My solution to rustlings course

error handling
enums.
strings
modules
hashmaps
quiz2

options

error handling

Error handling

.all-contributorsrc

@@ -2514,6 +2514,24 @@
       "contributions": [
         "content"
       ]
+    },
+    {
+      "login": "raymon-roos",
+      "name": "Raymon Roos",
+      "avatar_url": "https://avatars.githubusercontent.com/u/38888470?v=4",
+      "profile": "https://github.com/raymon-roos",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "sarupbanskota",
+      "name": "Sarup Banskota",
+      "avatar_url": "https://avatars.githubusercontent.com/u/3149580?v=4",
+      "profile": "https://codecrafters.io",
+      "contributions": [
+        "doc"
+      ]
     }
   ],
   "contributorsPerLine": 8,

AUTHORS.md

@@ -355,6 +355,8 @@ authors.
       <td align="center" valign="top" width="12.5%"><a href="https://github.com/VeeDeltaVee"><img src="https://avatars.githubusercontent.com/u/45564258?v=4?s=100" width="100px;" alt="Versha Dhankar"/><br /><sub><b>Versha Dhankar</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=VeeDeltaVee" title="Documentation">📖</a></td>
       <td align="center" valign="top" width="12.5%"><a href="http://0atman.com"><img src="https://avatars.githubusercontent.com/u/114097?v=4?s=100" width="100px;" alt="Tristram Oaten"/><br /><sub><b>Tristram Oaten</b></sub></a><br /><a href="#content-0atman" title="Content">🖋</a></td>
       <td align="center" valign="top" width="12.5%"><a href="https://github.com/danieltinazzi"><img src="https://avatars.githubusercontent.com/u/11833533?v=4?s=100" width="100px;" alt="Daniel Tinazzi"/><br /><sub><b>Daniel Tinazzi</b></sub></a><br /><a href="#content-danieltinazzi" title="Content">🖋</a></td>
+      <td align="center" valign="top" width="12.5%"><a href="https://github.com/raymon-roos"><img src="https://avatars.githubusercontent.com/u/38888470?v=4?s=100" width="100px;" alt="Raymon Roos"/><br /><sub><b>Raymon Roos</b></sub></a><br /><a href="#content-raymon-roos" title="Content">🖋</a></td>
+      <td align="center" valign="top" width="12.5%"><a href="https://codecrafters.io"><img src="https://avatars.githubusercontent.com/u/3149580?v=4?s=100" width="100px;" alt="Sarup Banskota"/><br /><sub><b>Sarup Banskota</b></sub></a><br /><a href="https://github.com/rust-lang/rustlings/commits?author=sarupbanskota" title="Documentation">📖</a></td>
     </tr>
   </tbody>
 </table>

README.md

@@ -154,6 +154,8 @@ Run the command `rustlings lsp` which will generate a `rust-project.json` at the
 
 Once you've completed Rustlings, put your new knowledge to good use! Continue practicing your Rust skills by building your own projects, contributing to Rustlings, or finding other open-source projects to contribute to.
 
+On [CodeCrafters](https://codecrafters.io/rust) you can get some quality practice through recreating different technologies from scratch in Rust (e.g Build your own BitTorrent, HTTP Server, SQLite, etc).
+
 ## Uninstalling Rustlings
 
 If you want to remove Rustlings from your system, there are two steps. First, you'll need to remove the exercises folder that the install script created

exercises/00_intro/intro1.rs

@@ -13,7 +13,6 @@
 // Execute `rustlings hint intro1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
     println!("Hello and");

exercises/00_intro/intro2.rs

@@ -5,8 +5,7 @@
 // Execute `rustlings hint intro2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
-    printline!("Hello there!")
+    let par: &str = "world";
+    println!("Hello {}!", par);
 }

exercises/01_variables/variables1.rs

@@ -5,9 +5,7 @@
 // Execute `rustlings hint variables1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
-    x = 5;
+    let x = 5;
     println!("x has the value {}", x);
 }

exercises/01_variables/variables2.rs

@@ -3,10 +3,8 @@
 // Execute `rustlings hint variables2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
-    let x;
+    let x = 5;
     if x == 10 {
         println!("x is ten!");
     } else {

