(*let module S = Set.Make (Text) in*)
(*let module M = Map.Make (String) in*)
(*let module I = Map.Make (Id) in*)
(*let aggr = I.empty, M.empty, M.empty, M.empty in*)
(*let fn (id, a, t, k) (n,_) =*)
(* let id = I.add n.Text.uuid n id in*)
(* let a =*)
(*   let f e a = M.update (e.Person.name) (function Some v -> Some (S.add n v) | None -> Some (S.singleton n)) a in*)
(*   Person.Set.fold f n.Text.authors a in*)
(* let t =*)
(*   let f e a = M.update e (function Some v -> Some (S.add n v) | None -> Some (S.singleton n)) a in*)
(*   String_set.fold f (Text.set "Topics" n) t in*)
(* let k =*)
(*   let f e a = M.update e (function Some v -> Some (S.add n v) | None -> Some (S.singleton n)) a in*)
(*   String_set.fold f (Text.set "Keywords" n) k in*)
(* (id, a, t, k)*)

module Make (Store : Store.T) = struct
  include Store
  let predicate fn opt = Option.(to_list @@ map fn opt)

  let authored query_string =
    let q = Person.Set.of_query @@ String_set.query query_string in
    fun n -> Person.Set.predicate q n.Text.authors

  let keyworded query_string =
    let q = String_set.query query_string in
    fun n -> String_set.(predicate q (Text.set "Keywords" n))

  let topics query_string =
    let q = String_set.query query_string in
    fun n -> String_set.(predicate q (Text.set "Topics" n))
end