[Fluxus] the end of push/pop?

[nik gaffney]

> I've added a new and fairly untested set of higher level control
> structures for manipulating objects and state in a cleaner and safer
> manner. The first two make push/pop, grab/ungrab obsolete as suggested
> some time ago. The second two are analogous to map and fold for lists
> (but not exactly the same), and should make pdata modifications and
> calculations simpler and a bit more expressive.

. ..now there is no turning back!