Fixed SAN parsing error

hrushikeshrv · Mar 3, 2023 · 56677df · 56677df
1 parent e44e702
commit 56677df
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Showing 3 changed files with 68 additions and 33 deletions.
diff --git a/chessengine/bitboard.py b/chessengine/bitboard.py
@@ -675,47 +675,71 @@ def move_san(self, move: str, side: str) -> None:
             else:
                 piece_moved = san_piece_map[groups[0].upper()]
 
-            end_pos = 2 ** coords_to_pos[groups[3].upper()]
+            end_pos = 2 ** coords_to_pos[groups[2].upper()]
             moves = self.get_moves(side, piece_moved)
+
             if groups[1] is None:
-                # No file provided in the SAN
+                # No rank or file provided in the SAN
                 candidate_move = None
                 for m in moves:
                     if m[1] == end_pos:
+                        if candidate_move:
+                            raise MoveError(
+                                f"{move} is ambiguous for {side}. Specify a file or rank to move from."
+                            )
+                        candidate_move = m
+                if candidate_move is None:
+                    raise MoveError(f"{move} is not a valid move for {side}.")
+                self.move(
+                    start=candidate_move[0],
+                    end=candidate_move[1],
+                    score=candidate_move[2],
+                )
+            elif groups[1].isalpha():
+                # File provided in the SAN
+                candidate_move = None
+                for m in moves:
+                    file = get_file(m[0])
+                    if groups[1].upper() == "ABCDEFGH"[file - 1] and m[1] == end_pos:
+                        if candidate_move:
+                            raise MoveError(
+                                f"{move} is ambiguous for {side}. Specify a rank to move from."
+                            )
+                        candidate_move = m
+                if candidate_move is None:
+                    raise MoveError(f"{move} is not valid for {side}.")
+                self.move(
+                    start=candidate_move[0],
+                    end=candidate_move[1],
+                    score=candidate_move[2],
+                )
+            elif groups[1].isnumeric():
+                # Rank provided in the SAN
+                candidate_move = None
+                for m in moves:
+                    rank = get_rank(m[0])
+                    if groups[1] == "12345678"[rank - 1] and m[1] == end_pos:
                         if candidate_move:
                             raise MoveError(
                                 f"{move} is ambiguous for {side}. Specify a file to move from."
                             )
                         candidate_move = m
                 if candidate_move is None:
                     raise MoveError(f"{move} is not a valid move for {side}.")
+                self.move(
+                    start=candidate_move[0],
+                    end=candidate_move[1],
+                    score=candidate_move[2],
+                )
+            elif groups[1].isalnum():
+                # Both rank and file provided in the SAN
+                start_pos = 2 ** coords_to_pos[groups[1].upper()]
+                for m in moves:
+                    if m[0] == start_pos and m[1] == end_pos:
+                        self.move(start=start_pos, end=end_pos, score=m[2])
+                        break
                 else:
-                    self.move(start=candidate_move[0], end=candidate_move[1])
-            else:
-                if groups[2] is None:
-                    # No rank provided in the SAN
-                    candidate_move = None
-                    for m in moves:
-                        file = get_file(m[0])
-                        if (
-                            groups[1].upper() == "ABCDEFGH"[file - 1]
-                            and m[1] == end_pos
-                        ):
-                            if candidate_move:
-                                raise MoveError(
-                                    f"{move} is ambiguous for {side}. Specify a file as well as rank to move from."
-                                )
-                            candidate_move = m
-                    if candidate_move is None:
-                        raise MoveError(f"{move} is not a valid move for {side}.")
-                    else:
-                        self.move(start=candidate_move[0], end=candidate_move[1])
-                else:
-                    # File and rank both present in the SAN
-                    start_pos = 2 ** coords_to_pos[groups[1].upper() + groups[2]]
-                    if (start_pos, end_pos) not in moves:
-                        raise MoveError(f"{move} is not a valid move for {side}.")
-                    self.move(start=start_pos, end=end_pos)
+                    raise MoveError(f"{move} is not a valid move for {side}.")
 
     def make_moves(self, *moves: Iterable[tuple[int, int]]) -> None:
         """

diff --git a/chessengine/lookup_tables.py b/chessengine/lookup_tables.py
@@ -325,6 +325,18 @@
     "B": "bishops",
     "N": "knights",
     "R": "rooks",
+    "\u2654": "kings",
+    "\u2655": "queens",
+    "\u2656": "rooks",
+    "\u2657": "bishops",
+    "\u2658": "knights",
+    "\u2659": "pawns",
+    "\u265A": "kings",
+    "\u265B": "queens",
+    "\u265C": "rooks",
+    "\u265D": "bishops",
+    "\u265E": "knights",
+    "\u265F": "pawns",
 }
 
 # fmt: off

diff --git a/chessengine/pgn/parser.py b/chessengine/pgn/parser.py
@@ -7,12 +7,11 @@
 from chessengine.pgn.node import GameNode, Game
 
 # groups()[0] = The piece moved, one of {K, Q, N, R, B}, None if a pawn was moved
-# groups()[1] = The file the piece was moved from. Present to resolve ambiguity, if any
-# groups()[2] = The rank the piece was moved from. Present to resolve ambiguity, if any
-# groups()[3] = The square the piece was moved to. Always non-null
-# groups()[4] = The piece a pawn was promoted to, if a pawn reached the last rank
+# groups()[1] = The file and/or the rank the piece was moved from. Present to resolve ambiguity, if any
+# groups()[2] = The square the piece was moved to. Always non-null
+# groups()[3] = The piece a pawn was promoted to, if a pawn reached the last rank
 SAN_MOVE_REGEX = re.compile(
-    "([KQNRB\u2654\u2655\u2656\u2657\u2658\u2659\u265A\u265B\u265C\u265D\u265E\u265F])?([a-h])?([1-8])?x?([a-h][1-8])=?([QNRB])?"
+    "([KQNRB\u2654\u2655\u2656\u2657\u2658\u2659\u265A\u265B\u265C\u265D\u265E\u265F])?([a-h1-8]{1,2})?x?([a-h][1-8])=?([QNRB])?"
 )
 MOVE_TEXT_COMMENT_REGEX = re.compile(
     r"\s*{.*?}\s*"