R: Register S4 classes

xml_document-class {xml2} | R Documentation

## Register S4 classes

### Description

Classes are exported so they can be re-used within S4 classes, see `methods::setOldClass()`.

`xml_document`: a complete document.

`xml_missing`: a missing object, e.g. for an empty result set.

`xml_node`: a single node in a document.

`xml_nodeset`: a set of nodes within a document.

[Package xml2 version 1.3.0 Index]