PG asked "How do you implement that in a language without macros?". I responded with a simplest translation of the example, but a more general solution exists too. Nothing stops me from using GObject instead of void*, which can provide named "places" and as much generic functionality as needed. `selector` and `action` can even operate on property tables, which would be a closer translation from lisp.
I was simply surprised that PG asked about something like that - I still think it's pretty simple and the code in C is as close to the macro as possible (with whatever object abstraction you need).
However I have to admit that I thought about other languages now and it seems that the described zap() is not possible in python... and that's interesting / worrying:
action(object[place])
cannot assign a new value to `object[place]`, while
I was simply surprised that PG asked about something like that - I still think it's pretty simple and the code in C is as close to the macro as possible (with whatever object abstraction you need).
However I have to admit that I thought about other languages now and it seems that the described zap() is not possible in python... and that's interesting / worrying:
cannot assign a new value to `object[place]`, while has to do the lookup twice.