org.organicdesign.fp.oneOf

Class None<T>

java.lang.Object

org.organicdesign.fp.oneOf.None<T>

All Implemented Interfaces:

Serializable, Option<T>

public final class None<T>
extends Object
implements Option<T>

Represents the absence of a value

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.organicdesign.fp.oneOf.Option

Option.Some<T>

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object other) Deprecated.
T	get() Return the value wrapped in this Option.
T	getOrElse(T t) If this is Some, return the value wrapped in this Option.
int	hashCode() Deprecated.
boolean	isSome() Is this Some?
<U> U	match(Fn1<T,U> has, Fn0<U> hasNot) Pass in a function to execute if its Some and another to execute if its None.
static <T> None<T>	none() Generic version of the singleton instance.
<U> Option<U>	then(Fn1<T,Option<U>> f) If this is Some, Apply the given function, else return None.
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.organicdesign.fp.oneOf.Option

of, some, someOrNullNoneOf

Method Detail

none

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

Generic version of the singleton instance.

Specified by:

none in interface Option<T>

get

public T get()

Return the value wrapped in this Option. Only safe to call this on Some.

Specified by:

get in interface Option<T>

getOrElse

public T getOrElse(T t)

If this is Some, return the value wrapped in this Option. Otherwise, return the given value.

Specified by:

getOrElse in interface Option<T>

isSome

public boolean isSome()

Is this Some?

Specified by:

isSome in interface Option<T>

match

public <U> U match(Fn1<T,U> has,
                   Fn0<U> hasNot)

Pass in a function to execute if its Some and another to execute if its None.

Specified by:

match in interface Option<T>

then

public <U> Option<U> then(Fn1<T,Option<U>> f)

If this is Some, Apply the given function, else return None. Use this to chain options together, failing fast at the first none() or continuing through as many operations that return some as possible.

Specified by:

then in interface Option<T>

hashCode

@Deprecated
public int hashCode()

Deprecated.

Valid, but deprecated because it's usually an error to call this in client code.

Overrides:

hashCode in class Object

equals

@Deprecated
public boolean equals(Object other)

Deprecated.

Valid, but deprecated because it's usually an error to call this in client code.

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object