Iterator

Core Idea

An iterator walks through data one item at a time while letting you compose transformations, filters, and reductions. In Rust the Iterator trait powers a shared vocabulary of methods such as map, filter, collect, and sum.

Why It Matters Here

Mathbong uses iterators as the hub for declarative data processing, collection traversal, and pairing with closures. They are not just a shorter loop style, but a way to read ownership and data flow more clearly.