io.lacuna.bifurcan.utils

Class Iterators

java.lang.Object

io.lacuna.bifurcan.utils.Iterators

public class Iterators
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Iterators.Indexed<T>
static class	Iterators.IteratorStack<V> A utility class for dynamically appending and prepending iterators to a collection, which itself can be iterated over.

Field Summary

Fields

Modifier and Type	Field and Description
static Iterator	EMPTY

Constructor Summary

Constructors

Constructor and Description
Iterators()

Method Summary

Modifier and Type	Method and Description
static <V> Iterator<V>	concat(Iterator<V>... iterators)
static <V> Iterator<V>	drop(Iterator<V> it, long n)
static <V> boolean	equals(Iterator<V> a, Iterator<V> b, BiPredicate<V,V> equals)
static <V> Iterator<V>	filter(Iterator<V> it, Predicate<V> f)
static <U,V> Iterator<V>	flatMap(Iterator<U> it, Function<U,Iterator<V>> f)
static <V> Iterator<V>	from(BooleanSupplier hasNext, Supplier<V> next)
static <V> Iterator<Iterators.Indexed<V>>	indexed(Iterator<V> it)
static <V> Iterator<Iterators.Indexed<V>>	indexed(Iterator<V> it, long offset)
static <U,V> Iterator<V>	map(Iterator<U> it, Function<U,V> f)
static <V> Iterator<V>	mergeSort(IList<Iterator<V>> iterators, Comparator<V> comparator)
static <V> Iterator<V>	onExhaustion(Iterator<V> it, Runnable f)
static <V> Iterator<V>	range(long max, LongFunction<V> f) Represents a range implicitly starting at 0.
static <V> Iterator<V>	range(long min, long max, LongFunction<V> f)
static <V> Iterator<V>	singleton(V val)
static <V> IDurableEncoding.SkippableIterator	skippable(Iterator<V> it)
static <V> Stream<V>	toStream(Iterator<V> it)
static <V> Stream<V>	toStream(Iterator<V> it, long estimatedSize)

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY

public static final Iterator EMPTY

Constructor Detail

Iterators

public Iterators()

Method Detail

mergeSort

public static <V> Iterator<V> mergeSort(IList<Iterator<V>> iterators,
                                        Comparator<V> comparator)

equals

public static <V> boolean equals(Iterator<V> a,
                                 Iterator<V> b,
                                 BiPredicate<V,V> equals)

from

public static <V> Iterator<V> from(BooleanSupplier hasNext,
                                   Supplier<V> next)

onExhaustion

public static <V> Iterator<V> onExhaustion(Iterator<V> it,
                                           Runnable f)

singleton

public static <V> Iterator<V> singleton(V val)

filter

public static <V> Iterator<V> filter(Iterator<V> it,
                                     Predicate<V> f)

Parameters:

it - an iterator

f - a predicate

Returns:

an iterator which only yields values that satisfy the predicate

map

public static <U,V> Iterator<V> map(Iterator<U> it,
                                    Function<U,V> f)

Parameters:

it - an iterator

f - a function which transforms values

Returns:

an iterator which yields the transformed values

flatMap

public static <U,V> Iterator<V> flatMap(Iterator<U> it,
                                        Function<U,Iterator<V>> f)

Parameters:

it - an iterator

f - a function which transforms values into iterators

Returns:

an iterator which yields the concatenation of the iterators

range

public static <V> Iterator<V> range(long min,
                                    long max,
                                    LongFunction<V> f)

Parameters:

min - an inclusive start of the range

max - an exclusive end of the range

f - a function which transforms a number in the range into a value

Returns:

an iterator which yields the values returned by f

range

public static <V> Iterator<V> range(long max,
                                    LongFunction<V> f)

Represents a range implicitly starting at 0.

Parameters:

max - an exclusive end of the range.

f - a function which transforms a number in the range into a value.

Returns:

an iterator which yields the values returned by f

concat

public static <V> Iterator<V> concat(Iterator<V>... iterators)

Parameters:

iterators - a list of iterators

Returns:

a concatenation of all iterators, in the order provided

drop

public static <V> Iterator<V> drop(Iterator<V> it,
                                   long n)

Parameters:

it - an iterator

n - the number of elements to drop, which may be larger than the number of values in the iterator

Returns:

an iterator with the first n values dropped

toStream

public static <V> Stream<V> toStream(Iterator<V> it)

toStream

public static <V> Stream<V> toStream(Iterator<V> it,
                                     long estimatedSize)

skippable

public static <V> IDurableEncoding.SkippableIterator skippable(Iterator<V> it)

indexed

public static <V> Iterator<Iterators.Indexed<V>> indexed(Iterator<V> it)

indexed

public static <V> Iterator<Iterators.Indexed<V>> indexed(Iterator<V> it,
                                                         long offset)