> For extra agony, try using the iedit emacs extension to change a symbol throughout the file. It's extremely laggy. The buffer data structure that Emacs uses

> For extra agony, try using the iedit emacs extension to change a symbol throughout the file. It's extremely laggy. The buffer data structure that Emacs uses -- a gap buffer -- has a fundamental incompatibility with making multiple "simultaneous" edits. Any attempt to do it in Elisp is going to be hacking (in a good way) around that. Performance will definitely degrade for a large buffer, because it has copy around most of the buffer contents for each edit. Full explanation here if you're curious: https://nullprogram.com/blog/2017/09/07/ https://nullprogram.com/blog/2017/09/07/