--- /dev/null
+(* Copyright (C) 2005, HELM Team.
+ *
+ * This file is part of HELM, an Hypertextual, Electronic
+ * Library of Mathematics, developed at the Computer Science
+ * Department, University of Bologna, Italy.
+ *
+ * HELM is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * HELM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HELM; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ *
+ * For details, see the HELM World-Wide-Web page,
+ * http://helm.cs.unibo.it/
+ *)
+
+(* $Id$ *)
+
+open Printf
+
+let debug = false
+let debug_print s = if debug then prerr_endline (Lazy.force s) else ()
+
+exception Error of string lazy_t
+let fail msg = raise (Error msg)
+
+type goal = ProofEngineTypes.goal
+
+module Stack =
+struct
+ type switch = Open of goal | Closed of goal
+ type locator = int * switch
+ type tag = [ `BranchTag | `FocusTag | `NoTag ]
+ type entry = locator list * locator list * locator list * tag
+ type t = entry list
+
+ let empty = [ [], [], [], `NoTag ]
+
+ let fold ~env ~cont ~todo init stack =
+ let rec aux acc depth =
+ function
+ | [] -> acc
+ | (locs, todos, conts, tag) :: tl ->
+ let acc = List.fold_left (fun acc -> env acc depth tag) acc locs in
+ let acc = List.fold_left (fun acc -> cont acc depth tag) acc conts in
+ let acc = List.fold_left (fun acc -> todo acc depth tag) acc todos in
+ aux acc (depth + 1) tl
+ in
+ assert (stack <> []);
+ aux init 0 stack
+
+ let iter ~env ~cont ~todo =
+ fold ~env:(fun _ -> env) ~cont:(fun _ -> cont) ~todo:(fun _ -> todo) ()
+
+ let map ~env ~cont ~todo =
+ let depth = ref ~-1 in
+ List.map
+ (fun (s, t, c, tag) ->
+ incr depth;
+ let d = !depth in
+ env d tag s, todo d tag t, cont d tag c, tag)
+
+ let is_open = function _, Open _ -> true | _ -> false
+ let close = function n, Open g -> n, Closed g | l -> l
+ let filter_open = List.filter is_open
+ let is_fresh =
+ function n, Open _ when n > 0 -> true | _,Closed _ -> true | _ -> false
+ let goal_of_loc = function _, Open g | _, Closed g -> g
+ let goal_of_switch = function Open g | Closed g -> g
+ let switch_of_loc = snd
+
+ let zero_pos = List.map (fun g -> 0, Open g)
+
+ let init_pos locs =
+ let pos = ref 0 in (* positions are 1-based *)
+ List.map (function _, sw -> incr pos; !pos, sw) locs
+
+ let extract_pos i =
+ let rec aux acc =
+ function
+ | [] -> fail (lazy (sprintf "relative position %d not found" i))
+ | (i', _) as loc :: tl when i = i' -> loc, (List.rev acc) @ tl
+ | hd :: tl -> aux (hd :: acc) tl
+ in
+ aux []
+
+ let deep_close gs =
+ let close _ _ =
+ List.map (fun l -> if List.mem (goal_of_loc l) gs then close l else l)
+ in
+ let rm _ _ = List.filter (fun l -> not (List.mem (goal_of_loc l) gs)) in
+ map ~env:close ~cont:rm ~todo:rm
+
+ let rec find_goal =
+ function
+ | [] -> raise (Failure "Continuationals.find_goal")
+ | (l :: _, _ , _ , _) :: _ -> goal_of_loc l
+ | ( _ , _ , l :: _, _) :: _ -> goal_of_loc l
+ | ( _ , l :: _, _ , _) :: _ -> goal_of_loc l
+ | _ :: tl -> find_goal tl
+
+ let is_empty =
+ function
+ | [] -> assert false
+ | [ [], [], [], `NoTag ] -> true
+ | _ -> false
+
+ let of_metasenv metasenv =
+ let goals = List.map (fun (g, _, _) -> g) metasenv in
+ [ zero_pos goals, [], [], `NoTag ]
+
+ let head_switches =
+ function
+ | (locs, _, _, _) :: _ -> List.map switch_of_loc locs
+ | [] -> assert false
+
+ let head_goals =
+ function
+ | (locs, _, _, _) :: _ -> List.map goal_of_loc locs
+ | [] -> assert false
+
+ let head_tag =
+ function
+ | (_, _, _, tag) :: _ -> tag
+ | [] -> assert false
+
+ let shift_goals =
