Hi Graham!
Now, if we wish to make a special version of a UGen by inheritance alone, we can already do this. By extending the UGen class you wish to use, you should be able to add or overwrite methods or variables.
But what about composition? What if we wish to chain together several already useful into some compound effects object (for brevity's sake, perhaps)?
You are definitely right. We've actually been planning something for this very purpose. In short, one should be able to define a UGen and use it as you would any other (e.g. in terms of =>), but you can't yet in the current version.
So, to get the behavior we are going for in the language, it seems like the most direct way would be to specify an in and out reference for the correct UGens like so:
public class StdFx extends UGen {
//preconstructor PoleZero pz => NRev nrev => pan2 p;
pz @=> this.in; p @=> this.out;
//other stuff ... }
So, will this kind of behavior be possible within the language as currently designed? I don't know.
This is certainly a (good) possibility. We are still toying with different ways to do this cleanly.
So, what's the plan for supporting this?
No specific date yet. It's been planned from since the beginning, but not much has been done yet. Perhaps this is a good time to iron it out, especially if there is demand. One potential roadblock is the unfinished garbage collector - this may add features to classes (like a finalize() method and others) and could affect how we deal with UGen's on connect and disconnect. Thank you for your thoughtful analysis of this feature. I fully agree with you. We'll priority boost this. Best wishes, Ge!