X-Git-Url: http://matita.cs.unibo.it/gitweb/?p=helm.git;a=blobdiff_plain;f=components%2Ftactics%2Fcontinuationals.ml;fp=components%2Ftactics%2Fcontinuationals.ml;h=044fa45c841cb61e39ecfbe335a14e20937160ec;hp=0000000000000000000000000000000000000000;hb=f61af501fb4608cc4fb062a0864c774e677f0d76;hpb=58ae1809c352e71e7b5530dc41e2bfc834e1aef1 diff --git a/components/tactics/continuationals.ml b/components/tactics/continuationals.ml new file mode 100644 index 000000000..044fa45c8 --- /dev/null +++ b/components/tactics/continuationals.ml @@ -0,0 +1,365 @@ +(* 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 " + + 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 +