MappingFunction (saxon JavaDoc)

All Known Implementing Classes:

ForExpression.MappingAction, StandardCollectionURIResolver.FileExpander
```
public interface MappingFunction<F extends Item<?>,T extends Item<?>>
```
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.

- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  SequenceIterator<? extends T> map(F item)
  Map one item to a sequence.

- Method Detail
  - map
```
SequenceIterator<? extends T> map(F 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