R/map_to_char.R

In WinVector/wrapr: Wrap R Tools for Debugging and Parametric Programming

#' format a map.
#'
#' @param mp named vector or list
#' @param ... not used, foce later arguments to bind by name.
#' @param sep separator suffix, what to put after commas
#' @param assignment assignment string
#' @param quote_fn string quoting function
#' @return character formatted representation
#'
#' @seealso \code{\link[base]{dput}}, \code{\link[utils]{capture.output}}
#'
#' @examples
#'
#' cat(map_to_char(c('a' = 'b', 'c' = 'd')))
#' cat(map_to_char(c('a' = 'b', 'd', 'e' = 'f')))
#' cat(map_to_char(c('a' = 'b', 'd' = NA, 'e' = 'f')))
#' cat(map_to_char(c(1, NA, 2)))
#'
#' @export
#'
map_to_char <- function(mp,
                        ...,
                        sep = " ",
                        assignment = "=",
                        quote_fn = base::shQuote) {
  stop_if_dot_args(substitute(list(...)), "wrapr::map_to_char")
  nms <- names(mp)
  vls <- as.character(mp)
  n <- length(vls)
  if(length(nms)<n) {
    nms <- c(nms, rep("", n - length(nms)))
  }
  nv <- character(n)
  for(i in seq_len(n)) {
    nmi <- nms[[i]]
    vli <- vls[[i]]
    qvli <- "NA"
    if(!is.na(vli)) {
      qvli <- quote_fn(vli)
    }
    if((!is.na(nmi))&&(nchar(nmi)>0)) {
      nv[[i]] <- paste(quote_fn(nmi), assignment, qvli)
    } else {
      nv[[i]] <- qvli
    }
  }
  paste0("c(", paste(nv, collapse = paste0(",", sep)), ")")
}