src/Pure/Isar/toplevel.ML
author wenzelm
Fri May 21 11:46:42 1999 +0200 (1999-05-21 ago)
changeset 6689 169e5b07ec06
parent 6664 f679ddd1ddd8
child 6965 a766de752996
permissions -rw-r--r--
tuned;
added prompt_state_fn hook;
added kill operation;
provide toplevel node history, nests with proof history;
toplevel prompt includes nest level;
more robust recovery from stale signatures;
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(*  Title:      Pure/Isar/toplevel.ML
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    ID:         $Id$
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    Author:     Markus Wenzel, TU Muenchen
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The Isabelle/Isar toplevel.
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*)
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signature TOPLEVEL =
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sig
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  datatype node = Theory of theory | Proof of ProofHistory.T
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  type state
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  val toplevel: state
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  val prompt_state_default: state -> string
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  val prompt_state_fn: (state -> string) ref
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  val print_state_default: state -> unit
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  val print_state_fn: (state -> unit) ref
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  val print_state: state -> unit
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  exception UNDEF
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  val node_history_of: state -> node History.T
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  val node_of: state -> node
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  val node_case: (theory -> 'a) -> (Proof.state -> 'a) -> state -> 'a
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  val theory_of: state -> theory
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  val sign_of: state -> Sign.sg
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  val proof_of: state -> Proof.state
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  type transition
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  exception TERMINATE
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  exception RESTART
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  exception BREAK of state
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  val undo_limit: bool -> int option
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  val empty: transition
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  val name: string -> transition -> transition
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  val position: Position.T -> transition -> transition
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  val interactive: bool -> transition -> transition
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  val print: transition -> transition
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  val reset: transition -> transition
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  val init: (state -> node) -> (node -> unit) -> (node -> unit) -> transition -> transition
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  val exit: transition -> transition
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  val kill: transition -> transition
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  val keep: (state -> unit) -> transition -> transition
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  val history: (node History.T -> node History.T) -> transition -> transition
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  val imperative: (unit -> unit) -> transition -> transition
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  val init_theory: (unit -> theory) -> (theory -> unit) -> (theory -> unit)
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    -> transition -> transition
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  val theory: (theory -> theory) -> transition -> transition
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  val theory_to_proof: (bool -> theory -> ProofHistory.T) -> transition -> transition
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  val proof: (ProofHistory.T -> ProofHistory.T) -> transition -> transition
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  val proof': (bool -> ProofHistory.T -> ProofHistory.T) -> transition -> transition
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  val proof_to_theory: (ProofHistory.T -> theory) -> transition -> transition
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  val trace: bool ref
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  val exn_message: exn -> string
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  type isar
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  val apply: bool -> transition -> state -> (state * (exn * string) option) option
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  val excursion: transition list -> unit
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  val set_state: state -> unit
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  val get_state: unit -> state
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  val exn: unit -> (exn * string) option
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  val >> : transition -> bool
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  val loop: isar -> unit
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end;
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structure Toplevel(*: TOPLEVEL *)=
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struct
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(** toplevel state **)
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(* datatype node *)
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datatype node =
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  Theory of theory |
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  Proof of ProofHistory.T;
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fun str_of_node (Theory _) = "in theory mode"
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  | str_of_node (Proof _) = "in proof mode";
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fun print_node (Theory thy) = Pretty.writeln (Pretty.block
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      [Pretty.str "Theory:", Pretty.brk 1, Pretty.str (PureThy.get_name thy),
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        Pretty.str " =", Pretty.brk 1, Display.pretty_theory thy])
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  | print_node (Proof prf) =
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      (writeln ("Proof: step #" ^ string_of_int (ProofHistory.position prf));
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        Proof.print_state (ProofHistory.current prf));
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(* datatype state *)
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datatype state = State of (node History.T * ((node -> unit) * (node -> unit))) list;
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val toplevel = State [];
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fun append_states (State ns) (State ms) = State (ns @ ms);
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fun str_of_state (State []) = "at top level"
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  | str_of_state (State ((node, _) :: _)) = str_of_node (History.current node);
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(* prompt_state hook *)
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fun prompt_state_default (State nodes) =
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  let val len = length nodes
