> The functional approach is obviously cleaner and clearer for per-function-call parameterization, while the OO based approach is cleaner and clearer (unsurpris

> The functional approach is obviously cleaner and clearer for per-function-call parameterization, while the OO based approach is cleaner and clearer (unsurprisingly) for per-object or per-class parameterization. Having programmed heavily in both functional and OO styles, I personally find the opposite to be true. I find the functional approach to be cleaner and clearer in general. I particularly find template methods to be egregious because when you override a callback method, it's not immediately clear that what is being overridden is even a callback. Additionally, in programming languages that don't require an "override" declaration to override a method, it's not immediately clear that a method is being overridden, rather than just a new method being defined. And with multiple inheritance, this is even worse, because you might have to look in a zillion different other places to even determine this. > Using functional idioms for categorical parameterization either involves recreating class-oriented structures or conceals (and makes less DRY) the categorical nature of the parameterization behind per-call overrides. Recreating class-oriented structures? There's no work to do this, and there's nothing non-DRY about it. E.g., see the book JavaScript the good parts. It shows you how to define objects using either JavaScript's OO-based mechanism or using a Scheme-like functional approach. The functional approach is elegant and popular.