[R] source files in temp environment

[Alexander Shenkin]

Hi all,

I often keep code in separate files for organizational purposes, and 
source() that code from higher level scripts.  One problem is that those 
sourced files often create temporary variables that I don't want to keep 
around.  I could clean up after myself with lots of rm()'s, but that's a 
pain, and is messy.

I'm wondering if one solution might be to source the code in a temporary 
environment, assign outputs of interest to the .GlobalEnv with <<-, and 
then delete the environment afterwards.  One way to do this:

file.r:
temp1 = 1
temp2 = 2
desired_var <<- temp1 + temp2

console:
temp_e = new.env()
source("file.r", local = temp_e)
rm(temp_e)

It's a bit messy to create and delete environments, so I tried what 
others have referred to:

source("file.r", local = attach(NULL))

This, however, results in a persistent "NULL" environment in the search 
path.

 > search()
".GlobalEnv"            "package:bindrcpp"      "NULL"
"tools:rstudio"         "package:stats"         "package:graphics" 
"package:grDevices"     "package:utils"         "package:datasets"
"package:methods"       "Autoloads"             "package:base"

Of course, functions are built to encapsulate like this (and do so in 
their own temporary environment), but in many cases, turning the sourced 
code into functions is possible but clunky.

Any thoughts or suggestions would be much appreciated.

Thanks,
Allie