SortKeyEvaluator

All Known Implementing Classes:

ForEachGroup, SortExpression
```
public interface SortKeyEvaluator
```
Callback interface used to evaluate sort keys. An instance of this class is passed to the SortedIterator, and is used whenever a sort key value needs to be computed.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`AtomicValue`	`evaluateSortKey(int n, XPathContext context)`	Evaluate the n'th sort key of the context item

- Method Detail
  - evaluateSortKey
```
AtomicValue evaluateSortKey(int n,
                            XPathContext context)
                     throws XPathException
```
    Evaluate the n'th sort key of the context item
    
    Parameters:
    
    n - the requested index
    
    context - the XPath context
    
    Returns:
    
    the evaluated sort key
    
    Throws:
    
    XPathException - if any error occurs