Safe way to eval expression

NAMESPACE

@@ -42,7 +42,6 @@ export(mcp)
 export(pid)
 export(point_measures)
 export(scp)
-export(update)
 export(width)
 export(winkler_score)
 import(forecast)

R/acp.R

@@ -31,7 +31,7 @@
 #' types 4 to 9 are for continuous quantiles. See the
 #' \code{\link[ggdist]{weighted_quantile}} function in the ggdist package.
 #' @param update If \code{TRUE}, the function will be compatible with the
-#' \code{\link[base]{update}} function, allowing for easy updates of conformal prediction.
+#' \code{update}(\link{update.cpforecast}) function, allowing for easy updates of conformal prediction.
 #' @param na.rm If \code{TRUE}, corresponding entries in sample values are removed
 #' if it is \code{NA} when calculating sample quantile.
 #' @param ... Other arguments are passed to the

R/conformal.R

@@ -7,7 +7,8 @@
 #' point forecasts and \code{ERROR} for forecast errors on validation set.
 #' See the results of a call to \code{\link{cvforecast}}.
 #' @param method A character string specifying the conformal method to be applied.
-#' Possible options include \code{"scp"} (\link{scp}), \code{"acp"} (\link{acp}), \code{"pid"} (\link{pid}), and \code{"mcp"} (\link{mcp}).
+#' Possible options include \code{"scp"} (\link{scp}), \code{"acp"}(\link{acp}),
+#' \code{"pid"}(\link{pid}), and \code{"mcp"}(\link{mcp}).
 #' @param ... Additional arguments to be passed to the selected conformal method.
 #'
 #' @examples

R/scp.R

@@ -51,7 +51,7 @@
 #' @param kess If \code{TRUE}, Kish's effective sample size is used for sample
 #' quantile computation.
 #' @param update If \code{TRUE}, the function will be compatible with the
-#' \code{\link[base]{update}} function, allowing for easy updates of conformal prediction.
+#' \code{update}(\link{update.cpforecast}) function, allowing for easy updates of conformal prediction.
 #' @param na.rm If \code{TRUE}, corresponding entries in sample values and weights
 #' are removed if either is \code{NA} when calculating sample quantile.
 #' @param ... Other arguments are passed to \code{weightfun}.

R/update.R

@@ -39,14 +39,7 @@
 #' summary(scpfc_update)
 #'
 #' @export
-update <- function(object, ...) {
-  UseMethod("update")
-}
-
-#' @rdname update
-#' @export
 update.cpforecast <- function(object, new_data, forecastfun, new_xreg = NULL, ...) {
-  # browser()
   level <- object$level
   alpha <- 1 - level / 100
   h <- dim(object$MEAN)[2]
@@ -70,16 +63,8 @@ update.cpforecast <- function(object, new_data, forecastfun, new_xreg = NULL, ..
 
   # Info required for model fitting
   cvcall <- object$model$cvforecast$call
-  if ("initial" %in% names(cvcall)) {
-    initial <- eval.parent(parse(text = as.character(cvcall)[names(cvcall) == "initial"]))
-  } else {
-    initial <- 1
-  }
-  if ("window" %in% names(cvcall)) {
-    window <- eval.parent(parse(text = as.character(cvcall)[names(cvcall) == "window"]))
-  } else {
-    window <- NULL
-  }
+  initial <- eval(get_call_arg_with_defaults(cvforecast, cvcall, "initial"), .GlobalEnv)
+  window <- eval(get_call_arg_with_defaults(cvforecast, cvcall, "window"), .GlobalEnv)
 
   # Model fitting and forecasting
   nfirst <- ifelse(forward, length(object$x) + 1L, length(object$x))

R/utils.R

@@ -0,0 +1,8 @@
+get_call_arg_with_defaults <- function(.f, call, arg) {
+  defaults <- formals(.f)
+  if(is.null(call[[arg]])) {
+    defaults[[arg]]
+  } else {
+    call[[arg]]
+  }
+}