Any examples to add, or you just want to leave it at pithy comment?
- array: not a singly-linked list.
- hash table: often an array of singly-linked lists, so not a list.
- red-black or AVL tree: can be built with cons cells.
- doubly-linked list: not a singly-linked list
- double-ended queue: array of double-ended queues, so not a list. Could also be implemented as a doubly-linked list.
I understand your point if you are speaking in literal terms about just simple cons cells, but in practical Lisp/Scheme code, you don’t really rely on just the basics to do things.
I think there’s a hyperfocus sometimes on the simplicity of the core of lisp, the apply/eval balance, but it’s quite possible and often easy and convenient to perform normal programming tasks with these languages as well.
Agreed.
> So what about streams? Functions? Closures? Call/cc structures?
Those are interesting examples. They are all data structures in a sense (especially streams and closures), but to me they are more like functions than data (yes, yes, functions are values, blah, blah). Call/cc is a reification of execution control; thinking of it in terms of data stretches my brain.