dmurdoch

# While in the top level directory of a package, run `dupnames()` to check the source for multiple
# definitions of the same identifier.  The *last* definition is the one that will be included in your 
# package; earlier ones are overwritten.

containsNames <- function(expr, names) {
  if (is.name(expr) && as.character(expr) %in% names)
    return(TRUE)
  if (is.call(expr)) {
    fn <- expr[[1]]
    if (is.name(fn) && as.character(fn) == "function")