consider a game featuring both a joker and an orphan
Yeow. Just as a practical matter, a game with both a Joker and an Orphan is unlikely to ever be supported by ChessV, and that probably goes for most any universal chess engine that wasn't built specifically for that.
ChessV has fundamental movements that are handled natively by the internal move generator, but some capabilities that you would like to be intrinsic to the piece itself are implemented by special Rules that are plugged into the game. For example, the internal move generator does not understand capture-by-advance. So the Advancer in Butterfly Chess gets this capability via the CaptureByAdvanceRule. The ImitatorRule doesn't "know" anything about the CaptureByAdvanceRule, so if you drop a Joker into Butterfly Chess, it will not be able to imitate the Advancer's power to capture by advance. This is unfortunate, but it is just a practical reality. In order for ChessV to do everything that it does as well as it does, and without bugs, some functions need to be encapsulated in a strict separation-of-concerns.
Besides, if we did contemplate a game with both of these pieces, I bet we could come up with a LOT of complex corner-cases where it isn't clear how they should interact anyway. (But that's just a hunch.)
Yeow. Just as a practical matter, a game with both a Joker and an Orphan is unlikely to ever be supported by ChessV, and that probably goes for most any universal chess engine that wasn't built specifically for that.
ChessV has fundamental movements that are handled natively by the internal move generator, but some capabilities that you would like to be intrinsic to the piece itself are implemented by special Rules that are plugged into the game. For example, the internal move generator does not understand capture-by-advance. So the Advancer in Butterfly Chess gets this capability via the CaptureByAdvanceRule. The ImitatorRule doesn't "know" anything about the CaptureByAdvanceRule, so if you drop a Joker into Butterfly Chess, it will not be able to imitate the Advancer's power to capture by advance. This is unfortunate, but it is just a practical reality. In order for ChessV to do everything that it does as well as it does, and without bugs, some functions need to be encapsulated in a strict separation-of-concerns.
Besides, if we did contemplate a game with both of these pieces, I bet we could come up with a LOT of complex corner-cases where it isn't clear how they should interact anyway. (But that's just a hunch.)