Tibble constructor and validator

Creates or validates a subclass of a tibble. These function is mostly useful for package authors that implement subclasses of a tibble, like sf or tsibble.

new_tibble() creates a new object as a subclass of tbl_df, tbl and data.frame. This function is optimized for performance, checks are reduced to a minimum.

validate_tibble() checks a tibble for internal consistency. Correct behavior can be guaranteed only if this function runs without raising an error.

new_tibble(x, ..., nrow, class = NULL, subclass = NULL)

validate_tibble(x)

Arguments

x	A tibble-like object.
...	Name-value pairs of additional attributes.
nrow	The number of rows, required.
class	Subclasses to assign to the new object, default: none.
subclass	Deprecated, retained for compatibility. Please use the class argument.

Construction

For new_tibble(), x must be a list. The ... argument allows adding more attributes to the subclass. An nrow argument is required. This should be an integer of length 1, and every element of the list x should have vctrs::vec_size() equal to this value. (But this is not checked by the constructor). This takes the place of the "row.names" attribute in a data frame. x must have names (or be empty), but the names are not checked for correctness.

Validation

validate_tibble() checks for "minimal" names and that all columns are vectors, data frames or matrices. It also makes sure that all columns have the same length, and that vctrs::vec_size() is consistent with the data.

See also

tibble() and as_tibble() for ways to construct a tibble with recycling of scalars and automatic name repair.

Examples

# The nrow argument is always required:
new_tibble(list(a = 1:3, b = 4:6), nrow = 3)
#> # A tibble: 3 x 2
#>       a     b
#>   <int> <int>
#> 1     1     4
#> 2     2     5
#> 3     3     6

# Existing row.names attributes are ignored:
try(new_tibble(iris, nrow = 3))
#> # A tibble: 3 x 5
#>   Sepal.Length Sepal.Width Petal.Length Petal.Width Species
#>          <dbl>       <dbl>        <dbl>       <dbl> <fct>  
#> 1          5.1         3.5          1.4         0.2 setosa 
#> 2          4.9         3            1.4         0.2 setosa 
#> 3          4.7         3.2          1.3         0.2 setosa 

# The length of all columns must be compatible with the nrow argument:
try(new_tibble(list(a = 1:3, b = 4:6), nrow = 2))
#> # A tibble: 2 x 2
#>       a     b
#>   <int> <int>
#> 1     1     4
#> 2     2     5