travisathougies is not alone on that. Every one of us functional programmers worth their salt will consider a sequence of transformations from one state to the next as a functional program, as long as there are no side effects outside the current function that may transform state in ways that aren't declared in the types of the input and return values (which would break the referential transparency).

Functional Reactive programming (i.e. combining functions over streams of mutating objects) is essentially that, and it's a pure functional paradigm, quite popular in front-end web development (and I hear it's even creeping its way into the back-end).