io.atlassian.fugue.extensions.step

Class OptionalStep1<A>

java.lang.Object

io.atlassian.fugue.extensions.step.OptionalStep1<A>

Type Parameters:

A - The type of the first defined value

public final class OptionalStep1<A>
extends Object

The first 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
OptionalStep1<A>	filter(Predicate<? super A> predicate) Apply the provided predicate with the previous step results.
<B> OptionalStep2<A,B>	then(Function<? super A,Optional<B>> functor) Apply the provided function with the previous Step results.
<B> OptionalStep2<A,B>	then(Supplier<Optional<B>> supplier) Apply the provided supplier with the previous Step results.
<Z> Optional<Z>	yield(Function<? super A,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 <B> OptionalStep2<A,B> then(Function<? super A,Optional<B>> 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:

B - The right hand side type of the next step result

Parameters:

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

Returns:

The next step class

then

public <B> OptionalStep2<A,B> then(Supplier<Optional<B>> 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(Function) in that the previous step results are not provided for the new step evaluation.

Type Parameters:

B - 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 OptionalStep1<A> filter(Predicate<? super A> 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(Function<? super A,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