[fouc]

Great blog post.. First time I've been sold on Rust, sounds like it's got some great features. Maybe I just had to hear about it from a Ruby dev. :)

Typos in the article: "slimed down", "you code could"

Is "needle_length = needle.length" actually necessary? I thought repeated calls would be zero cost, but I'm guessing I'm wrong.

[kibwen]

If Ruby is anything like Python, nonlocal name lookups in loops can indeed be performance bottlenecks.