Being a self-described programming-language programming language is an ambitious goal. To preserve predictability while permitting linguistic extension, Racket comes equipped with a module system carefully designed to accommodate composable and compilable macros. One of the module system’s foundational properties is its separate compilation guarantee, which imposes strong, unbreakable limits on the extent of compile-time side-effects. It is essential for preserving static guarantees in a world where compiling a module can execute arbitrary code, and despite numerous unsafe trapdoors that have crept into Racket since its birth as PLT Scheme, none have ever given the programmer the ability to cheat it.

Yet today, in this blog post, we’re going to do exactly that.

source: L