[gnugo-devel] arend_1_22.1: minor discard_redundant_move_reasons revision

[Arend Bayer]

- some comments added and a few stylistic changes around 
  discard_redundant_move_reasons
- unsafe tactical moves now taken care by discard_redundant_move_reasons
- FIXME added for reevaluate_ko_threats

This patch has no effects. It adresses a few comments Gunnar made on
my discard_redundant_move_reasons implementation, adds some comments, 
and moves another discard rule from estimate_xxx_value to discard_rules.

-Arend


Index: engine/move_reasons.c
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/move_reasons.c,v
retrieving revision 1.61
diff -u -r1.61 move_reasons.c
--- engine/move_reasons.c       13 Jan 2002 03:33:22 -0000      1.61
+++ engine/move_reasons.c       14 Jan 2002 21:10:46 -0000
@@ -77,10 +77,10 @@
 typedef int (*discard_condition_fn_ptr)(int pos, int what);
 
 struct discard_rule {
-  int reason_type[40];
+  int reason_type[MAX_REASONS];
   discard_condition_fn_ptr condition;
   int flags;
-  char trace_message[160];
+  char trace_message[MAX_TRACE_LENGTH];
 };
 
 
@@ -291,7 +291,9 @@
 /* Interprets the object of a reason and returns its position.
  * If the object is a pair (of worms or dragons), the position of the first
  * object is returned. (This is only used for trace outputs.) Returns
- * -1 if move does not point to a location.
+ * NO_MOVE if move does not point to a location.
+ * FIXME: This new function produces some code duplication with other
+ * trace output function. Do some code cleanup here.
  */
 static int
 get_pos(int reason, int what)
@@ -338,7 +340,7 @@
   case EXPAND_MOYO_MOVE:
   case MY_ATARI_ATARI_MOVE:
   case YOUR_ATARI_ATARI_MOVE:
-    return -1;
+    return NO_MOVE;
   }
   /* We shoud never get here: */
   gg_assert(1>2);
@@ -490,6 +492,10 @@
   return 0;
 }
 
+/* ---------------------------------------------------------------- */
+
+/* Functions used in discard_rules follow below. */
+
 /*
  * Check whether an attack move reason already is recorded for a move.
  * A negative value for 'what' means only match 'type'.
@@ -601,6 +607,12 @@
   return DRAGON2(dragons[what]).safety == INESSENTIAL; 
 }
 
+static int
+move_is_marked_unsafe(int pos, int what)
+{
+  UNUSED(what);
+  return !move[pos].move_safety;
+}
 
 static int
 either_move_redundant(int pos, int what)
@@ -1623,6 +1635,8 @@
  * The format is:
  * { List of reasons to which the rule applies, condition of the rule,
  * flags to be set, trace message }
+ * The condition must be of type discard_condition_fn_ptr, that is a pointer
+ * to a function with parameters (pos, what).
  */
 
 static struct discard_rule discard_rules[] =
@@ -1658,6 +1672,10 @@
       OWL_DEFEND_MOVE_BAD_KO, UNCERTAIN_OWL_DEFENSE, -1 },
     concerns_inessential_dragon, REDUNDANT,
     "  %1m: 0.0 - (uncertain) owl attack/defense of %1m (inessential)\n"},
+  { { ATTACK_MOVE, ATTACK_MOVE_GOOD_KO, ATTACK_MOVE_BAD_KO,
+      DEFEND_MOVE, DEFEND_MOVE_GOOD_KO, DEFEND_MOVE_BAD_KO, -1},
+    move_is_marked_unsafe, REDUNDANT,
+    "  %1m: 0.0 - tactical move vs %1m (unsafe move)\n"},
   { { -1 }, NULL, 0, ""}  /* Keep this entry at end of the list. */
 };
 
Index: engine/move_reasons.h
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/move_reasons.h,v
retrieving revision 1.11
diff -u -r1.11 move_reasons.h
--- engine/move_reasons.h       13 Jan 2002 03:33:22 -0000      1.11
+++ engine/move_reasons.h       14 Jan 2002 21:10:47 -0000
@@ -70,13 +70,15 @@
 #define EITHER_MOVE             100
 
 /* Bitmap values for move_reason.status */
-#define ACTIVE 0
-#define TERRITORY_REDUNDANT 1
+#define ACTIVE                  0
+#define TERRITORY_REDUNDANT     1
 #define STRATEGICALLY_REDUNDANT 2
-#define REDUNDANT 3
-#define SECONDARY 4
+#define REDUNDANT               (TERRITORY_REDUNDANT | STRATEGICALLY_REDUNDANT)
+#define SECONDARY               4
 
 #define MAX_REASONS 40
+
+#define MAX_TRACE_LENGTH  160
 
 #define HUGE_MOVE_VALUE 10.0*MAX_BOARD*MAX_BOARD
 
Index: engine/value_moves.c
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/value_moves.c,v
retrieving revision 1.1
diff -u -r1.1 value_moves.c
--- engine/value_moves.c        13 Jan 2002 15:22:58 -0000      1.1
+++ engine/value_moves.c        14 Jan 2002 21:10:58 -0000
@@ -1090,13 +1090,6 @@
        break;
       }
 
-      /* Strategically unsafe move. */
-      if (!move[pos].move_safety) {
-       DEBUG(DEBUG_MOVE_REASONS,
-             "    %1m: 0.0 - attack on %1m (unsafe move)\n", pos, aa);
-       break;
-      }
-
       this_value = 2 * worm[aa].effective_size;
 
       /* If the stones are dead, there is only a secondary value in
@@ -1142,13 +1135,6 @@
       /* 
        * Estimate value 
        */
-      if (!strategically_sound_defense(aa, pos)) {
-       DEBUG(DEBUG_MOVE_REASONS,
-             "    %1m: 0.0 - defense of %1m (strategically unsound defense)\n",
-             pos, aa);
-       break;
-      }        
-
       this_value = 2 * worm[aa].effective_size;
 
       /* If the stones are dead, we use the convention that
@@ -1631,20 +1617,6 @@
        if (worm[aa].defend_codes[0] == 0)
          break;
 
-       /* Require the defense to be strategically viable. */
-       if ((move_reasons[r].type == DEFEND_MOVE
-            || move_reasons[r].type == DEFEND_MOVE_GOOD_KO
-            || move_reasons[r].type == DEFEND_MOVE_BAD_KO)
-           && !strategically_sound_defense(aa, pos))
-         break;
-
-       /* Do the same for attack moves. */
-       if ((move_reasons[r].type == ATTACK_MOVE
-            || move_reasons[r].type == ATTACK_MOVE_GOOD_KO
-            || move_reasons[r].type == ATTACK_MOVE_BAD_KO)
-           && !move[pos].move_safety)
-         break;
-       
        /* FIXME: This is totally ad hoc, just guessing the value of
          *        potential cutting points.
         * FIXME: When worm[aa].cutstone2 == 1 we should probably add
@@ -2333,6 +2305,11 @@
 }
 
 
+/* This function is called if the biggest move on board was an illegal
+ * ko capture.
+ * FIXME: We need a check here whether the threat still works after
+ * the opponent fills in the ko (or resolves it in another way.)
+ */
 static void
 reevaluate_ko_threats(void)
 {