Roman Numerals. On the one hand, it’s hard to understand why anyone cares anymore. Some, like the late Rich Stevens considered them an anachronistic barbarism and labeled his books “Volume 1, 2, …” rather than the more conventional “Volume I, II, …”. Others continue to label volumes with the conventional Roman numerals and, of course, there’s all those buildings with their erection date labeled, of course, with Roman numerals on their facade.
It used to be that everyone learned how to read and write Roman numerals in School but, according to a teenager of my acquaintance, that’s no longer the case. Were it not for their ubiquitousness on the front of buildings and multivolume books, I’d be happy so see them disappear from our milieu but for the time being, it seems useful to be able to at least read them.
Really, it’s not much of an effort. There are only 7 symbols and they are combined in a regular way to form all the numbers that we’re apt to see today. It’s true that there’s more than one way to form some numbers but all of them are easy to decipher. It’s hard to see how anyone with more than a couple of brain cells to rub together would take more than 15 minutes to completely master the system.
Still, Common Lisp is famous for having functions to convert between Arabic and Roman numerals. That’s less true for Emacs Lisp but there are, apparently, some functions spread across a couple of packages to do the job. Charles Choi doesn’t like that so he wrote a package to provide the capability in a single package.
I suppose, if you squint hard enough, you can imagine cases where you might want to do this sort of thing programmatically but, really, it’s mostly too easy to do manually to need a function. Still, if you do have a need to do this programmatically, Choi has got you covered.