Throw error if field does not exist?

[hadley]

X <- R6Class("X")
x <- X$new()

x$X

Why isn't this an error?

[wch]

For the same reason this isn't an error:

e <- new.env()
e$x
# NULL

Changing the behavior would require adding a $.R6 method, but it would add a significant performance penalty.

[hadley]

Oh, right, I keep forgetting that we can't have a $ method 😞

[hadley]

It occurs to me that we might be able to make this fast by using object tables. Worth at least a small exploration.

[hadley]

object tables turn out to be fairly slow, so unlikely to be worth it.