net.sf.saxon.functions

Interface Fold

All Known Implementing Classes:

FoldLeftFn.FoldLeftFold

public interface Fold

Method Summary

Modifier and Type	Method and 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

Method Detail

processItem

void processItem(Item item)
          throws XPathException

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

Parameters:

item - the item to be processed from the input sequence

Throws:

XPathException - if a dynamic error occurs

isFinished

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.

Returns:

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

result

Sequence result()
         throws XPathException

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

Returns:

the result of the function

Throws:

XPathException - if a dynamic error occurs