net.sf.saxon.expr

Interface MappingFunction

All Known Implementing Classes:

ForExpression.MappingAction, SequenceMapper

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface MappingFunction

MappingFunction is an interface that must be satisfied by an object passed to a MappingIterator. It represents an object which, given an Item, can return a SequenceIterator that delivers a sequence of zero or more Items.

It maps an item of class F to a sequence of items of class T, returned as an iterator.

NOTE: Java allows a lambda expression to be used where an ItemMappingFunction is needed, but C# does not (it's not possible in C# to have a class implementing a delegate). So if a delegate is wanted, use SequenceMapper.

Method Summary

Modifier and Type	Method and Description
SequenceIterator	map(Item item) Map one item to a sequence.

Method Detail

map

SequenceIterator map(Item item)
              throws XPathException

Map one item to a sequence.

Parameters:

item - The item to be mapped.

Returns:

one of the following: (a) a SequenceIterator over the sequence of items that the supplied input item maps to, or (b) null if it maps to an empty sequence.

Throws:

XPathException - if a dynamic error occurs