Package panda.std.stream

Class PandaStream<T>

java.lang.Object

panda.std.stream.PandaStream<T>

Type Parameters:

T -

All Implemented Interfaces:

AutoCloseable

public class PandaStream<T>
extends Object
implements AutoCloseable

Simple wrapper to combine standard Stream API with wrappers like Option or Result, and some extra features. Most methods are lazy evaluated as in Stream API, but some of them are not! In most cases it shouldn't be a problem, but for huge sets or performance sensitive use-cases you should be aware of methods you use, especially these based on duplicate() feature.

Method Summary

Modifier and Type	Method	Description
Option<T>	any()
<R> PandaStream<Pair<T,R>>	associateWith(R value)
void	close()
<A, R> R	collect(Collector<? super T,A,R> collector)
PandaStream<T>	concat(Iterable<T> iterable)
PandaStream<T>	concat(Stream<T> stream)
PandaStream<T>	concat(PandaStream<T> pandaStream)
final PandaStream<T>	concat(T... elements)
long	count()
long	count(Predicate<T> predicate)
PandaStream<T>	distinct()
PandaStream<T>	duplicate()	Simulates the stream duplication mechanism.
static <T> PandaStream<T>	empty()
PandaStream<T>	filter(Predicate<T> predicate)
PandaStream<T>	filterNot(Predicate<T> predicate)
<E> Result<PandaStream<T>,E>	filterToResult(Function<? super T,Option<E>> predicate)
Option<T>	find(Predicate<T> predicate)
<R> Option<R>	findIterating(Function<? super T,Option<R>> predicate)
<R> PandaStream<R>	flatMap(Function<T,Iterable<R>> function)
<R> PandaStream<R>	flatMapStream(Function<T,Stream<R>> function)
<A, R> PandaStream<R>	flatMapWith(A with, BiFunction<A,T,Iterable<R>> function)
PandaStream<T>	forEach(Consumer<? super T> consumer)
<E> Result<PandaStream<T>,E>	forEachByResult(Function<T,Option<E>> predicate)
Option<T>	head()
<S> PandaStream<S>	is(Class<S> type)
PandaStream<T>	isNot(Class<?> type)
Iterator<T>	iterator()
Option<T>	last()
<R> PandaStream<R>	map(Function<T,R> function)
<R> PandaStream<R>	mapOpt(Function<T,Option<R>> function)
<A, R> PandaStream<R>	mapWith(A with, BiFunction<A,T,R> function)
static <T> PandaStream<T>	of(Iterable<T> iterable)
static <T> PandaStream<T>	of(Collection<T> collection)
static <T> PandaStream<T>	of(Stream<T> stream)
static <T> PandaStream<T>	of(T... array)
<R, E> Result<R,List<E>>	search(Function<T,Result<R,E>> searchFunction)	Find first element in stream or return all failures.
PandaStream<T>	skip(long n)
PandaStream<T>	sorted()
PandaStream<T>	sorted(Comparator<? super T> comparator)
<R> PandaStream<R>	stream(Function<Stream<T>,Stream<R>> function)
PandaStream<T>	takeWhile(Predicate<T> condition)
<E extends Exception> PandaStream<T>	throwIfNot(Predicate<T> condition, Function<T,E> exception)
T[]	toArray(IntFunction<T[]> function)
List<T>	toList()
<K, V> Map<K,V>	toMap(Function<T,K> keyMapper, Function<T,V> valueMapper)
<K, V> Map<K,V>	toMap(Supplier<Map<K,V>> mapSupplier, Function<T,K> keyMapper, Function<T,V> valueMapper)
<K, V> Map<K,V>	toMapByPair(Function<T,Pair<K,V>> mapper)
<K, V> Map<K,V>	toMapByPair(Supplier<Map<K,V>> mapSupplier, Function<T,Pair<K,V>> mapper)
Set<T>	toSet()
Stream<T>	toStream()
<R> PandaStream<R>	transform(Function<Stream<T>,Stream<R>> function)

Methods inherited from class java.lang.Object

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

Method Details

close

public void close()

