org.treetank.service.xml.xpath.expr

Class AbsExpression

java.lang.Object

org.treetank.axis.AbsAxis

org.treetank.service.xml.xpath.expr.AbsExpression

All Implemented Interfaces:

Iterable<Long>, Iterator<Long>

Direct Known Subclasses:

AbsFunction, AndExpr, CastableExpr, EveryExpr, InstanceOfExpr, LiteralExpr, OrExpr, SomeExpr, VarRefExpr

public abstract class AbsExpression
extends AbsAxis

AbstractExpression

Template for all expressions.

This class is a template for most complex expressions of the XPath 2.0 language. These expressions work like an axis, as all other XPath 2.0 expressions in this implementation, but the expression is only evaluated once. Therefore the axis returns true only for the first call and false for all others.

Constructor Summary

Constructors

Constructor and Description
AbsExpression(INodeReadTrx rtx) Constructor.

Method Summary

Methods

Modifier and Type	Method and Description
abstract AtomicValue	evaluate() Performs the expression dependent evaluation of the expression.
boolean	hasNext()
void	reset(long mNodeKey)

Methods inherited from class org.treetank.axis.AbsAxis

addAtomicToItemList, close, getItemList, getNode, getStartKey, isSelfIncluded, iterator, moveTo, next, remove, resetToLastKey, resetToStartKey

Methods inherited from class java.lang.Object

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

Constructor Detail

AbsExpression

public AbsExpression(INodeReadTrx rtx)

Constructor. Initializes the internal state.

Parameters:

rtx - Exclusive (immutable) trx to iterate with.

Method Detail

reset

public void reset(long mNodeKey)

Overrides:

reset in class AbsAxis

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<Long>

Specified by:

hasNext in class AbsAxis

evaluate

public abstract AtomicValue evaluate()
                              throws TTXPathException

Performs the expression dependent evaluation of the expression. (Template method)

Throws:

TTXPathException - if evaluation fails.