add a section for slots inside definition

[sensestage]

To keep them in one place, rather than define them on the fly in different parts of the code.

~queries = [ ... ], // or ~signals, ~returns?
~attributes = [ ... ], 
~slots = [
    \didFree -> { "I'm done".postln; },
    \didPrepare -> { ~parser.play }
];

[sensestage]

But perhaps you actually want to define the actions on state changes only when other code is set up.

[eirikblekesaune]

The concept of slots is still in a conception where it represent callbacks to state changes. IMO the concept has to evolve into a more generic concept for us to make something out of it.