Extension Proposal: Intercept

I'm working on an extension to add the ability to intercept function calls (and eventually method calls) in PHP and execute user-space code before/after the call. Currently I've got a working prototype and I've bounced the idea off the internals list with no objections thus far. I can't decide whether to call it "intercept" or "call_intercept". Any input is appreciated. One question: Should I use PECL_Gen to create the extension, or stick with ext_skel? - Gabriel =====