Removing elements in a nested R list by name

Question

I have a nested element like this

> x <- list(a=list(from="me", id="xyz"), b=list(comment=list(list(message="blabla", id="abc"), list(message="humbug", id="jkl"))), id="123")
> str(x)
List of 3
 $ a :List of 2
  ..$ from: chr "me"
  ..$ id  : chr "xyz"
 $ b :List of 1
  ..$ comment:List of 2
  .. ..$ :List of 2
  .. .. ..$ message: chr "blabla"
  .. .. ..$ id     : chr "abc"
  .. ..$ :List of 2
  .. .. ..$ message: chr "humbug"
  .. .. ..$ id     : chr "jkl"
 $ id: chr "123"

How can I remove all the elements with name id in all levels of the list? i.e. the expected output is

> str(x)
List of 2
 $ a:List of 1
  ..$ from: chr "me"
 $ b:List of 1
  ..$ comment:List of 2
  .. ..$ :List of 1
  .. .. ..$ message: chr "blabla"
  .. ..$ :List of 1
  .. .. ..$ message: chr "humbug"

Solutions using rlist package would be particularly welcome, but I'm happy with anything that works.

Answer 1

Recursion is also how I did it:

# recursive function to remove name from all levels of list
stripname <- function(x, name) {
    thisdepth <- depth(x)
    if (thisdepth == 0) {
        return(x)
    } else if (length(nameIndex <- which(names(x) == name))) {
        x <- x[-nameIndex]
    }
    return(lapply(x, stripname, name))
}

# function to find depth of a list element
# see http://stackoverflow.com/questions/13432863/determine-level-of-nesting-in-r
depth <- function(this, thisdepth=0){
    if (!is.list(this)) {
        return(thisdepth)
    } else{
        return(max(unlist(lapply(this,depth,thisdepth=thisdepth+1))))    
    }
}


str(stripname(x, "id"))
## List of 2
## $ a:List of 1
## ..$ from: chr "me"
## $ b:List of 1
## ..$ comment:List of 2
## .. ..$ :List of 1
## .. ..$ :List of 1
## .. .. ..$ message: chr "blabla"
## .. .. ..$ message: chr "humbug"