[Dart] Dart-02-14: Callable classes

		Dart-02: Language Tour
Dart-02-01		Important concepts
Dart-02-02		Keywords
Dart-02-03		Variables
Dart-02-04		Built-in types
Dart-02-05		Functions
Dart-02-06		Operators
Dart-02-07		Control flow statements
Dart-02-08		Exceptions
Dart-02-09		Classes
Dart-02-10		Generics
Dart-02-11		Libraries and visibility
Dart-02-12		Asynchrony support
Dart-02-13		Generators
Dart-02-14		Callable classes
Dart-02-15		Isolates
Dart-02-16		Typedefs
Dart-02-17		Metadata
Dart-02-18		Comments

Callable classes

Dart - Callable classes

Dart class의 instance가 함수처럼 호출되도록 하려면, call() method를 구현한다.

다음 예제에서, WannabeFunction class는 세 개의 string을 가져와 연결하고, 각각을 공백으로 구분하고, 느낌표를 추가하는 call() 함수를 정의한다.

class WannabeFunction {
  String call(String a, String b, String c) => '$a $b $c!';
}

var wf = WannabeFunction();
var out = wf('Hi', 'there', 'gang');

void main() => print(out);