Macro index_group 

macro_rules! index_group {
    (
        table = $table:ident,
        kind = $kind:ident,
        ty = $ty:ty,
        { $( $name:ident = $code:literal => $build:expr ),* $(,)? }
    ) => { ... };
}

Declares a kind-group of indices: per entry, emits a typed accessor pub fn <name>() -> <ty> and a row in the kind’s static table. The schema lives in the per-kind builder the entry’s expression calls; this macro only wires name/code to the builder and tags the kind.