> the Lua authors published a paper many years before PHP got closures (possibly more than a decade before?) that explained their technique for implementing pro

> the Lua authors published a paper many years before PHP got closures (possibly more than a decade before?) that explained their technique for implementing proper, quirk-free lexical closures in just a handful of lines of C-like example code That sounds interesting, do you have a link to that paper? (I couldn't find it with a quick Google.)