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

Is there a reason that this slightly more explicit
version [assign(envir=.GlobalEnv)] wouldn't work?

https://cran.r-project.org/web/packages/policies.html
- Packages should not modify the global environment (user?s workspace).

Bill Dunlap
TIBCO Software
wdunlap tibco.com

On Thu, Sep 3, 2020 at 2:36 PM Ben Bolker <bbolker at gmail.com> wrote:

  Is there a reason that this slightly more explicit version wouldn't

work?

pali_string_fix <- function() {
     assign("pali_alphabet",

stringi::stri_unescape_unicode(pali_alphabet),

            .GlobalEnv)
}


On 9/3/20 5:25 PM, Dan Zigmond wrote:

Thanks, Gabor. I want these to be easily available to package users

though

? that's why they are in the package. So I would rather not "hide"

them in

a local environment. This is fundamentally a data package, so access to
this data is the primary point of installing it.

Is there any other solution?

      Dan

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



On Thu, Sep 3, 2020 at 1:40 PM G?bor Cs?rdi <csardi.gabor at gmail.com>

wrote:

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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