com.landawn.abacus.util

Class Iterables

java.lang.Object

com.landawn.abacus.util.Iterables

public final class Iterables
extends Object

Note: This class includes codes copied from Apache Commons Lang, Google Guava and other open source projects under the Apache License 2.0. The methods copied from other libraries/frameworks/projects may be modified in this class.

This is a utility class for iterable data structures, including Collection/Array/Iterator.

The methods in this class should only read the input Collection/Array/Iterator parameters, not modify them.

See Also:

N, Iterators, Maps, StringUtil

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Iterables.SetView<E>

Method Summary

Modifier and Type	Method and Description
static <T extends Number> u.OptionalDouble	averageDouble(Collection<? extends T> c) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T extends Number> u.OptionalDouble	averageDouble(Collection<? extends T> c, int fromIndex, int toIndex) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T,E extends Exception> u.OptionalDouble	averageDouble(Collection<? extends T> c, int fromIndex, int toIndex, Throwables.ToDoubleFunction<? super T,E> func) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T,E extends Exception> u.OptionalDouble	averageDouble(Collection<? extends T> c, Throwables.ToDoubleFunction<? super T,E> func) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T extends Number> u.OptionalDouble	averageDouble(T[] a) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T extends Number> u.OptionalDouble	averageDouble(T[] a, int fromIndex, int toIndex) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T,E extends Exception> u.OptionalDouble	averageDouble(T[] a, int fromIndex, int toIndex, Throwables.ToDoubleFunction<? super T,E> func) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T,E extends Exception> u.OptionalDouble	averageDouble(T[] a, Throwables.ToDoubleFunction<? super T,E> func) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T extends Number> u.OptionalDouble	averageInt(Collection<? extends T> c) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T extends Number> u.OptionalDouble	averageInt(Collection<? extends T> c, int fromIndex, int toIndex) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T,E extends Exception> u.OptionalDouble	averageInt(Collection<? extends T> c, int fromIndex, int toIndex, Throwables.ToIntFunction<? super T,E> func) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T,E extends Exception> u.OptionalDouble	averageInt(Collection<? extends T> c, Throwables.ToIntFunction<? super T,E> func) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T extends Number> u.OptionalDouble	averageInt(T[] a) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T extends Number> u.OptionalDouble	averageInt(T[] a, int fromIndex, int toIndex) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T,E extends Exception> u.OptionalDouble	averageInt(T[] a, int fromIndex, int toIndex, Throwables.ToIntFunction<? super T,E> func) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T,E extends Exception> u.OptionalDouble	averageInt(T[] a, Throwables.ToIntFunction<? super T,E> func) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T extends Number> u.OptionalDouble	averageLong(Collection<? extends T> c) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T extends Number> u.OptionalDouble	averageLong(Collection<? extends T> c, int fromIndex, int toIndex) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T,E extends Exception> u.OptionalDouble	averageLong(Collection<? extends T> c, int fromIndex, int toIndex, Throwables.ToLongFunction<? super T,E> func) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T,E extends Exception> u.OptionalDouble	averageLong(Collection<? extends T> c, Throwables.ToLongFunction<? super T,E> func) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T extends Number> u.OptionalDouble	averageLong(T[] a) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T extends Number> u.OptionalDouble	averageLong(T[] a, int fromIndex, int toIndex) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T,E extends Exception> u.OptionalDouble	averageLong(T[] a, int fromIndex, int toIndex, Throwables.ToLongFunction<? super T,E> func) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <T,E extends Exception> u.OptionalDouble	averageLong(T[] a, Throwables.ToLongFunction<? super T,E> func) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.
