[sillysaurusx]

Incidentally, that link proves the point:

> In the presence of mutable objects, CDR coding becomes more complex. If a reference is updated to point to another object, but currently has an object stored in that field, the object must be relocated, along with any other pointers to it. Not only are such moves typically expensive or impossible, but over time they cause fragmentation of the store. This problem is typically avoided by using CDR coding only on immutable data structures.

This is exactly what I've been saying. Thank you for providing a formal reference to the idea.

(I'm a bit confused how we wound up talking past each other, since my original proposal was identical to CDR coding on immutable cons cells.)