These predicates check for a given type and whether the vector is "scalar", that is, of length 1.
is_scalar_list(x)is_scalar_atomic(x)
is_scalar_vector(x)
is_scalar_integer(x)
is_scalar_double(x)
is_scalar_character(x, encoding = NULL)
is_scalar_logical(x)
is_scalar_raw(x)
is_string(x, encoding = NULL)
is_scalar_bytes(x)
object to be tested.
Expected encoding of a string or character
vector. One of UTF-8, latin1, or unknown.