mapOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>(
  1. TResult? $default(
    1. MenuButtonDefault value
    )?, {
  2. TResult? webApp(
    1. MenuButtonWebApp value
    )?,
  3. TResult? commands(
    1. MenuButtonCommands value
    )?,
})

A variant of map that fallback to returning null.

It is equivalent to doing:

switch (sealedClass) {
  case final Subclass value:
    return ...;
  case _:
    return null;
}

Implementation

@optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>(
  TResult? Function(MenuButtonDefault value)? $default, {
  TResult? Function(MenuButtonWebApp value)? webApp,
  TResult? Function(MenuButtonCommands value)? commands,
}) {
  final _that = this;
  switch (_that) {
    case MenuButtonDefault() when $default != null:
      return $default(_that);
    case MenuButtonWebApp() when webApp != null:
      return webApp(_that);
    case MenuButtonCommands() when commands != null:
      return commands(_that);
    case _:
      return null;
  }
}