static <E> Iterables.SetView<E>	difference(Set<E> set1, Set<?> set2) Returns an unmodifiable view of the difference of two sets.
static <T,E extends Exception> Pair<u.Nullable<T>,u.Nullable<T>>	findFirstAndLast(Collection<? extends T> c, Throwables.Predicate<? super T,E> predicate) Find first and last.
static <T,E extends Exception,E2 extends Exception> Pair<u.Nullable<T>,u.Nullable<T>>	findFirstAndLast(Collection<? extends T> c, Throwables.Predicate<? super T,E> predicateForFirst, Throwables.Predicate<? super T,E2> predicateForLast) Find first and last.
static <T,E extends Exception> Pair<u.Nullable<T>,u.Nullable<T>>	findFirstAndLast(T[] a, Throwables.Predicate<? super T,E> predicate) Find first and last.
static <T,E extends Exception,E2 extends Exception> Pair<u.Nullable<T>,u.Nullable<T>>	findFirstAndLast(T[] a, Throwables.Predicate<? super T,E> predicateForFirst, Throwables.Predicate<? super T,E2> predicateForLast) Find first and last.
static <T,E extends Exception> Pair<u.OptionalInt,u.OptionalInt>	findFirstAndLastIndex(Collection<? extends T> c, Throwables.Predicate<? super T,E> predicate) Find first and last index.
static <T,E extends Exception,E2 extends Exception> Pair<u.OptionalInt,u.OptionalInt>	findFirstAndLastIndex(Collection<? extends T> c, Throwables.Predicate<? super T,E> predicateForFirst, Throwables.Predicate<? super T,E2> predicateForLast) Find first and last index.
static <T,E extends Exception> Pair<u.OptionalInt,u.OptionalInt>	findFirstAndLastIndex(T[] a, Throwables.Predicate<? super T,E> predicate) Find first and last index.
static <T,E extends Exception,E2 extends Exception> Pair<u.OptionalInt,u.OptionalInt>	findFirstAndLastIndex(T[] a, Throwables.Predicate<? super T,E> predicateForFirst, Throwables.Predicate<? super T,E2> predicateForLast) Find first and last index.
static <T,E extends Exception,E2 extends Exception> u.Nullable<T>	findFirstOrLast(Collection<? extends T> c, Throwables.Predicate<? super T,E> predicateForFirst, Throwables.Predicate<? super T,E2> predicateForLast) Find first or last.
static <T,E extends Exception,E2 extends Exception> u.Nullable<T>	findFirstOrLast(T[] a, Throwables.Predicate<? super T,E> predicateForFirst, Throwables.Predicate<? super T,E2> predicateForLast) Find first or last.
static <T,E extends Exception,E2 extends Exception> u.OptionalInt	findFirstOrLastIndex(Collection<? extends T> c, Throwables.Predicate<? super T,E> predicateForFirst, Throwables.Predicate<? super T,E2> predicateForLast)
static <T,E extends Exception,E2 extends Exception> u.OptionalInt	findFirstOrLastIndex(T[] a, Throwables.Predicate<? super T,E> predicateForFirst, Throwables.Predicate<? super T,E2> predicateForLast) Find first or last index.
static u.OptionalInt	indexOf(Collection<?> c, Object objToFind)
static u.OptionalInt	indexOf(Object[] a, Object objToFind)
static <E> Iterables.SetView<E>	intersection(Set<E> set1, Set<?> set2) Returns an unmodifiable view of the intersection of two sets.
static <T extends Comparable<? super T>> u.Nullable<T>	kthLargest(Collection<? extends T> c, int k) Returns Nullable.empty() if the specified Array/Collection is null or empty, or its length/size is less than k.
static <T> u.Nullable<T>	kthLargest(Collection<? extends T> c, int k, Comparator<? super T> cmp) Returns Nullable.empty() if the specified Array/Collection is null or empty, or its length/size is less than k.
static <T extends Comparable<? super T>> u.Nullable<T>	kthLargest(T[] a, int k) Returns Nullable.empty() if the specified Array/Collection is null or empty, or its length/size is less than k.
static <T> u.Nullable<T>	kthLargest(T[] a, int k, Comparator<? super T> cmp) Returns Nullable.empty() if the specified Array/Collection is null or empty, or its length/size is less than k.
static u.OptionalInt	lastIndexOf(Collection<?> c, Object objToFind)
static u.OptionalInt	lastIndexOf(Object[] a, Object objToFind)
static u.OptionalByte	max(byte... a) Returns OptionalByte.empty() if the specified Array/Collection is null or empty.
static u.OptionalChar	max(char... a) Returns OptionalChar.empty() if the specified Array/Collection is null or empty.
static <T extends Comparable<? super T>> u.Nullable<T>	max(Collection<? extends T> c) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	max(Collection<? extends T> c, Comparator<? super T> cmp) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static u.OptionalDouble	max(double... a) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty.
