R/options.R

In leonawicz/tabr: Music Notation Syntax, Manipulation, Analysis and Transcription in R

#' Options
#'
#' Options for tabr package.
#'
#' Currently only `lilypond`, `midi2ly` and `python` are used.
#' On Windows systems, if the system path for lilypond.exe, midi2ly and
#' python.exe are not stored in the system PATH environmental variable, they
#' must be provided by the user after loading the package.
#'
#' @param ... a list of options.
#'
#' @return The function prints all set options if called with no arguments.
#' When setting options, nothing is returned.
#' @export
#'
#' @examples
#' tabr_options()
#' lilypond_path <- "C:/lilypond-2.24.2/bin/lilypond.exe" # if installed here
#' tabr_options(lilypond = lilypond_path)
tabr_options <- function(...){
  x <- list(...)
  opts <- .tabr_env$opts
  if(length(x)){
    opts[names(x)] <- x
    .tabr_env$opts <- opts
    invisible()
  } else {
    opts
  }
}

.tabr_env <- new.env()