exercises/01_variables/variables3.rs

@@ -3,9 +3,8 @@
 // Execute `rustlings hint variables3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
-    let x: i32;
+    let x: i32 = 1;
     println!("Number {}", x);
 }

exercises/01_variables/variables4.rs

@@ -3,10 +3,9 @@
 // Execute `rustlings hint variables4` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
-    let x = 3;
+    let mut x = 3;
     println!("Number {}", x);
     x = 5; // don't change this line
     println!("Number {}", x);

exercises/01_variables/variables5.rs

@@ -3,11 +3,9 @@
 // Execute `rustlings hint variables5` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
     let number = "T-H-R-E-E"; // don't change this line
     println!("Spell a Number : {}", number);
-    number = 3; // don't rename this variable
+    let number = 3; // don't rename this variable
     println!("Number plus two is : {}", number + 2);
 }

exercises/01_variables/variables6.rs

@@ -3,9 +3,7 @@
 // Execute `rustlings hint variables6` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
-const NUMBER = 3;
+const NUMBER :u8 = 3;
 fn main() {
     println!("Number {}", NUMBER);
 }

exercises/02_functions/functions1.rs

@@ -3,8 +3,8 @@
 // Execute `rustlings hint functions1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
     call_me();
 }
+
+fn call_me() {}

exercises/02_functions/functions2.rs

@@ -3,13 +3,11 @@
 // Execute `rustlings hint functions2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
     call_me(3);
 }
 
-fn call_me(num:) {
+fn call_me(num: i32) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }

exercises/02_functions/functions3.rs

@@ -3,10 +3,9 @@
 // Execute `rustlings hint functions3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
-    call_me();
+    call_me(1000);
 }
 
 fn call_me(num: u32) {

exercises/02_functions/functions4.rs

@@ -8,14 +8,13 @@
 // Execute `rustlings hint functions4` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
     let original_price = 51;
     println!("Your sale price is {}", sale_price(original_price));
 }
 
-fn sale_price(price: i32) -> {
+fn sale_price(price: u32) -> u32 {
     if is_even(price) {
         price - 10
     } else {
@@ -23,6 +22,6 @@ fn sale_price(price: i32) -> {
     }
 }
 
-fn is_even(num: i32) -> bool {
+fn is_even(num: u32) -> bool {
     num % 2 == 0
 }

exercises/02_functions/functions5.rs

@@ -3,7 +3,6 @@
 // Execute `rustlings hint functions5` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
     let answer = square(3);
@@ -11,5 +10,5 @@ fn main() {
 }
 
 fn square(num: i32) -> i32 {
-    num * num;
+    num * num
 }

exercises/03_if/if1.rs

@@ -2,13 +2,16 @@
 //
 // Execute `rustlings hint if1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub fn bigger(a: i32, b: i32) -> i32 {
     // Complete this function to return the bigger number!
     // Do not use:
     // - another function call
     // - additional variables
+    if a > b {
+        return a;
+    }
+    b
 }
 
 // Don't mind this for now :)

exercises/03_if/if2.rs

@@ -5,13 +5,14 @@
 //
 // Execute `rustlings hint if2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub fn foo_if_fizz(fizzish: &str) -> &str {
     if fizzish == "fizz" {
         "foo"
+    } else if fizzish == "fuzz" {
+        "bar"
     } else {
-        1
+        "baz"
     }
 }
 

exercises/03_if/if3.rs

@@ -2,17 +2,16 @@
 //
 // Execute `rustlings hint if3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 pub fn animal_habitat(animal: &str) -> &'static str {
     let identifier = if animal == "crab" {
         1
     } else if animal == "gopher" {
-        2.0
+        2
     } else if animal == "snake" {
         3
     } else {
-        "Unknown"
+        0
     };
 
     // DO NOT CHANGE THIS STATEMENT BELOW

exercises/04_primitive_types/primitive_types1.rs

@@ -3,7 +3,6 @@
 // Fill in the rest of the line that has code missing! No hints, there's no
 // tricks, just get used to typing these :)
 
-// I AM NOT DONE
 
 fn main() {
     // Booleans (`bool`)
@@ -13,7 +12,7 @@ fn main() {
         println!("Good morning!");
     }
 
