
+
+/// Returns the index of the first item in [elements] where [predicate]
+/// evaluates to true.
+///
+/// Returns -1 if there are no items where [predicate] evaluates to true.
+int indexOf<T>(Iterable<T> elements, bool predicate(T element)) {
+  if (elements is List<T>) {
+    for (int i = 0; i < elements.length; i++) {
+      if (predicate(elements[i])) return i;
+    }
+    return -1;
+  }
+
+  int i = 0;
+  for (T element in elements) {
+    if (predicate(element)) return i;
+    i++;
+  }
+  return -1;
+}