Comment by lgessler

Essentially, yes, but in a way that sounds more careful than what you saw in that Fortran program. If it absolutely has to be stateful, like with a db connection for example, then there's no getting around that, but what you can do is (1) not bury it in a bunch of stateful objects that didn't have to be stateful, which can cause cascading errors when either one of them misbehaves and also makes it difficult to isolate any one stateful component for testing or re-use, and (2) use special wrappers around it that will make the statefulness easier to deal with. (For examples of (2), see Clojure atoms and the Clojure library mount: https://github.com/tolitius/mount )