Specified by:

close in interface AutoCloseable

stream

public <R> PandaStream<R> stream(Function<Stream<T>,Stream<R>> function)

concat

public PandaStream<T> concat(Stream<T> stream)

concat

public PandaStream<T> concat(PandaStream<T> pandaStream)

concat

public PandaStream<T> concat(Iterable<T> iterable)

concat

@SafeVarargs
public final PandaStream<T> concat(T... elements)

associateWith

public <R> PandaStream<Pair<T,R>> associateWith(R value)

transform

public <R> PandaStream<R> transform(Function<Stream<T>,Stream<R>> function)

map

public <R> PandaStream<R> map(Function<T,R> function)

mapWith

public <A,
R> PandaStream<R> mapWith(A with,
 BiFunction<A,T,R> function)

mapOpt

public <R> PandaStream<R> mapOpt(Function<T,Option<R>> function)

flatMap

public <R> PandaStream<R> flatMap(Function<T,Iterable<R>> function)

flatMapWith

public <A,
R> PandaStream<R> flatMapWith(A with,
 BiFunction<A,T,Iterable<R>> function)

flatMapStream

public <R> PandaStream<R> flatMapStream(Function<T,Stream<R>> function)

is

public <S> PandaStream<S> is(Class<S> type)

isNot

public PandaStream<T> isNot(Class<?> type)

filter

public PandaStream<T> filter(Predicate<T> predicate)

filterNot

public PandaStream<T> filterNot(Predicate<T> predicate)

filterToResult

public <E> Result<PandaStream<T>,E> filterToResult(Function<? super T,Option<E>> predicate)

search

public <R,
E> Result<R,List<E>> search(Function<T,Result<R,E>> searchFunction)

Find first element in stream or return all failures. The size of list with errors may be equal to number of all elements in stream, so it shouldn't be used with large datasets.

Type Parameters:

R - type of matched element

E - type of failures

Parameters:

searchFunction - search function may return success (matched element, terminates stream) or failure (to continue searching).

Returns:

result with matched element or list of failures

distinct

public PandaStream<T> distinct()

sorted

public PandaStream<T> sorted()

sorted

public PandaStream<T> sorted(Comparator<? super T> comparator)

skip

public PandaStream<T> skip(long n)

find

public Option<T> find(Predicate<T> predicate)

head

public Option<T> head()

last

public Option<T> last()

any

public Option<T> any()

count

public long count(Predicate<T> predicate)

count

public long count()

collect

public <A,
R> R collect(Collector<? super T,A,R> collector)

throwIfNot

public <E extends Exception> PandaStream<T> throwIfNot(Predicate<T> condition,
 Function<T,E> exception)

takeWhile

public PandaStream<T> takeWhile(Predicate<T> condition)

forEach

public PandaStream<T> forEach(Consumer<? super T> consumer)

forEachByResult

public <E> Result<PandaStream<T>,E> forEachByResult(Function<T,Option<E>> predicate)

findIterating

public <R> Option<R> findIterating(Function<? super T,Option<R>> predicate)

duplicate

public PandaStream<T> duplicate()

Simulates the stream duplication mechanism. The method transforms current stream into buffered list of elements and then recreates current stream and the duplicated one on top of that. This method should not be used to handle huge sets and may be a bottleneck if called often.

Returns:

duplicated stream

toArray

public T[] toArray(IntFunction<T[]> function)

toList

public List<T> toList()

toSet

public Set<T> toSet()

toMap

public <K,
V> Map<K,V> toMap(Function<T,K> keyMapper,
 Function<T,V> valueMapper)

toMap

public <K,
V> Map<K,V> toMap(Supplier<Map<K,V>> mapSupplier,
 Function<T,K> keyMapper,
 Function<T,V> valueMapper)

toMapByPair

public <K,
V> Map<K,V> toMapByPair(Supplier<Map<K,V>> mapSupplier,
 Function<T,Pair<K,V>> mapper)

toMapByPair

public <K,
V> Map<K,V> toMapByPair(Function<T,Pair<K,V>> mapper)

toStream

public Stream<T> toStream()

iterator

public Iterator<T> iterator()

of

public static <T> PandaStream<T> of(Stream<T> stream)

of

public static <T> PandaStream<T> of(Collection<T> collection)

of

public static <T> PandaStream<T> of(Iterable<T> iterable)

of

@SafeVarargs
public static <T> PandaStream<T> of(T... array)

empty

public static <T> PandaStream<T> empty()