When I go back to my old map/zip/method-chaining Rust code from a year or two ago, I regret doing so and wish I had written code as imperative sequential operat

When I go back to my old map/zip/method-chaining Rust code from a year or two ago, I regret doing so and wish I had written code as imperative sequential operations (looping over numeric ranges and container items, branching, and matching) like I write and understand today.