static u.OptionalFloat	max(float... a) Returns OptionalFloat.empty() if the specified Array/Collection is null or empty.
static u.OptionalInt	max(int... a) Returns OptionalInt.empty() if the specified Array/Collection is null or empty.
static <T extends Comparable<? super T>> u.Nullable<T>	max(Iterator<? extends T> iter) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	max(Iterator<? extends T> iter, Comparator<? super T> cmp) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static u.OptionalLong	max(long... a) Returns OptionalLong.empty() if the specified Array/Collection is null or empty.
static u.OptionalShort	max(short... a) Returns OptionalShort.empty() if the specified Array/Collection is null or empty.
static <T extends Comparable<? super T>> u.Nullable<T>	max(T[] a) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	max(T[] a, Comparator<? super T> cmp) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	maxBy(Collection<? extends T> c, Function<? super T,? extends Comparable> keyMapper) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	maxBy(Iterator<? extends T> iter, Function<? super T,? extends Comparable> keyMapper) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	maxBy(T[] a, Function<? super T,? extends Comparable> keyMapper) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T extends Comparable<? super T>> u.Nullable<T>	median(Collection<? extends T> c) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	median(Collection<? extends T> c, Comparator<? super T> cmp) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T extends Comparable<? super T>> u.Nullable<T>	median(T[] a) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	median(T[] a, Comparator<? super T> cmp) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	medianBy(Collection<? extends T> c, Function<? super T,? extends Comparable> keyMapper) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	medianBy(T[] a, Function<? super T,? extends Comparable> keyMapper) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static u.OptionalByte	min(byte... a) Returns OptionalByte.empty() if the specified Array/Collection is null or empty.
static u.OptionalChar	min(char... a) Returns OptionalChar.empty() if the specified Array/Collection is null or empty.
static <T extends Comparable<? super T>> u.Nullable<T>	min(Collection<? extends T> c) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	min(Collection<? extends T> c, Comparator<? super T> cmp) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static u.OptionalDouble	min(double... a) Returns OptionalDouble.empty() if the specified Array/Collection is null or empty.
static u.OptionalFloat	min(float... a) Returns OptionalFloat.empty() if the specified Array/Collection is null or empty.
static u.OptionalInt	min(int... a) Returns OptionalInt.empty() if the specified Array/Collection is null or empty.
static <T extends Comparable<? super T>> u.Nullable<T>	min(Iterator<? extends T> iter) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	min(Iterator<? extends T> iter, Comparator<? super T> cmp) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static u.OptionalLong	min(long... a) Returns OptionalLong.empty() if the specified Array/Collection is null or empty.
static u.OptionalShort	min(short... a) Returns OptionalShort.empty() if the specified Array/Collection is null or empty.
static <T extends Comparable<? super T>> u.Nullable<T>	min(T[] a) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	min(T[] a, Comparator<? super T> cmp) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	minBy(Collection<? extends T> c, Function<? super T,? extends Comparable> keyMapper) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	minBy(Iterator<? extends T> iter, Function<? super T,? extends Comparable> keyMapper) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> u.Nullable<T>	minBy(T[] a, Function<? super T,? extends Comparable> keyMapper) Returns Nullable.empty() if the specified Array/Collection is null or empty.
static <T> boolean	padLeft(List<T> list, int minLen, T objToAdd)
static <T> boolean	padRight(Collection<T> c, int minLen, T objToAdd)
static <E> Iterables.SetView<E>	symmetricDifference(Set<? extends E> set1, Set<? extends E> set2) Returns an unmodifiable view of the symmetric difference of two sets.
static <E> Iterables.SetView<E>	union(Set<? extends E> set1, Set<? extends E> set2) Returns an unmodifiable view of the union of two sets.

