[R-pkg-devel] visible binding for '<<-' assignment

Store the cached data in an environment within the package:

pali_data <- new.env(parent = emptyenv())

pali_string_fix <- function() {
  pali_data$alphabet <-
     stringi::stri_unescape_unicode(pali_alphabet)
...
}

Gabor

On Thu, Sep 3, 2020 at 9:33 PM Dan Zigmond <djz at shmonk.com> wrote:

Hi, all. I am developing a package that includes some global variables.
Because these are non-ASCII, I have escaped them. But then because these
are difficult to read, I want to provide an easy way for users to

unescape

all of them up front. Thus I have code like to create and save the data

in

global variables in one file:

pali_vowels <-
  c("a", "\u0101", "i", "\u012b", "u", "\u016b", "e", "o")
pali_consonants <-
  c("k", "kh", "g", "gh", "\u1e45",
    "c", "ch", "j", "jh", "\u00f1",
    "\u1e6d", "\u1e6dh", "\u1e0d", "\u1e0dh", "\u1e47",
    "t", "th", "d", "dh", "n",
    "p", "ph", "b", "bh", "m",
    "y", "r", "l", "v", "s", "h", "\u1e37", "\u1e43")
pali_alphabet <-c(pali_vowels, pali_consonants)
use_data(pali_alphabet, overwrite = TRUE)

and then I try to export a function like this in another file:

pali_string_fix <- function() {
  pali_alphabet <<-
     stringi::stri_unescape_unicode(pali_alphabet)
  # Several more of these...
  }

The idea is that users can run pali_string_fix() once when they load the
package and then they won't need to deal with all the Unicode escape
sequences after that.

However, this is getting rejected by the CRAN checks with the message:

* checking R code for possible problems ... [4s] NOTE
pali_string_fix: no visible binding for '<<-' assignment to
  'pali_alphabet'

I'm guessing this is because the data and the function are defined in
different files, so even though those globals are defined by my package,
that isn't obvious when the check is run on this code.

Does anyone have advice for how to fix this?

     Dan

.
-------------------------
Dan Zigmond
djz at shmonk.com

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