type-predicates: 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)
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.