In crowding/nse: Tools for Lazy and Non-Standard Evaluation

One small thing nse can't do.

Because nse returns to the user not the raw PROMSXP or DOTSXP, but a representations thereof, by using NSE one ends up copying promise objects, rather than transferring them. This means that one side effect of R's lazy evaluation can't be easily replicated.

f <- function(...) {
  g(...)
  list(g(...), ...)
}

f <- function(...) {
  g(...)
}

If we try to replicate the recursive call using nse constructors, we find that this effect is not duplicated.

crowding/nse documentation built on Jan. 5, 2024, 12:14 a.m.