movepick: 完成 next_move() 函数并应用

src/movepick.cpp

@@ -164,13 +164,35 @@ void MovePicker::score()
         }
 }
 
+/// MovePicker::select() returns the next move satisfying a predicate function.
+/// It never returns the TT move.
+template<MovePicker::PickType T, typename Pred>
+Move MovePicker::select(Pred filter)
+{
+    while (cur < endMoves) {
+        if (T == Best)
+            std::swap(*cur, *std::max_element(cur, endMoves));
+
+        if (*cur != ttMove && filter())
+            return *cur++;
+
+        cur++;
+    }
+    return MOVE_NONE;
+}
+
 /// MovePicker::next_move() is the most important method of the MovePicker class. It
 /// returns a new pseudo legal move every time it is called until there are no more
 /// moves left, picking the move with the highest score from a list of generated moves.
 Move MovePicker::next_move()
 {
-    // TODO
-    return MOVE_NONE;
+    endMoves = generate(pos, moves);
+    moveCount = endMoves - moves;
+
+    score();
+    partial_insertion_sort(moves, endMoves, -100);    // TODO: limit = -3000 * depth
+
+    return *moves;
 }
 
 #ifdef HOSTORY_HEURISTIC

src/movepick.h

@@ -69,9 +69,17 @@ public:
     }
 
     Position *pos;
+    Move ttMove { MOVE_NONE };
     ExtMove *cur, *endMoves;
     ExtMove moves[MAX_MOVES] { MOVE_NONE };
 
+    int moveCount{ 0 };
+
+    int move_count()
+    {
+        return moveCount;
+    }
+
 #ifdef HOSTORY_HEURISTIC
     // TODO: Fix size
     Score placeHistory[64];

src/search.cpp

@@ -730,23 +730,18 @@ Value search(Position *pos, Stack<Position> &ss, Depth depth, Depth originDepth,
     }
 
     MovePicker mp(pos);
-    mp.endMoves = generate(pos, mp.moves);
-    mp.score();
+    Move nextMove = mp.next_move();
+    int moveCount = mp.move_count();
 
-    partial_insertion_sort(mp.moves, mp.endMoves, -100);
-    ExtMove *cur = mp.moves;
-
-    int nchild = mp.endMoves - cur;
-
-    if (nchild == 1 && depth == originDepth) {
-        bestMove = mp.moves[0].move;
+    if (moveCount == 1 && depth == originDepth) {
+        bestMove = nextMove;
         bestValue = VALUE_UNIQUE;
         return bestValue;
     }
 
 #ifdef TRANSPOSITION_TABLE_ENABLE
 #ifdef PREFETCH_SUPPORT
-    for (int i = 0; i < nchild; i++) {
+    for (int i = 0; i < moveCount; i++) {
         TranspositionTable::prefetch(pos->next_primary_key(mp.moves[i].move));
     }
 
@@ -758,14 +753,14 @@ Value search(Position *pos, Stack<Position> &ss, Depth depth, Depth originDepth,
 #endif // PREFETCH_SUPPORT
 #endif // TRANSPOSITION_TABLE_ENABLE
 
-    for (int i = 0; i < nchild; i++) {
+    for (int i = 0; i < moveCount; i++) {
         ss.push(*(pos));
         Color before = pos->sideToMove;
         Move move = mp.moves[i].move;
         pos->do_move(move);
         Color after = pos->sideToMove;
 
-        if (gameOptions.getDepthExtension() == true && nchild == 1) {
+        if (gameOptions.getDepthExtension() == true && moveCount == 1) {
             epsilon = 1;
         } else {
             epsilon = 0;