Type predicates

Description

These type predicates aim to make type testing in R more consistent. They are wrappers around typeof, so operate at a level beneath S3/S4 etc.

Usage

is_list(x)

is_atomic(x)

is_vector(x)

is_numeric(x)

is_integer(x)

is_double(x)

is_character(x)

is_logical(x)

is_null(x)

is_function(x)

Arguments

Details

Compare to base R functions:

• Unlike is.atomic(), is_atomic() does not return TRUE for NULL.

• Unlike is.vector(), is_vector() test if an object is an atomic vector or a list. is.vector checks for the presence of attributes (other than name).

• is_numeric() is not generic so, (e.g.) dates and date times are TRUE, not FALSE.

• is_function() returns TRUE only for regular functions, not special or primitive functions.

See Also

bare-type-predicates scalar-type-predicates