isValidDirection function

bool isValidDirection(
  1. Direction newDir,
  2. Direction dir
)

Implementation

bool isValidDirection(Direction newDir, Direction dir) {
  return newDir != dir && (newDir == Direction.up && dir != Direction.down) ||
      (newDir == Direction.down && dir != Direction.up) ||
      (newDir == Direction.left && dir != Direction.right) ||
      (newDir == Direction.right && dir != Direction.left);
}