Is an Argument an Integer Scalar?

Checks if an argument is an integer scalar

assert_integer_scalar(
  arg,
  subset = "none",
  optional = FALSE,
  arg_name = rlang::caller_arg(arg),
  message = NULL,
  class = "assert_integer_scalar",
  call = parent.frame()
)

Arguments

arg

A function argument to be checked

Default value: none

subset

A subset of integers that arg should be part of.

Permitted values: "none", "positive", "non-negative", or "negative"
Default value: "none"

optional

Is the checked argument optional? If set to FALSE and arg is NULL then an error is thrown

Default value: FALSE

arg_name

string indicating the label/symbol of the object being checked.

Default value: rlang::caller_arg(arg)

message

string passed to cli::cli_abort(message). When NULL, default messaging is used (see examples for default messages). "{arg_name}" can be used in messaging.

Default value: NULL

class

Subclass of the condition.

call

The execution environment of a currently running function, e.g. call = caller_env(). The corresponding function call is retrieved and mentioned in error messages as the source of the error.

You only need to supply call when throwing a condition from a helper function which wouldn't be relevant to mention in the message.

Can also be NULL or a defused function call to respectively not display any call or hard-code a code to display.

For more information about error calls, see Including function calls in error messages.

Value

The function throws an error if arg is not an integer belonging to the specified subset. Otherwise, the input is returned invisibly.

Checks for valid input and returns warning or errors messages: assert_atomic_vector(), assert_character_scalar(), assert_character_vector(), assert_data_frame(), assert_date_vector(), assert_expr(), assert_expr_list(), assert_filter_cond(), assert_function(), assert_list_element(), assert_list_of(), assert_logical_scalar(), assert_named(), assert_numeric_vector(), assert_one_to_one(), assert_param_does_not_exist(), assert_s3_class(), assert_same_type(), assert_symbol(), assert_unit(), assert_vars(), assert_varval_list()

Examples

example_fun <- function(num1, num2) {
  assert_integer_scalar(num1, subset = "positive")
  assert_integer_scalar(num2, subset = "negative")
}

example_fun(1, -9)

try(example_fun(1.5, -9))
#> Error in example_fun(1.5, -9) : 
#>   Argument `num1` must be a positive integer scalar.

try(example_fun(2, 0))
#> Error in example_fun(2, 0) : 
#>   Argument `num2` must be a negative integer scalar.

try(example_fun("2", 0))
#> Error in example_fun("2", 0) : 
#>   Argument `num1` must be a positive integer scalar.

Arguments

Value

See also

Examples