Package com.apple.foundationdb.record.query.plan.temp

Class ChooseK

java.lang.Object

com.apple.foundationdb.record.query.plan.temp.ChooseK

@API(EXPERIMENTAL)
public class ChooseK
extends Object

Utility class to provide helpers related to enumeration of cross products.

Method Summary

Modifier and Type	Method	Description
static <T> EnumeratingIterable<T>	chooseK(Collection<T> elements, int numberOfElementsToChoose)	Create a EnumeratingIterable based on a set and a function describing the depends-on relationships between items in the given set.

Methods inherited from class java.lang.Object

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

Method Detail

chooseK

public static <T> EnumeratingIterable<T> chooseK(@Nonnull
                                                 Collection<T> elements,
                                                 int numberOfElementsToChoose)

Create a EnumeratingIterable based on a set and a function describing the depends-on relationships between items in the given set.

Type Parameters:

T - type

Parameters:

elements - the list of collections to create the iterable over

numberOfElementsToChoose - number k of elements to choose

Returns:

a new EnumeratingIterable that obeys the constraints as expressed in dependsOnFn in a sense that the iterators created by this iterator will not return orderings that violate the given depends-on constraints