I want to distribute an R object that is a function. For instance, say, here is my function:

f <- function(x) (x * x)
save(f, file = "f.rda")

Then,

load("f.rda")

gives me the function 'f', however, when I type

f
function(x) (x * x)

Is it possible to have this function f, but to hide what is in the source code.

I guess in some sense, I am probably asking for an equivalent to the pre-compiled "binary object file" without the source code.

Any suggestions will be greatly appreciated. I am not sure that this is necessarily possible.

CodePudding user response：

It should be possible to use a local environment / closure to do this. The following code uses a scoping assignment to expose f.

local({
g <- function (x) x * x; # "secret" algorithm!
f <<- function (x) g(x);
})

# g is not in scope here, although it is still bound in f's closure
f(4) # => 16

The result of print(f) only covers f itself only, and not the "secret" in g:

function (x) g(x)

This naturally won't hide the original file source or textual content itself.

As I don't actually use R, I've no idea if the environment can be reflected¹ to still expose g (and at some level it must be possible as a .rda file can be generated). However, this approach appears to fulfill the original requirement of not immediately exposing the algorithm.

¹As @HongOoi points out, the reflected environment (and thus g) can be accessed with environment(f)$g, which once again would expose the "secret".