Sun May 11 14:14:23 CEST 2008

inheritance for state threading

What is the practical reason for using threaded state instead of real
state? to simplify composition of code generators, primarily to allow
multiple applications without causing side-effects. It makes the life
of the optimization implementer easier.

This is probably a spot where multiple inheritance might be
appropriate: if there's no clear hierarchy to state extensions,
forcing one might not be a good idea.