diff options
Diffstat (limited to 'chess-pos.el')
| -rw-r--r-- | chess-pos.el | 33 |
1 files changed, 16 insertions, 17 deletions
diff --git a/chess-pos.el b/chess-pos.el index deedd48..c8321d2 100644 --- a/chess-pos.el +++ b/chess-pos.el @@ -913,11 +913,9 @@ If NO-CASTLING is non-nil, do not consider castling moves." chess-black-can-slide-to) target)) (while ray (let ((pos-piece (chess-pos-piece position (caar ray)))) - (if (memq pos-piece (cdar ray)) - (progn - (chess--add-candidate (caar ray)) - (setq ray nil)) - (setq ray (when (eq pos-piece ? ) (cdr ray))))))) + (setq ray (cond ((memq pos-piece (cdar ray)) + (chess--add-candidate (caar ray)) nil) + ((eq pos-piece ? ) (cdr ray))))))) ;; test for knights and pawns (dolist (p (if piece '(?P ?N) '(?p ?n))) @@ -949,15 +947,15 @@ If NO-CASTLING is non-nil, do not consider castling moves." ;; pawn movement, which is diagonal 1 when taking, but forward ;; 1 or 2 when moving (the most complex piece, actually) - ((= test-piece ?P) + ((eq test-piece ?P) (let ((p (chess-pos-piece position target)) (backward (if color chess-direction-south chess-direction-north))) - (if (if (= p ? ) + (if (if (eq p ? ) ;; check for en passant (and (= (chess-index-rank target) (if color 2 5)) (let ((ep (chess-pos-en-passant position))) (when ep - (= ep (chess-next-index target backward)))) + (= ep (funcall (if color #'+ #'-) target 8)))) (or (and (setq pos (chess-next-index target (if color chess-direction-southwest @@ -983,13 +981,14 @@ If NO-CASTLING is non-nil, do not consider castling moves." (chess-pos-piece-p position pos piece)) (chess--add-candidate pos))) (if (setq pos (chess-next-index target backward)) - (if (chess-pos-piece-p position pos piece) - (chess--add-candidate pos) - (if (and (chess-pos-piece-p position pos ? ) - (= (if color 4 3) (chess-index-rank target)) - (setq pos (chess-next-index pos backward)) - (chess-pos-piece-p position pos piece)) - (chess--add-candidate pos))))))) + (let ((pos-piece (chess-pos-piece position pos))) + (if (eq pos-piece piece) + (chess--add-candidate pos) + (if (and (eq pos-piece ? ) + (= (if color 4 3) (chess-index-rank target)) + (setq pos (funcall (if color #'+ #'-) pos 8)) + (chess-pos-piece-p position pos piece)) + (chess--add-candidate pos)))))))) ;; the rook, bishop and queen are the easiest; just look along ;; rank and file and/or diagonal for the nearest pieces! @@ -1084,13 +1083,13 @@ in check)." (cl-assert (> (length candidates) 0)) (let ((cand candidates) (piece (chess-pos-piece position (car candidates))) - other-piece en-passant-square last-cand king-pos) + (other-piece (chess-pos-piece position target)) + en-passant-square last-cand king-pos) (while cand (unwind-protect (progn ;; determine the resulting position (chess-pos-set-piece position (car cand) ? ) - (setq other-piece (chess-pos-piece position target)) (chess-pos-set-piece position target piece) (when (and (= piece (if color ?P ?p)) (let ((ep (chess-pos-en-passant position))) |