/*
* Copyright (c) 2011-2017 Pivotal Software Inc, All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package reactor.util.function;
import java.io.
Serializable;
import java.util.
Arrays;
import java.util.
Collections;
import java.util.
Iterator;
import java.util.
List;
import java.util.
Objects;
import java.util.function.
Function;
import reactor.util.annotation.
NonNull;
import reactor.util.annotation.
Nullable;
/**
* A tuple that holds two non-null values.
*
* @param <T1> The type of the first non-null value held by this tuple
* @param <T2> The type of the second non-null value held by this tuple
* @author Jon Brisbin
* @author Stephane Maldini
*/
@
SuppressWarnings("rawtypes")
public class
Tuple2<T1, T2> implements
Iterable<
Object>,
Serializable {
private static final long
serialVersionUID = -3518082018884860684L;
@
NonNull final T1
t1;
@
NonNull final T2
t2;
Tuple2(T1
t1, T2
t2) {
this.
t1 =
Objects.
requireNonNull(
t1, "t1");
this.
t2 =
Objects.
requireNonNull(
t2, "t2");
}
/**
* Type-safe way to get the fist object of this {@link Tuples}.
*
* @return The first object
*/
public T1
getT1() {
return
t1;
}
/**
* Type-safe way to get the second object of this {@link Tuples}.
*
* @return The second object
*/
public T2
getT2() {
return
t2;
}
/**
* Map the left-hand part (T1) of this {@link Tuple2} into a different value and type,
* keeping the right-hand part (T2).
*
* @param mapper the mapping {@link Function} for the left-hand part
* @param <R> the new type for the left-hand part
* @return a new {@link Tuple2} with a different left (T1) value
*/
public <R>
Tuple2<R, T2>
mapT1(
Function<T1, R>
mapper) {
return new
Tuple2<>(
mapper.
apply(
t1),
t2);
}
/**
* Map the right-hand part (T2) of this {@link Tuple2} into a different value and type,
* keeping the left-hand part (T1).
*
* @param mapper the mapping {@link Function} for the right-hand part
* @param <R> the new type for the right-hand part
* @return a new {@link Tuple2} with a different right (T2) value
*/
public <R>
Tuple2<T1, R>
mapT2(
Function<T2, R>
mapper) {
return new
Tuple2<>(
t1,
mapper.
apply(
t2));
}
/**
* Get the object at the given index.
*
* @param index The index of the object to retrieve. Starts at 0.
* @return The object or {@literal null} if out of bounds.
*/
@
Nullable
public
Object get(int
index) {
switch (
index) {
case 0:
return
t1;
case 1:
return
t2;
default:
return null;
}
}
/**
* Turn this {@code Tuple} into a {@link List List<Object>}.
* The list isn't tied to this Tuple but is a <strong>copy</strong> with limited
* mutability ({@code add} and {@code remove} are not supported, but {@code set} is).
*
* @return A copy of the tuple as a new {@link List List<Object>}.
*/
public
List<
Object>
toList() {
return
Arrays.
asList(
toArray());
}
/**
* Turn this {@code Tuple} into a plain {@code Object[]}.
* The array isn't tied to this Tuple but is a <strong>copy</strong>.
*
* @return A copy of the tuple as a new {@link Object Object[]}.
*/
public
Object[]
toArray() {
return new
Object[]{
t1,
t2};
}
/**
* Return an <strong>immutable</strong> {@link Iterator Iterator<Object>} around
* the content of this {@code Tuple}.
*
* @implNote As an {@link Iterator} is always tied to its {@link Iterable} source by
* definition, the iterator cannot be mutable without the iterable also being mutable.
* Since {@link Tuples} are <strong>immutable</strong>, so is the {@link Iterator}
* returned by this method.
*
* @return An unmodifiable {@link Iterator} over the elements in this Tuple.
*/
@
Override
public
Iterator<
Object>
iterator() {
return
Collections.
unmodifiableList(
toList()).
iterator();
}
@
Override
public boolean
equals(@
Nullable Object o) {
if (this ==
o) {
return true;
}
if (
o == null ||
getClass() !=
o.
getClass()) {
return false;
}
Tuple2<?, ?>
tuple2 = (
Tuple2<?, ?>)
o;
return
t1.
equals(
tuple2.
t1) &&
t2.
equals(
tuple2.
t2);
}
@
Override
public int
hashCode() {
int
result =
size();
result = 31 *
result +
t1.
hashCode();
result = 31 *
result +
t2.
hashCode();
return
result;
}
/**
* Return the number of elements in this {@literal Tuples}.
*
* @return The size of this {@literal Tuples}.
*/
public int
size() {
return 2;
}
/**
* A Tuple String representation is the comma separated list of values, enclosed
* in square brackets.
* @return the Tuple String representation
*/
@
Override
public final
String toString() {
return
Tuples.
tupleStringRepresentation(
toArray()).
insert(0, '[').
append(']').
toString();
}
}