Modifier and Type	Class and Description
public static class	Option.None< The type of the optional value. T> None is a singleton representation of the undefined `Option`.
public static class	Option.Some< The type of the optional value. T> Some represents a defined `Option`.

Modifier and Type	Field and Description
public static final long	serialVersionUID

Method Summary

Modifier and Type	Method and Description
public default < The new value type R> Option<R>	Returns: A new `Option` instance containing value of type `R` collect(PartialFunction<? super T, ? extends R> A function that is not necessarily defined on value of this option. partialFunction) Collects value that is in the domain of the given `partialFunction` by mapping the value to type `R`.
public boolean	equals(Object An object o) Redeclares io.vavr.Value.equals. Clarifies that values have a proper equals() method implemented.
public default Option<T>	Returns: `Some(value)` or `None` as specified filter(Predicate<? super T> A predicate which is used to test an optional value predicate) Returns `Some(value)` if this is a `Some` and the value satisfies the given predicate.
public default < Component type of the resulting Option U> Option<U>	Returns: a new `Option` flatMap(Function<? super T, ? extends Option<? extends U>> A mapper mapper) Maps the value to a new `Option` if this is a `Some`, otherwise returns `None`.
public default < type of the folded value U> U	Returns: A value of type U fold(Supplier<? extends U> maps the left value if this is a None ifNone, Function<? super T, ? extends U> maps the value if this is a Some f) Folds either the `None` or the `Some` side of the Option value.
public T	Returns: the value get() Redeclares io.vavr.Value.get. Gets the value if this is a `Some` or throws if this is a `None`.
public default T	Returns: This value, if this Option is defined or the `other` value, if this Option is empty. getOrElse(T An alternative value other) Overrides default io.vavr.Value.getOrElse. Returns the value if this is a `Some` or the `other` value if this is a `None`.
public default T	Returns: This value, if this Option is defined or the `other` value, if this Option is empty. getOrElse(Supplier<? extends T> An alternative value supplier supplier) Overrides default io.vavr.Value.getOrElse, io.vavr.Value.getOrElse. Returns the value if this is a `Some`, otherwise the `other` value is returned, if this is a `None`.
public default < A throwable X extends Throwable> T	Returns: This value, if this Option is defined, otherwise throws X getOrElseThrow(Supplier<X> An exception supplier exceptionSupplier) Overrides default io.vavr.Value.getOrElseThrow. Returns the value if this is a `Some`, otherwise throws an exception.
public int	hashCode() Redeclares io.vavr.Value.hashCode. Clarifies that values have a proper hashCode() method implemented.
public default boolean	Returns: false isAsync() Implements io.vavr.Value.isAsync. An `Option`'s value is computed synchronously.
public default boolean	Returns: true, if this `Option` has a defined value, false otherwise isDefined() Returns true, if this is `Some`, otherwise false, if this is `None`.
public boolean	Returns: true, if this `Option` is empty, false otherwise isEmpty() Redeclares io.vavr.Value.isEmpty. Returns true, if this is `None`, otherwise false, if this is `Some`.
public default boolean	Returns: false isLazy() Implements io.vavr.Value.isLazy. An `Option`'s value is computed eagerly.
public default boolean	Returns: `true` isSingleValued() Implements io.vavr.Value.isSingleValued. An `Option` is single-valued.
public default Iterator<T>	iterator() Implements io.vavr.Value.iterator. Returns a rich `io.vavr.collection.Iterator`.
public default < The new value type U> Option<U>	Returns: a new `Some` containing the mapped value if this Option is defined, otherwise `None`, if this is empty. map(Function<? super T, ? extends U> A value mapper mapper) Implements io.vavr.Value.map. Maps the value and wraps it in a new `Some` if this is a `Some`, returns `None`.
public static < Component type of the `Option`. T> Option<T>	Returns: the given `option` instance as narrowed type `Option<T>`. narrow(Option<? extends T> A `Option`. option) Narrows a widened `Option<?`
public static < component type T> Option<T>	Returns: the single instance of `None` none() Returns the single instance of `None`
public static < type of the value T> Option<T>	Returns: `Some(value)` if value is not `null`, `None` otherwise of(T A value value) Creates a new `Option` of a given value.
public static < type of the value T> Option<T>	Returns: `Some(optional.get())` if value is Java `Optional` is present, `None` otherwise ofOptional(Optional<? extends T> a given optional to wrap in `Option` optional) Wraps a Java Optional to a new Option
public default Option<T>	Returns: this `Option` onEmpty(Runnable a given Runnable to be run action) Runs a Java Runnable passed as parameter if this `Option` is empty.
public default Option<T>	Returns: this `Option` if it is nonempty, otherwise return the alternative. orElse(Option<? extends T> An alternative `Option` other) Returns this `Option` if it is nonempty, otherwise return the alternative.
public default Option<T>	Returns: this `Option` if it is nonempty, otherwise return the result of evaluating supplier. orElse(Supplier<? extends Option<? extends T>> An alternative `Option` supplier supplier) Returns this `Option` if it is nonempty, otherwise return the result of evaluating supplier.
public default Option<T>	Returns: this `Option` peek(Consumer<? super T> An action which can be applied to an optional value action) Implements io.vavr.Value.peek. Applies an action to this value, if this option is defined, otherwise does nothing.
public static < type of the Options T> Option<Seq<T>>	Returns: An `Option` of a `Seq` of results sequence(Iterable<? extends Option<? extends T>> An `Iterable` of `Option`s values) Reduces many `Option`s into a single `Option` by transforming an `Iterable<Option<?`
public static < type of the value T> Option<T>	Returns: `Some(value)` some(T A value value) Creates a new `Some` of a given value.
public String	toString() Redeclares io.vavr.Value.toString. Clarifies that values have a proper toString() method implemented.
public default < Type of transformation result U> U	Returns: An instance of type `U` transform(Function<? super Option<T>, ? extends U> A transformation f) Transforms this `Option`.
public static < The type of the given values. T, The mapped value type. U> Option<Seq<U>>	Returns: A `Option` of a `Seq` of results. traverse(Iterable<? extends T> An `Iterable` of values. values, Function<? super T, ? extends Option<? extends U>> A mapper of values to Options mapper) Maps the values of an iterable to a sequence of mapped values into a single `Option` by transforming an `Iterable<?`
public static < type of the optional value T> Option<T>	Returns: return `Some` of supplier's value if condition is true, or `None` in other case when(boolean A boolean value condition, Supplier<? extends T> An optional value supplier, may supply `null` supplier) Creates `Some` of suppliers value if condition is true, or `None` in other case
public static < type of the optional value T> Option<T>	Returns: return `Some` of value if condition is true, or `None` in other case when(boolean A boolean value condition, T An optional value, may be `null` value) Creates `Some` of value if condition is true, or `None` in other case

