aboutsummaryrefslogtreecommitdiffstats
path: root/lib/sublanguage.ml
blob: e8e511c97e0895ab0db8274a643851eb1346809b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
include Sublanguage_types
(** Effect classification for sublanguage operations.

    Categorically:
    - Query: a natural transformation between instance functors (DRL).
      Side-effect-free; the database state is unchanged.
    - Transition: a morphism in the category of database states (DDL, DML, ICL,
      DCL, and future TCL). Produces a new state via substitution (Harper, PFPL
      ch. 3-4).

    Future sublanguages:
    - TCL -> Transition (transaction boundaries are state morphisms with
      atomicity constraints)
    - PPL -> new effect class: potentially non-terminating computation
      (Turing-complete; breaks the termination guarantee of DRL)
    - ACL -> a functor restriction: narrows the admissible natural
      transformations based on authorization context *)

module type S = sig
  include Configuration.CONFIGURABLE

  type ast
  type error

  val name : string
  val parse_sexp : Sexplib.Sexp.t -> (ast, error) Result.t

  val execute : Sublanguage_context.t -> ast -> (result, error) Result.t

  val sexp_of_error : error -> Sexplib.Sexp.t
end