Methods inherited from class java.lang.Object

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

Method Detail

min

@SafeVarargs
public static u.OptionalChar min(char... a)

Returns OptionalChar.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

min

@SafeVarargs
public static u.OptionalByte min(byte... a)

Returns OptionalByte.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

min

@SafeVarargs
public static u.OptionalShort min(short... a)

Returns OptionalShort.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

min

@SafeVarargs
public static u.OptionalInt min(int... a)

Returns OptionalInt.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

min

@SafeVarargs
public static u.OptionalLong min(long... a)

Returns OptionalLong.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

min

@SafeVarargs
public static u.OptionalFloat min(float... a)

Returns OptionalFloat.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

min

@SafeVarargs
public static u.OptionalDouble min(double... a)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

max

@SafeVarargs
public static u.OptionalChar max(char... a)

Returns OptionalChar.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

max

@SafeVarargs
public static u.OptionalByte max(byte... a)

Returns OptionalByte.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

max

@SafeVarargs
public static u.OptionalShort max(short... a)

Returns OptionalShort.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

max

@SafeVarargs
public static u.OptionalInt max(int... a)

Returns OptionalInt.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

max

@SafeVarargs
public static u.OptionalLong max(long... a)

Returns OptionalLong.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

max

@SafeVarargs
public static u.OptionalFloat max(float... a)

Returns OptionalFloat.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

max

@SafeVarargs
public static u.OptionalDouble max(double... a)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

min

public static <T extends Comparable<? super T>> u.Nullable<T> min(T[] a)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

min

public static <T> u.Nullable<T> min(T[] a,
                                    Comparator<? super T> cmp)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

cmp -

Returns:

min

public static <T extends Comparable<? super T>> u.Nullable<T> min(Collection<? extends T> c)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

c -

Returns:

min

public static <T> u.Nullable<T> min(Collection<? extends T> c,
                                    Comparator<? super T> cmp)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

c -

cmp -

Returns:

min

public static <T extends Comparable<? super T>> u.Nullable<T> min(Iterator<? extends T> iter)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

iter -

Returns:

min

public static <T> u.Nullable<T> min(Iterator<? extends T> iter,
                                    Comparator<? super T> cmp)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

iter -

cmp -

Returns:

minBy

public static <T> u.Nullable<T> minBy(T[] a,
                                      Function<? super T,? extends Comparable> keyMapper)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

cmp -

Returns:

minBy

public static <T> u.Nullable<T> minBy(Collection<? extends T> c,
                                      Function<? super T,? extends Comparable> keyMapper)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

c -

cmp -

Returns:

minBy

public static <T> u.Nullable<T> minBy(Iterator<? extends T> iter,
                                      Function<? super T,? extends Comparable> keyMapper)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

iter -

cmp -

Returns:

max

public static <T extends Comparable<? super T>> u.Nullable<T> max(T[] a)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

max

public static <T> u.Nullable<T> max(T[] a,
                                    Comparator<? super T> cmp)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

cmp -

Returns:

max

public static <T extends Comparable<? super T>> u.Nullable<T> max(Collection<? extends T> c)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

c -

Returns:

max

public static <T> u.Nullable<T> max(Collection<? extends T> c,
                                    Comparator<? super T> cmp)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

c -

Returns:

max

public static <T extends Comparable<? super T>> u.Nullable<T> max(Iterator<? extends T> iter)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

iter -

Returns:

max

public static <T> u.Nullable<T> max(Iterator<? extends T> iter,
                                    Comparator<? super T> cmp)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

iter -

cmp -

Returns:

maxBy

public static <T> u.Nullable<T> maxBy(T[] a,
                                      Function<? super T,? extends Comparable> keyMapper)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

cmp -

Returns:

maxBy

public static <T> u.Nullable<T> maxBy(Collection<? extends T> c,
                                      Function<? super T,? extends Comparable> keyMapper)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

c -

cmp -

Returns:

maxBy

public static <T> u.Nullable<T> maxBy(Iterator<? extends T> iter,
                                      Function<? super T,? extends Comparable> keyMapper)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

iter -

cmp -

Returns:

median

public static <T extends Comparable<? super T>> u.Nullable<T> median(T[] a)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

Returns:

median

public static <T extends Comparable<? super T>> u.Nullable<T> median(Collection<? extends T> c)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

c -

Returns:

median

public static <T> u.Nullable<T> median(T[] a,
                                       Comparator<? super T> cmp)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

cmp -

Returns:

median

public static <T> u.Nullable<T> median(Collection<? extends T> c,
                                       Comparator<? super T> cmp)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

c -

cmp -

Returns:

medianBy

public static <T> u.Nullable<T> medianBy(T[] a,
                                         Function<? super T,? extends Comparable> keyMapper)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

a -

keyMapper -

Returns:

medianBy

public static <T> u.Nullable<T> medianBy(Collection<? extends T> c,
                                         Function<? super T,? extends Comparable> keyMapper)

Returns Nullable.empty() if the specified Array/Collection is null or empty.

Parameters:

c -

keyMapper -

Returns:

kthLargest

public static <T extends Comparable<? super T>> u.Nullable<T> kthLargest(Collection<? extends T> c,
                                                                         int k)

Returns Nullable.empty() if the specified Array/Collection is null or empty, or its length/size is less than k.

