Usage of nsIXPointerResult Interface

 Evaluate XPointer expression.

nsIXPointerResult evaluateXPointer(in DOMString expression)

 Evaluate an XPointer expression.

 @param aDocument   The document in which to evaluate.
 @param aExpression The XPointer expression string to evaluate.
 @return            The result.

nsIXPointerResult evaluate(in nsIDOMDocument aDocument, in DOMString aExpression)

 Evaluate.

 @param aDocument The document in which to resolve the XPointer.
 @param aContext  The XPointer context in which to process aData.
 @param aData     The data in the scheme that needs to be resolved.
 @return          The result of the evaluation.

nsIXPointerResult evaluate(in nsIDOMDocument aDocument, in nsIXPointerSchemeContext aContext, in DOMString aData)