With Elixir 1.18 nearing release and coming with improvements to the new Set Theoretic Type System, I’m curious how Ash will integrate the new type system. Will it generate the types for domains and resources? Will we get the compilation time feedback from the type system?
Currently, all type system improvements are “under the hood” so to speak. There is no real way to influence them except by perhaps us defining functions with clearer returns in cases where the type system cannot yet infer them. i.e ensuring that we pattern match on %Ash.Query{} etc.
However, I’ve spoken with @josevalim about this before, and the type system should be metaprogrammable in the same way that the rest of Elixir is (obviously not holding anyone to this as a commitment, but as I understand it it is the intention).
We currently do not generate dialyzer types except for very simple circumstances like Ash.Type.Enum, however as soon as it is possible to manually write Elixir’s type syntax, we will begin the process of adopting them across Ash on behalf of users. You should have to do very little to get tons of benefits.
All code interfaces will be fully typed automatically to the best extent that we can, and we will provide convenience types and/or functions for use in other scenarios.
There is still a lot of unknowns here, but IMO the type system will be a major leveling up for Elixir and it will especially enable us to do some very awesome things in Ash. It will, however, take a lot of time for that all to come to fruition.
Ash is already chock-full of type information that is used to verify Ash programs and validate data etc, and we intend to take full advantage of the set theoretic type system 
6 Likes
Thanks. I also think the new type system is going to be a major level up.
I suspected type support wouldn’t require any changes from Ash user’s. That’s the power of “deriving the rest”. 
2 Likes
