optimizations and bug fixes

1 files changed, 13 insertions, 8 deletions

diff --git a/chess-fen.el b/chess-fen.el
index 8dca4f6..b104f06 100644
--- a/chess-fen.el
+++ b/chess-fen.el
@@ -46,21 +46,24 @@
   (let ((i 0) (l (length fen))
 	(rank 0) (file 0) (c ?0)
 	(position (chess-pos-create t))
-	number)
-    (while (and (/= c ? ) (< i l))
+	error number)
+    (while (and (null error) (/= c ? ) (< i l))
       (setq c (aref fen i))
       (cond
        ((= c ?/)
 	(setq file 0 rank (1+ rank)))
        ((and (>= c ?1) (<= c ?9))
 	(setq file (+ file (- c ?0))))
-       ((/= c ? )
+       ((memq (upcase c) '(?K ?Q ?B ?N ?R ?P))
 	(chess-pos-set-piece position (chess-rf-to-index rank file) c)
-	(setq file (1+ file))))
+	(setq file (1+ file)))
+       (t (setq error t)))
       (setq i (1+ i)))
-    (chess-pos-set-side-to-move position (= (aref fen i) ?w))
+    (if (memq (aref fen i) '(?b ?w))
+	(chess-pos-set-side-to-move position (= (aref fen i) ?w))
+      (setq error t))
     (setq i (+ i 2) number nil)
-    (while (< i l)
+    (while (and (null error) (< i l))
       (setq c (aref fen i))
       (cond
        ((= c ?K) (chess-pos-set-can-castle position ?K t))
@@ -70,9 +73,11 @@
        ((and (>= c ?a) (<= c ?h))
 	(chess-pos-set-en-passant position (chess-coord-to-index
 					    (substring fen i (+ i 2))))
-	(setq i (1+ i))))
+	(setq i (1+ i)))
+       (t (setq error t)))
       (setq i (1+ i)))
-    position))
+    (unless error
+      position)))
 
 (defun chess-pos-to-fen (position &optional full)
   "Convert a chess POSITION to FEN-like notation.