Cleaning up the loop naming in rotate_nested_vectors

Author: upjohnc

lightning-invoice/src/utils.rs

@@ -276,7 +276,6 @@ where
 			});
 
 		phantom_hints.push(route_hints);
-
 	}
 
 	// We have one vector per real node involved in creating the phantom invoice. To distribute
@@ -289,19 +288,18 @@ where
 /// Draw items iteratively from multiple nested vectors.  The items are retrieved by index and
 /// rotates through the vectors - first the zero index then the first index then second index, etc.
 fn rotate_nested_vectors<T, I: Iterator<Item = T>>(mut vecs: Vec<I>) -> impl Iterator<Item = T> {
-	let mut idx = 0;
+	let mut iterations = 0;
 
 	core::iter::from_fn(move || {
 		let mut exhausted_vectors = 0;
 		loop {
 			if vecs.is_empty() {
 				return None;
 			}
-			let next_idx = idx % vecs.len();
-			let hint_opt = vecs[next_idx].next();
-			idx += 1;
-			if let Some(hint) = hint_opt {
-				return Some(hint);
+			let next_idx = iterations % vecs.len();
+			iterations += 1;
+			if let Some(item) = vecs[next_idx].next() {
+				return Some(item);
 			}
 			// exhausted_vectors increase when the "next_idx" vector is exhausted
 			exhausted_vectors += 1;
@@ -1915,7 +1913,6 @@ mod test {
 		}
 	}
 
-
 	#[test]
 	fn test_zip_nested_vectors() {
 		// two nested vectors