-    let // Finish the rest of this line like the example! Or make it be false!
+    let is_evening = true; // Finish the rest of this line like the example! Or make it be false!
     if is_evening {
         println!("Good evening!");
     }

exercises/04_primitive_types/primitive_types2.rs

@@ -3,7 +3,6 @@
 // Fill in the rest of the line that has code missing! No hints, there's no
 // tricks, just get used to typing these :)
 
-// I AM NOT DONE
 
 fn main() {
     // Characters (`char`)
@@ -19,7 +18,7 @@ fn main() {
         println!("Neither alphabetic nor numeric!");
     }
 
-    let // Finish this line like the example! What's your favorite character?
+    let your_character = '1'; // Finish this line like the example! What's your favorite character?
     // Try a letter, try a number, try a special character, try a character
     // from a different language than your own, try an emoji!
     if your_character.is_alphabetic() {

exercises/04_primitive_types/primitive_types3.rs

@@ -5,10 +5,9 @@
 // Execute `rustlings hint primitive_types3` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
 
 fn main() {
-    let a = ???
+    let a = [1;1000];
 
     if a.len() >= 100 {
         println!("Wow, that's a big array!");

exercises/04_primitive_types/primitive_types4.rs

@@ -5,13 +5,12 @@
 // Execute `rustlings hint primitive_types4` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
 
 #[test]
 fn slice_out_of_array() {
     let a = [1, 2, 3, 4, 5];
 
-    let nice_slice = ???
+    let nice_slice = &a[1..4];
 
     assert_eq!([2, 3, 4], nice_slice)
 }

exercises/04_primitive_types/primitive_types5.rs

@@ -5,11 +5,10 @@
 // Execute `rustlings hint primitive_types5` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
 
 fn main() {
     let cat = ("Furry McFurson", 3.5);
-    let /* your pattern here */ = cat;
+    let (name,age) = cat;
 
     println!("{} is {} years old.", name, age);
 }

exercises/04_primitive_types/primitive_types6.rs

@@ -6,13 +6,12 @@
 // Execute `rustlings hint primitive_types6` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
 
 #[test]
 fn indexing_tuple() {
     let numbers = (1, 2, 3);
     // Replace below ??? with the tuple indexing syntax.
-    let second = ???;
+    let second = numbers.1;
 
     assert_eq!(2, second,
         "This is not the 2nd number in the tuple!")

exercises/05_vecs/vecs1.rs

@@ -7,11 +7,10 @@
 //
 // Execute `rustlings hint vecs1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 fn array_and_vec() -> ([i32; 4], Vec<i32>) {
     let a = [10, 20, 30, 40]; // a plain array
-    let v = // TODO: declare your vector here with the macro for vectors
+    let v = vec![a[0],a[1],a[2],a[3]]; // TODO: declare your vector here with the macro for vectors
 
     (a, v)
 }

exercises/05_vecs/vecs2.rs

@@ -7,13 +7,11 @@
 //
 // Execute `rustlings hint vecs2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
     for element in v.iter_mut() {
         // TODO: Fill this up so that each element in the Vec `v` is
         // multiplied by 2.
-        ???
+        *element *= 2;
     }
 
     // At this point, `v` should be equal to [4, 8, 12, 16, 20].
@@ -21,11 +19,13 @@ fn vec_loop(mut v: Vec<i32>) -> Vec<i32> {
 }
 
 fn vec_map(v: &Vec<i32>) -> Vec<i32> {
-    v.iter().map(|element| {
-        // TODO: Do the same thing as above - but instead of mutating the
-        // Vec, you can just return the new number!
-        ???
-    }).collect()
+    v.iter()
+        .map(|element| {
+            // TODO: Do the same thing as above - but instead of mutating the
+            // Vec, you can just return the new number!
+            element * 2
+        })
+        .collect()
 }
 
 #[cfg(test)]

exercises/06_move_semantics/move_semantics1.rs

@@ -3,7 +3,6 @@
 // Execute `rustlings hint move_semantics1` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
 
 #[test]
 fn main() {
@@ -15,7 +14,7 @@ fn main() {
 }
 
 fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
-    let vec = vec;
+    let mut vec = vec;
 
     vec.push(88);
 

exercises/06_move_semantics/move_semantics2.rs

@@ -5,20 +5,18 @@
 // Execute `rustlings hint move_semantics2` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
-
 #[test]
 fn main() {
     let vec0 = vec![22, 44, 66];
 
