/**
* Copyright (c) 2016-present, RxJava Contributors.
*
* 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 io.reactivex.internal.functions;
import java.util.*;
import java.util.concurrent.*;
import org.reactivestreams.Subscription;
import io.reactivex.*;
import io.reactivex.exceptions.OnErrorNotImplementedException;
import io.reactivex.functions.*;
import io.reactivex.plugins.RxJavaPlugins;
import io.reactivex.schedulers.Timed;
/**
* Utility methods to convert the BiFunction, Function3..Function9 instances to Function of Object array.
*/
public final class Functions {
/** Utility class. */
private Functions() {
throw new IllegalStateException("No instances!");
}
public static <T1, T2, R> Function<Object[], R> toFunction(final BiFunction<? super T1, ? super T2, ? extends R> f) {
ObjectHelper.requireNonNull(f, "f is null");
return new Array2Func<T1, T2, R>(f);
}
public static <T1, T2, T3, R> Function<Object[], R> toFunction(final Function3<T1, T2, T3, R> f) {
ObjectHelper.requireNonNull(f, "f is null");
return new Array3Func<T1, T2, T3, R>(f);
}
public static <T1, T2, T3, T4, R> Function<Object[], R> toFunction(final Function4<T1, T2, T3, T4, R> f) {
ObjectHelper.requireNonNull(f, "f is null");
return new Array4Func<T1, T2, T3, T4, R>(f);
}
public static <T1, T2, T3, T4, T5, R> Function<Object[], R> toFunction(final Function5<T1, T2, T3, T4, T5, R> f) {
ObjectHelper.requireNonNull(f, "f is null");
return new Array5Func<T1, T2, T3, T4, T5, R>(f);
}
public static <T1, T2, T3, T4, T5, T6, R> Function<Object[], R> toFunction(
final Function6<T1, T2, T3, T4, T5, T6, R> f) {
ObjectHelper.requireNonNull(f, "f is null");
return new Array6Func<T1, T2, T3, T4, T5, T6, R>(f);
}
public static <T1, T2, T3, T4, T5, T6, T7, R> Function<Object[], R> toFunction(
final Function7<T1, T2, T3, T4, T5, T6, T7, R> f) {
ObjectHelper.requireNonNull(f, "f is null");
return new Array7Func<T1, T2, T3, T4, T5, T6, T7, R>(f);
}
public static <T1, T2, T3, T4, T5, T6, T7, T8, R> Function<Object[], R> toFunction(
final Function8<T1, T2, T3, T4, T5, T6, T7, T8, R> f) {
ObjectHelper.requireNonNull(f, "f is null");
return new Array8Func<T1, T2, T3, T4, T5, T6, T7, T8, R>(f);
}
public static <T1, T2, T3, T4, T5, T6, T7, T8, T9, R> Function<Object[], R> toFunction(
final Function9<T1, T2, T3, T4, T5, T6, T7, T8, T9, R> f) {
ObjectHelper.requireNonNull(f, "f is null");
return new Array9Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, R>(f);
}
/** A singleton identity function. */
static final Function<Object, Object> IDENTITY = new Identity();
/**
* Returns an identity function that simply returns its argument.
* @param <T> the input and output value type
* @return the identity function
*/
@SuppressWarnings("unchecked")
public static <T> Function<T, T> identity() {
return (Function<T, T>)IDENTITY;
}
public static final Runnable EMPTY_RUNNABLE = new EmptyRunnable();
public static final Action EMPTY_ACTION = new EmptyAction();
static final Consumer<Object> EMPTY_CONSUMER = new EmptyConsumer();
/**
* Returns an empty consumer that does nothing.
* @param <T> the consumed value type, the value is ignored
* @return an empty consumer that does nothing.
*/
@SuppressWarnings("unchecked")
public static <T> Consumer<T> emptyConsumer() {
return (Consumer<T>)EMPTY_CONSUMER;
}
public static final Consumer<Throwable> ERROR_CONSUMER = new ErrorConsumer();
/**
* Wraps the consumed Throwable into an OnErrorNotImplementedException and
* signals it to the plugin error handler.
