R/symbol_list.R

In import: An Import Mechanism for R

#' Process a symbol list provided passed as ellipses
#'
#' This function is used within a function that receives dot-arguments, and will
#' create a named character vector. It ensures that all entries are named, and
#' will use the value as name when it is missing.
#'
#' @param ... The ellipsis arguments to be converted.
#' @param .character_only A `logical` indicating whether `...` can be assumed to
#'   be charater strings.
#' @param .all A `logical` indicating whether to process all objects found in a
#'   given package or module. This variable is actually not used in this
#'   function and should probably either be removed or this function updated to
#'   utilize the value in a reasonable manner.
#'
#' @return A named character vector.
#'
#' @md
#' @noRd
symbol_list <- function(..., .character_only = FALSE, .all=FALSE)
{
  if (isTRUE(.character_only)) {
    dots <- unlist(list(...))
  } else {
    dots    <- eval(substitute(alist(...)), parent.frame(), parent.frame())
  }

  if (length(dots)==0) {
    # If .all was true, empty dots should no longer error
    return(character())
  }

  names   <- names(dots)
  unnamed <- if (is.null(names)) 1:length(dots) else which(names == "")
  dots    <- vapply(dots, symbol_as_character, character(1))

  names(dots)[unnamed] <- dots[unnamed]

  dots
}