R/utils.R

In sharlagelfand/dmc: Convert Colour to DMC Embroidery Floss and Back

check_colour <- function(colour) {
  if (missing(colour)) {
    stop("`colour` is missing, with no default.",
      call. = FALSE
    )
  } else if (!is.vector(colour) | length(colour) != 1 | !inherits(colour, "character")) {
    stop("`colour` must be a length 1 character vector.",
      call. = FALSE
    )
  } else if (!grepl("^#", colour) | nchar(colour) != 7) {
    stop('`colour` must be a hex code, e.g. with format "#FFFFFF".',
      call. = FALSE
    )
  }
}

check_n <- function(n) {
  if (length(n) != 1) {
    stop("`n` must be a length 1 positive integer vector.",
      call. = FALSE
    )
  } else if (!is.numeric(n) ||
    !(n %% 1 == 0) ||
    n <= 0 ||
    n == Inf) {
    stop("`n` must be a positive integer.",
      call. = FALSE
    )
  }
}

check_dmc <- function(dmc) {
  if (!all(dmc %in% dmc::floss[["dmc"]])) {
    stop('`dmc` is not a valid DMC floss identifier.\nSee floss[["dmc"]] for the full list of DMC colours.',
      call. = FALSE
    )
  }
}