[specialist]

Thanks for sharing Zed Shaw's wisdom. I will chew on it.

"Abstraction is used to reduce complexity."

My taxonomy: Abstractions hide complexity (bad), mental models simplify (good).

I'll consider how Shaw's worldview relates to my own.

"Indirection is used to reduce coupling or dependence."

My taxonomy: Indirection defers a design choice. A la Design Patterns.

One of my heuristics, when weighing alternatives, is to pick the design with the shallower stack depth. I'm just not smart enough to keep track of many moving parts.

FWIW: I see the 'isPrime' function more as macro (shorthand) done for legibility than a potent future cutpoint (eg Strategy).