Get a function from a package, abort if package not installed.
need_pkg.RdGet a function from a package, abort if package not installed.
See also
Other package dev:
get_package_fns(),
is_package(),
is_package_dev(),
pkg_chr_split_comma()
Examples
need_pkg("utils", "recover")
#> function ()
#> {
#> if (.isMethodsDispatchOn()) {
#> tState <- tracingState(FALSE)
#> on.exit(tracingState(tState))
#> }
#> calls <- sys.calls()
#> from <- 0L
#> n <- length(calls)
#> if (identical(sys.function(n), recover))
#> n <- n - 1L
#> for (i in rev(seq_len(n))) {
#> calli <- calls[[i]]
#> fname <- calli[[1L]]
#> if (!is.na(match(deparse(fname)[1L], c("methods::.doTrace",
#> ".doTrace")))) {
#> from <- i - 1L
#> break
#> }
#> }
#> if (from == 0L)
#> for (i in rev(seq_len(n))) {
#> calli <- calls[[i]]
#> fname <- calli[[1L]]
#> if (!is.name(fname) || is.na(match(as.character(fname),
#> c("recover", "stop", "Stop")))) {
#> from <- i
#> break
#> }
#> }
#> if (from > 0L) {
#> if (!interactive()) {
#> try(dump.frames())
#> cat(gettext("recover called non-interactively; frames dumped, use debugger() to view\n"))
#> return(NULL)
#> }
#> calls <- limitedLabels(calls[1L:from])
#> repeat {
#> which <- menu(calls, title = "\nEnter a frame number, or 0 to exit ")
#> if (which)
#> eval(substitute(browser(skipCalls = skip), list(skip = 7 -
#> which)), envir = sys.frame(which))
#> else break
#> }
#> }
#> else cat(gettext("No suitable frames for recover()\n"))
#> }
#> <environment: namespace:utils>