Could these containers be polymorphic with MonadRef instead of fixed at STM?

[3noch]

@ElvishJerricco pointed out this possibility. What do you think?

[nikita-volkov]

I'm rather skeptical, but what would be the use case?

[ElvishJerricco]

Well the point is that (at least at a hight level), there's no reason that mutable containers should be tied to STM. If I want to use a mutable hashmap from ST so that I can have the most efficient possible algorithm in my pure function, there's no reason it can't be the same hashmap implementation as the one I'd use in STM.

[nikita-volkov]

From the abstraction perspective this seems like a good idea. However, generalising it in such a way would complicate the API and what's worse, would make it harder to optimise the algorithm.