These type predicates aim to make type testing in R more
consistent. They are wrappers around base::typeof(), so operate
at a level beneath S3/S4 etc.
is_list(x, n = NULL)is_atomic(x, n = NULL)
is_vector(x, n = NULL)
is_integer(x, n = NULL)
is_double(x, n = NULL, finite = NULL)
is_character(x, n = NULL, encoding = NULL)
is_logical(x, n = NULL)
is_raw(x, n = NULL)
is_bytes(x, n = NULL)
is_null(x)
Object to be tested.
Expected length of a vector.
Whether values must be finite. Examples of non-finite
values are Inf, -Inf and NaN.
Expected encoding of a string or character
vector. One of UTF-8, latin1, or unknown.
Compared to base R functions:
The predicates for vectors include the n argument for
pattern-matching on the vector length.
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).