io.atlassian.fugue.extensions.step

Class OptionalStep2<A,B>

java.lang.Object

io.atlassian.fugue.extensions.step.OptionalStep2<A,B>

Type Parameters:

A - The type of the first defined value

B - The type of the second defined value

public final class OptionalStep2<A,B>
extends Object

The second step of the Optional type.

This class is not intended to be contructed manually, and should only be used as part of a Steps chain, started by Steps.begin(Optional)

Since:

4.7.0

See Also:

for usage examples, Optional

Method Summary

Modifier and Type	Method and Description
OptionalStep2<A,B>	filter(BiPredicate<? super A,? super B> predicate) Apply the provided predicate with the previous step results.
<C> OptionalStep3<A,B,C>	then(BiFunction<? super A,? super B,Optional<C>> functor) Apply the provided function with the previous Step results.
<C> OptionalStep3<A,B,C>	then(Supplier<Optional<C>> supplier) Apply the provided supplier with the previous Step results.
<Z> Optional<Z>	yield(BiFunction<? super A,? super B,Z> functor) Terminating step expression, that will provide the previous steps to this function and return the result as a of

Methods inherited from class java.lang.Object

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

Method Detail

then

public <C> OptionalStep3<A,B,C> then(BiFunction<? super A,? super B,Optional<C>> functor)

Apply the provided function with the previous Step results.

Internally this will perform a Optional.flatMap(Function) and the result will become the next step value.

Type Parameters:

C - The type of the next step result

Parameters:

functor - The functor to be applied as a flatMap with the previous steps

Returns:

The next step class

then

public <C> OptionalStep3<A,B,C> then(Supplier<Optional<C>> supplier)

Apply the provided supplier with the previous Step results.

Internally this will perform a Optional.flatMap(Function) and the supplier will become the next step value.

This is different to then(BiFunction) in that the previous step results are not provided for the new step evaluation.

Type Parameters:

C - The type of the next step result

Parameters:

supplier - The supplier to provide the result of the flatMap with the previous step.

Returns:

The next step class

filter

public OptionalStep2<A,B> filter(BiPredicate<? super A,? super B> predicate)

Apply the provided predicate with the previous step results.

Parameters:

predicate - The check that must be satisfied by contained values

Returns:

This step class with either the same last step value, or changed to empty

yield

public <Z> Optional<Z> yield(BiFunction<? super A,? super B,Z> functor)

Terminating step expression, that will provide the previous steps to this function and return the result as a of

Type Parameters:

Z - The type for the returned result

Parameters:

functor - The yield function to map on previous values

Returns:

An Optional containing this result or empty