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

Class AnyChildMatcher

java.lang.Object

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

All Implemented Interfaces:

ExpressionChildrenMatcher

@API(EXPERIMENTAL)
public class AnyChildMatcher
extends Object
implements ExpressionChildrenMatcher

An expression children matcher that tries to match any child to the given ExpressionMatcher, producing a stream of bindings that is the concatenation of the (possibly empty) streams of bindings from attempting to match each child to the given matcher.

Method Summary

Modifier and Type	Method	Description
static AnyChildMatcher	anyMatching(ExpressionMatcher<? extends Bindable> childMatcher)	Get a matcher that tries to match any child with the given ExpressionMatcher.
Stream<PlannerBindings>	matches(PlannerBindings outerBindings, List<? extends Bindable> children)	Apply this matcher to the children provided by the given iterator and produce a stream of possible bindings.

Methods inherited from class java.lang.Object

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

Method Detail

matches

@Nonnull
public Stream<PlannerBindings> matches(@Nonnull
                                       PlannerBindings outerBindings,
                                       @Nonnull
                                       List<? extends Bindable> children)

Description copied from interface: ExpressionChildrenMatcher

Apply this matcher to the children provided by the given iterator and produce a stream of possible bindings. If the match is not successful, produce an empty stream. Note that this method should not generally match to the children themselves; instead, it should delegate that work to one or more inner ExpressionMatchers.

Specified by:

matches in interface ExpressionChildrenMatcher

Parameters:

outerBindings - preexisting bindings supplied by the caller

children - a list of references to the children of a planner expression

Returns:

a stream of the possible bindings from applying this match to the children in the given iterator

anyMatching

@Nonnull
public static AnyChildMatcher anyMatching(@Nonnull
                                          ExpressionMatcher<? extends Bindable> childMatcher)

Get a matcher that tries to match any child with the given ExpressionMatcher.

Parameters:

childMatcher - an expression matcher to match any one of the children

Returns:

a matcher that tries to match any child with the given child matcher