RSXMLHandlers            Handlers for reading base S objects from XML
addHandlers              Merges XML data type handlers
fromXML                  Reads S object from XML representation
fromXML.object           ~~function to do ... ~~
getPrimitiveName         Gets internal name of S type
isComparator             Whether a call is a comparison operator
isLogicalExpression      Whether an call is a logical operator
readXMLObject            Load object from XML representation.
readXMLObject.default    Handles reading S object from XML representation
writeXML                 Write an XML representation of an object to an
                         XML connection
