Relative comment created with \#\< comment tags document something
designated by the location of the comment.
In general, the comment documents the previous symbol.
A comment will not be associated with any parse id that does not have
the same parent as the comment. For example,
pd_get_relative_comment_associated_ids(id, pd, .check = TRUE)id of the expression of interest
The parse-data information
Perform checks for input validation?
Returns a vector of the same length as id. Where the value is either the id of the associated object or NA if it cannot be associated.
function(x #< a valid comment )
would associate a valid comment with x, but
function(x) #< not a valid comment
would not.