ring.ml* splitted into ring.ml* and tacticals.ml*

[helm.git] / helm / gTopLevel / tacticals.ml

diff --git a/helm/gTopLevel/tacticals.ml b/helm/gTopLevel/tacticals.ml
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+(* Copyright (C) 2002, 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://cs.unibo.it/helm/.
+ *)
+
+open CicReduction
+open PrimitiveTactics
+open ProofEngineTypes
+open UriManager
+
+(** DEBUGGING *)
+
+  (** perform debugging output? *)
+let debug = false
+
+  (** debugging print *)
+let warn s =
+  if debug then
+    prerr_endline ("TACTICALS WARNING: " ^ s)
+
+(** AUX TACTIC{,AL}S *)
+
+  (**
+    naive implementation of ORELSE tactical, try a sequence of tactics in turn:
+    if one fails pass to the next one and so on, eventually raises (failure "no
+    tactics left")
+    TODO warning: not tail recursive due to "try .. with" boxing
+  *)
+let rec try_tactics ~(tactics: (string * tactic) list) ~status =
+  warn "in Ring.try_tactics";
+  match tactics with
+  | (descr, tac)::tactics ->
+      warn ("Ring.try_tactics IS TRYING " ^ descr);
+      (try
+        let res = tac ~status in
+        warn ("Ring.try_tactics: " ^ descr ^ " succedeed!!!");
+        res
+       with
+        e ->
+         match e with
+            (Fail _)
+          | (CicTypeChecker.NotWellTyped _)
+          | (CicUnification.UnificationFailed) ->
+              warn (
+                "Ring.try_tactics failed with exn: " ^
+                Printexc.to_string e);
+              try_tactics ~tactics ~status
+        | _ -> raise e (* [e] must not be caught ; let's re-raise it *)
+      )
+  | [] -> raise (Fail "try_tactics: no tactics left")
+
+let thens ~start ~continuations ~status =
+ let (proof,new_goals) = start ~status in
+  try
+   List.fold_left2
+    (fun (proof,goals) goal tactic ->
+      let (proof',new_goals') = tactic ~status:(proof,goal) in
+       (proof',goals@new_goals')
+    ) (proof,[]) new_goals continuations
+  with
+   Invalid_argument _ -> raise (Fail "thens: wrong number of new goals")
+
+let then_ ~start ~continuation ~status =
+ let (proof,new_goals) = start ~status in
+  List.fold_left
+   (fun (proof,goals) goal ->
+     let (proof',new_goals') = continuation ~status:(proof,goal) in
+      (proof',goals@new_goals')
+   ) (proof,[]) new_goals