Package net.sf.saxon.expr.sort

## Interface 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
      Throws:
        `XPathException`