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  in (if len < 2 then "" else string_of_int len) ^ Source.default_prompt end;
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val prompt_state_fn = ref prompt_state_default;
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fun prompt_state state = ! prompt_state_fn state;
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(* print_state hook *)
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fun print_topnode (State []) = ()
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  | print_topnode (State ((node, _) :: _)) = print_node (History.current node);
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fun print_state_default state =
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  let val ref (begin_state, end_state, _) = Goals.current_goals_markers in
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    if begin_state = "" then () else writeln begin_state;
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    print_topnode state;
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    if end_state = "" then () else writeln end_state
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  end;
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val print_state_fn = ref print_state_default;
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fun print_state state = ! print_state_fn state;
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(* top node *)
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exception UNDEF;
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fun node_history_of (State []) = raise UNDEF
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  | node_history_of (State ((node, _) :: _)) = node;
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val node_of = History.current o node_history_of;
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fun node_case f g state =
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  (case node_of state of
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    Theory thy => f thy
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  | Proof prf => g (ProofHistory.current prf));
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val theory_of = node_case I Proof.theory_of;
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val sign_of = Theory.sign_of o theory_of;
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val proof_of = node_case (fn _ => raise UNDEF) I;
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(** toplevel transitions **)
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exception TERMINATE;
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exception RESTART;
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exception BREAK of state;
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exception FAIL of exn * string;
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exception ROLLBACK of state * exn option;
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exception FAILURE of state * exn;
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(* recovery from stale signatures *)
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local
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fun is_stale state = Sign.is_stale (sign_of state) handle UNDEF => false;
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fun checkpoint_node true (Theory thy) = Theory (PureThy.checkpoint thy)
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  | checkpoint_node _ node = node;
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fun copy_node true (Theory thy) = Theory (Theory.copy thy)
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  | copy_node _ node = node;
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in
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fun node_trans _ _ _ (State []) = raise UNDEF
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  | node_trans int hist f (State ((node, term) :: nodes)) =
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      let
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        fun mk_state nd = State ((nd, term) :: nodes);
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        val cont_node = History.map (checkpoint_node int) node;
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        val back_node = History.map (copy_node int) cont_node;
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        val trans = if hist then History.apply_copy (copy_node int) else History.map;
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        val (result, opt_exn) = (mk_state (transform_error (trans (f int)) cont_node), None)
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          handle exn => (mk_state cont_node, Some exn);
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      in
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        if is_stale result then raise ROLLBACK (mk_state back_node, opt_exn)
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        else (case opt_exn of None => result | Some exn => raise FAILURE (result, exn))
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      end;
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fun check_stale state =
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  if not (is_stale state) then ()
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  else warning "Stale signature encountered!  Should redo current theory from start.";
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end;
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(* primitive transitions *)
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(*Important note: recovery from stale signatures is provided only for
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  theory-level operations via MapCurrent and AppCurrent.  Other node
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  or state operations should not touch signatures at all.*)
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datatype trans =
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  Reset |                                       (*empty toplevel*)
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  Init of (state -> node) * ((node -> unit) * (node -> unit)) |
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    (*push node; provide exit/kill operation*)
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  Exit |                                        (*pop node*)
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  Kill |                                        (*abort node*)
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  Keep of state -> unit |                       (*peek at state*)
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  History of node History.T -> node History.T | (*history operation (undo etc.)*)
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  MapCurrent of bool -> node -> node |          (*change node, bypassing history*)
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  AppCurrent of bool -> node -> node;           (*change node, recording history*)
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fun undo_limit int = if int then None else Some 0;
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local
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fun apply_tr _ Reset _ = toplevel
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  | apply_tr int (Init (f, term)) (state as State nodes) =
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      State ((History.init (undo_limit int) (f state), term) :: nodes)
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  | apply_tr _ Exit (State []) = raise UNDEF
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  | apply_tr _ Exit (State ((node, (exit, _)):: nodes)) =
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      (exit (History.current node); State nodes)
