Add standard_library_types solutions

exercises/standard_library_types/arc1.rs

@@ -4,18 +4,17 @@
 // somewhere. Try not to create any copies of the `numbers` Vec!
 // Execute `rustlings hint arc1` for hints :)
 
-// I AM NOT DONE
-
 #![forbid(unused_imports)] // Do not change this, (or the next) line.
 use std::sync::Arc;
 use std::thread;
 
 fn main() {
     let numbers: Vec<_> = (0..100u32).collect();
-    let shared_numbers = // TODO
+    let shared_numbers = Arc::new(numbers);
     let mut joinhandles = Vec::new();
 
     for offset in 0..8 {
+        let child_numbers = Arc::clone(&shared_numbers);
         joinhandles.push(thread::spawn(move || {
             let mut i = offset;
             let mut sum = 0;

exercises/standard_library_types/box1.rs

@@ -16,11 +16,9 @@
 //
 // Execute `rustlings hint box1` for hints :)
 
-// I AM NOT DONE
-
 #[derive(PartialEq, Debug)]
 pub enum List {
-    Cons(i32, List),
+    Cons(String, Box<List>),
     Nil,
 }
 
@@ -33,11 +31,11 @@ fn main() {
 }
 
 pub fn create_empty_list() -> List {
-    unimplemented!()
+    List::Nil
 }
 
 pub fn create_non_empty_list() -> List {
-    unimplemented!()
+    List::Cons(String::from("hello"), Box::new(List::Nil))
 }
 
 #[cfg(test)]

exercises/standard_library_types/iterators1.rs

@@ -1,24 +1,22 @@
 // iterators1.rs
-// 
+//
 //  Make me compile by filling in the `???`s
 //
 // 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 
+// This module helps you get familiar with the structure of using an iterator and
 // how to go through elements within an iterable collection.
-// 
+//
 // Execute `rustlings hint iterators1` for hints :D
 
-// I AM NOT DONE
-
-fn main () {
+fn main() {
     let my_fav_fruits = vec!["banana", "custard apple", "avocado", "peach", "raspberry"];
 
-    let mut my_iterable_fav_fruits = ???;   // TODO: Step 1
+    let mut my_iterable_fav_fruits = my_fav_fruits.iter();
 
     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(&"custard apple"));
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"avocado"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 2.1
+    assert_eq!(my_iterable_fav_fruits.next(), Some(&"peach"));
     assert_eq!(my_iterable_fav_fruits.next(), Some(&"raspberry"));
-    assert_eq!(my_iterable_fav_fruits.next(), ???);     // TODO: Step 3
+    assert_eq!(my_iterable_fav_fruits.next(), None);
 }

exercises/standard_library_types/iterators2.rs

@@ -7,13 +7,11 @@
 //         Try to ensure it returns a single string.
 // As always, there are hints if you execute `rustlings hint iterators2`!
 
-// I AM NOT DONE
-
 pub fn capitalize_first(input: &str) -> String {
     let mut c = input.chars();
     match c.next() {
         None => String::new(),
-        Some(first) => first.collect::<String>() + c.as_str(),
+        Some(first) => first.to_uppercase().collect::<String>() + c.as_str(),
     }
 }
 
@@ -37,14 +35,15 @@ mod tests {
     #[test]
     fn test_iterate_string_vec() {
         let words = vec!["hello", "world"];
-        let capitalized_words: Vec<String> = // TODO
+        let capitalized_words: Vec<String> =
+            words.iter().map(|word| capitalize_first(word)).collect();
         assert_eq!(capitalized_words, ["Hello", "World"]);
     }
 
     #[test]
     fn test_iterate_into_string() {
         let words = vec!["hello", " ", "world"];
-        let capitalized_words = // TODO
+        let capitalized_words: String = words.iter().map(|word| capitalize_first(word)).collect();
         assert_eq!(capitalized_words, "Hello World");
     }
 }

exercises/standard_library_types/iterators3.rs

@@ -7,8 +7,6 @@
 // Execute `rustlings hint iterators3` to get some hints!
 // Have fun :-)
 
-// I AM NOT DONE
-
 #[derive(Debug, PartialEq, Eq)]
 pub enum DivisionError {
     NotDivisible(NotDivisibleError),
@@ -24,7 +22,18 @@ pub struct NotDivisibleError {
 // This function should calculate `a` divided by `b` if `a` is
 // evenly divisible by b.
 // Otherwise, it should return a suitable error.
-pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {}
+pub fn divide(a: i32, b: i32) -> Result<i32, DivisionError> {
+    if b == 0 {
+        Err(DivisionError::DivideByZero)
+    } else if a % b == 0 {
+        Ok(a / b)
+    } else {
+        Err(DivisionError::NotDivisible(NotDivisibleError {
+            dividend: a,
+            divisor: b,
+        }))
+    }
+}
 
 #[cfg(test)]
 mod tests {
@@ -57,13 +66,11 @@ mod tests {
         assert_eq!(divide(0, 81), Ok(0));
     }
 
-    // Iterator exercises using your `divide` function
-    /*
     #[test]
     fn result_with_list() {
         let numbers = vec![27, 297, 38502, 81];
         let division_results = numbers.into_iter().map(|n| divide(n, 27));
-        let x //... Fill in here!
+        let x: Result<Vec<_>, _> = division_results.collect();
         assert_eq!(format!("{:?}", x), "Ok([1, 11, 1426, 3])");
     }
 
@@ -71,8 +78,7 @@ mod tests {
     fn list_of_results() {
         let numbers = vec![27, 297, 38502, 81];
         let division_results = numbers.into_iter().map(|n| divide(n, 27));
-        let x //... Fill in here!
+        let x: Vec<_> = division_results.collect();
         assert_eq!(format!("{:?}", x), "[Ok(1), Ok(11), Ok(1426), Ok(3)]");
     }
-    */
 }

exercises/standard_library_types/iterators4.rs

@@ -1,7 +1,5 @@
 // iterators4.rs
 
-// I AM NOT DONE
-
 pub fn factorial(num: u64) -> u64 {
     // Complete this function to return the factorial of num
     // Do not use:
@@ -12,6 +10,7 @@ pub fn factorial(num: u64) -> u64 {
     // For an extra challenge, don't use:
     // - recursion
     // Execute `rustlings hint iterators4` for hints.
+    (1..=num).product()
 }
 
 #[cfg(test)]