mlua-flow-ir

flow.ir async runtime + mlua binding. Layer 3 of the 4-layer flow.ir stack.

Re-exports the Pure Rust core (flow-ir-core) and adds AsyncDispatcher + eval_async (including Fanout join-mode support) + Lua module() binding.

Stack position

1. flow-ir-lua — Pure Lua DSL (separate repo, ecosystem-neutral)
2. flow-ir-core — Pure Rust schema + sync interpreter
3. mlua-flow-ir — this crate: async runtime + mlua binding
4. mlua-swarm-engine — host concerns (Spawner / Worker / Loop / AuthzPolicy / cp_state persist)

What's in

• All flow-ir-core schema types re-exported verbatim (Node / Expr / Dispatcher / EvalError / …)
• AsyncDispatcher trait + eval_async for tokio / async-runtime hosts
• Fanout parallel Step dispatch (All / Any / Race / AllSettled join modes) via eval_async
• module(lua) binding that registers flow.eval into a Lua state

Quick start (sync)

use mlua_flow_ir::{eval, Dispatcher, EvalError, Node};
use serde_json::{json, Value};

let node: Node = serde_json::from_value(json!({
    "kind": "step",
    "ref": "uppercase",
    "in": { "op": "path", "at": "$.input" },
    "out": { "op": "path", "at": "$.output" },
})).unwrap();

struct Fixture;
impl Dispatcher for Fixture {
    fn dispatch(&self, _r: &str, input: Value) -> Result<Value, EvalError> {
        if let Value::String(s) = input {
            Ok(Value::String(s.to_uppercase()))
        } else {
            Ok(input)
        }
    }
}

let result = eval(&node, json!({ "input": "hello" }), &Fixture).unwrap();
assert_eq!(result, json!({ "input": "hello", "output": "HELLO" }));

Async dispatch

use mlua_flow_ir::{eval_async, AsyncDispatcher, EvalError, Node};
use async_trait::async_trait;
use serde_json::Value;

struct AsyncFixture;

#[async_trait]
impl AsyncDispatcher for AsyncFixture {
    async fn dispatch(&self, _r: &str, input: Value) -> Result<Value, EvalError> {
        Ok(input)
    }
}

Feature flags

Default = lua54 + vendored, matching every existing consumer.

• Different Lua version: default-features = false, features = ["luajit", "vendored"]
• System Lua instead of vendored: drop vendored from the feature list
• Async-only, no Lua binding: default-features = false — mlua is not compiled in and module() is unavailable

License

MIT OR Apache-2.0