Parameters:

c -

k -

Returns:

kthLargest

public static <T extends Comparable<? super T>> u.Nullable<T> kthLargest(T[] a,
                                                                         int k)

Returns Nullable.empty() if the specified Array/Collection is null or empty, or its length/size is less than k.

Parameters:

a -

k -

Returns:

kthLargest

public static <T> u.Nullable<T> kthLargest(Collection<? extends T> c,
                                           int k,
                                           Comparator<? super T> cmp)

Returns Nullable.empty() if the specified Array/Collection is null or empty, or its length/size is less than k.

Parameters:

c -

k -

cmp -

Returns:

kthLargest

public static <T> u.Nullable<T> kthLargest(T[] a,
                                           int k,
                                           Comparator<? super T> cmp)

Returns Nullable.empty() if the specified Array/Collection is null or empty, or its length/size is less than k.

Parameters:

a -

k -

cmp -

Returns:

averageInt

public static <T extends Number> u.OptionalDouble averageInt(T[] a)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

Parameters:

a -

Returns:

averageInt

public static <T extends Number> u.OptionalDouble averageInt(T[] a,
                                                             int fromIndex,
                                                             int toIndex)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

Parameters:

a -

fromIndex -

toIndex -

Returns:

averageInt

public static <T,E extends Exception> u.OptionalDouble averageInt(T[] a,
                                                                  Throwables.ToIntFunction<? super T,E> func)
                                                           throws E extends Exception

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

E -

Parameters:

a -

func -

Returns:

Throws:

E - the e

E extends Exception

averageInt

public static <T,E extends Exception> u.OptionalDouble averageInt(T[] a,
                                                                  int fromIndex,
                                                                  int toIndex,
                                                                  Throwables.ToIntFunction<? super T,E> func)
                                                           throws E extends Exception

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

E -

Parameters:

a -

fromIndex -

toIndex -

func -

Returns:

Throws:

E - the e

E extends Exception

averageInt

public static <T extends Number> u.OptionalDouble averageInt(Collection<? extends T> c)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

Parameters:

c -

Returns:

averageInt

public static <T extends Number> u.OptionalDouble averageInt(Collection<? extends T> c,
                                                             int fromIndex,
                                                             int toIndex)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

Parameters:

c -

fromIndex -

toIndex -

Returns:

averageInt

public static <T,E extends Exception> u.OptionalDouble averageInt(Collection<? extends T> c,
                                                                  Throwables.ToIntFunction<? super T,E> func)
                                                           throws E extends Exception

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

E -

Parameters:

c -

func -

Returns:

Throws:

E - the e

E extends Exception

averageInt

public static <T,E extends Exception> u.OptionalDouble averageInt(Collection<? extends T> c,
                                                                  int fromIndex,
                                                                  int toIndex,
                                                                  Throwables.ToIntFunction<? super T,E> func)
                                                           throws E extends Exception

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

E -

Parameters:

c -

fromIndex -

toIndex -

func -

Returns:

Throws:

E - the e

E extends Exception

averageLong

public static <T extends Number> u.OptionalDouble averageLong(T[] a)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

Parameters:

a -

Returns:

averageLong

public static <T extends Number> u.OptionalDouble averageLong(T[] a,
                                                              int fromIndex,
                                                              int toIndex)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

Parameters:

a -

fromIndex -

toIndex -

Returns:

averageLong

public static <T,E extends Exception> u.OptionalDouble averageLong(T[] a,
                                                                   Throwables.ToLongFunction<? super T,E> func)
                                                            throws E extends Exception

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

E -

Parameters:

a -

func -

Returns:

Throws:

E - the e

E extends Exception

averageLong

public static <T,E extends Exception> u.OptionalDouble averageLong(T[] a,
                                                                   int fromIndex,
                                                                   int toIndex,
                                                                   Throwables.ToLongFunction<? super T,E> func)
                                                            throws E extends Exception

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

E -

Parameters:

a -

fromIndex -

toIndex -

func -

Returns:

Throws:

E - the e

E extends Exception

averageLong

public static <T extends Number> u.OptionalDouble averageLong(Collection<? extends T> c)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

Parameters:

c -

Returns:

averageLong

public static <T extends Number> u.OptionalDouble averageLong(Collection<? extends T> c,
                                                              int fromIndex,
                                                              int toIndex)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