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  | apply_tr _ Kill (State []) = raise UNDEF
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  | apply_tr _ Kill (State ((node, (_, kill)) :: nodes)) =
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      (kill (History.current node); State nodes)
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  | apply_tr _ (Keep f) state = (f state; state)
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  | apply_tr _ (History _) (State []) = raise UNDEF
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  | apply_tr _ (History f) (State ((node, term) :: nodes)) = State ((f node, term) :: nodes)
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  | apply_tr int (MapCurrent f) state = node_trans int false f state
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  | apply_tr int (AppCurrent f) state = node_trans int true f state;
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fun apply_union _ [] state = raise FAILURE (state, UNDEF)
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  | apply_union int (tr :: trs) state =
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      transform_error (apply_tr int tr) state
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        handle UNDEF => apply_union int trs state
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          | FAILURE (alt_state, UNDEF) => apply_union int trs alt_state
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          | exn as FAILURE _ => raise exn
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          | exn => raise FAILURE (state, exn);
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in
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fun apply_trans int trs state = (apply_union int trs state, None)
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  handle FAILURE (alt_state, exn) => (alt_state, Some exn) | exn => (state, Some exn);
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end;
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(* datatype transition *)
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datatype transition = Transition of
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 {name: string,
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  pos: Position.T,
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  int_only: bool,
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  print: bool,
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  trans: trans list};
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fun make_transition (name, pos, int_only, print, trans) =
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  Transition {name = name, pos = pos, int_only = int_only, print = print, trans = trans};
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fun map_transition f (Transition {name, pos, int_only, print, trans}) =
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  make_transition (f (name, pos, int_only, print, trans));
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val empty = make_transition ("<unknown>", Position.none, false, false, []);
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(* diagnostics *)
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fun str_of_transition (Transition {name, pos, ...}) = quote name ^ Position.str_of pos;
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fun command_msg msg tr = msg ^ "command " ^ str_of_transition tr;
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fun at_command tr = command_msg "At " tr ^ ".";
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fun type_error tr state =
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  ERROR_MESSAGE (command_msg "Illegal application of " tr ^ " " ^ str_of_state state);
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(* modify transitions *)
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fun name nm = map_transition
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  (fn (_, pos, int_only, print, trans) => (nm, pos, int_only, print, trans));
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fun position pos = map_transition
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  (fn (name, _, int_only, print, trans) => (name, pos, int_only, print, trans));
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fun interactive int_only = map_transition
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  (fn (name, pos, _, print, trans) => (name, pos, int_only, print, trans));
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val print = map_transition
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  (fn (name, pos, int_only, _, trans) => (name, pos, int_only, true, trans));
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fun add_trans tr = map_transition
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  (fn (name, pos, int_only, print, trans) => (name, pos, int_only, print, trans @ [tr]));
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(* build transitions *)
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val reset = add_trans Reset;
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fun init f exit kill = add_trans (Init (f, (exit, kill)));
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val exit = add_trans Exit;
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val kill = add_trans Kill;
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val keep = add_trans o Keep;
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val history = add_trans o History;
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val map_current = add_trans o MapCurrent;
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val app_current = add_trans o AppCurrent;
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fun imperative f = keep (fn _ => f ());
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fun init_theory f exit kill =
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  init (fn _ => Theory (f ()))
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    (fn Theory thy => exit thy | _ => raise UNDEF)
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    (fn Theory thy => kill thy | _ => raise UNDEF);
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fun theory f = app_current (fn _ => (fn Theory thy => Theory (f thy) | _ => raise UNDEF));
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fun theory_to_proof f =
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  app_current (fn int => (fn Theory thy => Proof (f int thy) | _ => raise UNDEF));
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fun proof' f = map_current (fn int => (fn Proof prf => Proof (f int prf) | _ => raise UNDEF));
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val proof = proof' o K;
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fun proof_to_theory f = map_current (fn _ => (fn Proof prf => Theory (f prf) | _ => raise UNDEF));
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(** toplevel transactions **)
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val trace = ref false;
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(* print exceptions *)
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fun raised name = "exception " ^ name ^ " raised";
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fun raised_msg name msg = raised name ^ ": " ^ msg;
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fun exn_message TERMINATE = "Exit."
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  | exn_message RESTART = "Restart."
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  | exn_message (BREAK _) = "Break."
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  | exn_message (FAIL (exn, msg)) = cat_lines [exn_message exn, msg]
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  | exn_message Interrupt = "Interrupt (exec)."
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  | exn_message ERROR = "ERROR."
