X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fuci.cpp;h=ae34043831cb19f39fa96fd7c9f677f7d68733a0;hp=6593d5ad25a6fe71f14b9b2c57f0c6071285f42e;hb=1e7aaed8bc;hpb=a46b53e1c21ba56b09d7d9e47335d383b5240ce0

diff --git a/src/uci.cpp b/src/uci.cpp
index 6593d5ad..ae340438 100644
--- a/src/uci.cpp
+++ b/src/uci.cpp
@@ -23,6 +23,7 @@
 ////
 
 #include <cassert>
+#include <cctype>
 #include <iostream>
 #include <sstream>
 #include <string>
@@ -53,6 +54,7 @@ namespace {
   void set_position(Position& pos, UCIParser& up);
   bool go(Position& pos, UCIParser& up);
   void perft(Position& pos, UCIParser& up);
+  Move parse_uci_move(const Position& pos, const std::string &str);
 }
 
 
@@ -132,6 +134,75 @@ bool execute_uci_command(const string& cmd) {
 
 namespace {
 
+  // parse_uci_move() takes a position and a string as input, and attempts to
+  // convert the string to a move, using simple coordinate notation (g1f3,
+  // a7a8q, etc.). In order to correctly parse en passant captures and castling
+  // moves, we need the position. This function is not robust, and expects that
+  // the input move is legal and correctly formatted.
+
+  Move parse_uci_move(const Position& pos, const std::string& str) {
+
+    Square from, to;
+    Piece piece;
+    Color us = pos.side_to_move();
+
+    if (str.length() < 4)
+        return MOVE_NONE;
+
+    // Read the from and to squares
+    from = make_square(file_from_char(str[0]), rank_from_char(str[1]));
+    to   = make_square(file_from_char(str[2]), rank_from_char(str[3]));
+
+    // Find the moving piece
+    piece = pos.piece_on(from);
+
+    // If the string has more than 4 characters, try to interpret the 5th
+    // character as a promotion.
+    if (str.length() > 4 && piece == piece_of_color_and_type(us, PAWN))
+    {
+        switch (tolower(str[4])) {
+        case 'n':
+            return make_promotion_move(from, to, KNIGHT);
+        case 'b':
+            return make_promotion_move(from, to, BISHOP);
+        case 'r':
+            return make_promotion_move(from, to, ROOK);
+        case 'q':
+            return make_promotion_move(from, to, QUEEN);
+        }
+    }
+
+    // En passant move? We assume that a pawn move is an en passant move
+    // if the destination square is epSquare.
+    if (to == pos.ep_square() && piece == piece_of_color_and_type(us, PAWN))
+        return make_ep_move(from, to);
+
+    // Is this a castling move? A king move is assumed to be a castling move
+    // if the destination square is occupied by a friendly rook, or if the
+    // distance between the source and destination squares is more than 1.
+    if (piece == piece_of_color_and_type(us, KING))
+    {
+        if (pos.piece_on(to) == piece_of_color_and_type(us, ROOK))
+            return make_castle_move(from, to);
+
+        if (square_distance(from, to) > 1)
+        {
+            // This is a castling move, but we have to translate it to the
+            // internal "king captures rook" representation.
+            SquareDelta delta = (to > from ? DELTA_E : DELTA_W);
+            Square s = from;
+
+            do s += delta;
+            while (   pos.piece_on(s) != piece_of_color_and_type(us, ROOK)
+                   && relative_rank(us, s) == RANK_1);
+
+            return relative_rank(us, s) == RANK_1 ? make_castle_move(from, s) : MOVE_NONE;
+        }
+    }
+
+    return make_move(from, to);
+  }
+
   // set_position() is called when Stockfish receives the "position" UCI
   // command. The input parameter is a UCIParser. It is assumed
   // that this parser has consumed the first token of the UCI command
@@ -170,7 +241,7 @@ namespace {
     StateInfo st;
     while (up >> token)
     {
-        move = move_from_uci(pos, token);
+        move = parse_uci_move(pos, token);
         pos.do_setup_move(move, st);
     }
     // Our StateInfo st is about going out of scope so copy
@@ -269,7 +340,7 @@ namespace {
         {
             int numOfMoves = 0;
             while (up >> token)
-                searchMoves[numOfMoves++] = move_from_uci(pos, token);
+                searchMoves[numOfMoves++] = parse_uci_move(pos, token);
 
             searchMoves[numOfMoves] = MOVE_NONE;
         }