check_required {rlang}

Check that argument is supplied

Description

Throws an error if x is missing.

Usage

check_required(x, arg = caller_arg(x), call = caller_env())

Arguments

x

A function argument. Must be a symbol.

arg

An argument name as a string. This argument will be mentioned in error messages as the input that is at the origin of a problem.

call

The execution environment of a currently running function, e.g. caller_env(). The function will be mentioned in error messages as the source of the error. See the call argument of abort() for more information.

See Also

arg_match()

Examples

f <- function(x)  {
  check_required(x)
}

# Fails because `x` is not supplied
try(f())

# Succeeds
f(NULL)