ContextMappingFunction

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 ContextMappingFunction
```
ContextMappingFunction is an interface that must be satisfied by an object passed to a ContextMappingIterator. It represents an object which, given an Item, can return a SequenceIterator that delivers a sequence of zero or more Items.
This is a specialization of the more general MappingFunction class: it differs in that each item being processed becomes the context item while it is being processed.

NOTE: because this class is converted to a delegate in C#, it should not be subclassed; it should only be implemented by lambda expressions.

- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  SequenceIterator map(XPathContext context)
  Map one item to a sequence.

- Method Detail
  - map
```
SequenceIterator map(XPathContext context)
              throws XPathException
```
    Map one item to a sequence.
    
    Parameters:
    
    context - The processing context. The item to be mapped is the context item identified from this context: the values of position() and last() also relate to the set of items being mapped
    
    Returns:
    
    a SequenceIterator over the sequence of items that the supplied input item maps to
    
    Throws:
    
    XPathException - if a dynamic error is detected