R/utility.R

In univariateML: Maximum Likelihood Estimation for Univariate Densities

#' Merges two lists.
#'
#' @keywords internal
#' @param x A list of default arguments.
#' @param y A list of supplied arguments
#' @param type If `merge`, the list will be merge with y
#' having priority; if `template`, named the elements of
#' y not in x will be discarded after merging.
#' @return A merged list where conflicts are solved in favor
#' of y. Does not preserve ordering.

listmerge <- function(x, y, type = c("merge", "template")) {
  type <- match.arg(type)

  if (length(y) == 0) {
    return(x)
  }

  ## Keep and not-keep are quite different.
  if (type == "merge") {
    matches <- match(names(y), names(x))
    elements_to_discard <- matches[!is.na(matches)]
    if (length(elements_to_discard) == 0) {
      combined <- c(y, x)
    } else {
      combined <- c(y, x[-elements_to_discard])
    }
    return(combined)
  }

  if (type == "template") {
    matches <- match(names(x), names(y))
    x[!is.na(matches)] <- y[matches[!is.na(matches)]]
    return(x)
  }
}

#' Input Checker for ML functions
#'
#' Checks that `x` in the ML functions is numeric and has only one dimension.
#'
#' @param x input to a `ML***` function.
#' @return `NULL`

ml_input_checker <- function(x) {
  assertthat::assert_that(is.numeric(x))
  msg <- paste0("x is not a numeric vector (NCOL(x) = ", NCOL(x), ")")
  assertthat::assert_that(NCOL(x) == 1, msg = msg)
}