Package me.lauriichan.laylib.command.util

Class Option<T>

java.lang.Object

me.lauriichan.laylib.command.util.Option<T>

public final class Option<T>
extends Object

Method Summary

Modifier and Type	Method	Description
Optional<T>	asOptional()	returns the value as an optional
static <T> Option<T>	empty()	Returns an empty Option instance.
boolean	equals(Object obj)	Indicates whether some other object is "equal to" this Option.
Option<T>	filter(Predicate<? super T> predicate)	If a value is present, and the value matches the given predicate, returns an Option describing the value, otherwise returns an empty Option.
<U> Option<U>	flatMap(Function<? super T,? extends Option<? extends U>> mapper)	If a value is present, returns the result of applying the given Option-bearing mapping function to the value, otherwise returns an empty Option.
T	get()	returns the value
int	hashCode()	Returns the hash code of the value, if present, otherwise 0 (zero) if no value is present.
void	ifAbsent(Runnable action)	If a value is absent, performs the given action with the value, otherwise does nothing.
void	ifPresent(Consumer<? super T> action)	If a value is present, performs the given action with the value, otherwise does nothing.
void	ifPresentOrElse(Consumer<? super T> action, Runnable emptyAction)	If a value is present, performs the given action with the value, otherwise performs the given empty-based action.
boolean	isEmpty()	If a value is not present, returns true, otherwise false.
boolean	isPresent()	If a value is present, returns true, otherwise false.
<U> Option<U>	map(Function<? super T,? extends U> mapper)	If a value is present, returns an Option describing the result of applying the given mapping function to the value, otherwise returns an empty Option.
static <T> Option<T>	of(T value)	Returns an Option describing the given value.
Option<T>	or(Supplier<? extends Option<? extends T>> supplier)	If a value is present, returns an Option describing the value, otherwise returns an Option produced by the supplying function.
T	orElse(T other)	If a value is present, returns the value, otherwise returns other.
T	orElseGet(Supplier<? extends T> supplier)	If a value is present, returns the value, otherwise returns the result produced by the supplying function.
T	orElseRun(Runnable runnable)	If a value is present, returns the value, otherwise runs runnable
T	orElseThrow()	If a value is present, returns the value, otherwise throws NoSuchElementException.
<X extends Throwable> T	orElseThrow(Supplier<? extends X> exceptionSupplier)	If a value is present, returns the value, otherwise throws an exception produced by the exception supplying function.
Stream<T>	stream()	If a value is present, returns a sequential Stream containing only that value, otherwise returns an empty Stream.
String	toString()	Returns a non-empty string representation of this Option suitable for debugging.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Details

empty

public static <T> Option<T> empty()

Returns an empty Option instance. No value is present for this Option.

Type Parameters:

T - The type of the non-existent value

Returns:

an empty Option

of

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

Returns an Option describing the given value.

Type Parameters:

T - the type of the value

Parameters:

value - the value to describe

Returns:

an Option with the value

asOptional

public Optional<T> asOptional()

returns the value as an optional

Returns:

the optional

get

public T get()

returns the value

Returns:

the value described by this Option

isPresent

public boolean isPresent()

If a value is present, returns true, otherwise false.

Returns:

true if a value is present, otherwise false

isEmpty

public boolean isEmpty()

If a value is not present, returns true, otherwise false.

Returns:

true if a value is not present, otherwise false

ifPresent

public void ifPresent(Consumer<? super T> action)

If a value is present, performs the given action with the value, otherwise does nothing.

Parameters:

action - the action to be performed, if a value is present

Throws:

NullPointerException - if value is present and the given action is null

ifPresentOrElse

public void ifPresentOrElse(Consumer<? super T> action,
 Runnable emptyAction)

If a value is present, performs the given action with the value, otherwise performs the given empty-based action.

Parameters:

action - the action to be performed, if a value is present

emptyAction - the empty-based action to be performed, if no value is present

Throws:

NullPointerException - if a value is present and the given action is null, or no value is present and the given empty-based action is null.

ifAbsent

public void ifAbsent(Runnable action)

If a value is absent, performs the given action with the value, otherwise does nothing.

