1 (* Copyright (C) 2002, HELM Team.
3 * This file is part of HELM, an Hypertextual, Electronic
4 * Library of Mathematics, developed at the Computer Science
5 * Department, University of Bologna, Italy.
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34 (** perform debugging output? *)
36 let debug_print = fun _ -> ()
38 (** debugging print *)
39 let info s = debug_print (lazy ("TACTICALS INFO: " ^ (Lazy.force s)))
41 module PET = ProofEngineTypes
44 let id_tac (proof,goal) =
45 let _, metasenv, _, _, _ = proof in
46 let _, _, _ = CicUtil.lookup_meta goal metasenv in
52 let fail_tac (proof,goal) =
53 let _, metasenv, _, _, _ = proof in
54 let _, _, _ = CicUtil.lookup_meta goal metasenv in
55 raise (PET.Fail (lazy "fail tactical"))
57 PET.mk_tactic fail_tac
61 (** TODO needed until tactics start returning both opened and closed goals
62 * First part of the function performs a diff among goals ~before tactic
63 * application and ~after it. Second part will add as both opened and closed
64 * the goals which are returned as opened by the tactic *)
65 let goals_diff ~before ~after ~opened =
66 let sort_opened opened add =
67 opened @ (List.filter (fun g -> not (List.mem g opened)) add)
71 (fun remove e -> if List.mem e after then remove else e :: remove)
76 (fun add e -> if List.mem e before then add else e :: add)
80 let add, remove = (* adds goals which have been both opened _and_ closed *)
82 (fun (add, remove) opened_goal ->
83 if List.mem opened_goal before
84 then opened_goal :: add, opened_goal :: remove
89 sort_opened opened add, remove
91 module ProofEngineStatus =
93 module Stack = Continuationals.Stack
95 (* The stack is used and saved only at the very end of the eval function;
96 it is read only at the beginning of the eval;
97 we need it just to apply several times in a row this machine to an
98 initial stack, i.e. to chain several applications of the machine together,
99 i.e. to dump and restore the state of the machine.
100 The stack is never used by the tactics: each tactic of type
101 PET.tactic ignore the stack. To make a tactic from the eval function
102 of a machine we apply the eval on a fresh stack (via the mk_tactic). *)
104 PET.status (* (proof, goal) *) * Stack.t
107 (PET.proof * goal list * goal list) * Stack.t
109 type tactic = PET.tactic
111 let id_tactic = id_tac
113 (* f is an eval function of a machine;
114 the machine is applied to a fresh stack and the final stack is read
115 back to obtain the result of the tactic *)
118 (fun (proof, goal) as pstatus ->
119 let stack = [ [ 1, Stack.Open goal ], [], [], `NoTag ] in
120 let istatus = pstatus, stack in
121 let (proof, _, _), stack = f istatus in
122 let opened = Continuationals.Stack.open_goals stack in
125 (* it applies a tactic ignoring (and preserving) the stack *)
126 let apply_tactic tac ((proof, _) as pstatus, stack) =
127 let proof', opened = PET.apply_tactic tac pstatus in
128 let before = PET.goals_of_proof proof in
129 let after = PET.goals_of_proof proof' in
130 let opened_goals, closed_goals = goals_diff ~before ~after ~opened in
131 (proof', opened_goals, closed_goals), stack
133 let get_status (status, _) = status
134 let get_proof ((proof, _, _), _) = proof
136 let goals ((_, opened, closed), _) = opened, closed
137 let set_goals (opened, closed) ((proof, _, _), stack) =
138 (proof, opened, closed), stack
140 (* Done only at the beginning of the eval of the machine *)
