1 unstable release

0.1.0 Jan 31, 2021

#1795 in Asynchronous

MIT license

6KB
80 lines

chikatetsu

An(other) actor framework for tokio.

Why?

Most other actor frameworks use some form of dyn Any, which is basically telling the compiler, "screw your type checking, I have Boxes".

Instead of using dynamic dispatch, we generate and enum that contains all possible types of messages an actor will handle. This is done automagically through a derive macro, and is handeled behind-the-scenes, so you technically never have to use the generated enum in your code (see example below).

use chikatetsu::prelude::*;

#[derive(PartialEq, Debug)]
pub struct Add(i32, i32);
#[derive(PartialEq, Debug)]
pub struct AddResult(i32);

#[derive(PartialEq, Debug)]
pub struct Subtract(i32, i32);
#[derive(PartialEq, Debug)]
pub struct SubtractResult(i32);

/*
Generated enums:
pub enum MathActorMessages {
    Add(Add),
    Subtract(Subtract),
}

pub enum MathActorReplies {
    AddResult(AddResult),
    SubtractResult(SubtractResult),
}
*/

#[derive(Actor)]
#[handles(Add, AddResult)]
#[handles(Subtract, SubtractResult)]
struct MathActor;

#[async_trait]
impl Handler<Add> for MathActor {
    async fn handle(&mut self, add: Add) -> AddResult {
        AddResult(add.0 + add.1)
    }
}

#[async_trait]
impl Handler<Subtract> for MathActor {
    async fn handle(&mut self, add: Subtract) -> SubtractResult {
        SubtractResult(add.0 - add.1)
    }
}

#[tokio::main]
async fn main() {
    let actor = MathActor.start();

    assert_eq!(AddResult(3), actor.send(Add(1, 2)).await);
    assert_eq!(SubtractResult(-1), actor.send(Subtract(1, 2)).await);
}

Dependencies

~4–10MB
~95K SLoC