1 files changed, 35 insertions, 21 deletions

diff --git a/include/ptn.c b/include/ptn.c
index 58648b9..1a333d7 100644
--- a/include/ptn.c
+++ b/include/ptn.c
@@ -5,26 +5,28 @@
 
 enum PTN_PARSE_RESULT
 parse_place(const uint8_t board_size, char *ptn,
-            uint8_t *location, enum STONE_VARIANT *stone) {
+            uint8_t *out_location, enum STONE_VARIANT *out_stone) {
+
+  if (board_size < 5 || board_size > 6) return PTN_INVALID;
 
   ASSERT_NONEMPTY;
 
-  *stone = STONE_FLAT;
+  *out_stone = STONE_FLAT;
   switch (*ptn) {
-    case 'C' : { ptn++; *stone = STONE_CAPSTONE; break; };
-    case 'S' : { ptn++; *stone = STONE_STANDING; break; };
+    case 'C' : { ptn++; *out_stone = STONE_CAPSTONE; break; };
+    case 'S' : { ptn++; *out_stone = STONE_STANDING; break; };
     case 'F' : { ptn++; break; };
   }
 
   ASSERT_MORE;
 
   if ( (*ptn < 'a') || (*ptn > '`' + board_size) ) return PTN_INVALID;
-  *location = *ptn - 'a';
+  *out_location = *ptn - 'a';
 
   ptn++; ASSERT_MORE;
 
   if ( (*ptn < '1') || (*ptn > board_size + '0') ) return PTN_INVALID;
-  *location += board_size * (*ptn - '1');
+  *out_location += board_size * (*ptn - '1');
 
   if (*(++ptn) > 0) return PTN_INVALID;
 
@@ -33,8 +35,10 @@ parse_place(const uint8_t board_size, char *ptn,
 
 enum PTN_PARSE_RESULT
 parse_move(const uint8_t board_size, char *ptn,
-           uint8_t *location, enum MOVE_DIRECTION *direction,
-           uint8_t *steps, uint8_t drops[5]) {
+           uint8_t *out_location, enum MOVE_DIRECTION *out_direction,
+           uint8_t *out_steps, uint8_t out_drops[5]) {
+
+  if (board_size < 5 || board_size > 6) return PTN_INVALID;
 
   ASSERT_NONEMPTY;
 
@@ -46,37 +50,47 @@ parse_move(const uint8_t board_size, char *ptn,
   }
 
   if ( (*ptn < 'a') || (*ptn > '`' + board_size) ) return PTN_INVALID;
-  *location = *ptn - 'a';
+  *out_location = *ptn - 'a';
 
   ptn++; ASSERT_MORE;
 
   if ( (*ptn < '1') || (*ptn > board_size + '0') ) return PTN_INVALID;
-  *location += board_size * (*ptn - '1');
+  *out_location += board_size * (*ptn - '1');
 
   ptn++; ASSERT_MORE;
 
   switch (*ptn) {
-    case '+': { *direction = M_UP;    break; }
-    case '-': { *direction = M_DOWN;  break; }
-    case '<': { *direction = M_LEFT;  break; }
-    case '>': { *direction = M_RIGHT; break; }
+    case '+': { *out_direction = M_UP;    break; }
+    case '-': { *out_direction = M_DOWN;  break; }
+    case '<': { *out_direction = M_LEFT;  break; }
+    case '>': { *out_direction = M_RIGHT; break; }
     default: return PTN_INVALID;
   }
 
-  ptn++; ASSERT_MORE;
+  ptn++;
+  // Handle the case '<column><row><direction>' as
+  // '1<column><row><direction>1' for convenience
+  if (*ptn == 0) {
+    if (picked_up == 0) {
+      *out_steps = 1;
+      out_drops[0] = 1;
+    } else {
+      return PTN_INVALID;
+    }
+  }
 
-  *steps = 0;
+  *out_steps = 0;
   uint8_t total = 0;
   while (*ptn) {
       if ( (*ptn < '1') || (*ptn > '0' + board_size) ) {
         return PTN_INVALID;
       }
-      // TODO: Correct?
-      if ( (*steps >= board_size) && *ptn) return PTN_INVALID;
 
-      drops[*steps] = *ptn - '0';
-      total += drops[*steps];
-      *steps += 1;
+      if ( (*out_steps + 1 >= board_size) && *ptn) return PTN_INVALID;
+
+      out_drops[*out_steps] = *ptn - '0';
+      total += out_drops[*out_steps];
+      *out_steps += 1;
       ptn++;
   }