As a best-selling author, I invite you to explore my books on Amazon . Don't forget to follow me on Medium and show your support. Thank you! Your support means the world! I remember when I first learned to loop over a list of numbers. I wrote a for loop with a counter, checked a condition, added things up manually. It worked, but I could feel the friction. Every time I wanted to change how I processed data, I had to rewrite the loop. Then I found iterators in Rust, and everything clicked. They are not just a tool for looping. They are a way to describe what you want to do, not how to do it. And the beauty is that the compiler turns that description into machine code that runs just as fast as the hand‑written loop you would have written yourself. Maybe faster. Let me walk you through this from the ground up. Suppose you have a list of sensor readings. Some are invalid – negative values.…