io.spine.server.tuple

Class Pair<A extends com.google.protobuf.Message,B>

java.lang.Object

io.spine.server.tuple.Tuple

io.spine.server.tuple.Pair<A,B>

Type Parameters:

A - the type of the first element

B - the type of the second element

All Implemented Interfaces:

java.io.Serializable, java.lang.Iterable<com.google.protobuf.Message>

public final class Pair<A extends com.google.protobuf.Message,B>
extends Tuple

A tuple with two elements.

The first element must be a non-default Message and not Empty.

The second element can be Message, Optional or Either.

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
A	getA() Obtains the first element of the tuple.
B	getB() Obtains the second element of the tuple.
static <A extends com.google.protobuf.Message,B extends com.google.protobuf.Message> Pair<A,B>	of(A a, B b) Creates a new pair of values.
static <A extends com.google.protobuf.Message,B extends Either> Pair<A,B>	withEither(A a, B b) Creates a pair with the second element of a type descending from Either.
static <A extends com.google.protobuf.Message,B extends com.google.protobuf.Message> Pair<A,java.util.Optional<B>>	withNullable(A a, B b) Creates a pair with optionally present second value.
static <A extends com.google.protobuf.Message,B extends com.google.protobuf.Message> Pair<A,java.util.Optional<B>>	withOptional(A a, java.util.Optional<B> b) Creates a pair with optionally present second value.

Methods inherited from class io.spine.server.tuple.Tuple

equals, get, hashCode, iterator

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Method Detail

of

public static <A extends com.google.protobuf.Message,B extends com.google.protobuf.Message> Pair<A,B> of(A a,
                                                                                                         B b)

Creates a new pair of values.

withNullable

public static <A extends com.google.protobuf.Message,B extends com.google.protobuf.Message> Pair<A,java.util.Optional<B>> withNullable(A a,
                                                                                                                                       B b)

Creates a pair with optionally present second value.

See Also:

Pair.withOptional(Message, Optional)

withOptional

public static <A extends com.google.protobuf.Message,B extends com.google.protobuf.Message> Pair<A,java.util.Optional<B>> withOptional(A a,
                                                                                                                                       java.util.Optional<B> b)

Creates a pair with optionally present second value.

See Also:

Pair.withNullable(Message, Message)

API Note:

This method treats a special case of construction using already available instance of Optional. This avoids unwrapping of Optional which would have been required for passing an optional value to Pair.withNullable(Message, Message).

withEither

public static <A extends com.google.protobuf.Message,B extends Either> Pair<A,B> withEither(A a,
                                                                                            B b)

Creates a pair with the second element of a type descending from Either.

getA

public A getA()

Obtains the first element of the tuple.

getB

public B getB()

Obtains the second element of the tuple.