Survey: what new bit of syntax would you like in base #RStats?

What should the following bits of syntax do?

* ===
* ++ And --
* +=
* //
* ?
* {{ }}
* [[[ ]]]
* <<==
* (?: X)

#RStats syntax hypothetical

df . filter(x > 3) . select(a, b, c)

Bare "." as pipe operator

@coolbutuseless
Something like python mean you?