use query_group_macro::query_group;

#[query_group]
pub trait ArityDb: salsa::Database {
    #[salsa::invoke_interned(one)]
    fn one(&self, a: ()) -> String;

    #[salsa::invoke_interned(two)]
    fn two(&self, a: (), b: ()) -> String;

    #[salsa::invoke_interned(three)]
    fn three(&self, a: (), b: (), c: ()) -> String;

    #[salsa::invoke_interned(none)]
    fn none(&self) -> String;
}

fn one(_db: &dyn ArityDb, _a: ()) -> String {
    String::new()
}

fn two(_db: &dyn ArityDb, _a: (), _b: ()) -> String {
    String::new()
}

fn three(_db: &dyn ArityDb, _a: (), _b: (), _c: ()) -> String {
    String::new()
}

fn none(_db: &dyn ArityDb) -> String {
    String::new()
}