diff options
Diffstat (limited to 'chess-pos.el')
| -rw-r--r-- | chess-pos.el | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/chess-pos.el b/chess-pos.el index 403b8ee..5cc463f 100644 --- a/chess-pos.el +++ b/chess-pos.el @@ -649,7 +649,8 @@ trying to move a blank square." (throw 'in-check t) (push candidate candidates))) -(defun chess-search-position (position target piece &optional check-only) +(defun chess-search-position (position target piece &optional + check-only no-castling) "Look on POSITION from TARGET for a PIECE that can move there. This routine looks along legal paths of movement for PIECE. It differs from `chess-pos-search', which is a more basic function that @@ -749,7 +750,7 @@ indices which indicate where a piece may have moved from." (apply 'chess-incr-index pos dir))))) ;; test whether the rook can move to the target by castling - (if (= test-piece ?R) + (if (and (= test-piece ?R) (not no-castling)) (let (rook) (if (and (equal target (chess-rf-to-index (if color 7 0) 5)) (setq rook (chess-pos-can-castle position @@ -777,12 +778,13 @@ indices which indicate where a piece may have moved from." (setq dirs (cdr dirs)))) ;; test whether the king can move to the target by castling - (if (or (and (equal target (chess-rf-to-index (if color 7 0) 6)) - (chess-pos-can-castle position (if color ?K ?k)) - (chess-ply-castling-changes position)) - (and (equal target (chess-rf-to-index (if color 7 0) 2)) - (chess-pos-can-castle position (if color ?Q ?q)) - (chess-ply-castling-changes position t))) + (if (and (not no-castling) + (or (and (equal target (chess-rf-to-index (if color 7 0) 6)) + (chess-pos-can-castle position (if color ?K ?k)) + (chess-ply-castling-changes position)) + (and (equal target (chess-rf-to-index (if color 7 0) 2)) + (chess-pos-can-castle position (if color ?Q ?q)) + (chess-ply-castling-changes position t)))) (chess--add-candidate (chess-pos-king-index position color))))) ;; the knight is a zesty little piece; there may be more than |