Are there good docs or even a tutorial on how to enable a class
to be prettyprinted with pp?

It looks like the sort of thing I could figure out in 5 or 6 hours
of experimentation. I'd rather not spend those if I can help it.

I did read this link, which is a reference:
http://cvs.m17n.org/~akr/pp/pp.html

It contains among other things the tantalizing entry:

   "To define your customized pretty printing function for your
    class, redefine a method pretty_print(pp) in the class. It
    takes an argument pp which is an instance of the class PP.
    The method should use PP#text, PP#breakable, PP#nest, PP#group
    and PP#pp to print the object."

But I don't grasp the details yet.


Hal