Is an Object Atomic or Recursive?

Description

is.atomic returns TRUE if x does not have a list structure and FALSE otherwise.

is.recursive returns TRUE if x has a recursive (list-like) structure and FALSE otherwise.

Usage

is.atomic(x)
is.recursive(x)

See Also

is.list, is.language, etc, and the demo("is.things").

Examples

is.a.r <- function(x) c(is.atomic(x), is.recursive(x))

is.a.r(c(a=1,b=3))# TRUE FALSE
is.a.r(list())    # FALSE TRUE ??
is.a.r(list(2))   # FALSE TRUE
is.a.r(lm)        #   "
is.a.r(y ~ x)     #   "
is.a.r(expression(x+1))# should be F-T (not in 0.62.3!)