fn serve

@error data Boom { m: str }

service Bank {
  @public @idempotent rpc hold(n: u64) -> u64
  @public @idempotent rpc unhold(n: u64) -> () | Boom
  @public @idempotent rpc refuse(n: u64) -> u64 | Boom
}

impl Bank {
  rpc hold(n) => n
  rpc unhold(n) { fail Boom{ m: "bank is down" } }
  rpc refuse(n) { fail Boom{ m: "no" } }
}

// the second step fails and its compensation never succeeds: the saga becomes stuck
saga pay(n: u64) -> u64 {
  Bank.hold(n)   undo h => Bank.unhold(h)
  -> Bank.refuse(n)
}

fn main() io, net, time, db {
  // `pay` is registered with serve("main.pay", ...) by the generated code; calling it only starts a saga
  match pay(3) {
    u64 v => print("done {v}")
    Boom b => print("boom")
    CompensationFailed c => print("stuck at step {c.step}")
    NetError e => print("net error")
  }
}

stuck at step 1