captureChecker :: Board -> Square -> [ Move ]
captureChecker b checker =
  let pt = fromJust $ pieceAt b checker
  in  sortBy captureHeuristics
      $ map (capturedPiece .~ Just pt) $ captureTo b checker
captureChecker :: Board -> Square -> [ Move ]
captureChecker b checker =
  let pt = fromJust $ pieceAt b checker
  in  sortBy captureHeuristics
      $ map (capturedPiece .~ Just pt) $ captureTo b checker
captureChecker b checker =
  let pt = fromJust $ pieceAt b checker
  in  sortBy captureHeuristics
      $ map (capturedPiece .~ Just pt) $ captureTo b checker