Check argument type (scalar)

These functions check that an argument is of the expected scalar type and produce friendly error messages otherwise.

Usage

check_bool(
  x,
  ...,
  allow_na = FALSE,
  allow_null = FALSE,
  arg = caller_arg(x),
  call = caller_env()
)

check_string(
  x,
  ...,
  allow_empty = TRUE,
  allow_na = FALSE,
  allow_null = FALSE,
  arg = caller_arg(x),
  call = caller_env()
)

check_name(
  x,
  ...,
  allow_null = FALSE,
  arg = caller_arg(x),
  call = caller_env()
)

Arguments

x

The argument to check.

...

Additional arguments passed to abort().

allow_na

Whether NA values are allowed.

allow_null

Whether NULL is allowed.

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.

allow_empty

Whether the empty string "" is allowed (check_string() only).

Value

NULL invisibly if the check passes, throws an error otherwise.

See also

Other input checkers: check_data_frame(), check_type_number, stop_input_type()

Examples

check_bool(TRUE)
try(check_bool(1))
#> Error in eval(expr, envir) : 
#>   `1` must be `TRUE` or `FALSE`, not the number 1.

check_string("hello")
try(check_string(42))
#> Error in eval(expr, envir) : 
#>   `42` must be a single string, not the number 42.