R/repair-names.R

In Robertus100/tibble: Simple Data Frames

#' Repair object names.
#'
#' `repair_names()` ensures its input has non-missing and
#' unique names (duplicated names get a numeric suffix). Valid names are
#' left as is.
#'
#' @param x A named vector.
#' @param prefix A string, the prefix to use for new column names.
#' @param sep A string inserted between the column name and de-duplicating
#'    number.
#' @return `x` with valid names.
#' @export
#' @examples
#' repair_names(list(3, 4, 5)) # works for lists, too
#' repair_names(mtcars) # a no-op
#' tbl <- as_tibble(structure(list(3, 4, 5), class = "data.frame"),
#'                  validate = FALSE)
#' repair_names(tbl)
repair_names <- function(x, prefix = "V", sep = "") {
  if (length(x) == 0) {
    names(x) <- character()
    return(x)
  }

  new_names <- make_unique(names2(x), prefix = prefix, sep = sep)
  setNames(x, new_names)
}

make_unique <- function(x, prefix = "V", sep = "") {
  blank <- x == ""

  # Ensure existing names are unique
  x[!blank] <- make.unique(x[!blank], sep = sep)

  # Replace blank names
  new_vars <- setdiff(paste(prefix, seq_along(x), sep = sep), x)
  x[blank] <- new_vars[seq_len(sum(blank))]

  x
}