R: Match an argument to a character vector

arg_match {rlang}

R Documentation

Match an argument to a character vector

This is equivalent to base::match.arg() with a few differences:

arg_match(arg, values = NULL)

`arg`	A symbol referring to an argument accepting strings.
`values`	The possible values that `arg` can take. If `NULL`, the values are taken from the function definition of the caller frame.

The string supplied to arg.

fn <- function(x = c("foo", "bar")) arg_match(x)
fn("bar")

# This would throw an informative error if run:
# fn("b")
# fn("baz")

[Package rlang version 0.2.1 Index]