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

Class MultiChildrenMatcher.SomeChildrenMatcher

java.lang.Object

com.apple.foundationdb.record.query.plan.temp.matchers.MultiChildrenMatcher

com.apple.foundationdb.record.query.plan.temp.matchers.MultiChildrenMatcher.SomeChildrenMatcher

All Implemented Interfaces:

ExpressionChildrenMatcher

Enclosing class:

MultiChildrenMatcher

public static class MultiChildrenMatcher.SomeChildrenMatcher
extends MultiChildrenMatcher

An expression children matcher that tries to match some children to a single ExpressionMatcher. Given a single ExpressionMatcher, this matcher tries to match it to every child. For the ones that match, it produces a stream of bindings containing the Cartesian product of the streams of bindings from each matching child, merged using PlannerBindings.mergedWith(PlannerBindings). Because the same matcher is used for all children, the merged bindings will map the single child matcher to a collected list of Bindables; such a binding must be retrieved using PlannerBindings.getAll(ExpressionMatcher) rather than the usual get() method.

Nested Class Summary

Nested classes/interfaces inherited from class com.apple.foundationdb.record.query.plan.temp.matchers.MultiChildrenMatcher

MultiChildrenMatcher.AllChildrenMatcher, MultiChildrenMatcher.SomeChildrenMatcher

Constructor Summary

Constructors

Constructor	Description
SomeChildrenMatcher(ExpressionMatcher<? extends Bindable> childMatcher)

Method Summary

Modifier and Type	Method	Description
protected Optional<Stream<PlannerBindings>>	onEmptyIndividualBindings(Stream<PlannerBindings> accumulatedStream)

Methods inherited from class com.apple.foundationdb.record.query.plan.temp.matchers.MultiChildrenMatcher

allMatching, matches, someMatching

Methods inherited from class java.lang.Object

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

Constructor Detail

SomeChildrenMatcher

public SomeChildrenMatcher(@Nonnull
                           ExpressionMatcher<? extends Bindable> childMatcher)

Method Detail

onEmptyIndividualBindings

@Nonnull
protected Optional<Stream<PlannerBindings>> onEmptyIndividualBindings(@Nonnull
                                                                      Stream<PlannerBindings> accumulatedStream)

Specified by:

onEmptyIndividualBindings in class MultiChildrenMatcher