selfdestructor.r

selfdestructor <- function(x) {
	if (is.numeric(x)) {
		fn <- paste0("selfdestructor_", x, "k")
	} else {
		fn <- paste0("selfdestructor_", x)
	}
	f <- function() {
		message("You specified: x = ", x)
		rm(list=fn, envir=.GlobalEnv)
		message("Poof!")
	}
	assign(fn, f, envir=.GlobalEnv)
	message("Assigned '", fn, "' to global environment.\n",
	  "You can run ", fn, "(), but be careful: it self-destructs!\n")
	gfn <- as.character(match.call())[1]
	message("This function, ", gfn, ", will self-destruct in")
	for (i in 5:1) {
	    cat(i, "\n")
	    system2("sleep", "1")
	}	
	rm(list=gfn, envir=.GlobalEnv)
	message("Floof!")
}

selfdestructor_ex.r

selfdestructor("Oh_no")
# Assigned 'selfdestructor_Oh_no' to global environment.
# You can run selfdestructor_Oh_no(), but be careful: it self-destructs!
# 
# This function, selfdestructor, will self-destruct in
# 5 
# 4 
# 3 
# 2 
# 1 
# Floof!

selfdestructor_Oh_no()
# You specified: x = Oh_no
# Poof!