Field Detail

serialVersionUID	back to summary
public static final long serialVersionUID

Method Detail

collect back to summary

collect	back to summary
public default <R> Option<R> collect(PartialFunction<? super T, ? extends R> partialFunction) Collects value that is in the domain of the given `partialFunction` by mapping the value to type `R`. `partialFunction.isDefinedAt(value)` If the element makes it through that filter, the mapped instance is wrapped in `Option` `R newValue = partialFunction.apply(value)` Parameters <R> The new value type partialFunction:PartialFunction<? super T, ? extends R> A function that is not necessarily defined on value of this option. Returns:Option<R> A new `Option` instance containing value of type `R` Exceptions NullPointerException: if `partialFunction` is null

public default <R> Option<R> collect(PartialFunction<? super T, ? extends R> partialFunction)

Collects value that is in the domain of the given partialFunction by mapping the value to type R.

partialFunction.isDefinedAt(value)

If the element makes it through that filter, the mapped instance is wrapped in Option

R newValue = partialFunction.apply(value)

Parameters

<R>: The new value type
partialFunction:PartialFunction<? super T, ? extends R>: A function that is not necessarily defined on value of this option.

Returns:Option<R>

A new Option instance containing value of type R

Exceptions

NullPointerException:: if partialFunction is null

equals	back to summary
public boolean equals(Object o) Redeclares io.vavr.Value.equals. Doc from io.vavr.Value.equals. Clarifies that values have a proper equals() method implemented. See Object.equals(Object). Parameters o:Object An object Returns:boolean true, if this equals o, false otherwise Annotations @Override

equals

back to summary

public boolean equals(Object o)

Redeclares io.vavr.Value.equals.

Doc from io.vavr.Value.equals.

Clarifies that values have a proper equals() method implemented.

See Object.equals(Object).

