Actions

action foo(a int, b string) {
    let cmd = Foo{a: a + 1, b: b}
    publish cmd
}

An action is a function callable from the application, which can perform data transformations and publish zero or more commands. The effects of an action are all or none – the commands published and side effects emitted will only be visible to the rest of the system if the entire action succeeds¹. An error that causes termination will result in no changes (see Errors in Actions).

1. This does not mean that the commands have any kind of atomic relationship in the rest of Aranya. They will be processed individually regardless of how they were published. ↩