cgp-handler 0.8.0-alpha

A language extension for Rust, with pluggable trait implementations at compile-time.
Documentation 
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use core::marker::PhantomData;

use cgp::component::UseDelegate;
use cgp::prelude::*;

use crate::UseInputDelegate;

#[async_trait]
#[cgp_component(Handler)]
#[prefix(@cgp.extra.handler in DefaultNamespace)]
#[derive_delegate(UseDelegate<Code>)]
#[derive_delegate(UseInputDelegate<Input>)]
#[use_type(HasErrorType.Error)]
pub trait CanHandle<Code, Input> {
    type Output;

    async fn handle(&self, _tag: PhantomData<Code>, input: Input) -> Result<Self::Output, Error>;
}

#[async_trait]
#[cgp_component(HandlerRef)]
#[prefix(@cgp.extra.handler in DefaultNamespace)]
#[derive_delegate(UseDelegate<Code>)]
#[derive_delegate(UseInputDelegate<Input>)]
#[use_type(HasErrorType.Error)]
pub trait CanHandleRef<Code, Input> {
    type Output;

    async fn handle_ref(
        &self,
        _tag: PhantomData<Code>,
        input: &Input,
    ) -> Result<Self::Output, Error>;
}