Thanks for the idea of looking at @+ and friend; $1 - $9 always bugged me too (though after having spent a little time hacking Forth, I flinch a little at any function that takes more than three parameters :-) , so the usefullness of actually having those extra parameters is lessened somewhat for me).

I agree on factoring out the common, rendering code. I've done that with my own projects, and put it into a utility REST::Dispatchable (not Renderer; I just came up with that name last night) class; I didn't include it here because I thought it might detract from the main subject.