Crate jigs 

jigs — explicit, composable, traceable processing pipelines.

A jig is one step in a request-to-response pipeline. Steps are chained with Request::then, Response::then and Branch::then, and the type system enforces ordering: once a Response exists you cannot fall back to chaining a Request-shaped step.

This crate is a thin facade. The runtime types live in jigs_core and the jig attribute macro lives in jigs_macros. With the optional trace feature, every #[jig] call site records its name, depth, outcome and wall-clock duration into a per-thread buffer exposed under trace.

Example

use jigs::{jig, jigs, Request, Response};

#[derive(Clone, Request)]
struct Msg(String);

#[derive(Clone, Response)]
struct Out(Result<String, String>);

#[jig]
fn validate(r: Msg) -> Msg { r }

#[jig]
fn handle(r: Msg) -> Out {
    Out::ok(format!("got {}", r.0))
}

let response = Msg("42".into()).then(validate).then(handle);
assert_eq!(response.0.unwrap(), "got 42");

Features

• trace — pulls in jigs_trace (data) and jigs_log (renderers), and instruments every #[jig] call.

Re-exports

pub use jigs_trace as trace;

pub use jigs_log as log;

pub use jigs_map as map;

Modules

json

JSON string escaping utility shared by rendering crates.

meta

Compile-time metadata for every #[jig] function in the binary.

Macros

fork

Multi-arm fork. Predicates are checked in order; the first match consumes the request and its jig is run. If none match, the _ => default arm runs. Every arm must produce the same Out type; each arm’s internal pipeline can have its own intermediate types.

impl_request

Wire a custom request type into the framework.

impl_response

Wire a custom response type into the framework.

jigs

Structs

ChainStep

One entry in a jig’s chain: the called jig’s name plus how it was composed with the surrounding pipeline.

JigMeta

Static description of one jig.

Pending

Wraps a future returned by an async jig so the chain remains spelled with .then.

Enums

Branch

Outcome of a guard jig: either continue with a (possibly transformed) request, or short-circuit the pipeline with a response.

ChainKind

How a chain entry was reached from the surrounding jig.

Traits

Jig

One step in a jigs pipeline. Any Fn(In) -> Out automatically implements this trait, so plain functions, closures, and #[jig]-annotated functions can all be chained with .then(...).

JigDef

Trait implemented by the zero-sized marker struct that the #[jig] macro emits alongside each jig function. The marker struct is named __Jig_<fn_name> to avoid namespace collisions with the function itself. The jigs! macro calls <Entry as JigDef>::collect to recursively gather metadata for every reachable jig, with no link-time registration.

Merge

Glue trait that lets a Branch::then(jig) accept a jig whose output is a request, a response, or another Branch, and merge the two outcomes into a single value.

Request

An inbound message flowing through a pipeline.

Response

An outbound message produced by a pipeline.

Status

Common interface used by tracing to inspect a jig’s outcome without knowing whether the value is a Request, Response, or Branch.

Step

Lifts the output of a jig into a future, so async and sync jigs can be chained uniformly inside a Pending chain. Sync values become a Ready future, a nested Pending is unwrapped to its inner future.

Attribute Macros

jig

Derive Macros

Request

Response