Module caps 

Capability markers (ReadFoo, …) from #[table] and tuple composition for context generics.

ReducerCaps / QueryCaps compose for nested pairs (A, B) and recurse for schema. CanRead / CanInsert / CanUpdate / CanDelete do not infer through (A, B) (Rust cannot express “either side” without overlapping impls). For multi-table reducer caps, use a module-local zero-sized struct and implement the needed Can* markers per row type (often via a small declarative macro in your crate), delegating ReducerCaps::extend_reducer_schema to a nested tuple of Read* / Insert* / … markers.

Traits

CanDelete

Delete access for Row.

CanInsert

Insert access for Row.

CanRead

Read access to rows of type Row (the #[table] struct).

CanUpdate

Update access for Row.

QueryCapPiece

One leaf of a query Caps tree.

QueryCaps

ReducerCapPiece

One leaf of a reducer Caps tree: contributes ReducerTableRef entries.

ReducerCaps

Composed reducer capabilities (markers, tuples, or ()).