*/
public static final Consumer<Throwable> ON_ERROR_MISSING = new OnErrorMissingConsumer();
public static final LongConsumer EMPTY_LONG_CONSUMER = new EmptyLongConsumer();
static final Predicate<Object> ALWAYS_TRUE = new TruePredicate();
static final Predicate<Object> ALWAYS_FALSE = new FalsePredicate();
static final Callable<Object> NULL_SUPPLIER = new NullCallable();
static final Comparator<Object> NATURAL_COMPARATOR = new NaturalObjectComparator();
@SuppressWarnings("unchecked")
public static <T> Predicate<T> alwaysTrue() {
return (Predicate<T>)ALWAYS_TRUE;
}
@SuppressWarnings("unchecked")
public static <T> Predicate<T> alwaysFalse() {
return (Predicate<T>)ALWAYS_FALSE;
}
@SuppressWarnings("unchecked")
public static <T> Callable<T> nullSupplier() {
return (Callable<T>)NULL_SUPPLIER;
}
/**
* Returns a natural order comparator which casts the parameters to Comparable.
* @param <T> the value type
* @return a natural order comparator which casts the parameters to Comparable
*/
@SuppressWarnings("unchecked")
public static <T> Comparator<T> naturalOrder() {
return (Comparator<T>)NATURAL_COMPARATOR;
}
static final class FutureAction implements Action {
final Future<?> future;
FutureAction(Future<?> future) {
this.future = future;
}
@Override
public void run() throws Exception {
future.get();
}
}
/**
* Wraps the blocking get call of the Future into an Action.
* @param future the future to call get() on, not null
* @return the new Action instance
*/
public static Action futureAction(Future<?> future) {
return new FutureAction(future);
}
static final class JustValue<T, U> implements Callable<U>, Function<T, U> {
final U value;
JustValue(U value) {
this.value = value;
}
@Override
public U call() throws Exception {
return value;
}
@Override
public U apply(T t) throws Exception {
return value;
}
}
/**
* Returns a Callable that returns the given value.
* @param <T> the value type
* @param value the value to return
* @return the new Callable instance
*/
public static <T> Callable<T> justCallable(T value) {
return new JustValue<Object, T>(value);
}
/**
* Returns a Function that ignores its parameter and returns the given value.
* @param <T> the function's input type
* @param <U> the value and return type of the function
* @param value the value to return
* @return the new Function instance
*/
public static <T, U> Function<T, U> justFunction(U value) {
return new JustValue<T, U>(value);
}
static final class CastToClass<T, U> implements Function<T, U> {
final Class<U> clazz;
CastToClass(Class<U> clazz) {
this.clazz = clazz;
}
@Override
public U apply(T t) throws Exception {
return clazz.cast(t);
}
}
/**
* Returns a function that cast the incoming values via a Class object.
* @param <T> the input value type
* @param <U> the output and target type
* @param target the target class
* @return the new Function instance
*/
public static <T, U> Function<T, U> castFunction(Class<U> target) {
return new CastToClass<T, U>(target);
}
static final class ArrayListCapacityCallable<T> implements Callable<List<T>> {
final int capacity;
ArrayListCapacityCallable(int capacity) {
this.capacity = capacity;
}
@Override
public List<T> call() throws Exception {
return new ArrayList<T>(capacity);
}
}
public static <T> Callable<List<T>> createArrayList(int capacity) {
return new ArrayListCapacityCallable<T>(capacity);
}
static final class EqualsPredicate<T> implements Predicate<T> {
final T value;
EqualsPredicate(T value) {
this.value = value;
}
@Override
public boolean test(T t) throws Exception {
return ObjectHelper.equals(t, value);
}
}
public static <T> Predicate<T> equalsWith(T value) {
return new EqualsPredicate<T>(value);
}
enum HashSetCallable implements Callable<Set<Object>> {
INSTANCE;
@Override
public Set<Object> call() throws Exception {
return new HashSet<Object>();
}
}
@SuppressWarnings({ "rawtypes", "unchecked" })
public static <T> Callable<Set<T>> createHashSet() {
return (Callable)HashSetCallable.INSTANCE;
}
static final class NotificationOnNext<T> implements Consumer<T> {
