org.modeshape.jcr.query.engine

Class ScanningQueryEngine.DynamicOperandFilter

java.lang.Object

org.modeshape.jcr.query.engine.ScanningQueryEngine.DynamicOperandFilter

All Implemented Interfaces:

NodeSequence.RowFilter

Enclosing class:

ScanningQueryEngine

protected abstract static class ScanningQueryEngine.DynamicOperandFilter
extends Object
implements NodeSequence.RowFilter

Interface for evaluating a DynamicOperand against the current row in a NodeSequence.Batch and returning the corresponding value.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ScanningQueryEngine.DynamicOperandFilter(RowExtractors.ExtractFromRow extractor)

Method Summary

Methods

Modifier and Type	Method and Description
protected abstract boolean	evaluate(Object leftHandValue) Determine whether the left hand side of the expression (as computed by the dynamic operation) will result in this row being included in the results.
boolean	isCurrentRowValid(NodeSequence.Batch batch) Determine if the current row in the given batch satisfies the filter and should be included in the results.

Methods inherited from class java.lang.Object

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

Constructor Detail

ScanningQueryEngine.DynamicOperandFilter

protected ScanningQueryEngine.DynamicOperandFilter(RowExtractors.ExtractFromRow extractor)

Method Detail

isCurrentRowValid

public boolean isCurrentRowValid(NodeSequence.Batch batch)

Description copied from interface: NodeSequence.RowFilter

Determine if the current row in the given batch satisfies the filter and should be included in the results.

Implementations should never call NodeSequence.Batch.hasNext() or NodeSequence.Batch.nextRow().

Specified by:

isCurrentRowValid in interface NodeSequence.RowFilter

Parameters:

batch - the batch that is at a valid row

Returns:

true if the current row is acceptable, or false if it should be excluded

evaluate

protected abstract boolean evaluate(Object leftHandValue)

Determine whether the left hand side of the expression (as computed by the dynamic operation) will result in this row being included in the results. Note that implementations will compare this left hand side for the row with a fixed right hand side value.

Parameters:

leftHandValue - the left hand side of the current row; may be null

Returns:

true if the left hand value satisfies this filter, or false otherwise