+ function
+ | _ :: (locs, _, _, _) :: _ -> List.map goal_of_loc locs
+ | [] -> assert false
+ | _ -> []
+
+ let open_goals stack =
+ let add_open acc _ _ l = if is_open l then goal_of_loc l :: acc else acc in
+ List.rev (fold ~env:add_open ~cont:add_open ~todo:add_open [] stack)
+
+ let (@+) = (@) (* union *)
+
+ let (@-) s1 s2 = (* difference *)
+ List.fold_right
+ (fun e acc -> if List.mem e s2 then acc else e :: acc)
+ s1 []
+
+ let (@~-) locs gs = (* remove some goals from a locators list *)
+ List.fold_right
+ (fun loc acc -> if List.mem (goal_of_loc loc) gs then acc else loc :: acc)
+ locs []
+
+ let pp stack =
+ let pp_goal = string_of_int in
+ let pp_switch =
+ function Open g -> "o" ^ pp_goal g | Closed g -> "c" ^ pp_goal g
+ in
+ let pp_loc (i, s) = string_of_int i ^ pp_switch s in
+ let pp_env env = sprintf "[%s]" (String.concat ";" (List.map pp_loc env)) in
+ let pp_tag = function `BranchTag -> "B" | `FocusTag -> "F" | `NoTag -> "N" in
+ let pp_stack_entry (env, todo, cont, tag) =
+ sprintf "(%s, %s, %s, %s)" (pp_env env) (pp_env todo) (pp_env cont)
+ (pp_tag tag)
+ in
+ String.concat " :: " (List.map pp_stack_entry stack)
+end
+
+module type Status =
+sig
+ type input_status
+ type output_status
+
+ type tactic
+ val mk_tactic : (input_status -> output_status) -> tactic
+ val apply_tactic : tactic -> input_status -> output_status
+
+ val goals : output_status -> goal list * goal list (** opened, closed goals *)
+ val get_stack : input_status -> Stack.t
+ val set_stack : Stack.t -> output_status -> output_status
+
+ val inject : input_status -> output_status
+ val focus : goal -> output_status -> input_status
+end
+
+module type C =
+sig
+ type input_status
+ type output_status
+ type tactic
+
+ type tactical =
+ | Tactic of tactic
+ | Skip
+
+ type t =
+ | Dot
+ | Semicolon
+
+ | Branch
+ | Shift
+ | Pos of int list
+ | Wildcard
+ | Merge
+
+ | Focus of goal list
+ | Unfocus
+
+ | Tactical of tactical
+
+ val eval: t -> input_status -> output_status
+end
+
+module Make (S: Status) =
+struct
+ open Stack
+
+ type input_status = S.input_status
+ type output_status = S.output_status
+ type tactic = S.tactic
+
+ type tactical =
+ | Tactic of tactic
+ | Skip
+
+ type t =
+ | Dot
+ | Semicolon
+ | Branch
+ | Shift
+ | Pos of int list
+ | Wildcard
+ | Merge
+ | Focus of goal list
+ | Unfocus
+ | Tactical of tactical
+
+ let pp_t =
+ function
+ | Dot -> "Dot"
+ | Semicolon -> "Semicolon"
+ | Branch -> "Branch"
+ | Shift -> "Shift"
+ | Pos i -> "Pos " ^ (String.concat "," (List.map string_of_int i))
+ | Wildcard -> "Wildcard"
+ | Merge -> "Merge"
+ | Focus gs ->
+ sprintf "Focus [%s]" (String.concat "; " (List.map string_of_int gs))
+ | Unfocus -> "Unfocus"
+ | Tactical _ -> "Tactical <abs>"
+
+ let eval_tactical tactical ostatus switch =
+ match tactical, switch with
+ | Tactic tac, Open n ->
+ let ostatus = S.apply_tactic tac (S.focus n ostatus) in
+ let opened, closed = S.goals ostatus in
+ ostatus, opened, closed
+ | Skip, Closed n -> ostatus, [], [n]
+ | Tactic _, Closed _ -> fail (lazy "can't apply tactic to a closed goal")
+ | Skip, Open _ -> fail (lazy "can't skip an open goal")
+
+ let eval cmd istatus =
+ let stack = S.get_stack istatus in
+ debug_print (lazy (sprintf "EVAL CONT %s <- %s" (pp_t cmd) (pp stack)));
+ let new_stack stack = S.inject istatus, stack in
+ let ostatus, stack =
+ match cmd, stack with
+ | _, [] -> assert false
+ | Tactical tac, (g, t, k, tag) :: s ->
+(* COMMENTED OUT TO ALLOW PARAMODULATION TO DO A
+ * auto paramodulation.try assumption.
