From bc9bca49ec4adfb9211e8429eb1d45021d9127c8 Mon Sep 17 00:00:00 2001
From: Petr Baudis <pasky@ucw.cz>
Date: Sat, 20 Feb 2010 00:31:40 +0100
Subject: [PATCH] board_is_valid_play(): Introduce to avoid stupid struct move
 setups

---
 board.h         | 19 +++++++++++++------
 playout/moggy.c | 12 +++++-------
 uct/tree.c      |  4 +---
 3 files changed, 19 insertions(+), 16 deletions(-)

diff --git a/board.h b/board.h
index 7f91ec3..b9917b1 100644
--- a/board.h
+++ b/board.h
@@ -289,6 +289,7 @@ typedef bool (*ppr_permit)(void *data, struct board *b, struct move *m);
 void board_play_random(struct board *b, enum stone color, coord_t *coord, ppr_permit permit, void *permit_data);
 
 /* Returns true if given move can be played. */
+static bool board_is_valid_play(struct board *b, enum stone color, coord_t coord);
 static bool board_is_valid_move(struct board *b, struct move *m);
 /* Returns true if ko was just taken. */
 static bool board_playing_ko_threat(struct board *b);
@@ -389,21 +390,21 @@ board_is_eyelike(struct board *board, coord_t *coord, enum stone eye_color)
 }
 
 static inline bool
-board_is_valid_move(struct board *board, struct move *m)
+board_is_valid_play(struct board *board, enum stone color, coord_t coord)
 {
-	if (board_at(board, m->coord) != S_NONE)
+	if (board_at(board, coord) != S_NONE)
 		return false;
-	if (!board_is_eyelike(board, &m->coord, stone_other(m->color)))
+	if (!board_is_eyelike(board, &coord, stone_other(color)))
 		return true;
 	/* Play within {true,false} eye-ish formation */
-	if (board->ko.coord == m->coord && board->ko.color == m->color)
+	if (board->ko.coord == coord && board->ko.color == color)
 		return false;
 #ifdef BOARD_TRAITS
 	/* XXX: Disallows suicide. */
-	return trait_at(board, m->coord, m->color).cap > 0;
+	return trait_at(board, coord, color).cap > 0;
 #else
 	int groups_in_atari = 0;
-	foreach_neighbor(board, m->coord, {
+	foreach_neighbor(board, coord, {
 		group_t g = group_at(board, c);
 		groups_in_atari += (board_group_info(board, g).libs == 1);
 	});
@@ -412,6 +413,12 @@ board_is_valid_move(struct board *board, struct move *m)
 }
 
 static inline bool
+board_is_valid_move(struct board *board, struct move *m)
+{
+	return board_is_valid_play(board, m->color, m->coord);
+}
+
+static inline bool
 board_playing_ko_threat(struct board *b)
 {
 	return !is_pass(b->ko.coord);
diff --git a/playout/moggy.c b/playout/moggy.c
index 5f75902..0b3e6ff 100644
--- a/playout/moggy.c
+++ b/playout/moggy.c
@@ -297,8 +297,8 @@ can_play_on_lib(struct playout_policy *p, struct board_state *s,
 		fprintf(stderr, "can capture group %d (%s)?\n",
 			g, coord2sstr(capture, b));
 	/* Does playing on the liberty usefully capture the group? */
-	struct move m; m.color = to_play; m.coord = capture;
-	if (board_is_valid_move(b, &m) && !is_bad_selfatari(b, to_play, capture)) {
+	if (board_is_valid_play(b, to_play, capture)
+	    && !is_bad_selfatari(b, to_play, capture)) {
 		group_trait_set(s, g, to_play, capturable, true);
 		return true;
 	}
@@ -537,8 +537,7 @@ check_group_atari(struct board *b, group_t group, enum stone owner,
 	for (int i = 0; i < 2; i++) {
 		coord_t lib = board_group_info(b, group).lib[i];
 		assert(board_at(b, lib) == S_NONE);
-		struct move m; m.color = to_play; m.coord = lib;
-		if (!board_is_valid_move(b, &m))
+		if (!board_is_valid_play(b, to_play, lib))
 			continue;
 
 		/* Don't play at the spot if it is extremely short
@@ -654,10 +653,9 @@ playout_moggy_choose(struct playout_policy *p, struct board *b, enum stone to_pl
 
 	/* Ko fight check */
 	if (!is_pass(b->last_ko.coord) && is_pass(b->ko.coord)
+	    && b->moves - b->last_ko_age < pp->koage
 	    && pp->korate > fast_random(100)) {
-		struct move pm = { .color = to_play, .coord = b->last_ko.coord };
-		if (b->moves - b->last_ko_age < pp->koage
-		    && board_is_valid_move(b, &pm)
+		if (board_is_valid_play(b, to_play, b->last_ko.coord)
 		    && !is_bad_selfatari(b, to_play, b->last_ko.coord))
 			return b->last_ko.coord;
 	}
diff --git a/uct/tree.c b/uct/tree.c
index dc3e102..7dcd322 100644
--- a/uct/tree.c
+++ b/uct/tree.c
@@ -702,13 +702,11 @@ tree_expand_node(struct tree *t, struct tree_node *node, struct board *b, enum s
 	bool map_consider[board_size2(b) + 1]; map.consider = &map_consider[1];
 	memset(map_prior, 0, sizeof(map_prior));
 	memset(map_consider, 0, sizeof(map_consider));
-	struct move pm = { .color = color };
 	map.consider[pass] = true;
 	foreach_point(b) {
 		if (board_at(b, c) != S_NONE)
 			continue;
-		pm.coord = c;
-		if (!board_is_valid_move(b, &pm))
+		if (!board_is_valid_play(b, color, c))
 			continue;
 		map.consider[c] = true;
 	} foreach_point_end;
-- 
2.11.4.GIT