Readonlygroupingencodes wrappers like {} or ()
allows to attach additional information to the node
the original string retrieved from R, can be used for further identification
OptionallocationThe location may differ from what is stated in Source#fullRange as it represents the location identified by the R parser.
Readonlytype
Holds a list of expressions (and hence may be the root of an AST, summarizing all expressions in a file). The
groupingproperty holds information on if the expression list is structural or created by a wrapper like{}or().