Package com.chemaxon.calculations.io

Class MemoizingIterator<E,R>

java.lang.Object

com.google.common.collect.UnmodifiableIterator<T>

com.google.common.collect.AbstractIterator<T>

com.chemaxon.calculations.io.CloseableAbstractIterator<OrderedElement<E>>

com.chemaxon.calculations.io.MemoizingIterator<E,R>

Type Parameters:

E - Type of iterated elements from the base CloseableIterator

R - Type of transformed elements available for retrieval

All Implemented Interfaces:

CloseableIterator<OrderedElement<E>>, MemoizedSparseCollection<R>, Closeable, AutoCloseable, Iterator<OrderedElement<E>>

Direct Known Subclasses:

SmilesMemoizingMoleculeIterator

@PublicAPI
@Beta
public class MemoizingIterator<E,R>
extends com.chemaxon.calculations.io.CloseableAbstractIterator<OrderedElement<E>>
implements MemoizedSparseCollection<R>

Decorate a CloseableIterator with the availability of retrieval of a transformation of the iterated elements. Typical application is to remember SMILES structure sources of Molecules imported with a MolImporter.

It is recommended to access the memoized items use only after AbstractIterator.hasNext() is false. Otherwise new structure might be collected upon the next AbstractIterator.hasNext() or AbstractIterator.next() invocation.

Please note that this class is marked with @Beta annotation, so it can be subject of incompatible changes or removal in later releases.

Method Summary

Modifier and Type	Method	Description
void	close()
protected OrderedElement<E>	computeNext()
R	getMemoized(int i)	Get a non-missing memoiozed.
Function<Integer,R>	getMemoizedFunction()	Function to access captured non-missing memoizeds.
Optional<R>	getMemoizedIfPresent(int i)	Get item when present.
R	getMemoizedOrDefault(int i, R defaultValue)	Get item when present or a default value when missing.
Function<Integer,R>	getMemoizedOrDefaultFunction(R defaultValue)	Function to access present items with a default value for missing items.
int	size()	Collected items count.

Methods inherited from class com.google.common.collect.AbstractIterator

endOfData, hasNext, next, peek

Methods inherited from class com.google.common.collect.UnmodifiableIterator

remove

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.chemaxon.calculations.io.CloseableIterator

forward, limit, limit, transform, transformIterator, transformMultipleElements

Methods inherited from interface java.util.Iterator

forEachRemaining, hasNext, next, remove

Method Detail

computeNext

protected OrderedElement<E> computeNext()

Specified by:

computeNext in class com.google.common.collect.AbstractIterator<OrderedElement<E>>

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface CloseableIterator<E>

size

public int size()

Description copied from interface: MemoizedSparseCollection

Collected items count. Including missing items.

Specified by:

size in interface MemoizedSparseCollection<E>

Returns:

collected items count

getMemoizedIfPresent

public Optional<R> getMemoizedIfPresent(int i)

Description copied from interface: MemoizedSparseCollection

Get item when present.

Specified by:

getMemoizedIfPresent in interface MemoizedSparseCollection<E>

Parameters:

i - Index which refers to either a missing or a present element

Returns:

Collected remembered element

getMemoized

public R getMemoized(int i)

Description copied from interface: MemoizedSparseCollection

Get a non-missing memoiozed.

Specified by:

getMemoized in interface MemoizedSparseCollection<E>

Parameters:

i - Index of an item which is not missing

Returns:

Collected remembered item

getMemoizedFunction

public Function<Integer,R> getMemoizedFunction()

Description copied from interface: MemoizedSparseCollection

Function to access captured non-missing memoizeds.

Specified by:

getMemoizedFunction in interface MemoizedSparseCollection<E>

Returns:

A Function of Integer to the memoized type T which delegates to MemoizedSparseCollection.getMemoized(int)

getMemoizedOrDefault

public R getMemoizedOrDefault(int i,
                              R defaultValue)

Description copied from interface: MemoizedSparseCollection

Get item when present or a default value when missing.

Specified by:

getMemoizedOrDefault in interface MemoizedSparseCollection<E>

Parameters:

i - Index which refers to either a missing or a present element

defaultValue - value for return when missing

Returns:

Collected remembered element or default when missing

getMemoizedOrDefaultFunction

public Function<Integer,R> getMemoizedOrDefaultFunction(R defaultValue)

Description copied from interface: MemoizedSparseCollection

Function to access present items with a default value for missing items.

Specified by:

getMemoizedOrDefaultFunction in interface MemoizedSparseCollection<E>

Parameters:

defaultValue - Value to return for missing items.

Returns:

A Function of Integer to the memoized type T which delegates to MemoizedSparseCollection.getMemoizedOrDefault(int, java.lang.Object)