From: Fabian Fichter <ianfab@users.noreply.github.com>
Date: Wed, 12 Feb 2020 21:26:26 +0000 (+0100)
Subject: Fix notation for pieces in hand in SFEN
X-Git-Url: http://winboard.nl/cgi-bin?a=commitdiff_plain;h=051d82c2c54042a65b8e76b18f0a91cc3aed97e5;p=fairystockfish.git

Fix notation for pieces in hand in SFEN

Prefix the piece letter by the piece count instead of repeating the letter.
Support old notation in parsing for backwards compatibility.

Closes #77.
---

diff --git a/src/position.cpp b/src/position.cpp
index ef0ed6a..4c5f7d4 100644
--- a/src/position.cpp
+++ b/src/position.cpp
@@ -416,12 +416,23 @@ Position& Position::set(const Variant* v, const string& fenStr, bool isChess960,
   if (sfen)
   {
       // Pieces in hand for SFEN
+      int handCount = 1;
       while ((ss >> token) && !isspace(token))
       {
           if (token == '-')
               continue;
+          else if (isdigit(token))
+          {
+              handCount = token - '0';
+              while (isdigit(ss.peek()) && ss >> token)
+                  handCount = 10 * handCount + (token - '0');
+          }
           else if ((idx = piece_to_char().find(token)) != string::npos)
-              add_to_hand(Piece(idx));
+          {
+              for (int i = 0; i < handCount; i++)
+                  add_to_hand(Piece(idx));
+              handCount = 1;
+          }
       }
       // Move count is in ply for SFEN
       ss >> std::skipws >> gamePly;
@@ -610,7 +621,12 @@ const string Position::fen(bool sfen, bool showPromoted, std::string holdings) c
       ss << (sideToMove == WHITE ? " b " : " w ");
       for (Color c : {WHITE, BLACK})
           for (PieceType pt = KING; pt >= PAWN; --pt)
-              ss << std::string(pieceCountInHand[c][pt], piece_to_char()[make_piece(c, pt)]);
+              if (pieceCountInHand[c][pt])
+              {
+                  if (pieceCountInHand[c][pt] > 1)
+                      ss << pieceCountInHand[c][pt];
+                  ss << piece_to_char()[make_piece(c, pt)];
+              }
       if (!count_in_hand(WHITE, ALL_PIECES) && !count_in_hand(BLACK, ALL_PIECES))
           ss << '-';
       ss << " " << gamePly + 1;