None<T> class final

Represents the absence of a value.

final none = None<int>();
print(none.isNone); // true

Inheritance

Constructors

hashCode → int: The hash code for this object.
no setteroverride
isNone → bool: Returns true if this is None.
no setterinherited
isSome → bool: Returns true if this is Some.
no setterinherited
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

filter(bool predicate(T t)) → Option<T>: Returns this Option if it is Some and predicate returns true. Otherwise returns None.
override
flatMap<R>(Option<R> f(T t)) → Option<R>: Chains a computation that returns an Option, avoiding nesting.
override
fold<W>(W onNone(), W onSome(T t)) → W: Applies onNone if this is None, or onSome if this is Some.
override
getOrElse(T defaultValue()) → T: Returns the contained value if Some, otherwise returns defaultValue.
override
map<R>(R f(T t)) → Option<R>: Transforms the contained value using f if this is Some.
override
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
tap(void action(T t)) → Option<T>: Executes action if this is Some, then returns this unchanged.
override
toNullable() → T?: Returns the contained value if Some, otherwise returns null.
override
toResult<L>(L onNone()) → Result<L, T>: Converts this Option to a Result.
override
toString() → String: A string representation of this object.
override