mapOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? mapOrNull<TResult extends Object?>({
  1. TResult? server(
    1. ServerFailure value
    )?,
  2. TResult? network(
    1. NetworkFailure value
    )?,
  3. TResult? unauthorized(
    1. UnauthorizedFailure value
    )?,
  4. TResult? timeout(
    1. TimeoutFailure value
    )?,
  5. TResult? cache(
    1. CacheFailure value
    )?,
  6. TResult? unexpected(
    1. UnexpectedFailure 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( ServerFailure value)?  server,TResult? Function( NetworkFailure value)?  network,TResult? Function( UnauthorizedFailure value)?  unauthorized,TResult? Function( TimeoutFailure value)?  timeout,TResult? Function( CacheFailure value)?  cache,TResult? Function( UnexpectedFailure value)?  unexpected,}){
final _that = this;
switch (_that) {
case ServerFailure() when server != null:
return server(_that);case NetworkFailure() when network != null:
return network(_that);case UnauthorizedFailure() when unauthorized != null:
return unauthorized(_that);case TimeoutFailure() when timeout != null:
return timeout(_that);case CacheFailure() when cache != null:
return cache(_that);case UnexpectedFailure() when unexpected != null:
return unexpected(_that);case _:
  return null;

}
}