Parameters

o:Object: An object

Returns:boolean

true, if this equals o, false otherwise

Annotations

@Override

filter back to summary

filter	back to summary
public default Option<T> filter(Predicate<? super T> predicate) Returns `Some(value)` if this is a `Some` and the value satisfies the given predicate. Otherwise `None` is returned. Parameters predicate:Predicate<? super T> A predicate which is used to test an optional value Returns:Option<T> `Some(value)` or `None` as specified

public default Option<T> filter(Predicate<? super T> predicate)

Returns Some(value) if this is a Some and the value satisfies the given predicate. Otherwise None is returned.

Parameters

predicate:Predicate<? super T>: A predicate which is used to test an optional value

Returns:Option<T>

Some(value) or None as specified

flatMap back to summary

flatMap	back to summary
public default <U> Option<U> flatMap(Function<? super T, ? extends Option<? extends U>> mapper) Maps the value to a new `Option` if this is a `Some`, otherwise returns `None`. Parameters <U> Component type of the resulting Option mapper:Function<? super T, ? extends Option<? extends U>> A mapper Returns:Option<U> a new `Option` Annotations @SuppressWarnings:unchecked

public default Option flatMap(Function<? super T, ? extends Option<? extends U>> mapper)

Maps the value to a new Option if this is a Some, otherwise returns None.

Parameters

: Component type of the resulting Option
mapper:Function<? super T, ? extends Option<? extends U>>: A mapper

Returns:Option

a new Option

Annotations

@SuppressWarnings:unchecked

fold back to summary

fold	back to summary
public default <U> U fold(Supplier<? extends U> ifNone, Function<? super T, ? extends U> f) Folds either the `None` or the `Some` side of the Option value. Parameters <U> type of the folded value ifNone:Supplier<? extends U> maps the left value if this is a None f:Function<? super T, ? extends U> maps the value if this is a Some Returns:U A value of type U

public default U fold(Supplier<? extends U> ifNone, Function<? super T, ? extends U> f)

Folds either the None or the Some side of the Option value.

Parameters

: type of the folded value
ifNone:Supplier<? extends U>: maps the left value if this is a None
f:Function<? super T, ? extends U>: maps the value if this is a Some

Returns:U

A value of type U

get back to summary

get	back to summary
public T get() Redeclares io.vavr.Value.get. Gets the value if this is a `Some` or throws if this is a `None`. Returns:T the value Annotations @Override Exceptions NoSuchElementException: if this is a `None`.

public T get()

Redeclares io.vavr.Value.get.

Gets the value if this is a Some or throws if this is a None.

Returns:T

the value

Annotations

@Override

Exceptions

NoSuchElementException:: if this is a None.

getOrElse back to summary

getOrElse	back to summary
public default T getOrElse(T other) Overrides default io.vavr.Value.getOrElse. Returns the value if this is a `Some` or the `other` value if this is a `None`. Please note, that the other value is eagerly evaluated. Parameters other:T An alternative value Returns:T This value, if this Option is defined or the `other` value, if this Option is empty. Annotations @Override

public default T getOrElse(T other)

Overrides default io.vavr.Value.getOrElse.

Returns the value if this is a Some or the other value if this is a None.

Please note, that the other value is eagerly evaluated.

Parameters

other:T: An alternative value

Returns:T

This value, if this Option is defined or the other value, if this Option is empty.

Annotations

@Override

getOrElse back to summary

getOrElse	back to summary
public default T getOrElse(Supplier<? extends T> supplier) Overrides default io.vavr.Value.getOrElse, io.vavr.Value.getOrElse. Returns the value if this is a `Some`, otherwise the `other` value is returned, if this is a `None`. Please note, that the other value is lazily evaluated. Parameters supplier:Supplier<? extends T> An alternative value supplier Returns:T This value, if this Option is defined or the `other` value, if this Option is empty. Annotations @Override

public default T getOrElse(Supplier<? extends T> supplier)

Overrides default io.vavr.Value.getOrElse, io.vavr.Value.getOrElse.

Returns the value if this is a Some, otherwise the other value is returned, if this is a None.

Please note, that the other value is lazily evaluated.

Parameters

supplier:Supplier<? extends T>: An alternative value supplier

Returns:T

This value, if this Option is defined or the other value, if this Option is empty.

Annotations

@Override

getOrElseThrow back to summary

getOrElseThrow	back to summary
public default <X extends Throwable> T getOrElseThrow(Supplier<X> exceptionSupplier) throws Supplier-:X Overrides default io.vavr.Value.getOrElseThrow. Returns the value if this is a `Some`, otherwise throws an exception. Parameters <X> A throwable exceptionSupplier:Supplier<X> An exception supplier Returns:T This value, if this Option is defined, otherwise throws X Annotations @Override Exceptions Supplier-:X: a throwable

public default <X extends Throwable> T getOrElseThrow(Supplier<X> exceptionSupplier) throws Supplier-:X

Overrides default io.vavr.Value.getOrElseThrow.