+ * EVEN IF NO GOALS ARE LEFT OPEN BY AUTO.
+
+ if g = [] then fail (lazy "can't apply a tactic to zero goals");
+
+*)
+ debug_print (lazy ("context length " ^string_of_int (List.length g)));
+ let rec aux s go gc =
+ function
+ | [] -> s, go, gc
+ | loc :: loc_tl ->
+ debug_print (lazy "inner eval tactical");
+ let s, go, gc =
+ if List.exists ((=) (goal_of_loc loc)) gc then
+ s, go, gc
+ else
+ let s, go', gc' = eval_tactical tac s (switch_of_loc loc) in
+ s, (go @- gc') @+ go', gc @+ gc'
+ in
+ aux s go gc loc_tl
+ in
+ let s0, go0, gc0 = S.inject istatus, [], [] in
+ let sn, gon, gcn = aux s0 go0 gc0 g in
+ debug_print (lazy ("opened: "
+ ^ String.concat " " (List.map string_of_int gon)));
+ debug_print (lazy ("closed: "
+ ^ String.concat " " (List.map string_of_int gcn)));
+ let stack =
+ (zero_pos gon, t @~- gcn, k @~- gcn, tag) :: deep_close gcn s
+ in
+ sn, stack
+ | Dot, ([], _, [], _) :: _ ->
+ (* backward compatibility: do-nothing-dot *)
+ new_stack stack
+ | Dot, (g, t, k, tag) :: s ->
+ (match filter_open g, k with
+ | loc :: loc_tl, _ -> new_stack (([ loc ], t, loc_tl @+ k, tag) :: s)
+ | [], loc :: k ->
+ assert (is_open loc);
+ new_stack (([ loc ], t, k, tag) :: s)
+ | _ -> fail (lazy "can't use \".\" here"))
+ | Semicolon, _ -> new_stack stack
+ | Branch, (g, t, k, tag) :: s ->
+ (match init_pos g with
+ | [] | [ _ ] -> fail (lazy "too few goals to branch");
+ | loc :: loc_tl ->
+ new_stack
+ (([ loc ], [], [], `BranchTag) :: (loc_tl, t, k, tag) :: s))
+ | Shift, (g, t, k, `BranchTag) :: (g', t', k', tag) :: s ->
+ (match g' with
+ | [] -> fail (lazy "no more goals to shift")
+ | loc :: loc_tl ->
+ new_stack
+ (([ loc ], t @+ filter_open g @+ k, [],`BranchTag)
+ :: (loc_tl, t', k', tag) :: s))
+ | Shift, _ -> fail (lazy "can't shift goals here")
+ | Pos i_s, ([ loc ], t, [],`BranchTag) :: (g', t', k', tag) :: s
+ when is_fresh loc ->
+ let l_js = List.filter (fun (i, _) -> List.mem i i_s) ([loc] @+ g') in
+ new_stack
+ ((l_js, t , [],`BranchTag)
+ :: (([ loc ] @+ g') @- l_js, t', k', tag) :: s)
+ | Pos _, _ -> fail (lazy "can't use relative positioning here")
+ | Wildcard, ([ loc ] , t, [], `BranchTag) :: (g', t', k', tag) :: s
+ when is_fresh loc ->
+ new_stack
+ (([loc] @+ g', t, [], `BranchTag)
+ :: ([], t', k', tag) :: s)
+ | Wildcard, _ -> fail (lazy "can't use wildcard here")
+ | Merge, (g, t, k,`BranchTag) :: (g', t', k', tag) :: s ->
+ new_stack ((t @+ filter_open g @+ g' @+ k, t', k', tag) :: s)
+ | Merge, _ -> fail (lazy "can't merge goals here")
+ | Focus [], _ -> assert false
+ | Focus gs, s ->
+ let stack_locs =
+ let add_l acc _ _ l = if is_open l then l :: acc else acc in
+ Stack.fold ~env:add_l ~cont:add_l ~todo:add_l [] s
+ in
+ List.iter
+ (fun g ->
+ if not (List.exists (fun l -> goal_of_loc l = g) stack_locs) then
+ fail (lazy (sprintf "goal %d not found (or closed)" g)))
+ gs;
+ new_stack ((zero_pos gs, [], [], `FocusTag) :: deep_close gs s)
+ | Unfocus, ([], [], [], `FocusTag) :: s -> new_stack s
+ | Unfocus, _ -> fail (lazy "can't unfocus, some goals are still open")
+ in
+ debug_print (lazy (sprintf "EVAL CONT %s -> %s" (pp_t cmd) (pp stack)));
+ S.set_stack stack ostatus
+end
+
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