-#include "stdint.h"
#include "yx_uint16.h"
extern char yx_uint16_cmp (struct yx_uint16 a, struct yx_uint16 b) {
if (a.y == b.y && a.x == b.x) return 1;
else return 0; }
+extern struct yx_uint16 mv_yx_in_dir (char d, struct yx_uint16 yx) {
+// Return yx coordinates one step to the direction d of yx.
+ if (d == NORTH) yx.y--;
+ else if (d == EAST) yx.x++;
+ else if (d == SOUTH) yx.y++;
+ else if (d == WEST) yx.x--;
+ return yx; }
+