final Consumer<? super Notification<T>> onNotification;
NotificationOnNext(Consumer<? super Notification<T>> onNotification) {
this.onNotification = onNotification;
}
@Override
public void accept(T v) throws Exception {
onNotification.accept(Notification.createOnNext(v));
}
}
static final class NotificationOnError<T> implements Consumer<Throwable> {
final Consumer<? super Notification<T>> onNotification;
NotificationOnError(Consumer<? super Notification<T>> onNotification) {
this.onNotification = onNotification;
}
@Override
public void accept(Throwable v) throws Exception {
onNotification.accept(Notification.<T>createOnError(v));
}
}
static final class NotificationOnComplete<T> implements Action {
final Consumer<? super Notification<T>> onNotification;
NotificationOnComplete(Consumer<? super Notification<T>> onNotification) {
this.onNotification = onNotification;
}
@Override
public void run() throws Exception {
onNotification.accept(Notification.<T>createOnComplete());
}
}
public static <T> Consumer<T> notificationOnNext(Consumer<? super Notification<T>> onNotification) {
return new NotificationOnNext<T>(onNotification);
}
public static <T> Consumer<Throwable> notificationOnError(Consumer<? super Notification<T>> onNotification) {
return new NotificationOnError<T>(onNotification);
}
public static <T> Action notificationOnComplete(Consumer<? super Notification<T>> onNotification) {
return new NotificationOnComplete<T>(onNotification);
}
static final class ActionConsumer<T> implements Consumer<T> {
final Action action;
ActionConsumer(Action action) {
this.action = action;
}
@Override
public void accept(T t) throws Exception {
action.run();
}
}
public static <T> Consumer<T> actionConsumer(Action action) {
return new ActionConsumer<T>(action);
}
static final class ClassFilter<T, U> implements Predicate<T> {
final Class<U> clazz;
ClassFilter(Class<U> clazz) {
this.clazz = clazz;
}
@Override
public boolean test(T t) throws Exception {
return clazz.isInstance(t);
}
}
public static <T, U> Predicate<T> isInstanceOf(Class<U> clazz) {
return new ClassFilter<T, U>(clazz);
}
static final class BooleanSupplierPredicateReverse<T> implements Predicate<T> {
final BooleanSupplier supplier;
BooleanSupplierPredicateReverse(BooleanSupplier supplier) {
this.supplier = supplier;
}
@Override
public boolean test(T t) throws Exception {
return !supplier.getAsBoolean();
}
}
public static <T> Predicate<T> predicateReverseFor(BooleanSupplier supplier) {
return new BooleanSupplierPredicateReverse<T>(supplier);
}
static final class TimestampFunction<T> implements Function<T, Timed<T>> {
final TimeUnit unit;
final Scheduler scheduler;
TimestampFunction(TimeUnit unit, Scheduler scheduler) {
this.unit = unit;
this.scheduler = scheduler;
}
@Override
public Timed<T> apply(T t) throws Exception {
return new Timed<T>(t, scheduler.now(unit), unit);
}
}
public static <T> Function<T, Timed<T>> timestampWith(TimeUnit unit, Scheduler scheduler) {
return new TimestampFunction<T>(unit, scheduler);
}
static final class ToMapKeySelector<K, T> implements BiConsumer<Map<K, T>, T> {
private final Function<? super T, ? extends K> keySelector;
ToMapKeySelector(Function<? super T, ? extends K> keySelector) {
this.keySelector = keySelector;
}
@Override
public void accept(Map<K, T> m, T t) throws Exception {
K key = keySelector.apply(t);
m.put(key, t);
}
}
public static <T, K> BiConsumer<Map<K, T>, T> toMapKeySelector(final Function<? super T, ? extends K> keySelector) {
return new ToMapKeySelector<K, T>(keySelector);
}
static final class ToMapKeyValueSelector<K, V, T> implements BiConsumer<Map<K, V>, T> {
private final Function<? super T, ? extends V> valueSelector;
private final Function<? super T, ? extends K> keySelector;
ToMapKeyValueSelector(Function<? super T, ? extends V> valueSelector,
Function<? super T, ? extends K> keySelector) {
this.valueSelector = valueSelector;
this.keySelector = keySelector;
}
@Override
public void accept(Map<K, V> m, T t) throws Exception {
K key = keySelector.apply(t);
V value = valueSelector.apply(t);
