It's not a problem that comes up that often, to be fair. Many of the cases where you think you'd need to split a string like that, you have some library doing the work for you. One of the main purposes is to figure out where valid cursor locations are in text editors... but in JavaScript, you just put a text field in your web page and let the browser do the heavy lifting. Same with text rendering... hand it off to a library which does the right thing.