-    let mut vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec(&vec0);
 
     assert_eq!(vec0, vec![22, 44, 66]);
     assert_eq!(vec1, vec![22, 44, 66, 88]);
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
-    let mut vec = vec;
+fn fill_vec(vec: &Vec<i32>) -> Vec<i32> {
+    let mut vec = vec.clone();
 
     vec.push(88);
 

exercises/06_move_semantics/move_semantics3.rs

@@ -6,18 +6,16 @@
 // Execute `rustlings hint move_semantics3` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
 
 #[test]
 fn main() {
     let vec0 = vec![22, 44, 66];
 
-    let mut vec1 = fill_vec(vec0);
-
+    let vec1 = fill_vec(vec0);
     assert_eq!(vec1, vec![22, 44, 66, 88]);
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
+fn fill_vec(mut vec: Vec<i32>) -> Vec<i32> {
     vec.push(88);
 
     vec

exercises/06_move_semantics/move_semantics4.rs

@@ -7,21 +7,17 @@
 // Execute `rustlings hint move_semantics4` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
-
 #[test]
 fn main() {
-    let vec0 = vec![22, 44, 66];
-
-    let mut vec1 = fill_vec(vec0);
+    let vec1 = fill_vec();
 
     assert_eq!(vec1, vec![22, 44, 66, 88]);
 }
 
 // `fill_vec()` no longer takes `vec: Vec<i32>` as argument - don't change this!
 fn fill_vec() -> Vec<i32> {
+    let mut vec = vec![22, 44, 66];
     // Instead, let's create and fill the Vec in here - how do you do that?
-    let mut vec = vec;
 
     vec.push(88);
 

exercises/06_move_semantics/move_semantics5.rs

@@ -6,14 +6,12 @@
 // Execute `rustlings hint move_semantics5` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
-
 #[test]
 fn main() {
     let mut x = 100;
     let y = &mut x;
-    let z = &mut x;
     *y += 100;
+    let z = &mut x;
     *z += 1000;
     assert_eq!(x, 1200);
 }

exercises/06_move_semantics/move_semantics6.rs

@@ -5,24 +5,23 @@
 // Execute `rustlings hint move_semantics6` or use the `hint` watch subcommand
 // for a hint.
 
-// I AM NOT DONE
-
 fn main() {
     let data = "Rust is great!".to_string();
 
-    get_char(data);
+    let letter = get_char(&data);
+    println!("Letter is {}", letter);
 
-    string_uppercase(&data);
+    string_uppercase(data);
 }
 
 // Should not take ownership
-fn get_char(data: String) -> char {
+fn get_char(data: &String) -> char {
     data.chars().last().unwrap()
 }
 
 // Should take ownership
-fn string_uppercase(mut data: &String) {
-    data = &data.to_uppercase();
+fn string_uppercase(mut data: String) {
+    data = data.to_uppercase();
 
     println!("{}", data);
 }

exercises/07_structs/structs1.rs

@@ -5,13 +5,13 @@
 // Execute `rustlings hint structs1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 struct ColorClassicStruct {
-    // TODO: Something goes here
+    red: u8,
+    green: u8,
+    blue: u8,
 }
 
-struct ColorTupleStruct(/* TODO: Something goes here */);
+struct ColorTupleStruct(u8,u8,u8);
 
 #[derive(Debug)]
 struct UnitLikeStruct;
@@ -23,7 +23,7 @@ mod tests {
     #[test]
     fn classic_c_structs() {
         // TODO: Instantiate a classic c struct!
-        // let green =
+       let green = ColorClassicStruct{red: 0, green: 255, blue: 0};
 
         assert_eq!(green.red, 0);
         assert_eq!(green.green, 255);
@@ -33,7 +33,7 @@ mod tests {
     #[test]
     fn tuple_structs() {
         // TODO: Instantiate a tuple struct!
-        // let green =
+        let green = (0,255,0);
 
         assert_eq!(green.0, 0);
         assert_eq!(green.1, 255);
@@ -43,7 +43,7 @@ mod tests {
     #[test]
     fn unit_structs() {
         // TODO: Instantiate a unit-like struct!
-        // let unit_like_struct =
+        let unit_like_struct = UnitLikeStruct;
         let message = format!("{:?}s are fun!", unit_like_struct);
 
