Package net.sf.saxon.functions

Class Sum.SumFold

java.lang.Object

net.sf.saxon.functions.Sum.SumFold

All Implemented Interfaces:

Fold

Enclosing class:

Sum

public static class Sum.SumFold
extends Object
implements Fold

Implementation of Fold class to do the summation in push mode

Constructor Summary

Constructors

Constructor	Description
SumFold(XPathContext context, AtomicValue zeroValue)

Method Summary

Modifier and Type	Method	Description
boolean	isFinished()	Ask whether the computation has completed.
void	processItem(Item item)	Process one item in the input sequence, returning a new copy of the working data
Sequence	result()	Compute the final result of the function, when all the input has been processed

Methods inherited from class java.lang.Object

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

Constructor Details

SumFold

public SumFold(XPathContext context,
 AtomicValue zeroValue)

Method Details

processItem

public void processItem(Item item)
                 throws XPathException

Process one item in the input sequence, returning a new copy of the working data

Specified by:

processItem in interface Fold

Parameters:

item - the item to be processed from the input sequence

Throws:

XPathException - if a dynamic error occurs

isFinished

public boolean isFinished()

Ask whether the computation has completed. A function that can deliver its final result without reading the whole input should return true; this will be followed by a call on result() to deliver the final result.

Specified by:

isFinished in interface Fold

Returns:

true if the result of the function is now available even though not all items in the sequence have been processed

result

public Sequence result()

Compute the final result of the function, when all the input has been processed

Specified by:

result in interface Fold

Returns:

the result of the function