This is one of those features that makes me envious of Kotlin. It's super nice to define nice higher order helpers (check Kotlin apply, with, let... and specially to use in DSLs. The typical "Object().then {}" pattern would be much nicer with this.
There has been some discussion in another thread on improvements over capture lists, this may be something related to it that would be good to think as a whole.
I would be really in favour of this, I'm just not sure at this point what's the best implementation or syntax, but that's why we have smarter people in the forums ^^