This is the bet Roc is taking. They call it "Opportunistic Mutation" and you can read about it at https://www.roc-lang.org/functional

I didn't see links on that page, but IIRC, there's a particular paper they reference as the main idea.

Python also detects this situation (at runtime using refcounts) and does in-place mutations where possible https://github.com/python/cpython/blob/a2ee89968299fc4f0da4b...