That's right, we are both using the same technique.
It's interesting to note though that the difference between this and a data structure is not that great. I haven't looked into it but I'm certain I've read somewhere that data structures as implemented in racket (which is what my example is written in) actually desugar into something like my example code.
I still like to use this technique here and there, especially when there will only be one copy of the structure in use in my program. This is because it's simply more convenient to write something like (counter++) rather than declaring a global COUNTER and typing in (set! COUNTER (add1 COUNTER)) etc.
It's interesting to note though that the difference between this and a data structure is not that great. I haven't looked into it but I'm certain I've read somewhere that data structures as implemented in racket (which is what my example is written in) actually desugar into something like my example code.
I still like to use this technique here and there, especially when there will only be one copy of the structure in use in my program. This is because it's simply more convenient to write something like (counter++) rather than declaring a global COUNTER and typing in (set! COUNTER (add1 COUNTER)) etc.