None<T extends Object> class final

A Monad that represents an Option that does not contain a value.

Inheritance
Available extensions

Constructors

None()
const

Properties

hashCode → int
The hash code for this object.
no setterinherited
props → List<Object?>
The list of properties that will be used to determine whether two instances are equal.
no setterinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
stringify → bool?
If set to true, the toString method will be overridden to output this instance's props.
no setterinherited
value → Unit
no setteroverride

Methods

asOption() → Option<T>
Returns this as a base Option type.
inherited
asVoid() → None<void>
Transforms the contained value to void.
override
end() → void
Suppresses the linter error must_use_monad.
inherited
filter(bool noFuturesAllowed(T value)) → None<T>
Returns None if the predicate noFuturesAllowed returns false. Otherwise, returns the original Option.
override
flatMap<R extends Object>(Option<R> noFuturesAllowed(T value)) → None<R>
Maps an Option<T> to Option<R> by applying a function that returns another Option.
override
flatten() → Option<T>

Available on Option<Option<T>>, provided by the FlattenOption2 extension

flatten() → Option<T>

Available on Option<Option<Option<T>>>, provided by the FlattenOption3 extension

flatten() → Option<T>

Available on Option<Option<Option<Option<T>>>>, provided by the FlattenOption4 extension

flatten() → Option<T>

Available on Option<Option<Option<Option<Option<T>>>>>, provided by the FlattenOption5 extension

flatten() → Option<T>

Available on Option<Option<Option<Option<Option<Option<T>>>>>>, provided by the FlattenOption6 extension

flatten() → Option<T>

Available on Option<Option<Option<Option<Option<Option<Option<T>>>>>>>, provided by the FlattenOption7 extension

flatten() → Option<T>

Available on Option<Option<Option<Option<Option<Option<Option<Option<T>>>>>>>>, provided by the FlattenOption8 extension

flatten() → Option<T>

Available on Option<Option<Option<Option<Option<Option<Option<Option<Option<T>>>>>>>>>, provided by the FlattenOption9 extension

flatten2() → Option<T>

Available on Option<Option<T>>, provided by the FlattenOption2 extension

flatten3() → Option<T>

Available on Option<Option<Option<T>>>, provided by the FlattenOption3 extension

flatten4() → Option<T>

Available on Option<Option<Option<Option<T>>>>, provided by the FlattenOption4 extension

flatten5() → Option<T>

Available on Option<Option<Option<Option<Option<T>>>>>, provided by the FlattenOption5 extension

flatten6() → Option<T>

Available on Option<Option<Option<Option<Option<Option<T>>>>>>, provided by the FlattenOption6 extension

flatten7() → Option<T>

Available on Option<Option<Option<Option<Option<Option<Option<T>>>>>>>, provided by the FlattenOption7 extension

flatten8() → Option<T>

Available on Option<Option<Option<Option<Option<Option<Option<Option<T>>>>>>>>, provided by the FlattenOption8 extension

flatten9() → Option<T>

Available on Option<Option<Option<Option<Option<Option<Option<Option<Option<T>>>>>>>>>, provided by the FlattenOption9 extension

fold(Option<Object>? onSome(Some<T> some), Option<Object>? onNone(None<T> none)) → Result<Option<Object>>
Folds the two cases of this Option into a single Result.
override
ifNone(void noFuturesAllowed()) → Result<None<T>>
Performs a side-effect if this is a None.
override
ifSome(void noFuturesAllowed(Some<T> some)) → Ok<None<T>>
Performs a side-effect with the contained value if this is a Some.
override
isNone() → bool
Returns true if this Option is a None.
override
isSome() → bool
Returns true if this Option is a Some.
override
map<R extends Object>(R noFuturesAllowed(T value)) → None<R>
Transforms the contained value using the mapper function noFuturesAllowed while preserving the Monad's structure.
override
map10<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>>>, provided by the MapMonad10 extension

map11<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>>>>, provided by the MapMonad11 extension

map12<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>>>>>, provided by the MapMonad12 extension

map13<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>>>>>>, provided by the MapMonad13 extension

map14<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>>>>>>>, provided by the MapMonad14 extension

map15<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>>>>>>>>, provided by the MapMonad15 extension

map16<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>>>>>>>>>, provided by the MapMonad16 extension

map17<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>>>>>>>>>>, provided by the MapMonad17 extension

