dot-optional_fn: Get an optional function without triggering a CRAN warning

In terminological/ggrrr: Addressing Annoyances and Irritations

Get an optional function without triggering a CRAN warning

Description

You want to use a function if it is installed but don't want it to be installed as part of your package and you don't want to reference it as part of the Imports or Suggests fields in a package DESCRIPTION.

Usage

.optional_fn(
  pkg,
  name,
  alt = function(...) {
     stop("function `", pkg, "::", name, "(...)` not available")

    }
)

Arguments

pkg	the package name
name	the function you wish to use
alt	a function that can be used instead

Value

the function you want if available or the alternative

Examples

fn = .optional_fn("openssl", "md5", digest::digest)
as.character(fn(as.raw(c(1,2,3))))

terminological/ggrrr documentation built on June 15, 2024, 6:35 a.m.