Returns the value if this is a Some, otherwise throws an exception.

Parameters

<X>: A throwable
exceptionSupplier:Supplier<X>: An exception supplier

Returns:T

This value, if this Option is defined, otherwise throws X

Annotations

@Override

Exceptions

Supplier-:X:: a throwable

hashCode	back to summary
public int hashCode() Redeclares io.vavr.Value.hashCode. Doc from io.vavr.Value.hashCode. Clarifies that values have a proper hashCode() method implemented. See Object.hashCode(). Returns:int The hashcode of this object Annotations @Override

hashCode

back to summary

public int hashCode()

Redeclares io.vavr.Value.hashCode.

Doc from io.vavr.Value.hashCode.

Clarifies that values have a proper hashCode() method implemented.

See Object.hashCode().

Returns:int

The hashcode of this object

Annotations

@Override

isAsync back to summary

isAsync	back to summary
public default boolean isAsync() Implements io.vavr.Value.isAsync. An `Option`'s value is computed synchronously. Returns:boolean false Annotations @Override

public default boolean isAsync()

Implements io.vavr.Value.isAsync.

An Option's value is computed synchronously.

Returns:boolean

false

Annotations

@Override

isDefined back to summary

isDefined	back to summary
public default boolean isDefined() Returns true, if this is `Some`, otherwise false, if this is `None`. Please note that it is possible to create `new Some(null)`, which is defined. Returns:boolean true, if this `Option` has a defined value, false otherwise

public default boolean isDefined()

Returns true, if this is Some, otherwise false, if this is None.

Please note that it is possible to create new Some(null), which is defined.

Returns:boolean: true, if this Option has a defined value, false otherwise

isEmpty back to summary

isEmpty	back to summary
public boolean isEmpty() Redeclares io.vavr.Value.isEmpty. Returns true, if this is `None`, otherwise false, if this is `Some`. Returns:boolean true, if this `Option` is empty, false otherwise Annotations @Override

public boolean isEmpty()

Redeclares io.vavr.Value.isEmpty.

Returns true, if this is None, otherwise false, if this is Some.

Returns:boolean

true, if this Option is empty, false otherwise

Annotations

@Override

isLazy back to summary

isLazy	back to summary
public default boolean isLazy() Implements io.vavr.Value.isLazy. An `Option`'s value is computed eagerly. Returns:boolean false Annotations @Override

public default boolean isLazy()

Implements io.vavr.Value.isLazy.

An Option's value is computed eagerly.

Returns:boolean

false

Annotations

@Override

isSingleValued back to summary

isSingleValued	back to summary
public default boolean isSingleValued() Implements io.vavr.Value.isSingleValued. An `Option` is single-valued. Returns:boolean `true` Annotations @Override

public default boolean isSingleValued()

Implements io.vavr.Value.isSingleValued.

An Option is single-valued.

Returns:boolean

true

Annotations

@Override

iterator back to summary

iterator	back to summary
public default Iterator<T> iterator() Implements io.vavr.Value.iterator. Doc from io.vavr.Value.iterator. Returns a rich `io.vavr.collection.Iterator`. Returns:Iterator<T> A new Iterator Annotations @Override

public default Iterator<T> iterator()

Implements io.vavr.Value.iterator.

Doc from io.vavr.Value.iterator.

Returns a rich io.vavr.collection.Iterator.

Returns:Iterator<T>

A new Iterator

Annotations

@Override

map back to summary

map	back to summary
public default <U> Option<U> map(Function<? super T, ? extends U> mapper) Implements io.vavr.Value.map. Maps the value and wraps it in a new `Some` if this is a `Some`, returns `None`. Parameters <U> The new value type mapper:Function<? super T, ? extends U> A value mapper Returns:Option<U> a new `Some` containing the mapped value if this Option is defined, otherwise `None`, if this is empty. Annotations @Override

public default Option map(Function<? super T, ? extends U> mapper)

Implements io.vavr.Value.map.

Maps the value and wraps it in a new Some if this is a Some, returns None.

Parameters

: The new value type
mapper:Function<? super T, ? extends U>: A value mapper

Returns:Option

a new Some containing the mapped value if this Option is defined, otherwise None, if this is empty.

