Package org.apache.qpid.server.query.engine.parsing.expression.set

Class EmptySetExpression<T,R>

java.lang.Object

org.apache.qpid.server.query.engine.parsing.expression.AbstractExpressionNode<T,R>

org.apache.qpid.server.query.engine.parsing.expression.set.AbstractSetExpression<T,R>

org.apache.qpid.server.query.engine.parsing.expression.set.EmptySetExpression<T,R>

Type Parameters:

T - Input parameter type

R - Output parameter type

All Implemented Interfaces:

Function<T,R>, Expression<T,R>, ExpressionNode<T,R>, SetExpression<T,R>

public class EmptySetExpression<T,R>
extends AbstractSetExpression<T,R>

Represents an empty set returned by a subquery

Field Summary

Fields inherited from class org.apache.qpid.server.query.engine.parsing.expression.set.AbstractSetExpression

_distinct

Fields inherited from class org.apache.qpid.server.query.engine.parsing.expression.AbstractExpressionNode

_metadata

Constructor Summary

Constructors

Constructor	Description
EmptySetExpression()	Initializes expression with a default distinct value (false)

Method Summary

Modifier and Type	Method	Description
R	apply(T value)	Shouldn't be called

Methods inherited from class org.apache.qpid.server.query.engine.parsing.expression.set.AbstractSetExpression

getProjections, getSelections

Methods inherited from class org.apache.qpid.server.query.engine.parsing.expression.AbstractExpressionNode

containsAggregation, ctx, evaluateChild, getAggregations, getAlias, getChild, getChildren, getParent, isAccessor, isInstantlyEvaluable, setAlias, setParent, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.qpid.server.query.engine.parsing.expression.Expression

andThen

Methods inherited from interface org.apache.qpid.server.query.engine.parsing.expression.ExpressionNode

containsAggregation, getAggregations, getAlias, getChildren, getParent, isAccessor, isInstantlyEvaluable, setAlias, setParent

Methods inherited from interface java.util.function.Function

andThen, compose

Constructor Detail

EmptySetExpression

public EmptySetExpression()

Initializes expression with a default distinct value (false)

Method Detail

apply

public R apply(T value)

Shouldn't be called

Parameters:

value - Object to handle

Returns:

Null