IMHO, do all you want on (A) "declarative code" and (B) "find the right abstraction—one that will make it easy to extend the problem" and I will applaud. Inde

IMHO, do all you want on (A) "declarative code" and (B) "find the right abstraction—one that will make it easy to extend the problem" and I will applaud. Indeed, as I entered grad school in applied math and had a good career going in software, two profs getting ready to teach a computing course asked what advice I would give. I responded with something like your (B). Also for (A), at times I tried to write code that would have some algebraic properties: E.g., as I was writing various sorting routines, routines to invert a permutation, to apply a permutation to an array, working with the fast Fourier transform, there were, of course for these topics, some cases where could regard calling one of the routines as something like an operator in parts of math/physics, get new operators by composing the other operators, and, then, saying when some of the operators were equal to some of the others,, net, nothing, or invert another one. I got some such before I got back to just get it done. But at this point, IMHO, for all can do on (A), (B), etc., my view is that the crucial part is missing: I urge to do all you can on (A), (B), etc. and then just take the attitude that the code doesn't mean anything at all, is just gibberish, and then get the important meaning by documentation in a natural language, e.g., English. E.g., in a physics text F = ma has with it one or more whole chapters of well written natural language explaining what the heck that equation and its symbols mean. We do not leave the math by itself as self-documenting, self-evident, clear, or any such thing. Then, write the documentation so well that, if had to select and keep just one of the code and the documentation, then definitely leap to keep the documentation: If the documentation is good, then can reconstruct the code fairly easily. Without the documentation, understanding the code well enough to reconstruct the documentation tends to be a really big puzzle problem and likely in principle impossible. Bluntly, knowledge and meaning are communicated in natural language. E.g., well written pure math is in complete sentences.