Package org.cactoos.scalar

Class Reduced<T>

java.lang.Object

org.cactoos.scalar.Reduced<T>

Type Parameters:

T - Scalar type

All Implemented Interfaces:

Scalar<T>

public final class Reduced<T>
extends Object
implements Scalar<T>

Reduces iterable via BiFunc.

 new Reduced<>(
     (first, last) -> first + last,
     new IterableOf<>(() -> 1L, () -> 2L, () -> 3L, () -> 4L)
 ).value() // returns 10L
 

Here is how you can use it to find one of items according to the specified BiFunc:

 final String apple = new Reduced<>(
     (first, last) -> first,
     new IterableOf<Scalar<String>>(
         () -> "Apple",
         () -> "Banana",
         () -> "Orange"
     )
 ).value();
 final String orange = new Reduced<>(
     (first, last) -> last,
     new IterableOf<Scalar<String>>(
         () -> "Apple",
         () -> "Banana",
         () -> "Orange"
     )
 ).value();
 

There is no thread-safety guarantee.

This class implements Scalar, which throws a checked Exception. This may not be convenient in many cases. To make it more convenient and get rid of the checked exception you can use the Unchecked decorator. Or you may use IoChecked to wrap it in an IOException.

Since:

0.30

Constructor Summary

Constructors

Constructor	Description
Reduced(Iterable<T> values, BiFunc<? super T,? super T,? extends T> reduce)	Ctor.
Reduced(BiFunc<? super T,? super T,? extends T> reduce, Iterable<? extends Scalar<? extends T>> scalars)	Ctor.
Reduced(BiFunc<? super T,? super T,? extends T> reduce, T... values)	Ctor.

Method Summary

Modifier and Type	Method	Description
T	value()	Convert it to the value.

Methods inherited from class java.lang.Object

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

Constructor Detail

Reduced

@SafeVarargs
public Reduced(BiFunc<? super T,? super T,? extends T> reduce,
               T... values)

Ctor.

Parameters:

reduce - Reducing function

values - Values to be wrapped as scalars

Reduced

public Reduced(Iterable<T> values,
               BiFunc<? super T,? super T,? extends T> reduce)

Ctor.

Parameters:

values - Values to be wrapped as scalars

reduce - Reducing function

Since:

0.55.0

Reduced

public Reduced(BiFunc<? super T,? super T,? extends T> reduce,
               Iterable<? extends Scalar<? extends T>> scalars)

Ctor.

Parameters:

reduce - Reducing function

scalars - The scalars

Method Detail

value

public T value()
        throws Exception

Description copied from interface: Scalar

Convert it to the value.

Specified by:

value in interface Scalar<T>

Returns:

The value

Throws:

Exception - If fails