m.put(key, value);
}
}
public static <T, K, V> BiConsumer<Map<K, V>, T> toMapKeyValueSelector(final Function<? super T, ? extends K> keySelector, final Function<? super T, ? extends V> valueSelector) {
return new ToMapKeyValueSelector<K, V, T>(valueSelector, keySelector);
}
static final class ToMultimapKeyValueSelector<K, V, T> implements BiConsumer<Map<K, Collection<V>>, T> {
private final Function<? super K, ? extends Collection<? super V>> collectionFactory;
private final Function<? super T, ? extends V> valueSelector;
private final Function<? super T, ? extends K> keySelector;
ToMultimapKeyValueSelector(Function<? super K, ? extends Collection<? super V>> collectionFactory,
Function<? super T, ? extends V> valueSelector, Function<? super T, ? extends K> keySelector) {
this.collectionFactory = collectionFactory;
this.valueSelector = valueSelector;
this.keySelector = keySelector;
}
@SuppressWarnings("unchecked")
@Override
public void accept(Map<K, Collection<V>> m, T t) throws Exception {
K key = keySelector.apply(t);
Collection<V> coll = m.get(key);
if (coll == null) {
coll = (Collection<V>)collectionFactory.apply(key);
m.put(key, coll);
}
V value = valueSelector.apply(t);
coll.add(value);
}
}
public static <T, K, V> BiConsumer<Map<K, Collection<V>>, T> toMultimapKeyValueSelector(
final Function<? super T, ? extends K> keySelector, final Function<? super T, ? extends V> valueSelector,
final Function<? super K, ? extends Collection<? super V>> collectionFactory) {
return new ToMultimapKeyValueSelector<K, V, T>(collectionFactory, valueSelector, keySelector);
}
enum NaturalComparator implements Comparator<Object> {
INSTANCE;
@SuppressWarnings("unchecked")
@Override
public int compare(Object o1, Object o2) {
return ((Comparable<Object>)o1).compareTo(o2);
}
}
@SuppressWarnings("unchecked")
public static <T> Comparator<T> naturalComparator() {
return (Comparator<T>)NaturalComparator.INSTANCE;
}
static final class ListSorter<T> implements Function<List<T>, List<T>> {
final Comparator<? super T> comparator;
ListSorter(Comparator<? super T> comparator) {
this.comparator = comparator;
}
@Override
public List<T> apply(List<T> v) {
Collections.sort(v, comparator);
return v;
}
}
public static <T> Function<List<T>, List<T>> listSorter(final Comparator<? super T> comparator) {
return new ListSorter<T>(comparator);
}
public static final Consumer<Subscription> REQUEST_MAX = new MaxRequestSubscription();
static final class Array2Func<T1, T2, R> implements Function<Object[], R> {
final BiFunction<? super T1, ? super T2, ? extends R> f;
Array2Func(BiFunction<? super T1, ? super T2, ? extends R> f) {
this.f = f;
}
@SuppressWarnings("unchecked")
@Override
public R apply(Object[] a) throws Exception {
if (a.length != 2) {
throw new IllegalArgumentException("Array of size 2 expected but got " + a.length);
}
return f.apply((T1)a[0], (T2)a[1]);
}
}
static final class Array3Func<T1, T2, T3, R> implements Function<Object[], R> {
final Function3<T1, T2, T3, R> f;
Array3Func(Function3<T1, T2, T3, R> f) {
this.f = f;
}
@SuppressWarnings("unchecked")
@Override
public R apply(Object[] a) throws Exception {
if (a.length != 3) {
throw new IllegalArgumentException("Array of size 3 expected but got " + a.length);
}
return f.apply((T1)a[0], (T2)a[1], (T3)a[2]);
}
}
static final class Array4Func<T1, T2, T3, T4, R> implements Function<Object[], R> {
final Function4<T1, T2, T3, T4, R> f;
Array4Func(Function4<T1, T2, T3, T4, R> f) {
this.f = f;
}
@SuppressWarnings("unchecked")
@Override
public R apply(Object[] a) throws Exception {
if (a.length != 4) {
throw new IllegalArgumentException("Array of size 4 expected but got " + a.length);
}
return f.apply((T1)a[0], (T2)a[1], (T3)a[2], (T4)a[3]);
}
}
static final class Array5Func<T1, T2, T3, T4, T5, R> implements Function<Object[], R> {
private final Function5<T1, T2, T3, T4, T5, R> f;
Array5Func(Function5<T1, T2, T3, T4, T5, R> f) {
this.f = f;
}
@SuppressWarnings("unchecked")
@Override
public R apply(Object[] a) throws Exception {
if (a.length != 5) {
