diff -r d1420f5c5704 -r 619f07c95894 src/chess/rules.h
--- a/src/chess/rules.h	Tue Aug 25 18:35:18 2026 +0200
+++ b/src/chess/rules.h	Tue Aug 25 18:59:18 2026 +0200
@@ -52,20 +52,20 @@
 #if __STDC_VERSION__ < 202310L
 /* since #warning is also a C23 feature, the only hope is this: */
 #pragma GCC warning "Type safety for enums is only available since C23"
-#define enum_uint8_t(name) enum e##name
-#define typedef_enum_uint8_t(name) typedef uint8_t name
+#define enum_byte(name) enum e##name
+#define typedef_enum_byte(name) typedef uint8_t name
 #else
-#define enum_uint8_t(name) enum e##name : uint8_t
-#define typedef_enum_uint8_t(name) typedef enum e##name name
+#define enum_byte(name) enum e##name : uint8_t
+#define typedef_enum_byte(name) typedef enum e##name name
 #endif
 
 #define ENPASSANT_THREAT 0x40u
 
-enum_uint8_t(Color) {
+enum_byte(Color) {
     WHITE = 0x10u,
     BLACK = 0x20u,
 };
-typedef_enum_uint8_t(Color);
+typedef_enum_byte(Color);
 
 static inline Color opponent_color(Color color) {
     return color == WHITE ? BLACK : WHITE;
@@ -81,7 +81,7 @@
 #define QUEEN  0x05u
 #define KING   0x06u
 
-enum_uint8_t(Piece) {
+enum_byte(Piece) {
     WPAWN   = WHITE|PAWN,
     WROOK   = WHITE|ROOK,
     WKNIGHT = WHITE|KNIGHT,
@@ -95,20 +95,20 @@
     BQUEEN  = BLACK|QUEEN,
     BKING   = BLACK|KING,
 };
-typedef_enum_uint8_t(Piece);
+typedef_enum_byte(Piece);
 
 #define POS_UNSPECIFIED 255u
-enum_uint8_t(Row) {
+enum_byte(Rank) {
     RANK_1 = 0, RANK_2, RANK_3, RANK_4, RANK_5, RANK_6, RANK_7, RANK_8,
     RANK_UNSPECIFIED = POS_UNSPECIFIED
 };
-typedef_enum_uint8_t(Row);
+typedef_enum_byte(Rank);
 
-enum_uint8_t(File) {
+enum_byte(File) {
     FILE_A = 0, FILE_B, FILE_C, FILE_D, FILE_E, FILE_F, FILE_G, FILE_H,
     FILE_UNSPECIFIED = POS_UNSPECIFIED
 };
-typedef_enum_uint8_t(File);
+typedef_enum_byte(File);
 
 typedef uint8_t Board[8][8];
 
@@ -123,9 +123,9 @@
     uint64_t movetime; /* the time for this move in microseconds */
     Piece piece;
     File fromfile;
-    Row fromrow;
+    Rank fromrank;
     File tofile;
-    Row torow;
+    Rank torank;
     Piece promotion;
     bool check; /* must always be set if checkmate is set */
     bool checkmate;
@@ -185,37 +185,34 @@
 #define piece_color(piece) ((uint8_t)(piece)&COLOR_MASK)
 #define mkpiece(type,color) (Piece)((type)|(color))
 
-#define mdst(m) (m)->torow, (m)->tofile
-#define msrc(m) (m)->fromrow, (m)->fromfile
-
 /** Checks if the index is specified and valid. */
 static inline bool isidx(uint8_t idx) {return idx < 8;}
 /** Checks if the index is unspecified or valid. */
 static inline bool isidxr(uint8_t idx) {return idx==POS_UNSPECIFIED || idx<8;}
 
 static inline bool isfile(char file) {return file >= 'a' && file <= 'h';}
-static inline bool isrow(char row) {return row >= '1' && row <= '8';}
+static inline bool isrank(char rank) {return rank >= '1' && rank <= '8';}
 
-static inline Row rowidx(char row) {return row-'1';}
+static inline Rank rankidx(char rank) {return rank-'1';}
 static inline File fileidx(char file) {return file-'a';}
 
