[R] Creating and manipulating environment within function

[Sebastien Bihorel]

Thanks Rui!

That does the trick indeed!
________________________________
From: Rui Barradas <ruipbarradas using sapo.pt>
Sent: Wednesday, March 30, 2022 17:39
To: Sebastien Bihorel <sebastien.bihorel using simulations-plus.com>; r-help using r-project.org <r-help using r-project.org>
Subject: Re: [R] Creating and manipulating environment within function

Hello,

Use ?assign instead. And there was a bug in manipulate_e1, it would
throw an error a not found.


create_e1 <- function(){
   assign("e1", new.env(), envir = globalenv())
   exists('e1', mode = 'environment')
}

manipulate_e1 <- function(a){
   if ( exists('e1', mode = 'environment') ) {
     assign(a, 1, envir = e1)
     TRUE
   } else {
     FALSE
   }
}

create_e1()
#> [1] TRUE

exists('e1', envir = globalenv())
#> [1] TRUE

x <- "vec"
e1$vec
#> NULL
manipulate_e1(x)
#> [1] TRUE
e1$vec
#> [1] 1


Hope this helps,

Rui Barradas

�s 21:29 de 30/03/2022, Sebastien Bihorel escreveu:
> Hi
>
> I am trying to create a set of functions to create and manipulate objects within a dedicated environment, which I was hoping to put directly under the global environment. However, my implementation (see code below) is facing some scoping issues: the environment created by one function does not appear to be accessible from outside the function.
>
> What would be the proper way to create a manipulation an environment in different functions?
>
> Thanks
>
> ```
> create_e1 <- function(){
>    e1 <- new.env(parent = globalenv())
>    exists('e1', mode = 'environment')
> }
> create_e1()
>
> manipulate_e1 <- function(){
>    if ( exists('e1', mode = 'environment') ) {
>      assign(a, 1, envir = e1)
>      TRUE
>    } else {
>      FALSE
>    }
> }
>
> exists('e1', envir = globalenv())
> manipulate_e1()
> ```
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