Mercurial > hg > terminal-chess / file diff

--- a/src/chess/rules.h	Mon Apr 27 18:06:00 2026 +0200
+++ b/src/chess/rules.h	Tue Apr 28 12:25:48 2026 +0200
@@ -63,8 +63,9 @@
 #define rowchr(row) (row+'1')
 #define filechr(file) (file+'a')
 
-#define chkidx(move) (isidx((move)->fromfile) && isidx((move)->fromrow) && \
-        isidx((move)->tofile) && isidx((move)->torow))
+#define chkidx_from(move) (isidx((move)->fromfile) && isidx((move)->fromrow))
+#define chkidx_to(move) (isidx((move)->tofile) && isidx((move)->torow))
+#define chkidx(move) (chkidx_from(move) && chkidx_to(move))
 
 /* secure versions - use, if index is not checked with isidx() */
 #define fileidx_s(c) (isfile(c)?fileidx(c):POS_UNSPECIFIED)
@@ -206,6 +207,12 @@
 /**
  * Evaluates a move syntactically and stores the move data in the specified
  * object.
+ *
+ * When short algebraic notation is used, the source position is determined by
+ * the evaluating the allowed moves according to the current game state.
+ *
+ * For a purely syntactic check, regardless of whether a piece exists that is
+ * allowed to move that way, use check_move().
  * 
  * @param gamestate the current game state
  * @param mstr the input string to parse
@@ -216,6 +223,16 @@
 int eval_move(GameState *gamestate, char *mstr, Move *move, uint8_t color);
 
 /**
+ * Syntactically checks a move without verifying that a piece exists that is
+ * allowed to move that way.
+ *
+ * @param mstr the input string to parse
+ * @param color the color of the player to evaluate the move for
+ * @return status code (see macros in this file for the list of codes)
+ */
+int check_move(char *mstr, uint8_t color);
+
+/**
  * Validates move by applying chess rules.
  * @param gamestate the current game state
  * @param move the move to validate