I replaced the Ustring functions with the basic byte-based functions, because processing was really slow. The basic functions will work for UTF-8 provided certain conditions are met, which are described in wikt:WT:LUA#Patterns. (The patternIsSimple function in ustring.lua is too conservative.) I confirmed that the output was the same by editing WP:SB with the "before" and "after" versions of the output. No diff was generated. Now the processing time is a fiftieth of what it was. — Eru·tuon 21:44, 5 November 2017 (UTC)[reply]