Annotations

@Override

narrow back to summary

narrow	back to summary
public static <T> Option<T> narrow(Option<? extends T> option) Narrows a widened `Option<? extends T>` to `Option<T>` by performing a type-safe cast. This is eligible because immutable/read-only collections are covariant. Parameters <T> Component type of the `Option`. option:Option<? extends T> A `Option`. Returns:Option<T> the given `option` instance as narrowed type `Option<T>`. Annotations @SuppressWarnings:unchecked

public static <T> Option<T> narrow(Option<? extends T> option)

Narrows a widened Option<? extends T> to Option<T> by performing a type-safe cast. This is eligible because immutable/read-only collections are covariant.

Parameters

<T>: Component type of the Option.
option:Option<? extends T>: A Option.

Returns:Option<T>

the given option instance as narrowed type Option<T>.

Annotations

@SuppressWarnings:unchecked

none back to summary

none	back to summary
public static <T> Option<T> none() Returns the single instance of `None` Parameters <T> component type Returns:Option<T> the single instance of `None`

public static <T> Option<T> none()

Returns the single instance of None

Parameters

<T>: component type

Returns:Option<T>

the single instance of None

of back to summary

of	back to summary
public static <T> Option<T> of(T value) Creates a new `Option` of a given value. Parameters <T> type of the value value:T A value Returns:Option<T> `Some(value)` if value is not `null`, `None` otherwise

public static <T> Option<T> of(T value)

Creates a new Option of a given value.

Parameters

<T>: type of the value
value:T: A value

Returns:Option<T>

Some(value) if value is not null, None otherwise

ofOptional back to summary

ofOptional	back to summary
public static <T> Option<T> ofOptional(Optional<? extends T> optional) Wraps a Java Optional to a new Option Parameters <T> type of the value optional:Optional<? extends T> a given optional to wrap in `Option` Returns:Option<T> `Some(optional.get())` if value is Java `Optional` is present, `None` otherwise Annotations @SuppressWarnings:OptionalUsedAsFieldOrParameterType

public static <T> Option<T> ofOptional(Optional<? extends T> optional)

Wraps a Java Optional to a new Option

Parameters

<T>: type of the value
optional:Optional<? extends T>: a given optional to wrap in Option

Returns:Option<T>

Some(optional.get()) if value is Java Optional is present, None otherwise

Annotations

@SuppressWarnings:OptionalUsedAsFieldOrParameterType

onEmpty back to summary

onEmpty	back to summary
public default Option<T> onEmpty(Runnable action) Runs a Java Runnable passed as parameter if this `Option` is empty. Parameters action:Runnable a given Runnable to be run Returns:Option<T> this `Option`

public default Option<T> onEmpty(Runnable action)

Runs a Java Runnable passed as parameter if this Option is empty.

Parameters

action:Runnable: a given Runnable to be run

Returns:Option<T>

this Option

orElse back to summary

orElse	back to summary
public default Option<T> orElse(Option<? extends T> other) Returns this `Option` if it is nonempty, otherwise return the alternative. Parameters other:Option<? extends T> An alternative `Option` Returns:Option<T> this `Option` if it is nonempty, otherwise return the alternative. Annotations @SuppressWarnings:unchecked

public default Option<T> orElse(Option<? extends T> other)

Returns this Option if it is nonempty, otherwise return the alternative.

Parameters

other:Option<? extends T>: An alternative Option

Returns:Option<T>

this Option if it is nonempty, otherwise return the alternative.

Annotations

@SuppressWarnings:unchecked

orElse back to summary

orElse	back to summary
public default Option<T> orElse(Supplier<? extends Option<? extends T>> supplier) Returns this `Option` if it is nonempty, otherwise return the result of evaluating supplier. Parameters supplier:Supplier<? extends Option<? extends T>> An alternative `Option` supplier Returns:Option<T> this `Option` if it is nonempty, otherwise return the result of evaluating supplier. Annotations @SuppressWarnings:unchecked

public default Option<T> orElse(Supplier<? extends Option<? extends T>> supplier)

Returns this Option if it is nonempty, otherwise return the result of evaluating supplier.

Parameters

supplier:Supplier<? extends Option<? extends T>>: An alternative Option supplier

Returns:Option<T>

this Option if it is nonempty, otherwise return the result of evaluating supplier.

