gates – Support for writing modular and customisable code

The pack­age pro­vides the means of writ­ing code in a mod­u­lar fash­ion: big macros or func­tions are di­vided into small chunks (called gates) with names, which can be ex­ter­nally con­trolled (e.g. they can be dis­abled, sub­jected to con­di­tion­als, loops...) and/or aug­mented with new chunks.
Thus com­plex code may eas­ily be cus­tomised with­out hav­ing to rewrite it, or even un­der­stand its im­ple­men­ta­tion: the be­hav­ior of ex­ist­ing gates can be mod­i­fied, and new ones can be added, with­out en­dan­ger­ing the whole de­sign. This al­lows code to be hacked in ways the orig­i­nal au­thors might have never en­vi­sioned.
The gates pack­age is im­ple­mented in­de­pen­dently for both TeX and Lua. The TeX im­ple­men­ta­tion, run­ning in any cur­rent en­vi­ron­ment, re­quires the texapi pack­age, whereas the Lua ver­sion can be run with any Lua in­ter­preter, not just LuaTeX.