Function that self destructs

Question

I read some post where Hadley made a joke about a self destructing function. I thought this would be relatively simple to implement but turns out it's not.

Here is an attempt to write a function named self_delete that is a quine and attempts to self destruct after printing its body. The idea was to search for the function's name in .GlobalEnv and delete it but that doesn't work. I would like to understand why this is the case.

self_delete<- function(){
   print(body(self_delete))
   rm(list=lsf.str(pattern="self_delete"))
 }

Calling the above prints the following as expected but does not delete itself from .Globalenv, what am I missing? I did try with rm and ls too with no luck

 self_delete()
{
    print(body(self_delete))
    rm(list = lsf.str(pattern = "self_delete"))
}

Answer 1

You forgot to set the envir argument to rm(), so it's trying to delete self_delete from the calling frame, not from globalenv().

This works:

self_delete <- function(){
  print(body(self_delete))
  rm("self_delete", envir = globalenv())
}