Code review request for my first crate

code review
1

I've just published my first crate and would appreciate any suggestions: https://github.com/imbolc/step-machine

2

My first feedback: include a link to the docs in your README, or at least a link to the crates.io page.

1 Like
3

I'm a little confused by

pub trait State<M: State<M>> {
    type Error: Debug;
    fn next(self) -> Result<Option<M>, Self::Error>;
}

This send very confusing, it looks like you could create type A that is a State<B>, and that seems like it would be very confusing.

Why not simply use

pub trait State : DeserializeOwned + Serialize {
    type Error: Debug;
    fn next(self) -> Result<Option<Self>, Self::Error>;
}

This would simplify the bounds in various places in your code and make it obvious that the State isn't going to be changing type.

4

it looks like you could create type A that is a State<B>

That's right, B here is an enum wrapping all the states including A. We need enum wrapper to unambiguously serialize / deserialize states.

fn next(self) -> Result<Option<Self>, Self::Error>

It meant to return the enum wrapper around any of possible states, rather then the state itself eg: Ok(Some(if foo { FirstState.into() } else { SecondState.into() }))

5

And why not just implement State on the even [correction: enum] itself?

6

I don't understand, could you show the code you mean

7

This topic was automatically closed 90 days after the last reply. We invite you to open a new topic if you have further questions or comments.