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

Class TypeMatcher<T extends Bindable>

java.lang.Object

com.apple.foundationdb.record.query.plan.temp.matchers.TypeMatcher<T>

Type Parameters:

T - the planner expression type that this matcher binds to

All Implemented Interfaces:

ExpressionMatcher<T>

Direct Known Subclasses:

QuantifierMatcher, TypeWithPredicateMatcher

@API(EXPERIMENTAL)
public class TypeMatcher<T extends Bindable>
extends Object
implements ExpressionMatcher<T>

A matcher that is specified by the class of its expression: to match any of several types of expressions, they must all implement a common interface (which itself extends PlannerExpression). The bindings produced by this matcher provide access to a single expression only, and allow it to be accessed by the rule.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	TypeMatcher(Class<? extends T> expressionClass, ExpressionChildrenMatcher childrenMatcher)

Method Summary

Modifier and Type	Method	Description
ExpressionChildrenMatcher	getChildrenMatcher()	Return the child matchers of this matcher as a list.
Class<? extends Bindable>	getRootClass()	Get a class or interface extending RelationalExpression that is a super class of every planner expression that this matcher can match.
Stream<PlannerBindings>	matchWith(ExpressionRef<? extends RelationalExpression> ref)	Attempt to match this matcher against the given expression reference.
Stream<PlannerBindings>	matchWith(Quantifier quantifier)	Attempt to match this matcher against the given Quantifier.
Stream<PlannerBindings>	matchWith(RelationalExpression expression)	Attempt to match this matcher against the given ExpressionMatcher.
Stream<PlannerBindings>	matchWith(QueryPredicate predicate)	Attempt to match this matcher against the given QueryPredicate.
static <U extends Bindable> TypeMatcher<U>	of(Class<? extends U> expressionClass)
static <U extends Bindable> TypeMatcher<U>	of(Class<? extends U> expressionClass, ExpressionChildrenMatcher childrenMatcher)
static <U extends Bindable> TypeMatcher<U>	of(Class<? extends U> expressionClass, ExpressionMatcher<? extends Bindable>... children)

Methods inherited from class java.lang.Object

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

Constructor Detail

TypeMatcher

protected TypeMatcher(@Nonnull
                      Class<? extends T> expressionClass,
                      @Nonnull
                      ExpressionChildrenMatcher childrenMatcher)

Method Detail

getRootClass

@Nonnull
public Class<? extends Bindable> getRootClass()

Description copied from interface: ExpressionMatcher

Get a class or interface extending RelationalExpression that is a super class of every planner expression that this matcher can match. Ideally, it should be the lowest such class but it may not be. A planner will generally use this method to quickly determine a set of rules that could match an expression, without considering each rule and trying to apply it. A good implementation of this method helps the planner match rules efficiently.

Specified by:

getRootClass in interface ExpressionMatcher<T extends Bindable>

Returns:

a class object for a class that is a super class of every planner expression this matcher can match

getChildrenMatcher

@Nonnull
public ExpressionChildrenMatcher getChildrenMatcher()

Description copied from interface: ExpressionMatcher

Return the child matchers of this matcher as a list.

Specified by:

getChildrenMatcher in interface ExpressionMatcher<T extends Bindable>

Returns:

a list of the child matchers of this matcher

of

public static <U extends Bindable> TypeMatcher<U> of(@Nonnull
                                                     Class<? extends U> expressionClass)

of

@SafeVarargs
public static <U extends Bindable> TypeMatcher<U> of(@Nonnull
                                                     Class<? extends U> expressionClass,
                                                     @Nonnull
                                                     ExpressionMatcher<? extends Bindable>... children)

of

public static <U extends Bindable> TypeMatcher<U> of(@Nonnull
                                                     Class<? extends U> expressionClass,
                                                     @Nonnull
                                                     ExpressionChildrenMatcher childrenMatcher)

matchWith

@Nonnull
public Stream<PlannerBindings> matchWith(@Nonnull
                                         ExpressionRef<? extends RelationalExpression> ref)

Description copied from interface: ExpressionMatcher

Attempt to match this matcher against the given expression reference. Note that implementations of matchWith() should only attempt to match the given root with this planner expression and should not call into the ExpressionChildrenMatcher returned by ExpressionMatcher.getChildrenMatcher() or attempt to access the members of the given reference.

Specified by:

matchWith in interface ExpressionMatcher<T extends Bindable>

Parameters:

ref - a reference to match with

Returns:

a stream of PlannerBindings containing the matched bindings, or an empty stream is no match was found

matchWith

@Nonnull
public Stream<PlannerBindings> matchWith(@Nonnull
                                         RelationalExpression expression)

Description copied from interface: ExpressionMatcher

Attempt to match this matcher against the given ExpressionMatcher. Note that implementations of matchWith() should only attempt to match the given root with this planner expression and should not call into the ExpressionChildrenMatcher returned by ExpressionMatcher.getChildrenMatcher() or attempt to access children of the given expression.

Specified by:

matchWith in interface ExpressionMatcher<T extends Bindable>

Parameters:

expression - a planner expression to match with

Returns:

a stream of PlannerBindings containing the matched bindings, or an empty stream is no match was found

matchWith

@Nonnull
public Stream<PlannerBindings> matchWith(@Nonnull
                                         QueryPredicate predicate)

Description copied from interface: ExpressionMatcher

Attempt to match this matcher against the given QueryPredicate. Note that implementations of matchWith() should only attempt to match the given root with this planner expression and should not call into the ExpressionChildrenMatcher returned by ExpressionMatcher.getChildrenMatcher() or attempt to access children of the given expression.

Specified by:

matchWith in interface ExpressionMatcher<T extends Bindable>

Parameters:

predicate - a predicate to match with

Returns:

a stream of PlannerBindings containing the matched bindings, or an empty stream is no match was found

matchWith

@Nonnull
public Stream<PlannerBindings> matchWith(@Nonnull
                                         Quantifier quantifier)

Description copied from interface: ExpressionMatcher

Attempt to match this matcher against the given Quantifier. Note that implementations of matchWith() should only attempt to match the given root with this planner expression and should not call into the ExpressionChildrenMatcher returned by ExpressionMatcher.getChildrenMatcher() or attempt to access children of the given expression.

Specified by:

matchWith in interface ExpressionMatcher<T extends Bindable>

Parameters:

quantifier - a quantifier to match with

Returns:

a stream of PlannerBindings containing the matched bindings, or an empty stream is no match was found