-static inline char rowchr(Row row) {return (char)row+'1';}
+static inline char rankchr(Rank rank) {return (char)rank+'1';}
 static inline char filechr(File file) {return (char)file+'a';}
 
 
 static inline void enpassant_threat_add(GameState *gamestate,
-        Row row, File file) {
-    gamestate->board[row][file] |= ENPASSANT_THREAT;
+        Rank rank, File file) {
+    gamestate->board[rank][file] |= ENPASSANT_THREAT;
 }
 
 static inline void enpassant_threat_remove(GameState *gamestate,
-        Row row, File file) {
-    gamestate->board[row][file] &= ~ENPASSANT_THREAT;
+        Rank rank, File file) {
+    gamestate->board[rank][file] &= ~ENPASSANT_THREAT;
 }
 
 static inline bool enpassant_threat_exists(const GameState *gamestate,
-        Row row, File file) {
-    return gamestate->board[row][file] & ENPASSANT_THREAT;
+        Rank rank, File file) {
+    return gamestate->board[rank][file] & ENPASSANT_THREAT;
 }
 
 static inline bool is_game_drawn(const GameState *gamestate) {
@@ -232,7 +229,7 @@
     return gamestate->moves[gamestate->movecount - 1].check;
 }
 
-static inline Color field_color(Row r, File f) {
+static inline Color field_color(Rank r, File f) {
     return (r + f) % 2 == 0 ? BLACK : WHITE;
 }
 
@@ -292,35 +289,35 @@
  * Returns the piece at the specified position.
  *
  * @param gamestate the current game state
- * @param row the row
+ * @param rank the rank
  * @param file the file
  * @return the piece at the specified position
  */
-Piece piece_at(const GameState *gamestate, Row row, File file);
+Piece piece_at(const GameState *gamestate, Rank rank, File file);
 
 /**
  * Places a piece at the specified position in the current game state.
  *
  * @param gamestate the current game state
- * @param row the row
+ * @param rank the rank
  * @param file the file
  * @param piece the piece to place at the specified position
  */
-void piece_set(GameState *gamestate, Row row, File file, Piece piece);
+void piece_set(GameState *gamestate, Rank rank, File file, Piece piece);
 
 /**
  * Removes the piece at the specified position in the current game state.
  *
  * @param gamestate the current game state
- * @param row the row
+ * @param rank the rank
  * @param file the file
  */
-static inline void piece_remove(GameState *gamestate, Row row, File file) {
-    piece_set(gamestate, row, file, 0);
+static inline void piece_remove(GameState *gamestate, Rank rank, File file) {
+    piece_set(gamestate, rank, file, 0);
 }
 
 typedef size_t(*moves_generator_func)(const GameState *gamestate,
-        Color c, Row r, File f, Move *moves);
+        Color c, Rank r, File f, Move *moves);
 
 /**
  * Calculates all allowed moves for a specific piece.
@@ -328,13 +325,13 @@
  * Use the macros for the specific pieces instead.
  *
  * @param gamestate the current gamestate
- * @param r the row of the piece
+ * @param r the rank of the piece
  * @param f the file of the piece
  * @param moves target array for the list of moves
  * @return the number of moves stored in the @p moves array
  */
 size_t piece_moves_allowed(const GameState *gamestate,
-        Row r, File f, Move *moves);
+        Rank r, File f, Move *moves);
 
 /**
  * Internal function used to filter out illegal moves.
@@ -343,14 +340,14 @@
  *
  * @param gamestate the current gamestate
  * @param c color of the piece
- * @param r the row of the piece
+ * @param r the rank of the piece
  * @param f the file of the piece
  * @param moves target array for the list of moves
  * @param func a function that unconditionally generates the moves
  * @return the number of moves stored in the @p moves array
  */
 size_t filter_moves_allowed(const GameState *gamestate,
-    Color c, Row r, File f, Move *moves, moves_generator_func func);
+    Color c, Rank r, File f, Move *moves, moves_generator_func func);
 
