A few folks suggested I try lazy enumerables to make my extremely chained style practical. I was curious about the actual costs of my style, so it’s time for lies and microbenchmarks! Turns out naively chaining a bunch of maps together isn’t very costly, so go with that to start.

Lazy came in much slower than consolidating the logic in one loop or chaining them without lazy. I thought, I must not have used lazy properly. Turns out, I’m probably showing that laziness isn’t well suited to iterating over collections without an early termination clause (e.g. a take, first, or find) and that for small collections (like an 87-line /etc/passwd), the cost of the lazy plumbing can noticeably outweigh the work done inside the loops. Thanks to Rein Heinrich for talking me to the bottom line!