- port tests from Python's construct (construct/construct/protocols/application and construct/tests) and P5's Data::ParseBinary
- remove requirement to Array[Inner].new for arrays
- polish up `indirect-type` and/or add alternatives?
- polish up trait naming and return values
- endianness!
- int64/uint64 (currently weird in rakudo)
- custom bigint code for int128 and beyond (Int with user-specified bit-width)
- use something other than experimental pack to pack/unpack
- sub-byte data structures?
- parse from files/streams
