Clean up and unify exercises

exercises/18_iterators/iterators1.rs

@@ -1,24 +1,28 @@
-// iterators1.rs
-//
 // When performing operations on elements within a collection, iterators are
 // essential. This module helps you get familiar with the structure of using an
 // iterator and how to go through elements within an iterable collection.
 //
 // Make me compile by filling in the `???`s
-//
-// Execute `rustlings hint iterators1` or use the `hint` watch subcommand for a
-// hint.
 
-#[test]
 fn main() {
-    let my_fav_fruits = vec!["banana", "custard apple", "avocado", "peach", "raspberry"];
-
-    let mut my_iterable_fav_fruits = ???;   // TODO: Step 1
-
-    assert_eq!(my_iterable_fav_fruits.next(), Some(&"banana"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 2
-    assert_eq!(my_iterable_fav_fruits.next(), Some(&"avocado"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 3
-    assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 4
+    // You can optionally experiment here.
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn iterators() {
+        let my_fav_fruits = vec!["banana", "custard apple", "avocado", "peach", "raspberry"];
+
+        let mut my_iterable_fav_fruits = ???;   // TODO: Step 1
+
+        assert_eq!(my_iterable_fav_fruits.next(), Some(&"banana"));
+        assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 2
+        assert_eq!(my_iterable_fav_fruits.next(), Some(&"avocado"));
+        assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 3
+        assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry"));
+        assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 4
+    }
 }

exercises/18_iterators/iterators2.rs

@@ -1,10 +1,5 @@
-// iterators2.rs
-//
 // In this exercise, you'll learn some of the unique advantages that iterators
 // can offer. Follow the steps to complete the exercise.
-//
-// Execute `rustlings hint iterators2` or use the `hint` watch subcommand for a
-// hint.
 
 // Step 1.
 // Complete the `capitalize_first` function.

exercises/18_iterators/iterators3.rs

@@ -1,13 +1,8 @@
-// iterators3.rs
-//
 // This is a bigger exercise than most of the others! You can do it! Here is
 // your mission, should you choose to accept it:
 // 1. Complete the divide function to get the first four tests to pass.
 // 2. Get the remaining tests to pass by completing the result_with_list and
 //    list_of_results functions.
-//
-// Execute `rustlings hint iterators3` or use the `hint` watch subcommand for a
-// hint.
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum DivisionError {

exercises/18_iterators/iterators4.rs

@@ -1,8 +1,3 @@
-// iterators4.rs
-//
-// Execute `rustlings hint iterators4` or use the `hint` watch subcommand for a
-// hint.
-
 pub fn factorial(num: u64) -> u64 {
     // Complete this function to return the factorial of num
     // Do not use:
@@ -12,7 +7,6 @@ pub fn factorial(num: u64) -> u64 {
     // - additional variables
     // For an extra challenge, don't use:
     // - recursion
-    // Execute `rustlings hint iterators4` for hints.
 }
 
 fn main() {

exercises/18_iterators/iterators5.rs

@@ -1,5 +1,3 @@
-// iterators5.rs
-//
 // Let's define a simple model to track Rustlings exercise progress. Progress
 // will be modelled using a hash map. The name of the exercise is the key and
 // the progress is the value. Two counting functions were created to count the
@@ -7,9 +5,6 @@
 // functionality using iterators. Try not to use imperative loops (for, while).
 // Only the two iterator methods (count_iterator and count_collection_iterator)
 // need to be modified.
-//
-// Execute `rustlings hint iterators5` or use the `hint` watch subcommand for a
-// hint.
 
 use std::collections::HashMap;