Annotations

@SuppressWarnings:unchecked

peek back to summary

peek	back to summary
public default Option<T> peek(Consumer<? super T> action) Implements io.vavr.Value.peek. Applies an action to this value, if this option is defined, otherwise does nothing. Parameters action:Consumer<? super T> An action which can be applied to an optional value Returns:Option<T> this `Option` Annotations @Override

public default Option<T> peek(Consumer<? super T> action)

Implements io.vavr.Value.peek.

Applies an action to this value, if this option is defined, otherwise does nothing.

Parameters

action:Consumer<? super T>: An action which can be applied to an optional value

Returns:Option<T>

this Option

Annotations

@Override

sequence back to summary

sequence	back to summary
public static <T> Option<Seq<T>> sequence(Iterable<? extends Option<? extends T>> values) Reduces many `Option`s into a single `Option` by transforming an `Iterable<Option<? extends T>>` into a `Option<Seq<T>>`. If any of the Options are `Option.None`, then this returns `Option.None`. Parameters <T> type of the Options values:Iterable<? extends Option<? extends T>> An `Iterable` of `Option`s Returns:Option<Seq<T>> An `Option` of a `Seq` of results Exceptions NullPointerException: if `values` is null

public static <T> Option<Seq<T>> sequence(Iterable<? extends Option<? extends T>> values)

Reduces many Options into a single Option by transforming an Iterable<Option<? extends T>> into a Option<Seq<T>>. If any of the Options are Option.None, then this returns Option.None.

Parameters

<T>: type of the Options
values:Iterable<? extends Option<? extends T>>: An Iterable of Options

Returns:Option<Seq<T>>

An Option of a Seq of results

Exceptions

NullPointerException:: if values is null

some back to summary

some	back to summary
public static <T> Option<T> some(T value) Creates a new `Some` of a given value. The only difference to `Option#of(Object)` is, when called with argument `null`. `Option.of(null); // = None Option.some(null); // = Some(null)` Parameters <T> type of the value value:T A value Returns:Option<T> `Some(value)`

public static <T> Option<T> some(T value)

Creates a new Some of a given value.

The only difference to Option#of(Object) is, when called with argument null.


Option.of(null);   // = None
Option.some(null); // = Some(null)

Parameters

<T>: type of the value
value:T: A value

Returns:Option<T>

Some(value)

toString	back to summary
public String toString() Redeclares io.vavr.Value.toString. Doc from io.vavr.Value.toString. Clarifies that values have a proper toString() method implemented. See Object.toString(). Returns:String A String representation of this object Annotations @Override

toString

back to summary

public String toString()

Redeclares io.vavr.Value.toString.

Doc from io.vavr.Value.toString.

Clarifies that values have a proper toString() method implemented.

See Object.toString().

Returns:String

A String representation of this object

Annotations

@Override

transform back to summary

transform	back to summary
public default <U> U transform(Function<? super Option<T>, ? extends U> f) Transforms this `Option`. Parameters <U> Type of transformation result f:Function<? super Option<T>, ? extends U> A transformation Returns:U An instance of type `U` Exceptions NullPointerException: if `f` is null

public default U transform(Function<? super Option<T>, ? extends U> f)

Transforms this Option.

Parameters

: Type of transformation result
f:Function<? super Option<T>, ? extends U>: A transformation

Returns:U

An instance of type U

Exceptions

NullPointerException:: if f is null

traverse back to summary

traverse	back to summary
public static <T, U> Option<Seq<U>> traverse(Iterable<? extends T> values, Function<? super T, ? extends Option<? extends U>> mapper) Maps the values of an iterable to a sequence of mapped values into a single `Option` by transforming an `Iterable<? extends T>` into a `Option<Seq<U>>`. Parameters <T> The type of the given values. <U> The mapped value type. values:Iterable<? extends T> An `Iterable` of values. mapper:Function<? super T, ? extends Option<? extends U>> A mapper of values to Options Returns:Option<Seq<U>> A `Option` of a `Seq` of results. Exceptions NullPointerException: if values or f is null.

public static <T, U> Option<Seq> traverse(Iterable<? extends T> values, Function<? super T, ? extends Option<? extends U>> mapper)

Maps the values of an iterable to a sequence of mapped values into a single Option by transforming an Iterable<? extends T> into a Option<Seq>.

Parameters

<T>: The type of the given values.
: The mapped value type.
values:Iterable<? extends T>: An Iterable of values.
mapper:Function<? super T, ? extends Option<? extends U>>: A mapper of values to Options

Returns:Option<Seq>

A Option of a Seq of results.

