Maximally Powerful, Minimally Useful

It’s well known that there is a trade-off in language and systems design between expressiveness and analyzability. That is, the more expressive a language or system is, the less we can reason about it, and vice versa. The more capable the system, the less comprehensible it is.

This principle is very widely applicable, and it’s a useful thing to keep in mind when designing languages and libraries. A practical implication of being aware of this principle is that we always make components exactly...