For quite a while now I've been thinking about how useful a macro system could be in Perl. Ever since I finished reading Paul Graham's "On Lisp"
I've been certain. A well designed macro system would provide Perl programmers with optimization and code-generation powers at least an order of magnitude beyond what we have now.
The question, I believe, is one of design. What kind of a macro system suites Perl best? Obviously CPP is far too rigid. A system based on Filters is possible but it seems to me that dealing with Perl at the textual level is not necessarily the right way to go. On the other hand, a macro system that worked at the B:: level might be too hard to use.
So, I put it to the Monks - what kind of a macro system should Perl have? What are the most important features of a macro system and what can we do without?