Parameters:

c -

fromIndex -

toIndex -

Returns:

averageLong

public static <T,E extends Exception> u.OptionalDouble averageLong(Collection<? extends T> c,
                                                                   Throwables.ToLongFunction<? super T,E> func)
                                                            throws E extends Exception

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

E -

Parameters:

c -

func -

Returns:

Throws:

E - the e

E extends Exception

averageLong

public static <T,E extends Exception> u.OptionalDouble averageLong(Collection<? extends T> c,
                                                                   int fromIndex,
                                                                   int toIndex,
                                                                   Throwables.ToLongFunction<? super T,E> func)
                                                            throws E extends Exception

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

E -

Parameters:

c -

fromIndex -

toIndex -

func -

Returns:

Throws:

E - the e

E extends Exception

averageDouble

public static <T extends Number> u.OptionalDouble averageDouble(T[] a)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

Parameters:

a -

Returns:

averageDouble

public static <T extends Number> u.OptionalDouble averageDouble(T[] a,
                                                                int fromIndex,
                                                                int toIndex)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

Parameters:

a -

fromIndex -

toIndex -

Returns:

averageDouble

public static <T,E extends Exception> u.OptionalDouble averageDouble(T[] a,
                                                                     Throwables.ToDoubleFunction<? super T,E> func)
                                                              throws E extends Exception

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

E -

Parameters:

a -

func -

Returns:

Throws:

E - the e

E extends Exception

averageDouble

public static <T,E extends Exception> u.OptionalDouble averageDouble(T[] a,
                                                                     int fromIndex,
                                                                     int toIndex,
                                                                     Throwables.ToDoubleFunction<? super T,E> func)
                                                              throws E extends Exception

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

E -

Parameters:

a -

fromIndex -

toIndex -

func -

Returns:

Throws:

E - the e

E extends Exception

averageDouble

public static <T extends Number> u.OptionalDouble averageDouble(Collection<? extends T> c)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

Parameters:

c -

Returns:

averageDouble

public static <T extends Number> u.OptionalDouble averageDouble(Collection<? extends T> c,
                                                                int fromIndex,
                                                                int toIndex)

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

Parameters:

c -

fromIndex -

toIndex -

Returns:

averageDouble

public static <T,E extends Exception> u.OptionalDouble averageDouble(Collection<? extends T> c,
                                                                     Throwables.ToDoubleFunction<? super T,E> func)
                                                              throws E extends Exception

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

E -

Parameters:

c -

func -

Returns:

Throws:

E - the e

E extends Exception

averageDouble

public static <T,E extends Exception> u.OptionalDouble averageDouble(Collection<? extends T> c,
                                                                     int fromIndex,
                                                                     int toIndex,
                                                                     Throwables.ToDoubleFunction<? super T,E> func)
                                                              throws E extends Exception

Returns OptionalDouble.empty() if the specified Array/Collection is null or empty, or fromIndex == toIndex.

Type Parameters:

T -

E -

Parameters:

c -

fromIndex -

toIndex -

func -

Returns:

Throws:

E - the e

E extends Exception

indexOf

public static u.OptionalInt indexOf(Object[] a,
                                    Object objToFind)

indexOf

public static u.OptionalInt indexOf(Collection<?> c,
                                    Object objToFind)

lastIndexOf

public static u.OptionalInt lastIndexOf(Object[] a,
                                        Object objToFind)

lastIndexOf

public static u.OptionalInt lastIndexOf(Collection<?> c,
                                        Object objToFind)

findFirstOrLastIndex

public static <T,E extends Exception,E2 extends Exception> u.OptionalInt findFirstOrLastIndex(T[] a,
                                                                                              Throwables.Predicate<? super T,E> predicateForFirst,
                                                                                              Throwables.Predicate<? super T,E2> predicateForLast)
                                                                                       throws E extends Exception,
                                                                                              E2 extends Exception

Find first or last index.

Type Parameters:

T - the generic type

E - the element type

E2 - the generic type

Parameters:

a - the a

predicateForFirst - the predicate for first

predicateForLast - the predicate for last

Returns:

the optional int

Throws:

E - the e

E2 - the e2

E extends Exception

findFirstOrLastIndex

public static <T,E extends Exception,E2 extends Exception> u.OptionalInt findFirstOrLastIndex(Collection<? extends T> c,
                                                                                              Throwables.Predicate<? super T,E> predicateForFirst,
                                                                                              Throwables.Predicate<? super T,E2> predicateForLast)
                                                                                       throws E extends Exception,
                                                                                              E2 extends Exception

Throws:

E extends Exception

findFirstAndLastIndex

public static <T,E extends Exception> Pair<u.OptionalInt,u.OptionalInt> findFirstAndLastIndex(T[] a,
                                                                                              Throwables.Predicate<? super T,E> predicate)
                                                                                       throws E extends Exception

Find first and last index.