throw new IllegalArgumentException("Array of size 5 expected but got " + a.length);
}
return f.apply((T1)a[0], (T2)a[1], (T3)a[2], (T4)a[3], (T5)a[4]);
}
}
static final class Array6Func<T1, T2, T3, T4, T5, T6, R> implements Function<Object[], R> {
final Function6<T1, T2, T3, T4, T5, T6, R> f;
Array6Func(Function6<T1, T2, T3, T4, T5, T6, R> f) {
this.f = f;
}
@SuppressWarnings("unchecked")
@Override
public R apply(Object[] a) throws Exception {
if (a.length != 6) {
throw new IllegalArgumentException("Array of size 6 expected but got " + a.length);
}
return f.apply((T1)a[0], (T2)a[1], (T3)a[2], (T4)a[3], (T5)a[4], (T6)a[5]);
}
}
static final class Array7Func<T1, T2, T3, T4, T5, T6, T7, R> implements Function<Object[], R> {
final Function7<T1, T2, T3, T4, T5, T6, T7, R> f;
Array7Func(Function7<T1, T2, T3, T4, T5, T6, T7, R> f) {
this.f = f;
}
@SuppressWarnings("unchecked")
@Override
public R apply(Object[] a) throws Exception {
if (a.length != 7) {
throw new IllegalArgumentException("Array of size 7 expected but got " + a.length);
}
return f.apply((T1)a[0], (T2)a[1], (T3)a[2], (T4)a[3], (T5)a[4], (T6)a[5], (T7)a[6]);
}
}
static final class Array8Func<T1, T2, T3, T4, T5, T6, T7, T8, R> implements Function<Object[], R> {
final Function8<T1, T2, T3, T4, T5, T6, T7, T8, R> f;
Array8Func(Function8<T1, T2, T3, T4, T5, T6, T7, T8, R> f) {
this.f = f;
}
@SuppressWarnings("unchecked")
@Override
public R apply(Object[] a) throws Exception {
if (a.length != 8) {
throw new IllegalArgumentException("Array of size 8 expected but got " + a.length);
}
return f.apply((T1)a[0], (T2)a[1], (T3)a[2], (T4)a[3], (T5)a[4], (T6)a[5], (T7)a[6], (T8)a[7]);
}
}
static final class Array9Func<T1, T2, T3, T4, T5, T6, T7, T8, T9, R> implements Function<Object[], R> {
final Function9<T1, T2, T3, T4, T5, T6, T7, T8, T9, R> f;
Array9Func(Function9<T1, T2, T3, T4, T5, T6, T7, T8, T9, R> f) {
this.f = f;
}
@SuppressWarnings("unchecked")
@Override
public R apply(Object[] a) throws Exception {
if (a.length != 9) {
throw new IllegalArgumentException("Array of size 9 expected but got " + a.length);
}
return f.apply((T1)a[0], (T2)a[1], (T3)a[2], (T4)a[3], (T5)a[4], (T6)a[5], (T7)a[6], (T8)a[7], (T9)a[8]);
}
}
static final class Identity implements Function<Object, Object> {
@Override
public Object apply(Object v) {
return v;
}
@Override
public String toString() {
return "IdentityFunction";
}
}
static final class EmptyRunnable implements Runnable {
@Override
public void run() { }
@Override
public String toString() {
return "EmptyRunnable";
}
}
static final class EmptyAction implements Action {
@Override
public void run() { }
@Override
public String toString() {
return "EmptyAction";
}
}
static final class EmptyConsumer implements Consumer<Object> {
@Override
public void accept(Object v) { }
@Override
public String toString() {
return "EmptyConsumer";
}
}
static final class ErrorConsumer implements Consumer<Throwable> {
@Override
public void accept(Throwable error) {
RxJavaPlugins.onError(error);
}
}
static final class OnErrorMissingConsumer implements Consumer<Throwable> {
@Override
public void accept(Throwable error) {
RxJavaPlugins.onError(new OnErrorNotImplementedException(error));
}
}
static final class EmptyLongConsumer implements LongConsumer {
@Override
public void accept(long v) { }
}
static final class TruePredicate implements Predicate<Object> {
@Override
public boolean test(Object o) {
return true;
}
}
static final class FalsePredicate implements Predicate<Object> {
@Override
public boolean test(Object o) {
return false;
}
}
static final class NullCallable implements Callable<Object> {
@Override
public Object call() {
return null;
}
}
static final class NaturalObjectComparator implements Comparator<Object> {
@SuppressWarnings({ "unchecked", "rawtypes" })
@Override
public int compare(Object a, Object b) {
return ((Comparable)a).compareTo(b);
}
}
static final class MaxRequestSubscription implements Consumer<Subscription> {
@Override
public void accept(Subscription t) throws Exception {
t.request(Long.MAX_VALUE);
}
}
}