Check if an object is a list and not a dataframe or tibble

check_list() and check_is_list() functions validate if the given object is a list and not a dataframe or tibble. check_list() raises an error if the object is not a list, while check_is_list() returns TRUE if the object is a list, and FALSE otherwise.

Usage

check_list(lst, par_name = "lst")

check_is_list(lst)

Arguments

lst: The object to check.
par_name: A name for the parameter lst to display in error messages.

Value

check_list(): Returns the input object lst if it is a valid list, or raises an error if the object is not a list.
check_is_list(): Logical value, TRUE if the object is a list, FALSE otherwise.

Examples

# Examples for check_list()
# -------------------------

check_list(list(1, 2, 3))
#> [[1]]
#> [1] 1
#> 
#> [[2]]
#> [1] 2
#> 
#> [[3]]
#> [1] 3
#> 

try(check_list(data.frame(a = 1:3)))
#> Error in check_list(data.frame(a = 1:3)) : 
#>   Expected 'lst' to be a list but got data.frame

try(check_list(tibble::tibble(a = 1:3)))
#> Error in check_list(tibble::tibble(a = 1:3)) : 
#>   Expected 'lst' to be a list but got tbl_df tbl data.frame

check_list(list("a", "b", "c"))
#> [[1]]
#> [1] "a"
#> 
#> [[2]]
#> [1] "b"
#> 
#> [[3]]
#> [1] "c"
#> 

try(check_list(3))
#> Error in check_list(3) : Expected 'lst' to be a list but got numeric

# Examples for check_is_list()
# ----------------------------

check_is_list(list(1, 2, 3))
#> [1] TRUE

check_is_list(data.frame(a = 1:3))
#> [1] FALSE

check_is_list(tibble::tibble(a = 1:3))
#> [1] FALSE

check_is_list(list("a", "b", "c"))
#> [1] TRUE

check_is_list(3)
#> [1] FALSE