If you replace an element of an #Rstats list with NULL, it shortens the list.
Well, sometimes.
> a = list(1, 2, 3, 4, 5)
> b = list(8, NULL, 10)
> length(a)
[1] 5
> a[2:4] = b
> length(a)
[1] 5
> a
[[1]]
[1] 1
[[2]]
[1] 8
[[3]]
NULL
[[4]]
[1] 10
[[5]]
[1] 5
> a[3] = NULL
> length(a)
[1] 4
@peterdrake For every rule, there is an exception 😅