This comes up every time newLISP is introduced somewhere. I'm not a developer who ever tried to create or invent a new language, so my knowledge is really limited regarding which memory management is advanced or dumb.

BUT I've used newLISP in many web business applications, which are still used by hundreds of users, under load and I've never ran into trouble. Developing and coding such big projects has been great (we used newLISP contexts a lot).

I'm trying to say: in practice I don't care about internal memeory management if the language does it job. And in my opinion newLISP is a good tool to solve real world problems.

A brief skim of the document suggests:

- single-reference-only for expressions (so, static object lifetime); deletion is delayed until a stack slot gets reused, allowing return values

- assignment to variables or values passed into functions are done by copy

- EXCEPT certain types are passed into functions by reference as an optimisation

So, basically, values are owned by either the stack or a variable. Assignment to a stack cell destroys what was there before. To keep a stacked value, it needs to be copied into a variable.

That all seems pretty intelligent, and I might steal the idea; except that I don't see any mention of how cyclic data structures or mutable data structures are implemented. Does anyone know how these are handled?

For mutable structures you use the "context" concept, which is also used to build a form of OOP.

For cyclic data structures, I'm not sure. I think one can pass a function, a list or a context to a function that expects a list. This it might do the trick.

From Wikipedia:

> Sharing of sub-objects among objects, cyclic structures, or multiple variables pointing to the same object are not supported in newLISP.

Dang.