map18<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>>>>>>>>>>>, provided by the MapMonad18 extension

map2<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Object>>, provided by the MapMonad2 extension

map3<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Object>>>, provided by the MapMonad3 extension

map4<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Object>>>>, provided by the MapMonad4 extension

map5<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Object>>>>>, provided by the MapMonad5 extension

map6<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>, provided by the MapMonad6 extension

map7<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>, provided by the MapMonad7 extension

map8<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>, provided by the MapMonad8 extension

map9<R extends Object>(R mapper(T)) → TReduced<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>>, provided by the MapMonad9 extension

mapSome(Some<T> noFuturesAllowed(Some<T> some)) → None<T>
Transforms the inner Some instance if this is a Some.
override
none() → Ok<None<T>>
Safely gets the None instance. Returns an Ok on None, or an Err on Some.
override
noneOr(Option<T> other) → None<T>
Returns this if it's None, otherwise returns the other Option.
override
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
orNull() → T?
Returns the contained value or null.
override
reduce<R extends Object>() → Resolvable<Option<R>>
Reduces the monad to a Resolvable of an Option of type R.
inherited
some() → Err<Some<T>>
Safely gets the Some instance. Returns an Ok on Some, or an Err on None.
override
someOr(Option<T> other) → Option<T>
Returns this if it's Some, otherwise returns the other Option.
override
swap() → Some<Option<T>>

Available on Option<Some<T>>, provided by the OptionSomeSwapX extension

swap() → Result<Option<T>>

Available on Option<Result<T>>, provided by the OptionResultSwapX extension

swap() → Async<Option<T>>

Available on Option<Async<T>>, provided by the OptionAsyncSwapX extension

swap() → Some<None<T>>

Available on None<Some<T>>, provided by the NoneSomeSwapX extension

swap() → Resolvable<Option<T>>

Available on Option<Resolvable<T>>, provided by the OptionResolvableSwapX extension

swap() → Sync<Option<T>>

Available on Option<Sync<T>>, provided by the OptionSyncSwapX extension

swap() → None<Option<T>>

Available on Option<None<T>>, provided by the OptionNoneSwapX extension

swap() → Err<Option<T>>

Available on Option<Err<T>>, provided by the OptionErrSwapX extension

swap() → Result<None<T>>

Available on None<Result<T>>, provided by the NoneResultSwapX extension

swap() → Async<None<T>>

Available on None<Async<T>>, provided by the NoneAsyncSwapX extension

swap() → Err<None<T>>

Available on None<Err<T>>, provided by the NoneErrSwapX extension

swap() → Ok<None<T>>

Available on None<Ok<T>>, provided by the NoneOkSwapX extension

swap() → Option<None<T>>

Available on None<Option<T>>, provided by the NoneOptionSwapX extension

swap() → Resolvable<None<T>>

Available on None<Resolvable<T>>, provided by the NoneResolvableSwapX extension

swap() → Sync<None<T>>

Available on None<Sync<T>>, provided by the NoneSyncSwapX extension

swap() → Ok<Option<T>>

Available on Option<Ok<T>>, provided by the OptionOkSwapX extension

toString() → String
A string representation of this object.
inherited
toUnit() → Option<Unit>

Available on Option<Object>, provided by the ToUnitOnObjectOption extension

toUnit() → Monad<Unit>

Available on Monad<Object>, provided by the ToUnitOnObjectMonad extension

toUnit() → None<Unit>

Available on None<Object>, provided by the ToUnitOnObjectNone extension

transf<R extends Object>([R noFuturesAllowed(T e)?]) → Ok<None<R>>
Transforms the Monad's generic type from T to R.
override
unwrap() → T
Unsafely returns the contained value. Throws Err the Monad is an Err or None.
override
unwrapOr(T fallback) → T
Returns the contained value, or the fallback if the Monad is in an Err or None state.
override
wrapAsync() → Async<None<T>>
Wraps this Monad in an Async.
override
wrapOk() → Ok<None<T>>
Wraps this Monad in an Ok.
override
wrapResolvable() → Resolvable<None<T>>
Wraps this Monad in a Resolvable.
override
wrapSome() → Some<None<T>>
Wraps this Monad in a Some.
override
wrapSync() → Sync<None<T>>
Wraps this Monad in a Sync.
override

Operators

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