diff -r 6008840b859e -r 6a26114297a1 src/chess/pawn.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/chess/pawn.c	Mon Mar 31 11:16:32 2014 +0200
@@ -0,0 +1,97 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2014 Mike Becker. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "pawn.h"
+#include "rules.h"
+
+_Bool pawn_chkrules(Board board, Move *move) {
+    int8_t d = ((move->piece & COLOR_MASK) == WHITE ? -1 : 1);
+    
+    if (move->torow == (d < 0 ? 7 : 0)) {
+        if (move->promotion) {
+            uint8_t promopiece = move->promotion & PIECE_MASK;
+            if (!promopiece || promopiece == PAWN || promopiece == KING) {
+                return 0;
+            }
+        } else {
+            return 0;
+        }
+    } else {
+        if (move->promotion) {
+            return 0;
+        }
+    }
+    
+    if (move->capture) {
+        if (move->fromrow == move->torow + d && (
+            move->fromfile == move->tofile + 1 ||
+            move->fromfile == move->tofile - 1)) {
+
+            return mdst(board,move)
+                || (board[move->fromrow][move->tofile] & ENPASSANT_THREAT);
+        } else {
+            return 0;
+        }
+    } else {
+        if (move->fromfile == move->tofile) {
+            return (move->fromrow == move->torow + d) ||
+                (move->fromrow == (d < 0 ? 1 : 6) && /* advanced first move */
+                move->fromrow == move->torow + d*2);
+        } else {
+            return 0;
+        }
+    }
+}
+
+_Bool pawn_isblocked(Board board, Move *move) {
+    return mdst(board,move) && !move->capture;
+}
+
+int pawn_getlocation(Board board, Move *move) {
+    int8_t d = ((move->piece & COLOR_MASK) == WHITE ? -1 : 1);
+    
+    if (move->fromfile == POS_UNSPECIFIED) {
+        move->fromfile = move->tofile;
+    }
+    move->fromrow = move->torow + d;
+    if (move->fromrow > 6) {
+        return INVALID_POSITION;
+    } else {
+        /* advanced first move */
+        if (move->fromrow == (d < 0 ? 2 : 5) &&
+            msrc(board,move) != move->piece) {
+
+            move->fromrow += d;
+            if (move->fromrow > 6) {
+                return INVALID_POSITION;
+            }
+        }
+    }
+    return VALID_MOVE_SYNTAX;
+}