playing with letting R objects know their own names

what_is_my_name.R

# how to make R objects know their own names?

# this works with commands run in the global environment, but not inside functions
this_call <- function() {
  file1 <- tempfile("Rrawhist")
  savehistory(file1)
  rawhist <- readLines(file1)
  rawhist[length(rawhist)]
}

my_name <- function () {
  expr <- parse(text = this_call())[[1]]
  if (length(expr) != 3) {
    return(NULL)
  }
  as.character(expr[[2]])
}

new_object <- function() {
  list(my_name_is = my_name())
}

x <- new_object()
x
# $my_name_is
# [1] "x"

blah <- function() {
  x <- new_object()
  x
}

blah()
# $my_name_is
# NULL