TaskResult<T extends Object, E extends Object> class abstract

A type that represents either ok/success or err/failure result, and is referred from rust's std::Result enum.

Note that if you want to catch exceptions from async task such as Future.microtask, you can not only use runZonedGuarded, but also use Future<Result> as return type and await the Future whenever you want.

Implementers

• Err
• Ok

Constructors

TaskResult.err(E _error)

Creates an err result, with given non-null data. Note that this constructor can not be used to instantiate TaskResult, use Err instead.

const

TaskResult.ok(T _data)

Creates an ok result, with given non-null data. Note that this constructor can not be used to instantiate TaskResult, use Ok instead.

const

Properties

data → T?

Returns the data of the result, this value will not be null if isOk is true.

no setter

error → E?

Returns the error of the result, this value will not be null if isErr is true.

no setter

hashCode → int

The hash code for this object.

no setter, override

isErr → bool

Returns true if the result is err, which means error is not null.

no setter

isOk → bool

Returns true if the result is ok, which means data is not null.

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

and<U extends Object>(TaskResult<U, E> res) → TaskResult<U, E>

Returns res if ok, otherwise returns error in corresponding type.

andThen<U extends Object>(TaskResult<U, E> op(T data)) → TaskResult<U, E>

Returns the result computed by op, otherwise returns error in corresponding type.

andThenAsync<U extends Object>(FutureOr<TaskResult<U, E>> op(T data)) → Future<TaskResult<U, E>>

This is the async version of andThen.

expect(Object msg) → T

Unwraps the result, returns data if ok, otherwise throws given msg.

expectErr(Object msg) → E

Unwraps the result, returns error if err, otherwise throws given msg.

inspect(void op(T data)) → TaskResult<T, E>

Calls given op if ok and returns the result as is.

inspectAsync(FutureOr<void> op(T data)) → Future<TaskResult<T, E>>

This is the async version of inspect.

inspectErr(void op(E error)) → TaskResult<T, E>

Calls given op if err and returns the result as is.

inspectErrAsync(FutureOr<void> op(E error)) → Future<TaskResult<T, E>>

This is the async version of inspectErr.

map<U extends Object>(U op(T data)) → TaskResult<U, E>

Maps the result to result with data computed by given op.

mapAsync<U extends Object>(FutureOr<U> op(T data)) → Future<TaskResult<U, E>>

This is the async version of map.

mapErr<F extends Object>(F op(E error)) → TaskResult<T, F>

Maps the result to result with target error computed by given op.

mapErrAsync<F extends Object>(FutureOr<F> op(E error)) → Future<TaskResult<T, F>>

This is the async version of mapOrElse.

mapOr<U extends Object>(U defaultValue, U op(T data)) → TaskResult<U, E>

Maps the result to result with data computed by given defaultValue value and op.

mapOrAsync<U extends Object>(U defaultValue, FutureOr<U> op(T data)) → Future<TaskResult<U, E>>

This is the async version of mapOr.

mapOrElse<U extends Object>(U defaultValue(E error), U op(T data)) → TaskResult<U, E>

Maps the result to result with data computed by given defaultValue and op.

mapOrElseAsync<U extends Object>(FutureOr<U> defaultValue(E error), FutureOr<U> op(T data)) → Future<TaskResult<U, E>>

This is the async version of mapOrElse.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

or<F extends Object>(TaskResult<T, F> res) → TaskResult<T, F>

Returns res if err, otherwise returns data in corresponding type.

orElse<F extends Object>(TaskResult<T, F> op(E error)) → TaskResult<T, F>

Returns the result computed by op, otherwise returns data in corresponding type.

orElseAsync<F extends Object>(FutureOr<TaskResult<T, F>> op(E error)) → Future<TaskResult<T, F>>

This is the async version of orElse.

toString() → String

A string representation of this object.

override

unwrap() → T

Unwraps the result, returns data if ok, otherwise throws error.

unwrapErr() → E

Unwraps the result, returns error if err, otherwise throws data.

unwrapOr(T defaultValue) → T

Unwraps the result, returns data if ok, otherwise returns given defaultValue.

unwrapOrElse(T op(E error)) → T

Unwraps the result, returns data if ok, otherwise computes it from given op.

unwrapOrElseAsync(FutureOr<T> op(E error)) → Future<T>

This is the async version of unwrapOrElse.

Operators

operator ==(Object other) → bool

The equality operator.

override