From 7c78f52a8973dd611a217ea47af6e213f5841356 Mon Sep 17 00:00:00 2001
From: Denys Duchier <denys.duchier@univ-orleans.fr>
Date: Thu, 1 Dec 2011 22:48:28 +0100
Subject: [PATCH] support search options, added 'restart'

---
 library/gecode/gecode-common.icc           | 13 ++++++++--
 library/gecode/gecode_yap.cc               |  6 +++--
 library/gecode/gecode_yap_hand_written.yap | 28 +++++++++++++++++++++-
 3 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/library/gecode/gecode-common.icc b/library/gecode/gecode-common.icc
index 029227e17..6e83ddcc2 100644
--- a/library/gecode/gecode-common.icc
+++ b/library/gecode/gecode-common.icc
@@ -73,6 +73,13 @@ namespace generic_gecode
     virtual GenericSpace* next(void) { return engine.next(); }
   };
 
+  struct GenericRestart: GenericEngine
+  {
+    Restart<GenericSpace> engine;
+    GenericRestart(GenericSpace* s): engine(s) {}
+    virtual GenericSpace* next(void) { return engine.next(); }
+  };
+
   struct GenericSpace: Space
   {
     Optimizing optim;
@@ -137,12 +144,14 @@ namespace generic_gecode
     BoolVar get_bvar(int i) const { return (_bvars) ? (*_bvars)[i] : bvars[i]; }
     SetVar get_svar(int i) const { return (_svars) ? (*_svars)[i] : svars[i]; }
 
-    GenericEngine* new_engine()
+    GenericEngine* new_engine(bool restart=false)
     {
       freeze();
       return (optim.what == Optimizing::OPT_NONE)
 	? static_cast<GenericEngine*>(new GenericDFS(this))
-	: static_cast<GenericEngine*>(new GenericBAB(this));
+	: (restart
+	   ? static_cast<GenericEngine*>(new GenericRestart(this))
+	   : static_cast<GenericEngine*>(new GenericBAB(this)));
     }
 
     int _new_ivar(IntVar& v)
diff --git a/library/gecode/gecode_yap.cc b/library/gecode/gecode_yap.cc
index 51e0d4dd2..c45b28397 100644
--- a/library/gecode/gecode_yap.cc
+++ b/library/gecode/gecode_yap.cc
@@ -156,8 +156,10 @@ extern "C"
   {
     YAP_Term arg1 = YAP_ARG1;
     YAP_Term arg2 = YAP_ARG2;
+    YAP_Term arg3 = YAP_ARG3;
+    bool restart = YAP_IntOfTerm(YAP_ArgOfTerm(1, arg3));
     GenericSpace* space = gecode_Space_from_term(arg1);
-    GenericEngine* engine = space->new_engine();
+    GenericEngine* engine = space->new_engine(restart);
     YAP_Term y_engine =
       YAP_NewOpaqueObject(gecode_engine_tag, sizeof(GenericEngine*));
     GenericEngine** ptr =
@@ -1045,7 +1047,7 @@ extern "C"
     gecode_engine_handler.fail_handler = gecode_engine_fail_handler;
     gecode_engine_handler.write_handler = gecode_engine_write_handler;
     gecode_engine_tag = YAP_NewOpaqueType(&gecode_engine_handler);
-    YAP_UserCPredicate("gecode_new_engine", gecode_new_engine, 2);
+    YAP_UserCPredicate("gecode_new_engine", gecode_new_engine, 3);
 #ifdef DISJUNCTOR
     // opaque disjunctors and clauses
     gecode_disjunctor_handler.write_handler = gecode_disjunctor_write_handler;
diff --git a/library/gecode/gecode_yap_hand_written.yap b/library/gecode/gecode_yap_hand_written.yap
index 466670b93..7f43205b1 100644
--- a/library/gecode/gecode_yap_hand_written.yap
+++ b/library/gecode/gecode_yap_hand_written.yap
@@ -344,13 +344,38 @@ maximize(Space,IVar1,IVar2) :-
 	assert_is_IntVar(IVar2,IVar2_),
 	gecode_space_maximize_ratio(Space_,IVar1_,IVar2_).
 
+gecode_search_options_init(search_options(0)).
+
+gecode_search_options_offset(restart,0).
+
+gecode_search_options_from_alist(L,O) :-
+    gecode_search_options_init(O),
+    gecode_search_options_process_alist(L,O).
+
+gecode_search_options_process_alist([],O).
+gecode_search_options_process_alist([F=V|L],O) :- !,
+    gecode_search_options_set(F,V,O),
+    gecode_search_options_process_alist(L,O).
+gecode_search_options_process_alist([F|L],O) :- !,
+    gecode_search_options_set(F,1,O),
+    gecode_search_options_process_alist(L,O).
+
+gecode_search_options_set(F,V,O) :-
+    gecode_search_options_offset(F,I),
+    setarg(I,O,V).
+
 search(Space, Solution) :-
+    search(Space, Solution, []).
+
+search(Space, Solution, Alist) :-
 	assert_is_Space(Space,Space_),
 	assert_var(Solution),
-	gecode_new_engine(Space_,Engine_),
+	gecode_search_options_from_alist(Alist,O),
+	gecode_new_engine(Space_,Engine_,O),
 	gecode_engine_search(Engine_,Solution_),
 	Solution='Space'(Solution_).
 
+
 %% INSPECTING VARIABLES
 
 get_for_vars([],Space,[],F).
@@ -647,6 +672,7 @@ new_setvars_(L,Space,N,X1,X2) :- length(L,N), new_setvars(L,Space,X1,X2).
 (X := clause(Disj)) :- !, new_clause(X,Disj).
 
 (X := search(Y)) :- !, search(Y,X).
+(X := search(Y,L)) :- !, search(Y,X,L).
 
 % these should be autogenerated:
 (C += forward(X,Y)) :- !, new_forward(C,X,Y).