Source file snapshot.ml

open Core
open! Import
open Types.Kind
module Node = Types.Node

type 'a t = 'a Types.Snapshot.t =
  { main : 'a Node.t
  ; at : Time_ns.t
  ; before : 'a
  ; value_at : 'a Node.t
  ; clock : (Types.Clock.t[@sexp.opaque])
  }
[@@deriving fields, sexp_of]

let invariant invariant_a t =
  Invariant.invariant [%here] t [%sexp_of: _ t] (fun () ->
    let check f = Invariant.check_field t f in
    Fields.iter
      ~main:
        (check (fun (main : _ Node.t) ->
           assert (Scope.is_top main.created_in);
           match main.kind with
           | Invalid -> () (* happens when snapshotting an invalid node *)
           | Const _ -> () (* happens after the snapshot *)
           | Snapshot t' -> assert (phys_equal t t')
           | _ -> assert false))
      ~at:ignore
      ~before:(check invariant_a)
      ~value_at:ignore
      ~clock:ignore)
;;