You can define types for fields with Dialyzer:
defmodule Foo do
defstruct [:a, :b]
@type t :: %__MODULE__{a: integer(), b: binary()}
end
hauleth
4
wanton7
Check this thread Facebook is writing a new, statically typed language to run on the BEAM?!
Maybe that flows to Elixir too if it’s viable for Erlang.
2
Exadra37
Thanks for the suggestion, but I was not talking about Dializer, instead about Elixir itself.
0
wanton7
Sure for fastest available static typing. But Gleam is not Elixir, it’s a different language.
0
lpil
Creator of Gleam
I suspect that even if a team stared work today it would be several years before static typing is ready for Elixir. I’m not aware of any current work being done in this area I’m afraid.
0
wanton7
Not same as static typing but I can remember reading from somewhere that Elixir team is now looking into type inference.
0
lpil
Creator of Gleam
venkatd
I think Elixir could take inspiration from parts of Typescript for the following reasons:
- It uses a structural typing system. Meaning if two types have the same fields, they are treated as the same type. This matches very well with pattern matching.
- Typescript has similar constraints. It has to target javascript which is a dynamic language and play nice with the outside world.
That being said, I think most of typescript’s concepts would be overkill in Elixir. (Generics for example.) But I think the following features from Typescript could be looked to for inspiration:
- Interfaces
- Union types
- type aliases
- typeof guards (could probably reuse the same guard syntax in Elixir)
I think, similar to Typescript, we wouldn’t provide runtime guarantees. If a type is declared incorrectly, the code may still crash at runtime on something like a pattern match failure. The goal would be catching compile time errors and improved editor/refactoring support.
Even without the strong guarantees, this may be a worthwhile pursuit because of the productivity benefits we would get from refactoring and intellisense in vscode.
0
ityonemo
I think it’s possible to go much farther than that. One attractive solution is to build a bolt-on solution on top of compiler hooks. That way you could have static type inference as a library. Those who wish to have it can use it; those who do not need not use it.
0