[Jeff_Brown]

Amen. I've been coding a big hobby project in Rust since July, after having spent years using Haskell for such things. I chose Rust because the primary DB I wanted to use (TypeDB) only had drivers for Rust and Python at the time. Rust is popular relative to Haskell, so I thought others might be more likely to sign on, and the type system seemed almost as expressive.

But since purity is not encoded in Rust's type system, any function might do any kind of IO -- in particular, read from or write to disk or one of the DBs. That makes the logic much harder to reason about.

(Also, Rust's syntax is so noisy and verbose that it's harder to see what's going on, and less context fits in my head at one time. I'm getting better at paying that cost, but I wish it weren't there.)

I can't say I made the wrong decision, but I often fantasize about moving most of the logic into Haskell and just calling Rust from Haskell when I need to call TypeDB from Rust.

[yobbo]

Db access in rust typically needs some sort of handle and a mutex. Limiting access to the handle makes the rest of the code pure with respect to the db. The handle plays a similar role to the IO type.

Actor-like patterns makes this nice. Message-objects can be passed to/from a module with db-access or other io.

[kephasp]

How can you prevent code from creating a handle in a new place?