Package ai.timefold.solver.core.impl.bavet.common.index

Class FilteredUniqueRandomIterator<T>

java.lang.Object

ai.timefold.solver.core.impl.bavet.common.index.FilteredUniqueRandomIterator<T>

Type Parameters:

T -

All Implemented Interfaces:

UniqueRandomIterator<T>, Iterator<T>

@NullMarked
public final class FilteredUniqueRandomIterator<T>
extends Object
implements UniqueRandomIterator<T>

Unlike DefaultUniqueRandomIterator, this class only returns elements that match the given filter. Because we can't predict how many elements will be filtered out, and because we don't want to pre-filter the entire list, this class may need to try multiple times to find a matching element.

Method Summary

Modifier and Type	Method	Description
boolean	hasNext()	Returns whether there are no more elements to pick from.
T	next()	Picks a random element from the list which has not already been removed.
void	remove()	Removes a random element in the underlying list which has not already been removed.

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

Method Details

hasNext

public boolean hasNext()

Description copied from interface: UniqueRandomIterator

Returns whether there are no more elements to pick from. In case of FilteredUniqueRandomIterator, this method may return false positives, as it cannot predict how many elements will be filtered out.

Specified by:

hasNext in interface Iterator<T>

Specified by:

hasNext in interface UniqueRandomIterator<T>

Returns:

true if there are no more elements to pick from, false otherwise

next

public T next()

Description copied from interface: UniqueRandomIterator

Picks a random element from the list which has not already been removed. Once an element of the list is removed either via UniqueRandomIterator.remove(), it will never be returned again by this method.

Specified by:

next in interface Iterator<T>

Specified by:

next in interface UniqueRandomIterator<T>

Returns:

a random element from the list which has not already been removed

remove

public void remove()

Description copied from interface: UniqueRandomIterator

Removes a random element in the underlying list which has not already been removed. Once this method returns, no subsequent UniqueRandomIterator.next() will return this element ever again.

Specified by:

remove in interface Iterator<T>

Specified by:

remove in interface UniqueRandomIterator<T>