Collect export tag information
create_export_block(expr, ref, info, mod_ns)parse_object(info, expr, mod_ns)
roxygen2_object(alias, value, type)
The unevaluated expression represented by the tag.
The code reference srcref represented by the tag.
The object name.
The object value.
The object type.
create_export_block returns an object of type
roxy_block represents an exported declaration expression, along with
its source code location.