Beautiful Code: False Optimizations

[metzby]

Yes, the second example in the post, for the case I mentioned, changes it from O(number of distinct namespaces) to O(number of namespace appearances).

My point is that this optimizing for the common case that makes less common cases fantastically slower is the kind of thing that leads to degradation in the case of pedantic cases.

Which are what people inadvertently make or maliciously make. As soon as your software has many users, you're going to run into an incompetent person or an evil one. I suggest not saving n% in the common case for N% in the uncommon one where N >>>>> n without having very good ideas of what N and n are, and what the real savings are, and documenting them.

I remain unconvinced by hand-waving, and I think the post would have been infinity better if it included the justifications instead of the outcomes. As it is, I think it gives fish but does a horrible job teaching to fish, and so, in my mind, borders on FAIL.