Exceptions

NullPointerException:: if values or f is null.

when back to summary

when	back to summary
public static <T> Option<T> when(boolean condition, Supplier<? extends T> supplier) Creates `Some` of suppliers value if condition is true, or `None` in other case Parameters <T> type of the optional value condition:boolean A boolean value supplier:Supplier<? extends T> An optional value supplier, may supply `null` Returns:Option<T> return `Some` of supplier's value if condition is true, or `None` in other case Exceptions NullPointerException: if the given `supplier` is null

public static <T> Option<T> when(boolean condition, Supplier<? extends T> supplier)

Creates Some of suppliers value if condition is true, or None in other case

Parameters

<T>: type of the optional value
condition:boolean: A boolean value
supplier:Supplier<? extends T>: An optional value supplier, may supply null

Returns:Option<T>

return Some of supplier's value if condition is true, or None in other case

Exceptions

NullPointerException:: if the given supplier is null

when back to summary

when	back to summary
public static <T> Option<T> when(boolean condition, T value) Creates `Some` of value if condition is true, or `None` in other case Parameters <T> type of the optional value condition:boolean A boolean value value:T An optional value, may be `null` Returns:Option<T> return `Some` of value if condition is true, or `None` in other case

public static <T> Option<T> when(boolean condition, T value)

Creates Some of value if condition is true, or None in other case

Parameters

<T>: type of the optional value
condition:boolean: A boolean value
value:T: An optional value, may be null

Returns:Option<T>

return Some of value if condition is true, or None in other case

io.vavr.control back to summary

public final Class Option.None<T>

Class Inheritance

extends Object
implements Option<T>, Serializable

java.lang.Object
io.vavr.control.Option.None

All Implemented Interfaces

java.io.Serializable, io.vavr.control.Option, io.vavr.Value, java.lang.Iterable

Type Parameters

<T>: The type of the optional value.

None is a singleton representation of the undefined Option.

Author: Daniel Dietrich

Field Summary

Modifier and Type	Field and Description
private static final Option.None<?>	INSTANCE The singleton instance of None.
private static final long	serialVersionUID Hides io.vavr.control.Option.serialVersionUID.

Constructor Summary

Access	Constructor and Description
private	None() Hidden constructor.

Method Summary

Modifier and Type	Method and Description
public boolean	equals(Object An object o) Overrides java.lang.Object.equals. Implements io.vavr.control.Option.equals. Clarifies that values have a proper equals() method implemented.
public T	get() Implements io.vavr.control.Option.get. Gets the value if this is a `Some` or throws if this is a `None`.
public int	hashCode() Overrides java.lang.Object.hashCode. Implements io.vavr.control.Option.hashCode. Clarifies that values have a proper hashCode() method implemented.
public boolean	isEmpty() Implements io.vavr.control.Option.isEmpty. Returns true, if this is `None`, otherwise false, if this is `Some`.
private Object	Returns: The singleton instance of None. readResolve() Instance control for object serialization.
public String	stringPrefix() Implements io.vavr.Value.stringPrefix. Returns the name of this Value type, which is used by toString().
public String	toString() Overrides java.lang.Object.toString. Implements io.vavr.control.Option.toString. Clarifies that values have a proper toString() method implemented.

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll wait wait wait

Field Detail

INSTANCE	back to summary
private static final Option.None<?> INSTANCE The singleton instance of None.

serialVersionUID	back to summary
private static final long serialVersionUID Hides io.vavr.control.Option.serialVersionUID.

Constructor Detail

None	back to summary
private None() Hidden constructor.

Method Detail

equals	back to summary
public boolean equals(Object o) Overrides java.lang.Object.equals. Implements io.vavr.control.Option.equals. Doc from io.vavr.Value.equals. Clarifies that values have a proper equals() method implemented. See Object.equals(Object). Parameters o:Object An object Returns:boolean true, if this equals o, false otherwise Annotations @Override

equals

back to summary

public boolean equals(Object o)

Overrides java.lang.Object.equals.

Implements io.vavr.control.Option.equals.

Doc from io.vavr.Value.equals.

Clarifies that values have a proper equals() method implemented.

See Object.equals(Object).

Parameters

o:Object: An object

Returns:boolean

true, if this equals o, false otherwise

Annotations

@Override

get back to summary

get	back to summary
public T get() Implements io.vavr.control.Option.get. Doc from io.vavr.control.Option.get. Gets the value if this is a `Some` or throws if this is a `None`. Returns:T the value Annotations @Override

public T get()

Implements io.vavr.control.Option.get.