         assert_eq!(message, "UnitLikeStructs are fun!");

exercises/07_structs/structs2.rs

@@ -5,8 +5,6 @@
 // Execute `rustlings hint structs2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[derive(Debug)]
 struct Order {
     name: String,
@@ -38,7 +36,11 @@ mod tests {
     fn your_order() {
         let order_template = create_order_template();
         // TODO: Create your own order using the update syntax and template above!
-        // let your_order =
+        let your_order = Order{
+            name: "Hacker in Rust".to_string(),
+            count: 1,
+            ..order_template
+        };
         assert_eq!(your_order.name, "Hacker in Rust");
         assert_eq!(your_order.year, order_template.year);
         assert_eq!(your_order.made_by_phone, order_template.made_by_phone);

exercises/07_structs/structs3.rs

@@ -7,7 +7,6 @@
 // Execute `rustlings hint structs3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 #[derive(Debug)]
 struct Package {
@@ -31,12 +30,14 @@ impl Package {
         }
     }
 
-    fn is_international(&self) -> ??? {
+    fn is_international(&self) -> bool {
         // Something goes here...
+        return self.sender_country != self.recipient_country;
     }
 
-    fn get_fees(&self, cents_per_gram: u32) -> ??? {
+    fn get_fees(&self, cents_per_gram: u32) -> u32 {
         // Something goes here...
+        self.weight_in_grams * cents_per_gram
     }
 }
 

exercises/08_enums/enums1.rs

@@ -2,11 +2,14 @@
 //
 // No hints this time! ;)
 
-// I AM NOT DONE
 
 #[derive(Debug)]
 enum Message {
     // TODO: define a few types of messages as used below
+    Quit,
+    Echo,
+    Move,
+    ChangeColor,
 }
 
 fn main() {

exercises/08_enums/enums2.rs

@@ -3,11 +3,14 @@
 // Execute `rustlings hint enums2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 #[derive(Debug)]
 enum Message {
     // TODO: define the different variants used below
+    Move { x: u8, y: u8 },
+    Echo(String),
+    ChangeColor(u8, u8, u8),
+    Quit,
 }
 
 impl Message {

exercises/08_enums/enums3.rs

@@ -5,10 +5,12 @@
 // Execute `rustlings hint enums3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 enum Message {
     // TODO: implement the message variant types based on their usage below
+    ChangeColor(u8, u8, u8),
+    Echo(String),
+    Move(Point),
+    Quit,
 }
 
 struct Point {
@@ -44,6 +46,20 @@ impl State {
         // TODO: create a match expression to process the different message variants
         // Remember: When passing a tuple as a function argument, you'll need extra parentheses:
         // fn function((t, u, p, l, e))
+		match message {
+            Message::ChangeColor(r, g, b) => {
+                self.color = (r, g, b);
+            }
+            Message::Echo(m) => {
+                self.message = m;
+            }
+            Message::Move(Point { x, y }) => {
+                self.position = Point { x, y };
+            }
+            Message::Quit => {
+                self.quit = true;
+            }
+        }
     }
 }
 

exercises/09_strings/strings1.rs

@@ -5,7 +5,6 @@
 // Execute `rustlings hint strings1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn main() {
     let answer = current_favorite_color();
@@ -13,5 +12,5 @@ fn main() {
 }
 
 fn current_favorite_color() -> String {
-    "blue"
+    "blue".to_string()
 }

exercises/09_strings/strings2.rs

@@ -5,11 +5,9 @@
 // Execute `rustlings hint strings2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 fn main() {
     let word = String::from("green"); // Try not changing this line :)
-    if is_a_color_word(word) {
+    if is_a_color_word(&word) {
         println!("That is a color word I know!");
     } else {
         println!("That is not a color word I know.");

exercises/09_strings/strings3.rs

@@ -3,21 +3,21 @@
 // Execute `rustlings hint strings3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 fn trim_me(input: &str) -> String {
     // TODO: Remove whitespace from both ends of a string!
-    ???
+    input.trim().to_string()
 }
 
 fn compose_me(input: &str) -> String {
     // TODO: Add " world!" to the string! There's multiple ways to do this!
-    ???
+    let return_string = input.to_string() + " world!";
+    return_string
 }
 
 fn replace_me(input: &str) -> String {
     // TODO: Replace "cars" in the string with "balloons"!
-    ???
+    input.replace("cars", "balloons")
 }
 
 #[cfg(test)]

exercises/09_strings/strings4.rs

@@ -7,7 +7,6 @@
 //
 // No hints this time!
 
