Update charted to 0.4.8 and roll

packages/quiver_iterables/lib/src/min_max.dart

-// Copyright 2013 Google Inc. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-part of quiver.iterables;
-
-/// Returns the maximum value in [i], according to the order specified by the
-/// [compare] function, or `null` if [i] is empty.
-///
-/// The compare function must act as a [Comparator]. If [compare] is omitted,
-/// [Comparable.compare] is used. If [i] contains null elements, an exception
-/// will be thrown.
-///
-dynamic max(Iterable i, [Comparator compare = Comparable.compare]) =>
-    i.isEmpty ? null : i.reduce((a, b) => compare(a, b) > 0 ? a : b);
-
-/// Returns the minimum value in [i], according to the order specified by the
-/// [compare] function, or `null` if [i] is empty.
-///
-/// The compare function must act as a [Comparator]. If [compare] is omitted,
-/// [Comparable.compare] is used. If [i] contains null elements, an exception
-/// will be thrown.
-dynamic min(Iterable i, [Comparator compare = Comparable.compare]) =>
-    i.isEmpty ? null : i.reduce((a, b) => compare(a, b) < 0 ? a : b);
-
-/// Returns the minimum and maximum values in [i], according to the order
-/// specified by the [compare] function, in an [Extent] instance. Always returns
-/// an [Extent], but [Extent.min] and [Extent.max] may be `null` if [i] is empty.
-///
-/// The compare function must act as a [Comparator]. If [compare] is omitted,
-/// [Comparable.compare] is used. If [i] contains null elements, an exception
-/// will be thrown.
-///
-/// If [i] is empty, an [Extent] is returned with [:null:] values for [:min:] and
-/// [:max:], since there are no valid values for them.
-Extent extent(Iterable i, [Comparator compare = Comparable.compare]) {
-  var iterator = i.iterator;
-  var hasNext = iterator.moveNext();
-  if (!hasNext) return new Extent(null, null);
-  var max = iterator.current;
-  var min = iterator.current;
-  while (iterator.moveNext()) {
-    if (compare(max, iterator.current) < 0) max = iterator.current;
-    if (compare(min, iterator.current) > 0) min = iterator.current;
-  }
-  return new Extent(min, max);
-}
-
-class Extent {
-  final min;
-  final max;
-  Extent(this.min, this.max);
-}