Dartのクラス継承、Implicit Interface、Mix-inについて ref: http://qiita.com/t_hara/items/11555bd3720912bb0ccc

call_method.dart

class Foo {
  String call() => "foo";
}

class Greeting {
  void call(String name) => print("Hello, ${name}");
}

void main() {
  var f = new Foo();
  var g = new Greeting();
  g(f());   // Hello, foo
}

class_inheritance.dart

class Person {
  final String _name;
  Person(this._name);
  String get name => _name;
}

// クラス継承
class NewType extends Person {
  NewType(String name) : super(name);
}

implicit_interface.dart

// 分かりやすくするために冗長な記述にしています

class Person {
  final String _name;
  Person(this._name);
  String get name => _name;
}

// クラス継承
class NewType extends Person {
  NewType(String name) : super(name);
}

// 暗黙的インタフェースを実装
class MutablePerson implements Person {
  String _mutableName;
  MutablePerson(this._mutableName);
  // Personインタフェースのget nameを実装
  String get name => _mutableName;
  String set name(value) {
    this._mutableName = value;
  }
}

implicit_interface_2.dart

class Person {
  final String name;
  Person(this.name);
}

// クラス継承
class NewType extends Person {
  NewType(String name) : super(name);
}

// 暗黙的インタフェースを実装
class MutablePerson implements Person {
  String name;
  MutablePerson(this.name);
}

mixin_application

class Person {
  final String name;
  Person(this.name);
  String toString() => name;
}

/// Mix-in
class Storable {
  void save() => print(this);
}

// コンストラクタを定義しているため、mix-in適用できない
//class Storable {
//  Storable();
//  void save() => print(this);
//}

// Object以外を継承しているため、mix-in適用できない
//class Base{}
//class Storable extends Base {
//  void save() => print(this);
//}

// superを参照しているため、mix-in適用できない
//class Storable {
//  void save() => print(this);
//  String toString() => super.toString();
//}

/// Mix-in Application
class StorablePerson = Person with Storable;

void main() {
  var p = new StorablePerson()..name = "t_hara";
  p.save();
}

mixin_application2

class StorablePerson extends Person with Storable {
  StorablePerson(String name) : super(name);
}

mixin_composition

class Person {
  final String name;
  Person(this.name);
  String toString() => name;
}

/// Mix-in
abstract class Storable {
  void save() => print(this);
}

/// Mix-in
abstract class Genderable {
  Gender gender;
}

class Gender {
  static const Gender MALE = const Gender._("MALE");
  static const Gender FEMALE = const Gender._("FEMALE");
  final String _value;
  const Gender._(this._value);
  String toString() => _value;
}

/// Mix-in
abstract class Locatable {
  String location;
}

/// Mix-in Composition
abstract class FamilyRegister = Person with Genderable, Locatable;

/// Mix-in Application
class StorablePerson extends FamilyRegister with Storable {
  StorablePerson(String name) : super(name);
  String toString() => "${this.name}, ${this.gender}, ${this.location}";
}

void main() {
  var p = new StorablePerson("t_hara")
          ..gender = Gender.MALE
          ..location = "Aichi";
  p.save();
}