try_na

gistfile1.txt

try_na <- function(...){
  f_list <- purrr::map(list(...),rlang::as_function)
  f_len <- length(f_list)
  function(.x) {
    out <- rep(NA,length(.x))
    i <- 1
    while(any(is.na(out)) & i <= f_len){
      out[is.na(out)] <- f_list[[i]](.x[is.na(out)])
      i <- i + 1
    }
    out
  }
}

fun <- try_na(~log(.x),~log(-.x))
fun(-10:10)

my_date_parser <- try_na(
  ~readr::parse_date(.,format="%d-%b-%y",locale=locale("fr")),
  ~as.numeric(.)
  )