src/Pure/PIDE/protocol.ML

keep memo_exec execution running, which is important to cancel goal forks eventually;
run as nested worker task to keep main group valid, even after cancelation of removed subgroups;
do not memoize interrupt, but absorb it silently in main execution;
Goal.purge_futures: rough sanity check of group status;

(*  Title:      Pure/PIDE/protocol.ML
    Author:     Makarius

Protocol message formats for interactive proof documents.
*)

structure Protocol: sig end =
struct

val _ =
  Isabelle_Process.protocol_command "echo" (fn args => List.app writeln args);

val _ =
  Isabelle_Process.protocol_command "Document.define_command"
    (fn [id, name, text] =>
      Document.change_state (Document.define_command (Document_ID.parse id) name text));

val _ =
  Isabelle_Process.protocol_command "Document.discontinue_execution"
    (fn [] => Execution.discontinue ());

val _ =
  Isabelle_Process.protocol_command "Document.update"
    (fn [old_id_string, new_id_string, edits_yxml] => Document.change_state (fn state =>
      let
        val _ = Execution.discontinue ();

        val old_id = Document_ID.parse old_id_string;
        val new_id = Document_ID.parse new_id_string;
        val edits =
          YXML.parse_body edits_yxml |>
            let open XML.Decode in
              list (pair string
                (variant
                 [fn ([], []) => Document.Clear,  (* FIXME unused !? *)
                  fn ([], a) => Document.Edits (list (pair (option int) (option int)) a),
                  fn ([], a) =>
                    let
                      val (master, (name, (imports, (keywords, errors)))) =
                        pair string (pair string (pair (list string)
                          (pair (list (pair string
                            (option (pair (pair string (list string)) (list string)))))
                            (list string)))) a;
                      val imports' = map (rpair Position.none) imports;
                      val header = Thy_Header.make (name, Position.none) imports' keywords;
                    in Document.Deps (master, header, errors) end,
                  fn (a, []) => Document.Perspective (map int_atom a)]))
            end;

        val (removed, assign_update, state') = Document.update old_id new_id edits state;
        val _ = List.app Execution.terminate removed;
        val _ = Goal.purge_futures removed;
        val _ = List.app Isabelle_Process.reset_tracing removed;

        val _ =
          Output.protocol_message Markup.assign_update
            ((new_id, assign_update) |>
              let open XML.Encode
              in pair int (list (pair int (list int))) end
              |> YXML.string_of_body);
      in Document.start_execution state' end));

val _ =
  Isabelle_Process.protocol_command "Document.remove_versions"
    (fn [versions_yxml] => Document.change_state (fn state =>
      let
        val versions =
          YXML.parse_body versions_yxml |>
            let open XML.Decode in list int end;
        val state1 = Document.remove_versions versions state;
        val _ = Output.protocol_message Markup.removed_versions versions_yxml;
      in state1 end));

val _ =
  Isabelle_Process.protocol_command "Document.dialog_result"
    (fn [serial, result] =>
      Active.dialog_result (Markup.parse_int serial) result
        handle exn => if Exn.is_interrupt exn then () (*sic!*) else reraise exn);

end;