Type Parameters:

T - the generic type

E - the element type

Parameters:

a - the a

predicate - the predicate

Returns:

the pair

Throws:

E - the e

E extends Exception

findFirstAndLastIndex

public static <T,E extends Exception,E2 extends Exception> Pair<u.OptionalInt,u.OptionalInt> findFirstAndLastIndex(T[] a,
                                                                                                                   Throwables.Predicate<? super T,E> predicateForFirst,
                                                                                                                   Throwables.Predicate<? super T,E2> predicateForLast)
                                                                                                            throws E extends Exception,
                                                                                                                   E2 extends Exception

Find first and last index.

Type Parameters:

T - the generic type

E - the element type

E2 - the generic type

Parameters:

a - the a

predicateForFirst - the predicate for first

predicateForLast - the predicate for last

Returns:

the pair

Throws:

E - the e

E2 - the e2

E extends Exception

findFirstAndLastIndex

public static <T,E extends Exception> Pair<u.OptionalInt,u.OptionalInt> findFirstAndLastIndex(Collection<? extends T> c,
                                                                                              Throwables.Predicate<? super T,E> predicate)
                                                                                       throws E extends Exception

Find first and last index.

Type Parameters:

T - the generic type

E - the element type

Parameters:

c - the c

predicate - the predicate

Returns:

the pair

Throws:

E - the e

E extends Exception

findFirstAndLastIndex

public static <T,E extends Exception,E2 extends Exception> Pair<u.OptionalInt,u.OptionalInt> findFirstAndLastIndex(Collection<? extends T> c,
                                                                                                                   Throwables.Predicate<? super T,E> predicateForFirst,
                                                                                                                   Throwables.Predicate<? super T,E2> predicateForLast)
                                                                                                            throws E extends Exception,
                                                                                                                   E2 extends Exception

Find first and last index.

Type Parameters:

T - the generic type

E - the element type

E2 - the generic type

Parameters:

c - the c

predicateForFirst - the predicate for first

predicateForLast - the predicate for last

Returns:

the pair

Throws:

E - the e

E2 - the e2

E extends Exception

findFirstOrLast

public static <T,E extends Exception,E2 extends Exception> u.Nullable<T> findFirstOrLast(T[] a,
                                                                                         Throwables.Predicate<? super T,E> predicateForFirst,
                                                                                         Throwables.Predicate<? super T,E2> predicateForLast)
                                                                                  throws E extends Exception,
                                                                                         E2 extends Exception

Find first or last.

Type Parameters:

T - the generic type

E - the element type

E2 - the generic type

Parameters:

a - the a

predicateForFirst - the predicate for first

predicateForLast - the predicate for last

Returns:

the nullable

Throws:

E - the e

E2 - the e2

E extends Exception

findFirstOrLast

public static <T,E extends Exception,E2 extends Exception> u.Nullable<T> findFirstOrLast(Collection<? extends T> c,
                                                                                         Throwables.Predicate<? super T,E> predicateForFirst,
                                                                                         Throwables.Predicate<? super T,E2> predicateForLast)
                                                                                  throws E extends Exception,
                                                                                         E2 extends Exception

Find first or last.

Type Parameters:

T - the generic type

E - the element type

E2 - the generic type

Parameters:

c - the c

predicateForFirst - the predicate for first

predicateForLast - the predicate for last

Returns:

the nullable

Throws:

E - the e

E2 - the e2

E extends Exception

findFirstAndLast

public static <T,E extends Exception> Pair<u.Nullable<T>,u.Nullable<T>> findFirstAndLast(T[] a,
                                                                                         Throwables.Predicate<? super T,E> predicate)
                                                                                  throws E extends Exception

Find first and last.

Type Parameters:

T - the generic type

E - the element type

Parameters:

a - the a

predicate - the predicate

Returns:

the pair

Throws:

E - the e

E extends Exception

findFirstAndLast

public static <T,E extends Exception,E2 extends Exception> Pair<u.Nullable<T>,u.Nullable<T>> findFirstAndLast(T[] a,
                                                                                                              Throwables.Predicate<? super T,E> predicateForFirst,
                                                                                                              Throwables.Predicate<? super T,E2> predicateForLast)
                                                                                                       throws E extends Exception,
                                                                                                              E2 extends Exception

Find first and last.

