javascalautils

Class LeftProjection<L,R>

java.lang.Object

javascalautils.LeftProjection<L,R>

All Implemented Interfaces:

Serializable, Iterable<L>

public class LeftProjection<L,R>
extends Object
implements Iterable<L>, Serializable

This is a left-biased wrapper for an instance of Either.

Since:

1.1

Author:

Peter Nerg

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
Option<T>	asOption() Returns the value of the Right/Left in Some side in case the projection matches the side, else None.
boolean	exists(java.util.function.Predicate<L> predicate) Returns false if Right or returns the result of applying the predicate to the Left value.
Option<Either<L,R>>	filter(java.util.function.Predicate<L> predicate) Returns a Some wrapping the Either if it's a Left and the value of the Left matches the predicate, else None .
<T> Either<T,R>	flatMap(java.util.function.Function<L,Left<T,R>> function) If this projection contains a Left then a new Left is returned containing the value from the original Right mapped via the provided function, else the contained Either is returned as is.
boolean	forAll(java.util.function.Predicate<L> predicate) Returns true if Right or returns the result of applying the predicate to the Left value.
T	get() Returns the value of the Right/Left side in case the projection matches the side, else throw NoSuchElementException.
L	getOrElse(java.util.function.Supplier<L> supplier) Returns the value if this is a Left else the value provided by the supplier.
Iterator<T>	iterator() Returns the iterator of the Right/Left side in case the projection matches the side.
<T> Either<T,R>	map(java.util.function.Function<L,T> function) If this projection contains a Left then a new Left is returned containing the value from the original Right mapped via the provided function, else the contained Either is returned as is.
T	orNull() Returns the value of this projection if it is of the correct type else null.
java.util.stream.Stream<T>	stream() Returns the stream of the Right/Left side in case the projection matches the side.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Method Detail

exists

public boolean exists(java.util.function.Predicate<L> predicate)

Returns false if Right or returns the result of applying the predicate to the Left value.

Parameters:

predicate - The predicate to apply

Returns:

If this is a Left and the predicate matches the value

getOrElse

public L getOrElse(java.util.function.Supplier<L> supplier)

Returns the value if this is a Left else the value provided by the supplier.

Parameters:

supplier - The supplier

Returns:

The value

filter

public Option<Either<L,R>> filter(java.util.function.Predicate<L> predicate)

Returns a Some wrapping the Either if it's a Left and the value of the Left matches the predicate, else None .

Parameters:

predicate - The predicate to apply

Returns:

The resulting Option of the filter operation

forAll

public boolean forAll(java.util.function.Predicate<L> predicate)

Returns true if Right or returns the result of applying the predicate to the Left value.

Parameters:

predicate - The predicate to apply

Returns:

If it is a match

map

public <T> Either<T,R> map(java.util.function.Function<L,T> function)

If this projection contains a Left then a new Left is returned containing the value from the original Right mapped via the provided function, else the contained Either is returned as is.

Type Parameters:

T - The type to return as the new Left

Parameters:

function - The function

Returns:

Mapped Either

flatMap

public <T> Either<T,R> flatMap(java.util.function.Function<L,Left<T,R>> function)

If this projection contains a Left then a new Left is returned containing the value from the original Right mapped via the provided function, else the contained Either is returned as is.

Type Parameters:

T - The type to return as the new Left

Parameters:

function - The function

Returns:

Mapped Either

Since:

1.2

asOption

public Option<T> asOption()

Returns the value of the Right/Left in Some side in case the projection matches the side, else None.
That is:
If this is a RightProjection with a Right
or
If this is a LeftProjection with a Left.
Then then return Some containing the value of the Left/Right.
Any other case, return None.

Returns:

The Option

get

public T get()

Returns the value of the Right/Left side in case the projection matches the side, else throw NoSuchElementException.
That is:
If this is a RightProjection with a Right
or
If this is a LeftProjection with a Left.
Then return the value of the Left/Right.
Any other case, throw NoSuchElementException.

Returns:

The value

iterator

public Iterator<T> iterator()

Returns the iterator of the Right/Left side in case the projection matches the side.
That is:
If this is a RightProjection with a Right
or
If this is a LeftProjection with a Left.
Then return an iterator with the value for the Left/Right.
Else return an empty iterator

Specified by:

iterator in interface Iterable<T>

Returns:

The iterator

stream

public java.util.stream.Stream<T> stream()

Returns the stream of the Right/Left side in case the projection matches the side.
That is:
If this is a RightProjection with a Right
or
If this is a LeftProjection with a Left.
Then return a stream with the value for the Left/Right.
Else return an empty stream

Returns:

The stream

orNull

public T orNull()

Returns the value of this projection if it is of the correct type else null.
That is:
If this is a RightProjection with a Right
or
If this is a LeftProjection with a Left.
Then return the value of the Left/Right.
Any other case, return null.
In an essence this is a specialized version of getOrElse(Supplier) where the supplier returns null.
getOrElse(() -> null)

Returns:

The value or null