types: 新增 is_ok(Move m) 函数

顺带新增未完成的 Position::legal() 函数。

src/position.cpp

@@ -349,6 +349,39 @@ const string Position::fen() const
 }
 
 
+/// Position::legal() tests whether a pseudo-legal move is legal
+
+bool Position::legal(Move m) const
+{
+    assert(is_ok(m));
+
+    Color us = sideToMove;
+    Square from = from_sq(m);
+    Square to = to_sq(m);
+
+    if (phase == PHASE_MOVING && type_of(move) != MOVETYPE_REMOVE) {
+        if (color_of(moved_piece(m)) != us) {
+            return false;
+        }
+    }
+
+    // TODO: Add more
+
+    return true;
+}
+
+
+/// Position::pseudo_legal() takes a random move and tests whether the move is
+/// pseudo legal. It is used to validate moves from TT that can be corrupted
+/// due to SMP concurrent access or hash position key aliasing.
+
+bool Position::pseudo_legal(const Move m) const
+{
+    // TODO
+    return legal(m);
+}
+
+
 /// Position::do_move() makes a move, and saves all information necessary
 /// to a StateInfo object. The move is assumed to be legal. Pseudo-legal
 /// moves should be filtered out before this function is called.

src/position.h

@@ -84,6 +84,7 @@ public:
     // Properties of moves
     bool legal(Move m) const;
     bool pseudo_legal(const Move m) const;
+    Piece moved_piece(Move m) const;
 
     // Doing and undoing moves
     void do_move(Move m, StateInfo &newSt);
@@ -262,6 +263,11 @@ inline bool Position::empty(Square s) const
     return piece_on(s) == NO_PIECE;
 }
 
+inline Piece Position::moved_piece(Move m) const
+{
+    return piece_on(from_sq(m));
+}
+
 template<PieceType Pt> inline int Position::count(Color c) const
 {
     if (Pt == ON_BOARD) {

src/types.h

@@ -523,11 +523,9 @@ inline const Move reverse_move(Move m)
     return make_move(to_sq(m), from_sq(m));
 }
 
-#if 0
-constexpr bool is_ok(Move m)
+static inline bool is_ok(Move m)
 {
     return from_sq(m) != to_sq(m); // Catch MOVE_NULL and MOVE_NONE
 }
-#endif
 
 #endif // #ifndef TYPES_H_INCLUDED