Type Parameters:

T - the generic type

E - the element type

E2 - the generic type

Parameters:

a - the a

predicateForFirst - the predicate for first

predicateForLast - the predicate for last

Returns:

the pair

Throws:

E - the e

E2 - the e2

E extends Exception

findFirstAndLast

public static <T,E extends Exception> Pair<u.Nullable<T>,u.Nullable<T>> findFirstAndLast(Collection<? extends T> c,
                                                                                         Throwables.Predicate<? super T,E> predicate)
                                                                                  throws E extends Exception

Find first and last.

Type Parameters:

T - the generic type

E - the element type

Parameters:

c - the c

predicate - the predicate

Returns:

the pair

Throws:

E - the e

E extends Exception

findFirstAndLast

public static <T,E extends Exception,E2 extends Exception> Pair<u.Nullable<T>,u.Nullable<T>> findFirstAndLast(Collection<? extends T> c,
                                                                                                              Throwables.Predicate<? super T,E> predicateForFirst,
                                                                                                              Throwables.Predicate<? super T,E2> predicateForLast)
                                                                                                       throws E extends Exception,
                                                                                                              E2 extends Exception

Find first and last.

Type Parameters:

T - the generic type

E - the element type

E2 - the generic type

Parameters:

c - the c

predicateForFirst - the predicate for first

predicateForLast - the predicate for last

Returns:

the pair

Throws:

E - the e

E2 - the e2

E extends Exception

padLeft

public static <T> boolean padLeft(List<T> list,
                                  int minLen,
                                  T objToAdd)

padRight

public static <T> boolean padRight(Collection<T> c,
                                   int minLen,
                                   T objToAdd)

union

public static <E> Iterables.SetView<E> union(Set<? extends E> set1,
                                             Set<? extends E> set2)

Returns an unmodifiable view of the union of two sets. The returned set contains all elements that are contained in either backing set. Iterating over the returned set iterates first over all the elements of set1, then over each element of set2, in order, that is not contained in set1.

Results are undefined if set1 and set2 are sets based on different equivalence relations (as HashSet, TreeSet, and the Map.keySet() of an IdentityHashMap all are).

intersection

public static <E> Iterables.SetView<E> intersection(Set<E> set1,
                                                    Set<?> set2)

Returns an unmodifiable view of the intersection of two sets. The returned set contains all elements that are contained by both backing sets. The iteration order of the returned set matches that of set1.

Results are undefined if set1 and set2 are sets based on different equivalence relations (as HashSet, TreeSet, and the keySet of an IdentityHashMap all are).

Note: The returned view performs slightly better when set1 is the smaller of the two sets. If you have reason to believe one of your sets will generally be smaller than the other, pass it first. Unfortunately, since this method sets the generic type of the returned set based on the type of the first set passed, this could in rare cases force you to make a cast, for example:

 Set<Object> aFewBadObjects = ...
 Set<String> manyBadStrings = ...

 // impossible for a non-String to be in the intersection
 SuppressWarnings("unchecked")
 Set<String> badStrings = (Set) Sets.intersection(
     aFewBadObjects, manyBadStrings);
 

This is unfortunate, but should come up only very rarely.

difference

public static <E> Iterables.SetView<E> difference(Set<E> set1,
                                                  Set<?> set2)

Returns an unmodifiable view of the difference of two sets. The returned set contains all elements that are contained by set1 and not contained by set2. set2 may also contain elements not present in set1; these are simply ignored. The iteration order of the returned set matches that of set1.

Results are undefined if set1 and set2 are sets based on different equivalence relations (as HashSet, TreeSet, and the keySet of an IdentityHashMap all are).

symmetricDifference

public static <E> Iterables.SetView<E> symmetricDifference(Set<? extends E> set1,
                                                           Set<? extends E> set2)

Returns an unmodifiable view of the symmetric difference of two sets. The returned set contains all elements that are contained in either set1 or set2 but not in both. The iteration order of the returned set is undefined.

Results are undefined if set1 and set2 are sets based on different equivalence relations (as HashSet, TreeSet, and the keySet of an IdentityHashMap all are).

Since:

3.0