Hi list, thanks very much for all your help. I realized that i can use the _outlet and _outconnect structures to get the successors of an object. As the struct definitions are hidden in a *.c-file and not publicly declared in a header file: can they be subject to severe changes in a future version of pd? For the moment i'm quite satisfied with this solution - i only need top-down signal flow (for spectral data, btw.), so i do not need to know the predecessors of an object.
greetings, Thomas