 /**
  * Determines a list of theoretically possible moves to the specified field.
@@ -362,7 +359,7 @@
  * must be set, too.
  *
  * @param gamestate the current game state
- * @param row row of the field to check
+ * @param rank rank of the field to check
  * @param file file of the field to check
  * @param color the color of the piece that should move to the field
  * @param moves the array where to store the moves
@@ -371,7 +368,7 @@
  * @return true, if any piece of the specified color can move to the specified
  * field regardless of being pinned
  */
-bool get_candidates(const GameState *gamestate, Row row, File file,
+bool get_candidates(const GameState *gamestate, Rank rank, File file,
         Color color, Move* moves, size_t* movecount);
 
 /**
@@ -385,7 +382,7 @@
  * must be set, too.
  *
  * @param gamestate the current game state
- * @param row row of the field to check
+ * @param rank rank of the field to check
  * @param file file of the field to check
  * @param color the color of the piece that should move to the field
  * @param moves the array where to store the moves
@@ -394,7 +391,7 @@
  * @return true, if any piece of the specified color can move to the specified
  * field and is not pinned
  */
-bool get_real_candidates(const GameState *gamestate, Row row, File file,
+bool get_real_candidates(const GameState *gamestate, Rank rank, File file,
         Color color, Move* moves, size_t* movecount);
 
 /**
@@ -407,7 +404,7 @@
  * must be set, too.
  * 
  * @param gamestate the current game state
- * @param row row of the field to check
+ * @param rank rank of the field to check
  * @param file file of the field to check
  * @param color the color of the piece that should threaten the field
  * @param threats the array where to store the threats
@@ -416,7 +413,7 @@
  * @return true, if any piece of the specified color threatens the specified
  * field
  */
-bool get_threats(const GameState *gamestate, Row row, File file,
+bool get_threats(const GameState *gamestate, Rank rank, File file,
         Color color, Move* threats, size_t* threatcount);
 
 /**
@@ -427,7 +424,7 @@
  * must be set, too.
  * 
  * @param gamestate the current game state
- * @param row row of the field to check
+ * @param rank rank of the field to check
  * @param file file of the field to check
  * @param color the color of the piece that should threaten the field
  * @param threats the array where to store the threats
@@ -436,7 +433,7 @@
  * @return true, if any piece of the specified color threatens the specified
  * field and is not pinned
  */
-bool get_real_threats(const GameState *gamestate, Row row, File file,
+bool get_real_threats(const GameState *gamestate, Rank rank, File file,
         Color color, Move* threats, size_t* threatcount);
 
 /**
@@ -446,14 +443,14 @@
  * capture an opponent piece on this field, regardless of being pinned.
  * 
  * @param gamestate the current game state
- * @param row row of the field to check
+ * @param rank rank of the field to check
  * @param file file of the field to check
  * @param color the color of the piece that should cover the field
  * @return true, if any piece of the specified color threatens the specified
  * field
  */
-#define is_covered(gamestate, row, file, color) \
-    get_threats(gamestate, row, file, color, NULL, NULL)
+#define is_covered(gamestate, rank, file, color) \
+    get_threats(gamestate, rank, file, color, NULL, NULL)
 
 /**
  * Checks, if a specified field is attacked by a piece of a certain color.
@@ -462,14 +459,14 @@
  * therefore able to perform the move.
  * 
  * @param gamestate the current game state
- * @param row row of the field to check
+ * @param rank rank of the field to check
  * @param file file of the field to check
  * @param color the color of the piece that should cover the field
  * @return true, if any piece of the specified color threatens the specified
  * field and could capture an opponent piece
  */
-#define is_attacked(gamestate, row, file, color) \
-    get_real_threats(gamestate, row, file, color, NULL, NULL)
+#define is_attacked(gamestate, rank, file, color) \
+    get_real_threats(gamestate, rank, file, color, NULL, NULL)
 
 /**
  * Checks, if a specified field is protected by a piece of a certain color.
@@ -478,13 +475,13 @@
  * that field or move to that field (and is not pinned).
  * 
  * @param gamestate the current game state
- * @param row row of the field to check
+ * @param rank rank of the field to check
  * @param file file of the field to check
  * @param color the color of the piece that should cover the field
  * @return true, if any piece (excluding the king) of the specified color
  * can move to the specified field (including capturing moves)
  */
-bool is_protected(const GameState *gamestate, Row row, File file, Color color);
+bool is_protected(const GameState *gamestate, Rank rank, File file, Color color);
 
 /**
  * Checks, if the specified move cannot be performed, because the piece is