A SortedMap in Dart.

Provide a Comparator on construction to specify any custom sorting by key, value, or a combination of both.

Also includes the ability to limit the map's capacity. If the map's capacity is limited you can specify whether to eject over capacity entries from either the beginning or end of the sort when a new entry is added.

## Usage

A simple usage example:

``````import 'package:comparator_sorted_map/comparator_sorted_map.dart';

void main() {

//Sort by value
SortedMap sortByValue = SortedMap(comparator: (a, b) => a.value.compareTo(b.value));
sortByValue[0] = 'Z';
sortByValue[1] = 'Y';
sortByValue[2] = 'X';

Iterable keys = sortByValue.keys;
print(keys);
//Should print [2, 1, 0]

Iterable values = sortByValue.values;
print(values);
//Should print ['X', 'Y', 'Z']

//Sort by key
SortedMap sortByKey = SortedMap(comparator: (a, b) => a.key.compareTo(b.key));
sortByKey[2] = 'X';
sortByKey[0] = 'Y';
sortByKey[1] = 'Z';

keys = sortByKey.keys;
print(keys);
//Should print [0, 1, 2]

values = sortByKey.values;
print(values);
//Should print ['Y', 'Z', 'X']

//Limit Capacity
SortedMap limitedCapacityMap = SortedMap(
comparator: (a, b) => a.value.compareTo(b.value),
capacity: 2,
ejectFrom: EjectFrom.END
);
limitedCapacityMap[0] = 'Z';
limitedCapacityMap[1] = 'Y';
limitedCapacityMap[2] = 'X';

keys = limitedCapacityMap.keys;
print(keys);
//Should print [2, 1]

values = limitedCapacityMap.values;
print(values);
//Should print ['X', 'Y']
}
``````

## Features and bugs

Please file feature requests and bugs at the issue tracker.

## Libraries

comparator_sorted_map
A SortedMap implementation that relies on a provided Comparator for sorting. Also supports limiting the map capacity and ejecting over-capacity entries from either the beginning or the end.