Dynamic and Function

main.dart

  dynamic applyA(dynamic x) {
  if (x is Function) {
    return (dynamic f) {
      return (dynamic y) {
        return f(x(y));
      };
    };
  } else {
    return (dynamic f) {
      return f(x);
    };
  }
}

dynamic applyB(dynamic x) {
  return (dynamic f) {
    return (dynamic y) {
      if (x is Function) {
        return f(x(y));
      } else {
        return f(x);
      }
    };
  };
}    

void main() {
  const one = 1;
  addOne(int x) => x + 1;
  addTwo(int x) => x + 2;
  
  final resultA = applyA(one)(addOne); 
  final resultB = applyB(one)(addOne);
  final resultC = applyA(addOne)(addTwo)(one);
  final resultD = applyB(addOne)(addTwo)(one);
  
  print('A=$resultA\nB=$resultB\nC=$resultC\nD=$resultD');
}