For this design they just replace the pointer to the symbol in the
method's literal frame with a pointer to an object which then points to
that symbol and which also adds the needed information (class / compiled
I plan to browse the Exupery sources to see what its PICs are like, but
for now I just took a quick look at the various presentations that are
available and saw a thread on this list from October 2008. My impression
so far is that PICs are short code fragments with pointers to classes
and which are treated mostly like native methods.
If there are more details anywhere, it would be very helpful.