Parameters:

action - the action to be performed, if a value is absent

Throws:

NullPointerException - if value is absent and the given action is null

filter

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

If a value is present, and the value matches the given predicate, returns an Option describing the value, otherwise returns an empty Option.

Parameters:

predicate - the predicate to apply to a value, if present

Returns:

an Option describing the value of this Option, if a value is present and the value matches the given predicate, otherwise an empty Option

Throws:

NullPointerException - if the predicate is null

map

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

If a value is present, returns an Option describing the result of applying the given mapping function to the value, otherwise returns an empty Option.

If the mapping function returns a null result then this method returns an empty Option.

Type Parameters:

U - The type of the value returned from the mapping function

Parameters:

mapper - the mapping function to apply to a value, if present

Returns:

an Option describing the result of applying a mapping function to the value of this Option, if a value is present, otherwise an empty Option

Throws:

NullPointerException - if the mapping function is null

flatMap

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

If a value is present, returns the result of applying the given Option-bearing mapping function to the value, otherwise returns an empty Option.

This method is similar to map(Function), but the mapping function is one whose result is already an Option, and if invoked, flatMap does not wrap it within an additional Option.

Type Parameters:

U - The type of value of the Option returned by the mapping function

Parameters:

mapper - the mapping function to apply to a value, if present

Returns:

the result of applying an Option-bearing mapping function to the value of this Option, if a value is present, otherwise an empty Option

Throws:

NullPointerException - if the mapping function is null or returns a null result

or

public Option<T> or(Supplier<? extends Option<? extends T>> supplier)

If a value is present, returns an Option describing the value, otherwise returns an Option produced by the supplying function.

Parameters:

supplier - the supplying function that produces an Option to be returned

Returns:

returns an Option describing the value of this Option, if a value is present, otherwise an Option produced by the supplying function.

Throws:

NullPointerException - if the supplying function is null or produces a null result

stream

public Stream<T> stream()

If a value is present, returns a sequential Stream containing only that value, otherwise returns an empty Stream.

Returns:

the optional value as a Stream

orElse

public T orElse(T other)

If a value is present, returns the value, otherwise returns other.

Parameters:

other - the value to be returned, if no value is present. May be null.

Returns:

the value, if present, otherwise other

orElseGet

public T orElseGet(Supplier<? extends T> supplier)

If a value is present, returns the value, otherwise returns the result produced by the supplying function.

Parameters:

supplier - the supplying function that produces a value to be returned

Returns:

the value, if present, otherwise the result produced by the supplying function

Throws:

NullPointerException - if no value is present and the supplying function is null

orElseRun

public T orElseRun(Runnable runnable)

If a value is present, returns the value, otherwise runs runnable

Returns:

the value described by this Option

Throws:

NullPointerException - if no value is present and the runnable is null

orElseThrow

public T orElseThrow()

If a value is present, returns the value, otherwise throws NoSuchElementException.

Returns:

the non-null value described by this Option

Throws:

NoSuchElementException - if no value is present

orElseThrow

public <X extends Throwable> T orElseThrow(Supplier<? extends X> exceptionSupplier)
                                    throws X

If a value is present, returns the value, otherwise throws an exception produced by the exception supplying function.

Type Parameters:

X - Type of the exception to be thrown

Parameters:

exceptionSupplier - the supplying function that produces an exception to be thrown

Returns:

the value, if present

Throws:

X - if no value is present

NullPointerException - if no value is present and the exception supplying function is null

equals

public boolean equals(Object obj)

Indicates whether some other object is "equal to" this Option. The other object is considered equal if:

• it is also an Option and;
• both instances have no value present or;
• the present values are "equal to" each other via equals().

Overrides:

equals in class Object

Parameters:

obj - an object to be tested for equality

Returns:

true if the other object is "equal to" this object otherwise false

hashCode

public int hashCode()

Returns the hash code of the value, if present, otherwise 0 (zero) if no value is present.

Overrides:

hashCode in class Object

Returns:

hash code value of the present value or 0 if no value is present

toString

public String toString()

Returns a non-empty string representation of this Option suitable for debugging. The exact presentation format is unspecified and may vary between implementations and versions.

Overrides:

toString in class Object

Returns:

the string representation of this instance