when<TResult extends Object?> method

@optionalTypeArgs TResult when<TResult extends Object?>(TResult $default(@JsonKey.new(name: 'user') String? username, @JsonKey.new(name: 'pass') String? password))

A switch-like method, using callbacks.

As opposed to map, this offers destructuring. It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case Subclass2(:final field2):
    return ...;
}

Implementation

@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function(@JsonKey(name: 'user')  String? username, @JsonKey(name: 'pass')  String? password)  $default,) {final _that = this;
switch (_that) {
case _HTTPAccount():
return $default(_that.username,_that.password);case _:
  throw StateError('Unexpected subclass');

}
}