Get currently called function to write anonymous recursive function

Question

How can I get the current function within a function for recursive applying? Here is a trivial example:

myfun <- function(x) {
  if(is.list(x)){
    lapply(x, myfun)
  } else {
    length(x)
  }
}

I would like to make it anonymous instead, however I don't know how to tell lapply to use the current function when it has no name. I tried Recall but that doesn't work:

(function(x) {
  if(is.list(x)){
    lapply(x, Recall)
  } else {
    length(x)
  }
})(cars)

Also match.call()[[1]] doesn't help for anonymous functions.

Answer 1

It is sys.function(0) , for example to compute the square of a list recursively :

(function(x) {
  if(length(x)>2){
    lapply(x,sys.function(0))
  } else {
    x^2
  }
})(list(1,2,3))

 [[1]]
[1] 1

[[2]]
[1] 4

[[3]]
[1] 9

Answer 2

What you are looking for is, I think, sys.function:

> (function() print(sys.function(1)))()
function() print(sys.function(1))

Recall actually says:

local for another way to write anonymous recursive functions.

The idea is that you define the name locally:

local(myfun <- function(...) { ... myfun(...) ... })

and it is not defined outside.