Package org.javimmutable.collections.iterators

Class GenericIterator<T>

java.lang.Object

org.javimmutable.collections.iterators.AbstractSplitableIterator<T>

org.javimmutable.collections.iterators.GenericIterator<T>

All Implemented Interfaces:

Iterator<T>, SplitableIterator<T>

@ThreadSafe
public class GenericIterator<T>
extends AbstractSplitableIterator<T>

A mutable class implementing the SplitableIterator interface in a reusable way. Maintains a current position in the collection it iterates over and delegates to a "state" object provided by the collection to move forward inside the collection. To implement spliterator functionality for parallel streams it limits itself to a specific subset of the collection by way of an offset (current position) and limit (stopping position).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	GenericIterator.Iterable<T>	Interface for collections that can be iterated over by GenericIterator using State objects to track the progress of the iteration.
static interface	GenericIterator.State<T>	Interface for objects that track the current position of an iteration in progress.

Constructor Summary

Constructors

Constructor	Description
GenericIterator(GenericIterator.Iterable<T> root, int offset, int limit)

Method Summary

Modifier and Type	Method	Description
boolean	hasNext()
boolean	isSplitAllowed()	Tests to determine if this Iterator is capable of splitting into two new Iterators.
static <T> GenericIterator.State<T>	multiIterableState(GenericIterator.State<T> parent, Indexed<? extends GenericIterator.Iterable<T>> children, int offset, int limit)	Returns a State for iterating multiple collections (Iterables) that are themselves stored in an Indexed collection.
static <T> GenericIterator.State<T>	multiValueState(GenericIterator.State<T> parent, Indexed<T> values, int offset, int limit)	Returns a State for iterating multiple values stored in an Indexed collection.
T	next()
static <T> GenericIterator.Iterable<T>	singleValueIterable(T value)	Returns an Iterable for iterating a single value.
static <T> GenericIterator.State<T>	singleValueState(GenericIterator.State<T> parent, T value, int offset, int limit)	Returns a State for iterating a single value.
SplitIterator<T>	splitIterator()	Whenever isSplitAllowed returns true this method can be used to create two new SplitableIterators that collectively visit all the same elements as this Iterator.
static <A, B> GenericIterator.Iterable<B>	transformIterable(GenericIterator.Iterable<A> source, Func1<A,B> transforminator)	Returns an Iterable for iterating over another Iterable's values but transforming each of those values using a function before returning to its caller.
static <A, B> GenericIterator.State<B>	transformState(GenericIterator.State<B> parent, GenericIterator.State<A> source, Func1<A,B> transforminator)	Returns a State for iterating over another State's values but transforming each of those values using a function before returning to its caller.

Methods inherited from class org.javimmutable.collections.iterators.AbstractSplitableIterator

spliterator

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Constructor Details

GenericIterator

public GenericIterator(@Nonnull
 GenericIterator.Iterable<T> root,
 int offset,
 int limit)

Method Details

hasNext

public boolean hasNext()

next

public T next()

isSplitAllowed

public boolean isSplitAllowed()

Description copied from interface: SplitableIterator

Tests to determine if this Iterator is capable of splitting into two new Iterators.

splitIterator

@Nonnull
public SplitIterator<T> splitIterator()

Description copied from interface: SplitableIterator

Whenever isSplitAllowed returns true this method can be used to create two new SplitableIterators that collectively visit all the same elements as this Iterator. Whenever isSplitAllowed returns false this method throws UnsupportedOperationException.

Returns:

two new SplitableIterators spanning the same elements as this

singleValueState

public static <T> GenericIterator.State<T> singleValueState(GenericIterator.State<T> parent,
 T value,
 int offset,
 int limit)

Returns a State for iterating a single value.

singleValueIterable

public static <T> GenericIterator.Iterable<T> singleValueIterable(T value)

Returns an Iterable for iterating a single value.

multiValueState

public static <T> GenericIterator.State<T> multiValueState(@Nullable
 GenericIterator.State<T> parent,
 @Nonnull
 Indexed<T> values,
 int offset,
 int limit)

Returns a State for iterating multiple values stored in an Indexed collection.

multiIterableState

public static <T> GenericIterator.State<T> multiIterableState(@Nullable
 GenericIterator.State<T> parent,
 @Nonnull
 Indexed<? extends GenericIterator.Iterable<T>> children,
 int offset,
 int limit)

Returns a State for iterating multiple collections (Iterables) that are themselves stored in an Indexed collection.

transformState

public static <A,
B> GenericIterator.State<B> transformState(@Nullable
 GenericIterator.State<B> parent,
 @Nullable
 GenericIterator.State<A> source,
 @Nonnull
 Func1<A,B> transforminator)

Returns a State for iterating over another State's values but transforming each of those values using a function before returning to its caller.

transformIterable

public static <A,
B> GenericIterator.Iterable<B> transformIterable(@Nonnull
 GenericIterator.Iterable<A> source,
 @Nonnull
 Func1<A,B> transforminator)

Returns an Iterable for iterating over another Iterable's values but transforming each of those values using a function before returning to its caller.