I am reading “Domain modelling made functional” and many ideas resonate with me. The examples are in F♯ but some ideas are general and transferrable to all languages. One idea is that we should write types like UnverifiedEmail and VerifiedEmail and then @type unvalidated_email() :: String.t() …

Probably too naive an approach for your purpose - but here it is .

Erlang and Elixir are more on the dynamic typed languages field. If you want strong guarantees at compile time, you should try Haskell, OCaml or F#.

Thanks. I need OTP so I won’t move to other language. I am just researching tools that might improve design in the project. I’ll check out Witchcraft GitHub - witchcrafters/witchcraft: Monads and other dark magic for Elixir · GitHub It is not really idiomatic so I wanted to check if I can “simulate”…

[image] Gleam, a statically typed language for the Erlang VM Chat / Discussions (archived) Gleam is a statically typed language for the Erlang VM that I have been slowly building over the last year or so. I’ve had a few people ask me about it so I’m making this…

The problem is that both types are defined as String.t(), what you want to do is define the types in some way that they can not mix. such as {:validated_email, String.t()} and {:unvalidated_email, String.t()} then dialyzer (and your pattern matching) can validate things. @type validated_email() :: …

I believe the “standard Elixir” way would be using tuples like @zkessin mentioned above; I read the Elixir form: {:ok, value} as mostly-equivalent to the Elm/Haskell form: Ok value Code can pattern-match values out of a tuple in function heads / case blocks. case some_value do {:ok, result} ->…

Honestly, you cannot validate that on compile time, but you can enforce that on runtime via pattern matching. I would suggest something like this, although I feel it’s a bit of overkill: def an_email(), do: %UnvalidatedEmail{email: "foo@bar.com"} @spec validate(UnvalidatedEmail.t) :: Email.t def v…

Hello, you are not alone to “resonate” with the ideas presented in this great book :wink: When I tried to reproduce in Elixir some on the examples given, I used the “all is struct” approach and the typed_struct library. Then played with VSCode and dialyzer (using the dialyzer underspecs and oversp…

So, there is at least a couple of different methods. Using tagged tuples, structs, macros with structs alone, macros generating structs and types like in typed_struct or algae. Building on that there are a couple of libraries for handling flows with errors ok_jose, exceptional, witchcraft (which h…

It has been some time since you’ve asked this question. Have you settled on a pattern you enjoy using? If so, mind sharing a contrived elixir example? Thank you

Modeling domain with types in Elixir

Questions & Help Questions

stefanluptak February 28, 2019, 7:56am 5