Option<T extends Object> class sealed

A Monad that represents an optional value: every Option is either Some and contains a value, or None and does not.

Inheritance

• Object
• Monad<T>
• Option

Implemented types

• SyncImpl<T>

Available extensions

• FlattenOptionExt2
• FlattenOptionExt3
• FlattenOptionExt4
• FlattenOptionExt5
• FlattenOptionExt6
• FlattenOptionExt7
• FlattenOptionExt8
• FlattenOptionExt9
• MapMonadExt2
• MapMonadExt3
• MapMonadExt4
• MapMonadExt5
• MapMonadExt6
• MapMonadExt7
• MapMonadExt8
• MapMonadExt9
• MapMonadExt10
• SwapOptionAsyncExt
• SwapOptionErrExt
• SwapOptionNoneExt
• SwapOptionOkExt
• SwapOptionResolvableExt
• SwapOptionResultExt
• SwapOptionSomeExt
• SwapOptionSyncExt
• ToUnitOnObjectMonad
• ToUnitOnObjectOption
• ToVoidOnMonadExt
• ToVoidOnOptionExt
• WrapOnMonadExt
• WrapOnOptionExt

Constructors

Option.from(T? value)

Creates an Option from a nullable value.

factory

Option.fromNullable(T? value)

factory

Properties

hashCode → int

The hash code for this object.

no setter, inherited

props → List<Object?>

The list of properties that will be used to determine whether two instances are equal.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

stringify → bool?

If set to true, the toString method will be overridden to output this instance's props.

no setter, inherited

value → FutureOr<Object>

final, inherited

Methods

asOption() → Option<T>

Returns this as a base Option type.

end() → void

Suppresses the linter error must_use_monad.

override

filter(bool noFutures(T value)) → Option<T>

Returns None if the predicate noFutures returns false. Otherwise, returns the original Option.

flatMap<R extends Object>(Option<R> noFutures(T value)) → Option<R>

Maps an Option<T> to Option<R> by applying a function that returns another Option.

flatten() → Option<T>

Available on Option<Option<Option<Option<Option<Option<Option<Option<Option<T>>>>>>>>>, provided by the FlattenOptionExt9 extension

flatten() → Option<T>

Available on Option<Option<T>>, provided by the FlattenOptionExt2 extension

flatten() → Option<T>

Available on Option<Option<Option<T>>>, provided by the FlattenOptionExt3 extension

flatten() → Option<T>

Available on Option<Option<Option<Option<T>>>>, provided by the FlattenOptionExt4 extension

flatten() → Option<T>

Available on Option<Option<Option<Option<Option<T>>>>>, provided by the FlattenOptionExt5 extension

flatten() → Option<T>

Available on Option<Option<Option<Option<Option<Option<T>>>>>>, provided by the FlattenOptionExt6 extension

flatten() → Option<T>

Available on Option<Option<Option<Option<Option<Option<Option<T>>>>>>>, provided by the FlattenOptionExt7 extension

flatten() → Option<T>

Available on Option<Option<Option<Option<Option<Option<Option<Option<T>>>>>>>>, provided by the FlattenOptionExt8 extension

flatten2() → Option<T>

Available on Option<Option<T>>, provided by the FlattenOptionExt2 extension

flatten3() → Option<T>

Available on Option<Option<Option<T>>>, provided by the FlattenOptionExt3 extension

flatten4() → Option<T>

Available on Option<Option<Option<Option<T>>>>, provided by the FlattenOptionExt4 extension

flatten5() → Option<T>

Available on Option<Option<Option<Option<Option<T>>>>>, provided by the FlattenOptionExt5 extension

flatten6() → Option<T>

Available on Option<Option<Option<Option<Option<Option<T>>>>>>, provided by the FlattenOptionExt6 extension

flatten7() → Option<T>

Available on Option<Option<Option<Option<Option<Option<Option<T>>>>>>>, provided by the FlattenOptionExt7 extension

flatten8() → Option<T>

Available on Option<Option<Option<Option<Option<Option<Option<Option<T>>>>>>>>, provided by the FlattenOptionExt8 extension

flatten9() → Option<T>

Available on Option<Option<Option<Option<Option<Option<Option<Option<Option<T>>>>>>>>>, provided by the FlattenOptionExt9 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.

ifNone(void noFutures(Option<T> self, None<T> none)) → Result<Option<T>>

Performs a side-effect if this is a None.

ifSome(void noFutures(Option<T> self, Some<T> some)) → Result<Option<T>>

Performs a side-effect with the contained value if this is a Some.

isNone() → bool

Returns true if this Option is a None.

isSome() → bool

Returns true if this Option is a Some.

map<R extends Object>(R noFutures(T value)) → Option<R>

Transforms the contained value using the mapper function noFutures while preserving the Monad's structure.

