Struct Next 

pub struct Next { /* private fields */ }

Opaque continuation passed to a Middleware. Calling Next::run proceeds to the next middleware in the chain or to the Terminal if the chain is exhausted.

The middleware chain is held as a shared Arc<[_]> walked with an index cursor, so advancing the pipeline is a reference-count bump rather than a per-dispatch allocation of the chain.

Implementations

impl Next

pub fn new( middlewares: impl Into<Arc<[Arc<dyn DynMiddleware>]>>, terminal: Arc<dyn Terminal>, ) -> Self

Builds a new Next from a chain of middlewares and a terminal.

Middlewares are executed in the order they appear: the first one wraps the second, which wraps the third, and so on. The chain accepts any Into<Arc<[_]>>, so a freshly built Vec or a pre-shared Arc<[_]> (cloned once per dispatch as a reference-count bump) both work.

pub async fn run( self, envelope: &MessageEnvelope, ctx: &HandlerContext, ) -> Result<BoxOutput, HexeractError>

Advances the pipeline by one step.

The context’s cancellation token is observed before each step: a middleware that cancels the token short-circuits the rest of the chain at the next Next::run call, and the Terminal is never reached. A step that is already executing is not interrupted.

Errors

Returns HexeractError::Cancelled if the context’s cancellation token fired, or the HexeractError produced by the next middleware in the chain or by the Terminal when the chain is exhausted.