Recursively determine how deep a list is nested in R

list.depth.R

list.depth <- function(this, thisdepth = 0) {
# http://stackoverflow.com/a/13433689/1270695
  if(!is.list(this)) {
    return(thisdepth)
  } else {
    return(max(unlist(lapply(this, list.depth, thisdepth = thisdepth+1))))    
  }
}