folding with strings

"Folding with strings" can refer to a few different things, so I'll try to provide a few different answers depending on what you're looking for!

If you're referring to the concept of "folding" in functional programming, that typically involves taking a collection (like a list or array) and reducing it down to a single value. This can be done by repeatedly applying a function to the elements of the collection, "folding" them together until there's only one element left. For example, if you had a list of numbers and wanted to find their sum, you could use the fold function to repeatedly add them together:

let numbers = [1, 2, 3, 4, 5];
let sum = numbers.fold(0, |acc, x| acc + x);
// sum is now 15

However, I'm not sure how this relates to the "strings" part of your question! If you could provide more context or clarify what you're looking for, I might be able to give a more specific answer.