R/config.R

In mlr-org/mlrng: Machine Learning in R - Next Generation

#' @title Configuration
#' @name mlrng-config
#'
#' @param conf (`character(1)`)\cr
#'   Location of the configuration file to load or write.
#'
#' @description
#' The following options are currently supported to be set via [base::options()].
#' \describe{
#'   \item{`mlrng.verbose`}{
#'     Verbosity. Set to `FALSE` to suppress some output.
#'   }
#'   \item{`mlrng.debug`}{
#'     Debug mode. Set to `TRUE` to enable additional output and some (slower) checks.
#'   }
#'   \item{`mlrng.keep.train.output`}{
#'     Store the output of the models in the log file. Default: `FALSE`.
#'   }
#'   \item{`mlrng.continue.on.learner.error`}{
#'     Keep running if a learner encounters a problem. The resulting model will be a model fitted by a dummy learner.
#'   }
#'   \item{`mlrng.train.encapsulation`}{
#'     Control how the training of learners is encapsulated. \dQuote{none} means no encapsulation but also no logging (fastest).
#'     If set to \dQuote{evaluate} (default), the package \pkg{evaluate} is used to run the model fit.
#'     If set to \dQuote{callr}, the package \pkg{callr} starts the training in a separate R process to guard your session against segfaults.
#'   }
#' }
#'
#' These options may be set in a configuration file which is automatically parsed on package load.
#' To get the location according to your operating system, see the example.
#' `readMlrngConfig()` reads a configuration file and returns its settings in a named list,
#' `writeMlrngConfig()` writes a configuration file with all currently set options.
#' @examples
#' # Location of the config file for your system:
#' conf = file.path(rappdirs::user_config_dir("mlrng"), "config.yml")
#' print(conf)
#'
#' # Current settings:
#' print(readMlrngConfig())


#' @rdname mlrng-config
#' @export
readMlrngConfig = function(conf = file.path(rappdirs::user_config_dir("mlrng"), "config.yml")) {
  # keep it very simple and dep free here
  if (!file.exists(conf))
    return(list())

  opts = try(yaml::read_yaml(conf))
  if (is.null(opts)) # empty config file
    return(list())
  if (inherits(opts, "try-error") || !is.list(opts)) {
    warning(sprintf("Config file '%s' seems to be syntactically invalid", conf))
    return(list())
  }

  names(opts) = sprintf("mlrng.%s", names(opts))
  return(opts)
}

#' @rdname mlrng-config
#' @export
writeMlrngConfig = function(conf = file.path(rappdirs::user_config_dir("mlrng"), "config.yml")) {
  assertPathForOutput(conf, overwrite = TRUE)
  if (!dir.exists(dirname(conf)))
    dir.create(dirname(conf), recursive = TRUE)
  opts = options()
  opts = opts[stri_startswith_fixed(names(opts), "mlrng.")]
  names(opts) = stri_sub(names(opts), from = 7L)
  yaml::write_yaml(opts, file = conf)
}