assert_list_of: Is an Argument a List of Objects of a Specific S3 Class or...

In admiraldev: Utility Functions and Development Tools for the Admiral Package Family

Is an Argument a List of Objects of a Specific S3 Class or Type?

Description

Checks if an argument is a list of objects inheriting from the S3 class or type specified.

Usage

assert_list_of(
  arg,
  cls,
  named = FALSE,
  optional = TRUE,
  arg_name = rlang::caller_arg(arg),
  message = NULL,
  class = "assert_list_of",
  call = parent.frame()
)

Arguments

arg	A function argument to be checked Default value none
cls	The S3 class or type to check for Default value none
named	If set to TRUE, an error is issued if not all elements of the list are named. Default value FALSE
optional	Is the checked argument optional? If set to FALSE and arg is NULL then an error is thrown Default value TRUE
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 a list or if arg is a list but its elements are not objects inheriting from class or of type class. Otherwise, the input is returned invisibly.

See Also

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_integer_scalar(), assert_list_element(), 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(list) {
  assert_list_of(list, "data.frame")
}

example_fun(list(mtcars, iris))

try(example_fun(list(letters, 1:10)))

try(example_fun(c(TRUE, FALSE)))

example_fun2 <- function(list) {
  assert_list_of(list, "numeric", named = TRUE)
}
try(example_fun2(list(1, 2, 3, d = 4)))

admiraldev documentation built on June 26, 2025, 1:09 a.m.