142 (* Done only at the end of the eval of the machine *)
143 let set_stack stack (opstatus, _) = opstatus, stack
145 let inject ((proof, _), stack) = ((proof, [], []), stack)
146 let focus goal ((proof, _, _), stack) = (proof, goal), stack
149 module S = ProofEngineStatus
150 module C = Continuationals.Make (S)
152 type tactic = S.tactic
154 let fold_eval status ts =
156 List.fold_left (fun istatus t -> S.focus ~-1 (C.eval t istatus)) status ts
160 (* Tacticals implemented on top of tynycals *)
162 let thens ~start ~continuations =
166 ([ C.Tactical (C.Tactic start); C.Branch ]
167 @ (HExtlib.list_concat ~sep:[ C.Shift ]
168 (List.map (fun t -> [ C.Tactical (C.Tactic t) ]) continuations))
171 let then_ ~start ~continuation =
174 let ostatus = C.eval (C.Tactical (C.Tactic start)) istatus in
175 let opened,closed = S.goals ostatus in
179 fold_eval (S.focus ~-1 ostatus)
181 C.Tactical (C.Tactic continuation) ])
187 (HExtlib.list_concat ~sep:[ C.Semicolon ]
188 (List.map (fun t -> [ C.Tactical (C.Tactic t) ]) tactics)))
190 (* Tacticals that cannot be implemented on top of tynycals *)
193 let rec first ~(tactics: (string * tactic) list) status =
194 info (lazy "in Tacticals.first");
196 [] -> raise (PET.Fail (lazy "first: no tactics left"))
197 | (descr, tac)::tactics ->
198 info (lazy ("Tacticals.first IS TRYING " ^ descr));
200 let res = PET.apply_tactic tac status in
201 info (lazy ("Tacticals.first: " ^ descr ^ " succedeed!!!"));
204 PET.Fail _ -> first ~tactics status
206 PET.mk_tactic (first ~tactics)
209 let rec do_tactic ~n ~tactic =
213 PET.apply_tactic id_tac status
216 (then_ ~start:tactic ~continuation:(do_tactic ~n:(n-1) ~tactic))
219 (* This applies tactic and catches its possible failure *)
220 let try_tactic ~tactic =
221 let try_tactic status =
223 PET.apply_tactic tactic status
224 with (PET.Fail _) as e ->
226 "Tacticals.try_tactic failed with exn: " ^ Printexc.to_string e));
227 PET.apply_tactic id_tac status
229 PET.mk_tactic try_tactic
231 let rec repeat_tactic ~tactic =
232 ProofEngineTypes.mk_tactic
234 ProofEngineTypes.apply_tactic
236 ~continuation:(try_tactic (repeat_tactic ~tactic))) status)
238 (* This tries tactics until one of them solves the goal *)
239 let solve_tactics ~tactics =
240 let rec solve_tactics ~(tactics: (string * tactic) list) status =
241 info (lazy "in Tacticals.solve_tactics");
243 | (descr, currenttactic)::moretactics ->
244 info (lazy ("Tacticals.solve_tactics is trying " ^ descr));
246 let (proof, opened) as output_status =
247 PET.apply_tactic currenttactic status
250 | [] -> info (lazy ("Tacticals.solve_tactics: " ^ descr ^
251 " solved the goal!!!"));
253 | _ -> info (lazy ("Tacticals.solve_tactics: try the next tactic"));
254 raise (PET.Fail (lazy "Goal not solved"))
255 with (PET.Fail _) as e ->
257 "Tacticals.solve_tactics: current tactic failed with exn: "
258 ^ Printexc.to_string e));
259 solve_tactics ~tactics:moretactics status)
262 (lazy "solve_tactics cannot solve the goal"))
264 PET.mk_tactic (solve_tactics ~tactics)
266 let progress_tactic ~tactic =
267 let msg = lazy "Failed to progress" in
268 let progress_tactic (((_,metasenv,_,_,_),_) as istatus) =
269 let ((_,metasenv',_,_,_),_) as ostatus =
270 PET.apply_tactic tactic istatus
273 If just the index of some metas changes the tactic is recognized
274 as a progressing one. This is wrong. *)
275 if metasenv' = metasenv then
280 PET.mk_tactic progress_tactic