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  | exn_message (ERROR_MESSAGE msg) = msg
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  | exn_message (THEORY (msg, _)) = msg
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  | exn_message (ProofContext.CONTEXT (msg, _)) = msg
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  | exn_message (Proof.STATE (msg, _)) = msg
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  | exn_message (ProofHistory.FAIL msg) = msg
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  | exn_message (Attrib.ATTRIB_FAIL info) = fail_message "attribute" info
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  | exn_message (Method.METHOD_FAIL info) = fail_message "method" info
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  | exn_message (Syntax.AST (msg, _)) = raised_msg "AST" msg
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  | exn_message (TYPE (msg, _, _)) = raised_msg "TYPE" msg
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  | exn_message (TERM (msg, _)) = raised_msg "TERM" msg
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  | exn_message (THM (msg, _, _)) = raised_msg "THM" msg
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  | exn_message Library.OPTION = raised "Library.OPTION"
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  | exn_message (Library.LIST msg) = raised_msg "Library.LIST" msg
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  | exn_message exn = General.exnMessage exn
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and fail_message kind ((name, pos), exn) =
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  "Error in " ^ kind ^ " " ^ name ^ Position.str_of pos ^ ":\n" ^ exn_message exn;
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fun print_exn None = ()
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  | print_exn (Some (exn, s)) = error_msg (cat_lines [exn_message exn, s]);
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(* the Isar source of transitions *)
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type isar =
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  (transition, (transition option,
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    (OuterLex.token, (OuterLex.token,
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      Position.T * (Symbol.symbol, (string, unit) Source.source) Source.source)
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          Source.source) Source.source) Source.source) Source.source;
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(* transform interrupt (non-polymorphic) *)
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fun transform_interrupt_state f x =
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  let val y = ref (None: (state * exn option) option);
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  in exhibit_interrupt (fn () => y := Some (f x)) (); the (! y) end;
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fun transform_interrupt_isar f x =
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  let val y = ref (None: (transition * isar) option option);
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  in exhibit_interrupt (fn () => y := Some (f x)) (); the (! y) end;
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(* apply transitions *)
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local
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fun app int (tr as Transition {trans, int_only, print, ...}) state =
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  let
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    val _ =
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      if int orelse not int_only then ()
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      else warning (command_msg "Executing interactive-only " tr);
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    val (result, opt_exn) =
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      (if ! trace then (writeln (command_msg "" tr); timeap) else I) (apply_trans int trans) state;
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    val _ = if int andalso print then print_state result else ();
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  in (result, apsome (fn UNDEF => type_error tr state | exn => exn) opt_exn) end;
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in
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fun apply int tr st =
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  (case transform_interrupt_state (app int tr) st of
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    (_, Some TERMINATE) => None
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  | (_, Some RESTART) => Some (toplevel, None)
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  | (state', Some (FAIL (exn_info as (BREAK break_state, _)))) =>
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      Some (append_states break_state state', Some exn_info)
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  | (state', Some (FAIL exn_info)) => Some (state', Some exn_info)
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  | (_, Some (ROLLBACK (back_state, opt_exn))) =>
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      (warning (command_msg "Rollback after " tr);
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        Some (back_state, apsome (fn exn => (exn, at_command tr)) opt_exn))
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  | (state', Some exn) => Some (state', Some (exn, at_command tr))
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  | (state', None) => Some (state', None));
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end;
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   402
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(* excursion: toplevel -- apply transformers -- toplevel *)
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local
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fun excur [] x = x
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  | excur (tr :: trs) x =
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      (case apply false tr x of
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        Some (x', None) => excur trs x'
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      | Some (x', Some exn_info) => raise FAIL exn_info
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      | None => raise FAIL (TERMINATE, at_command tr));
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   413
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   414
in
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   416
fun excursion trs =
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  (case excur trs (State []) of
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   418
    State [] => ()
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  | _ => raise ERROR_MESSAGE "Open block(s) pending at end of input");
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   420
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   421
end;
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   422
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   423
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   424
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   425
(** interactive transformations **)
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   426
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   427
(* the global state reference *)
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   428
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   429
val global_state = ref (toplevel, None: (exn * string) option);
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   430
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   431
fun set_state state = global_state := (state, None);
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   432
fun get_state () = fst (! global_state);
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   433
fun exn () = snd (! global_state);
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   434
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   435
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   436
(* apply transformers to global state *)
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   437
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   438
nonfix >>;
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   439
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   440
fun >> tr =
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   441
  (case apply true tr (get_state ()) of
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   442
    None => false
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   443
  | Some (state', exn_info) =>
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   444
      (global_state := (state', exn_info);
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   445
        check_stale state'; print_exn exn_info;
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   446
        true));
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   447
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   448
fun get_interruptible src =
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  Some (transform_interrupt_isar Source.get_single src)
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   450
    handle Interrupt => None;
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   451
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   452
fun raw_loop src =
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  (case get_interruptible (Source.set_prompt (prompt_state (get_state ())) src) of
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   454
    None => (writeln "\nInterrupt (read)."; raw_loop src)
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   455
  | Some None => ()
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   456
  | Some (Some (tr, src')) => if >> tr then raw_loop src' else ());
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   457
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   458
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   459
fun loop src = mask_interrupt raw_loop src;
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   460
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   461
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   462
end;