persistent 1.0.0

Efficient persistent data structures for Dart. "Persistent" means immutable here, not "saved on disk".

Efficient Persistent Data Structures

Mostly efficient persistent maps and sets for now. Also option types.

"Persistent" means immutable here, not "saved on disk".

import 'package:persistent/persistent.dart';

main() {
  final emptyMap = new PersistentMap<String,int>();
  final m1 = emptyMap.insert('a', 1).insert('b', 2);
  final m2 = new PersistentMap<String,int>.fromMap({'a': 3, 'c': 4});

  print(m1);  // {a: 1, b: 2}
  print(m2);  // {c: 4, a: 3}
  print(m1.lookup('a'));  // Option.some(1)
  print(m1.lookup('c'));  // Option.none()

  final m3 = m1.delete('a');
  print(m1);  // {a: 1, b: 2}
  print(m3);  // {b: 2}

  final m4 = m1.union(m2, (n,m) => n + m);
  print(m4);  // {c: 4, a: 4, b: 2}

  final m5 = m1.mapValues((n) => n + 1);
  print(m5);  // {a: 2, b: 3}

  final m6 = m1.adjust('a', (n) => n + 1);
  print(m6);  // {a: 2, b: 2}
}

Try it!

git clone https://github.com/polux/persistent.git
cd persistent
pub install
dart example/map_example.dart
dart example/set_example.dart
dart test/map_bench.dart

More

See ImplementationDetails and the generated API documentation for more information.