[ List Earliest Comments Only For Pages | Games | Rated Pages | Rated Games | Subjects of Discussion ]
Check out Janggi (Korean Chess), our featured variant for December, 2024.
Check out Janggi (Korean Chess), our featured variant for December, 2024.
I meant: would it be possible to clear a piece from an occupied square by 'free-dropping' an empty square on top of it (e.g. by entering @-f1). And come to think of it: the code that checked the promotion just looks whether the piece at 'dest' after the move is still 'moved'. But what if someone would have really entered the typo R a1-f1; Q-a1; ? Presumably that would leave a Rook at f1, so you would not catch that. Would it have free-dropped a Queen at a1 after the Rook moved ('fertile Rook')? Or is there some intrinsic test on the input that enforces that promotion moves can only free-drop on dest? (Probably not, because that would make the mention of any square redundant.) Because the promotion move doesn't set any variable similar to dest, it isn't clear to me how you could test whether free-drops go to an allowed square.
BTW, some variants allow only promotion of a piece that was lost before, and in those it can make sense to collect the captured pieces in a separate area (without color flip), and move them from there to effect promotion.
'Locust capture' in general is capturing a piece on a square you are not moving to. Like capture in Checkers, or e.p. capture in orthodox Chess. But in these two cases the capture is an implicit side effect of the move. So the Pawn subroutine can recognize e.p. capture, and automatically remove the victim, without the user having to enter any additional moves. (I guess promotion in Shatranj or Makruk could also be handled that way.) The problem arises when the capture would be optional. E.g. in Odin's Rune Chess a Forest Ox moves and captures like a Knight, but can in addition remove one other enemy piece adjacent to its destination. So there you would somehow have to indicate whether you want to do that, and if so, which of the (possibly eight) adjacent pieces. F c3-e4; @-d5; could be a suitable notation for that, if such a thing were allowed.