override

map10<R extends Object>(R mapper(T)) → TResolvableOption<Object>

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>>>, provided by the MapMonadExt10 extension

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

Available on Monad<Monad<Object>>, provided by the MapMonadExt2 extension

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

Available on Monad<Monad<Monad<Object>>>, provided by the MapMonadExt3 extension

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

Available on Monad<Monad<Monad<Monad<Object>>>>, provided by the MapMonadExt4 extension

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

Available on Monad<Monad<Monad<Monad<Monad<Object>>>>>, provided by the MapMonadExt5 extension

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

Available on Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>, provided by the MapMonadExt6 extension

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

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>, provided by the MapMonadExt7 extension

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

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>, provided by the MapMonadExt8 extension

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

Available on Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Monad<Object>>>>>>>>>, provided by the MapMonadExt9 extension

mapSome(Some<T> noFutures(Some<T> some)) → Option<T>

Transforms the inner Some instance if this is a Some.

none() → Result<None<T>>

Safely gets the None instance. Returns an Ok on None, or an Err on Some.

noneOr(Option<T> other) → Option<T>

Returns this if it's None, otherwise returns the other Option.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

orNull() → T?

Returns the contained value or null.

raw({required FutureOr<Object> onErr(Err<Object> err), required FutureOr<Object> onNone()}) → FutureOr<Object>

The low-level primitive for reducing a Monad chain. It recursively unwraps all Monad layers to return the innermost raw value, forcing the caller to handle terminal states via callbacks.

inherited

rawAsync() → Async<Object>

Reduces any Monad chain to a single Async.

inherited

rawSync() → Sync<Object>

Safely reduces any Monad chain to a single Sync.

inherited

reduce<R extends Object>() → TResolvableOption<R>

Reduces any nested Monad structure into a single TResolvableOption.

inherited

some() → Result<Some<T>>

Safely gets the Some instance. Returns an Ok on Some, or an Err on None.

someOr(Option<T> other) → Option<T>

Returns this if it's Some, otherwise returns the other Option.

swap() → Result<Option<T>>

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

swap() → Sync<Option<T>>

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

swap() → Resolvable<Option<T>>

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

swap() → Some<Option<T>>

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

swap() → Ok<Option<T>>

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

swap() → Err<Option<T>>

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

swap() → None<Option<T>>

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

swap() → Async<Option<T>>

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

toString() → String

A string representation of this object.

inherited

toUnit() → Monad<Unit>

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

toUnit() → Option<Unit>

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

toVoid() → Monad<void>

Available on Monad<T>, provided by the ToVoidOnMonadExt extension

toVoid() → Option<void>

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

transf<R extends Object>([R noFutures(T e)?]) → Result<Option<R>>

Transforms the Monad's generic type from T to R.

override

unwrap() → T

Strongly discouraged: Unsafely returns the contained value.

override

unwrapOr(T fallback) → T

Returns the contained value, or the fallback if the Monad is in an Err or None state.

override

wrapInAsync() → Async<M>

Available on M, provided by the WrapOnMonadExt extension

wrapInOk() → Ok<M>

Available on M, provided by the WrapOnMonadExt extension

wrapInResolvable() → Resolvable<M>

Available on M, provided by the WrapOnMonadExt extension

wrapInSome() → Some<M>

Available on M, provided by the WrapOnMonadExt extension

wrapInSync() → Sync<M>

Available on M, provided by the WrapOnMonadExt extension

wrapValueInAsync() → Monad<Async<T>>

Available on M, provided by the WrapOnMonadExt extension

wrapValueInAsync() → Option<Async<T>>

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

wrapValueInOk() → Monad<Ok<T>>

Available on M, provided by the WrapOnMonadExt extension

wrapValueInOk() → Option<Ok<T>>

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

wrapValueInResolvable() → Monad<Resolvable<T>>

Available on M, provided by the WrapOnMonadExt extension

wrapValueInResolvable() → Option<Resolvable<T>>

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

wrapValueInSome() → Monad<Some<T>>

Available on M, provided by the WrapOnMonadExt extension

wrapValueInSome() → Option<Some<T>>

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

wrapValueInSync() → Monad<Sync<T>>

Available on M, provided by the WrapOnMonadExt extension

wrapValueInSync() → Option<Sync<T>>

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

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

combine2<T1 extends Object, T2 extends Object>(Option<T1> o1, Option<T2> o2) → Option<(T1, T2)>

Combines 2 Option monads into 1 containing a tuple of their values if all are Some.

combine3<T1 extends Object, T2 extends Object, T3 extends Object>(Option<T1> o1, Option<T2> o2, Option<T3> o3) → Option<(T1, T2, T3)>

Combines 3 Option monads into 1 containing a tuple of their values if all are Some.