com.saperion.database.query.predicates

Class IsEmpty<ElementType,CollectionType extends Collection<ElementType>>

java.lang.Object

com.saperion.database.query.QueryExpression<ExpressionType>

com.saperion.database.query.NodeExpression<ResultExpressionType>

com.saperion.database.query.UnaryOperator<CollectionType,Boolean>

com.saperion.database.query.predicates.IsEmpty<ElementType,CollectionType>

All Implemented Interfaces:

Serializable

public class IsEmpty<ElementType,CollectionType extends Collection<ElementType>>
extends UnaryOperator<CollectionType,Boolean>

A QueryExpression that checks whether its operand is an empty list.

Author:

jschwarz

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
IsEmpty(QueryExpression<? extends CollectionType> operand)

Method Summary

Modifier and Type	Method and Description
protected void	finishAccept(QueryExpressionVisitor visitor) This method invokes the appropriate callback of the visitor for the current node, after its children are visited.
protected void	startAccept(QueryExpressionVisitor visitor) This method invokes the appropriate callback of the visitor for the current node, before its children are visited.

Methods inherited from class com.saperion.database.query.UnaryOperator

getOperand, setOperand, toString

Methods inherited from class com.saperion.database.query.NodeExpression

accept, getChildren, setChild

Methods inherited from class com.saperion.database.query.QueryExpression

getExpressionType

Methods inherited from class java.lang.Object

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

Constructor Detail

IsEmpty

public IsEmpty(QueryExpression<? extends CollectionType> operand)

Method Detail

startAccept

protected void startAccept(QueryExpressionVisitor visitor)

Description copied from class: NodeExpression

This method invokes the appropriate callback of the visitor for the current node, before its children are visited.

Specified by:

startAccept in class NodeExpression<Boolean>

Parameters:

visitor - the visitor visiting this expression

finishAccept

protected void finishAccept(QueryExpressionVisitor visitor)

Description copied from class: NodeExpression

This method invokes the appropriate callback of the visitor for the current node, after its children are visited.

Specified by:

finishAccept in class NodeExpression<Boolean>

Parameters:

visitor - the visitor visiting this expression