assert_list_of {admiraldev}R Documentation

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


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


assert_list_of(arg, class, named = FALSE, optional = TRUE)



A function argument to be checked


The S3 class or type to check for


If set to TRUE, an error is issued if not all elements of the list are named.


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


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_list(), assert_expr(), 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()


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)))

[Package admiraldev version 1.0.0 Index]