rlang (version 0.1)

arg_match: Match an argument to a character vector

Description

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

• Partial matches trigger an error.

• Error messages are a bit more informative and obey the tidyverse standards.

Usage

arg_match(arg, values = NULL)

Arguments

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.

Value

The string supplied to arg.

Examples

# NOT RUN {
fn <- function(x = c("foo", "bar")) arg_match(x)
fn("bar")

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