The digits crate is a linked list implementation of a score card flipper. But
in this case it's with any characters you want and you can enumerate through
possibilities beyond the numeric limits intrinsic in basic numerc types like
Primary use case would be brute forcing character sequences.
This struct acts similar to a full number with a custom numeric character base. But the underlying implementation is a linked list where all the methods recurse as far as need to to implement the operations.