The default behaviour of a missing entry in an environment

Inconsistent with what happens for lists:

x <- list()
x$b

NULL

and attributes:

attr(x, "b")

NULL

Ah, I see. I would claim that the same argument for default safety should apply here too.

It is already a little stricter than $ on a list:

x$longname <- 1
x$long

[1] 1

e$longname <- 1
e$long

NULL

I apologize that I cannot say that this is a good idea for reasons of safety and readability.

so I supposed we could make it even more strict, but there is an awful lot of code out there that uses tests like

if (!is.null(x <- e$b)) { do something with x }

and all of that would break.

Unfortunately, such code does make it harder to detect programming errors.
I understand should the hands of R be tied by backwards-compatability; bad habits are hard to break.
Thanks for your time.

-Trishank