Short form field expressions

[mnordine]

class User {
  String name;
  int age;
  String? bestFriend;

  User({required this.name, required this.age, this.bestFriend});

  bool get canVote => age >= 18;
}

void main() {
  var john = User(name: 'John Doe', age: 19, bestFriend: 'Mary');
  var mary = User(name: 'Mary Smith', age: 17);
  var users = [john, mary];
  
  // Long form
  var names = users.map((user) => user.name);
  var canVote = users.where((user) => user.canVote);
  var hasBestFriend = users.where((user) => user.bestFriend != null);
  
  // Short form
  var names = users.map(.name);
  var canVote = users.where(.canVote);
  var bestFriends = users.map(.bestFriend); // compile-time error because it's nullable? Use long form instead?
}

[eernstg]

Cf. #8 and #265.