Macro id

macro_rules! id {
    ($world:ident) => { ... };
    ($world:ident [$rank:expr_2021]) => { ... };
    ($world:ident [$rank:expr_2021] . $actor:ident) => { ... };
    ($world:ident [$rank:expr_2021] . $actor:ident [$pid:expr_2021]) => { ... };
    ($world:ident . $actor:ident) => { ... };
    ($world:ident [$rank:expr_2021] . $actor:ident [$pid:expr_2021] [$port:expr_2021]) => { ... };
}

Statically create a WorldId, ProcId, ActorId or GangId, given the concrete syntax documented in Reference:

assert_eq!(id!(hello), WorldId("hello".into()));
assert_eq!(id!(hello[0]), ProcId::Ranked(WorldId("hello".into()), 0));
assert_eq!(
    id!(hello[0].actor),
    ActorId(
        ProcId::Ranked(WorldId("hello".into()), 0),
        "actor".into(),
        0
    )
);
assert_eq!(
    id!(hello[0].actor[1]),
    ActorId(
        ProcId::Ranked(WorldId("hello".into()), 0),
        "actor".into(),
        1
    )
);
assert_eq!(
    id!(hello.actor),
    GangId(WorldId("hello".into()), "actor".into())
);

Prefer to use the id macro to construct identifiers in code, as it guarantees static validity, and preserves and reinforces the uniform concrete syntax of identifiers throughout.