Support cl-algebraic-data-type

[jsjolen]

https://github.com/tarballs-are-good/cl-algebraic-data-type

The cl-adt library compiles down to structs, we should be able to write a TEMPLATE form for defdata.

This is half a feature request, half a "I'll do it sometime".

What do you think about this idea? Just off the top of your head I mean :-)

[cosmos72]

Definitely interesting :-)