Result<O, E> class abstract

A Result is an object which can hold two possible values, an Ok or an Err.

Example:

Result<String, Exception> getData() {
  return Ok('value');
}
void main() {
  final result = getData();
  result.fold(
    (ok) => print(ok),
    (err) => print(err),
  );
}

Example 2: using Result inside of a Cubit

class MyCubit extends Cubit<MyState> {
 MyCubit(): super(MyInitialState());

  void login(String username, String password) async {
    final result = await myRepository.login(username, password);
    result.fold(
      (ok) => emit(MyLoggedInState(ok));
      (err) => emit(MyFailedLoginState(err));
    );
  }
}
Implementers

Constructors

Result()
const
Result.ofSync(O function())
Creates a Result from a synchronous callback Can be used to simplify the creation of a result when the error type is known.
factory

Properties

hashCode → int
The hash code for this object.
no setterinherited
isErr → bool
returns whether the result is Err without exposing the value.
no setter
isOk → bool
returns whether the result is Ok without exposing the value.
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

err() → E?
Returns the Err value as nullable.
fold<B>(B ok(O ok), B err(E err)) → B
Breaks the result into Ok or Err.
map<A, B>({A ok(O ok)?, B err(E err)?}) → Result<A, B>
Take the current Result and transform it's values to a new Result.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
ok() → O?
Returns the Ok value as nullable.
toString() → String
A string representation of this object.
override
unwrap([dynamic reason]) → O
Unwrap the result to get the Ok value.

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Static Methods

of<O, E>(FutureOr<O> function()) → Future<Result<O, E>>
Creates a Result from an asynchronous callback Can be used to simplify the creation of a result when the error type is known.