None (Java Scala Utils 1.10 API)

java.lang.Object
- javascalautils.None<T>

Type Parameters:

T - The type of the value represented by this instance

All Implemented Interfaces:

Serializable, Iterable<T>, Option<T>
```
public final class None<T>
extends Object
implements Option<T>, Serializable
```
Represents an empty Option.
The None is a replacement for null values representing a non-existing value.
One can consider None as a collection of size 0.
Instances of None should not be created directly, rather use the factory methods provided on Option.
- Option.empty()
- Option.None()
Since None anyways cannot represent a value it is preferable to use it as a singleton saving unnecessary instance creation.
For examples on usage refer to the documentation for Option.
Since:

1.0

Author:

Peter Nerg

See Also:

Serialized Form

Field Summary
- Fields inherited from interface javascalautils.Option
  DEFAULT_NONE

Constructor Summary

Constructors
Constructor and Description

None()

Constructors
Constructor and Description
`None()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`equals(Object other)` Returns `true` if other is a `None` as `None` is stateless comparing it to some other None is therefore always the same, `false` otherwise.
`boolean`	`exists(java.util.function.Predicate<T> predicate)` Always returns `false`.
`<R> Option<R>`	`flatMap(java.util.function.Function<T,Option<R>> function)` Always returns `this`.
`T`	`get()` Always throws `NoSuchElementException` since None cannot per definition hold any value.
`T`	`getOrElse(java.util.function.Supplier<T> supplier)` Always the value provided by the supplier.
`int`	`hashCode()` Always returns `0` as None is stateless and has no value.
`Iterator<T>`	`iterator()` Always returns an empty iterator.
`<R> Option<R>`	`map(java.util.function.Function<T,R> function)` Always returns `this`.
`Option<T>`	`orElse(java.util.function.Supplier<Option<T>> supplier)` Always the value provided by the supplier.
`java.util.stream.Stream<T>`	`stream()` Always returns an empty stream.
`<R> Either<T,R>`	`toLeft(java.util.function.Supplier<R> right)` Returns a `Right` containing the value from the provided supplier.
`<L> Either<L,T>`	`toRight(java.util.function.Supplier<L> left)` Returns a `Left` containing the value from the provided supplier.
`String`	`toString()` Returns a String representation of the instance.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface javascalautils.Option
apply, asOptional, contains, count, empty, filter, filterNot, forall, isDefined, isEmpty, iterator, None, ofOptional, orNull, stream

Methods inherited from interface java.lang.Iterable
forEach, spliterator

- Constructor Detail
  - None
```
public None()
```
- Method Detail
  - get
```
public T get()
```
    Always throws NoSuchElementException since None cannot per definition hold any value.
    
    Specified by:
    
    get in interface Option<T>
    
    Returns:
    
    The value of the Option
    
    Since:
    
    1.0
  - getOrElse
```
public T getOrElse(java.util.function.Supplier<T> supplier)
```
    Always the value provided by the supplier.
    
    Specified by:
    
    getOrElse in interface Option<T>
    
    Parameters:
    
    supplier - The supplier to use in case this is a None
    
    Returns:
    
    The value of the Option or the value provided by the supplier
    
    Since:
    
    1.0
  - exists
```
public boolean exists(java.util.function.Predicate<T> predicate)
```
    Always returns false.
    I.e. the predicate is never used as None represents nothing/no value.
    
    Specified by:
    
    exists in interface Option<T>
    
    Parameters:
    
    predicate - The predicate
    
    Returns:
    
    If the predicate matches
    
    Since:
    
    1.0
  - map
```
public <R> Option<R> map(java.util.function.Function<T,R> function)
```
    Always returns this.
    I.e. the function is never used as None represents nothing/no value.
    
    Specified by:
    
    map in interface Option<T>
    
    Type Parameters:
    
    R - The type for the return value from the function
    
    Parameters:
    
    function - The function to use
    
    Returns:
    
    The Option containing the mapped value
    
    Since:
    
    1.0
  - flatMap
```
public <R> Option<R> flatMap(java.util.function.Function<T,Option<R>> function)
```
    Always returns this.
    I.e. the function is never used as None represents nothing/no value.
    
    Specified by:
    
    flatMap in interface Option<T>
    
    Type Parameters:
    
    R - The type for the return value from the function
    
    Parameters:
    
    function - The function to use
    
    Returns:
    
    The Option containing the mapped value
    
    Since:
    
    1.2, 1.0
  - orElse
```
public Option<T> orElse(java.util.function.Supplier<Option<T>> supplier)
```
    Always the value provided by the supplier.
    
    Specified by:
    
    orElse in interface Option<T>
    
    Parameters:
    
    supplier - The supplier to use in case of None
    
    Returns:
    
    The value provided by the supplier
    
    Since:
    
    1.0
  - toLeft
```
public <R> Either<T,R> toLeft(java.util.function.Supplier<R> right)
```
    Returns a Right containing the value from the provided supplier.
    
    Specified by:
    
    toLeft in interface Option<T>
    
    Type Parameters:
    
    R - The type in case Right returned
    
    Parameters:
    
    right - The supplier to use in case this is a None
    
    Returns:
    
    The Either instance
    
    Since:
    
    1.4, 1.0
  - toRight
```
public <L> Either<L,T> toRight(java.util.function.Supplier<L> left)
```
    Returns a Left containing the value from the provided supplier.
    
    Specified by:
    
    toRight in interface Option<T>
    
    Type Parameters:
    
    L - The type in case Left returned
    
    Parameters:
    
    left - The supplier to use in case this is a None
    
    Returns:
    
    The Either instance
    
    Since:
    
    1.4, 1.0
  - equals
```
public boolean equals(Object other)
```
    Returns true if other is a None as None is stateless comparing it to some other None is therefore always the same, false otherwise.
    
    Overrides:
    
    equals in class Object
    
    Parameters:
    
    other - The other object to compare to
    
    Returns:
    
    true if other is None, false otherwise
    
    Since:
    
    1.0
  - hashCode
```
public int hashCode()
```
    Always returns 0 as None is stateless and has no value.
    
    Overrides:
    
    hashCode in class Object
    
    Returns:
    
    0
    
    Since:
    
    1.0
  - toString
```
public String toString()
```
    Returns a String representation of the instance.
    
    Overrides:
    
    toString in class Object
    
    Since:
    
    1.0
  - iterator
```
public final Iterator<T> iterator()
```
    Always returns an empty iterator.
    
    Specified by:
    
    iterator in interface Iterable<T>
    
    Returns:
    
    An empty iterator
    
    Since:
    
    1.0
  - stream
```
public final java.util.stream.Stream<T> stream()
```
    Always returns an empty stream.
    
    Returns:
    
    An empty stream
    
    Since:
    
    1.0

Class None<T>

Field Summary

Fields inherited from interface javascalautils.Option

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface javascalautils.Option

Methods inherited from interface java.lang.Iterable

Constructor Detail

None

Method Detail

get

getOrElse

exists

map

flatMap

orElse

toLeft

toRight

equals

hashCode

toString

iterator

stream