Doc from io.vavr.control.Option.get.

Gets the value if this is a Some or throws if this is a None.

Returns:T

the value

Annotations

@Override

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. Implements io.vavr.control.Option.hashCode. Doc from io.vavr.Value.hashCode. Clarifies that values have a proper hashCode() method implemented. See Object.hashCode(). Returns:int The hashcode of this object Annotations @Override

hashCode

back to summary

public int hashCode()

Overrides java.lang.Object.hashCode.

Implements io.vavr.control.Option.hashCode.

Doc from io.vavr.Value.hashCode.

Clarifies that values have a proper hashCode() method implemented.

See Object.hashCode().

Returns:int

The hashcode of this object

Annotations

@Override

isEmpty back to summary

isEmpty	back to summary
public boolean isEmpty() Implements io.vavr.control.Option.isEmpty. Doc from io.vavr.control.Option.isEmpty. Returns true, if this is `None`, otherwise false, if this is `Some`. Returns:boolean true, if this `Option` is empty, false otherwise Annotations @Override

public boolean isEmpty()

Implements io.vavr.control.Option.isEmpty.

Doc from io.vavr.control.Option.isEmpty.

Returns true, if this is None, otherwise false, if this is Some.

Returns:boolean

true, if this Option is empty, false otherwise

Annotations

@Override

readResolve back to summary

readResolve	back to summary
private Object readResolve() Instance control for object serialization. Returns:Object The singleton instance of None. See Also `Serializable`

private Object readResolve()

Instance control for object serialization.

Returns:Object: The singleton instance of None.
See Also: Serializable

stringPrefix	back to summary
public String stringPrefix() Implements io.vavr.Value.stringPrefix. Doc from io.vavr.Value.stringPrefix. Returns the name of this Value type, which is used by toString(). Returns:String This type name. Annotations @Override

stringPrefix

back to summary

public String stringPrefix()

Implements io.vavr.Value.stringPrefix.

Doc from io.vavr.Value.stringPrefix.

Returns the name of this Value type, which is used by toString().

Returns:String

This type name.

Annotations

@Override

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Implements io.vavr.control.Option.toString. Doc from io.vavr.Value.toString. Clarifies that values have a proper toString() method implemented. See Object.toString(). Returns:String A String representation of this object Annotations @Override

toString

back to summary

public String toString()

Overrides java.lang.Object.toString.

Implements io.vavr.control.Option.toString.

Doc from io.vavr.Value.toString.

Clarifies that values have a proper toString() method implemented.

See Object.toString().

Returns:String

A String representation of this object

Annotations

@Override

io.vavr.control back to summary

public final Class Option.Some<T>

Class Inheritance

extends Object
implements Option<T>, Serializable

java.lang.Object
io.vavr.control.Option.Some

All Implemented Interfaces

java.io.Serializable, io.vavr.control.Option, io.vavr.Value, java.lang.Iterable

Type Parameters

<T>: The type of the optional value.

Some represents a defined Option. It contains a value which may be null. However, to create an Option containing null, new Some(null) has to be called. In all other cases Option#of(Object) is sufficient.

Author: Daniel Dietrich

Field Summary

Modifier and Type	Field and Description
private static final long	serialVersionUID Hides io.vavr.control.Option.serialVersionUID.
private final T	value

Constructor Summary

Access	Constructor and Description
private	Some(T A value, may be null value) Creates a new Some containing the given value.

Method Summary

Modifier and Type	Method and Description
public boolean	equals(Object An object obj) Overrides java.lang.Object.equals. Implements io.vavr.control.Option.equals. Clarifies that values have a proper equals() method implemented.
public T	get() Implements io.vavr.control.Option.get. Gets the value if this is a `Some` or throws if this is a `None`.
public int	hashCode() Overrides java.lang.Object.hashCode. Implements io.vavr.control.Option.hashCode. Clarifies that values have a proper hashCode() method implemented.
public boolean	isEmpty() Implements io.vavr.control.Option.isEmpty. Returns true, if this is `None`, otherwise false, if this is `Some`.
public String	stringPrefix() Implements io.vavr.Value.stringPrefix. Returns the name of this Value type, which is used by toString().
public String	toString() Overrides java.lang.Object.toString. Implements io.vavr.control.Option.toString. Clarifies that values have a proper toString() method implemented.