Option<TValue> class sealed

A type that can be either Some or None.

Some is a type that contains a value of type TValue. None is a type that does not contain a value.

This class is meant to be used as a return type for functions that may return either a value or nothing, to avoid the need for null checks.

Implementers

• None
• Some

Annotations

• @immutable

Constructors

Option.none()

Creates a None instance.

const

factory

Option.some(TValue value)

Creates a Some instance.

const

factory

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

map<T>({required T onSome(TValue value), required T onNone()}) → T

Maps the Option to a new Option based on the provided onSome and onNone functions.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

onNone(void onNone()) → Option<TValue>

Calls the provided onNone function if the Option is a None instance.

onSome(void onSome(TValue value)) → Option<TValue>

Calls the provided onSome function if the Option is a Some instance.

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

from<TValue>(TValue? value) → Option<TValue>