rlist functions report error when the first element is NULL

[happyshows]

Please see example below, I tried list.map and list.first, I'm pretty sure it applies to most of the functions.

I'm wondering if this is an expected behavior.

Having a NULL as the first element of the List of List could happen when I am saving the interim filtered result. Applying list.clean before any operation I want to do seems to be a bit excessive.

Can you suggest a better way of handling my situation?

> t <- list(a = NULL, b = list(x=1,y=2),c=list(x=2,y=5,z=4))
> t1 <- list(b = list(x=1,y=2),c=list(x=2,y=5,z=4))
> t %>% list.map(y)
Error in eval(expr, envir, enclos) : object 'y' not found
> t1 %>% list.map(y)
$b
[1] 2

$c
[1] 5

> t %>% list.first()
NULL
> t1 %>% list.first()
$x
[1] 1

$y
[1] 2

[renkun-ken]

I suggest that you use list.filter to exclude the elements in which y is not available before using list.map.