-// I AM NOT DONE
 
 fn string_slice(arg: &str) {
     println!("{}", arg);
@@ -17,14 +16,14 @@ fn string(arg: String) {
 }
 
 fn main() {
-    ???("blue");
-    ???("red".to_string());
-    ???(String::from("hi"));
-    ???("rust is fun!".to_owned());
-    ???("nice weather".into());
-    ???(format!("Interpolation {}", "Station"));
-    ???(&String::from("abc")[0..1]);
-    ???("  hello there ".trim());
-    ???("Happy Monday!".to_string().replace("Mon", "Tues"));
-    ???("mY sHiFt KeY iS sTiCkY".to_lowercase());
+    string_slice("blue");
+    string("red".to_string());
+    string(String::from("hi"));
+    string("rust is fun!".to_owned());
+    string_slice("nice weather".into());
+    string(format!("Interpolation {}", "Station"));
+    string_slice(&String::from("abc")[0..1]);
+    string_slice("  hello there ".trim());
+    string("Happy Monday!".to_string().replace("Mon", "Tues"));
+    string("mY sHiFt KeY iS sTiCkY".to_lowercase());
 }

exercises/10_modules/modules1.rs

@@ -3,7 +3,6 @@
 // Execute `rustlings hint modules1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 mod sausage_factory {
     // Don't let anybody outside of this module see this!
@@ -11,7 +10,7 @@ mod sausage_factory {
         String::from("Ginger")
     }
 
-    fn make_sausage() {
+    pub fn make_sausage() {
         get_secret_recipe();
         println!("sausage!");
     }

exercises/10_modules/modules2.rs

@@ -7,12 +7,11 @@
 // Execute `rustlings hint modules2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 mod delicious_snacks {
     // TODO: Fix these use statements
-    use self::fruits::PEAR as ???
-    use self::veggies::CUCUMBER as ???
+    pub use self::fruits::PEAR as fruit;
+    pub use self::veggies::CUCUMBER as veggie;
 
     mod fruits {
         pub const PEAR: &'static str = "Pear";

exercises/10_modules/modules3.rs

@@ -8,10 +8,9 @@
 // Execute `rustlings hint modules3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 // TODO: Complete this use statement
-use ???
+use std::time::*;
 
 fn main() {
     match SystemTime::now().duration_since(UNIX_EPOCH) {

exercises/11_hashmaps/hashmaps1.rs

@@ -11,17 +11,18 @@
 // Execute `rustlings hint hashmaps1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 use std::collections::HashMap;
 
 fn fruit_basket() -> HashMap<String, u32> {
-    let mut basket = // TODO: declare your hash map here.
+    let mut basket = HashMap::new();
 
     // Two bananas are already given for you :)
     basket.insert(String::from("banana"), 2);
 
     // TODO: Put more fruits in your basket here.
+    basket.insert(String::from("apple"), 3);
+    basket.insert(String::from("cherry"),1);
 
     basket
 }

exercises/11_hashmaps/hashmaps2.rs

@@ -14,7 +14,6 @@
 // Execute `rustlings hint hashmaps2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
 
 use std::collections::HashMap;
 
@@ -40,6 +39,7 @@ fn fruit_basket(basket: &mut HashMap<Fruit, u32>) {
         // TODO: Insert new fruits if they are not already present in the
         // basket. Note that you are not allowed to put any type of fruit that's
         // already present!
+        basket.entry(fruit).or_insert(1);
     }
 }
 
@@ -81,7 +81,7 @@ mod tests {
         let count = basket.values().sum::<u32>();
         assert!(count > 11);
     }
-    
+
     #[test]
     fn all_fruit_types_in_basket() {
         let mut basket = get_fruit_basket();

exercises/11_hashmaps/hashmaps3.rs

@@ -14,8 +14,6 @@
 // Execute `rustlings hint hashmaps3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 use std::collections::HashMap;
 
 // A structure to store the goal details of a team.
@@ -39,6 +37,22 @@ fn build_scores_table(results: String) -> HashMap<String, Team> {
         // will be the number of goals conceded from team_2, and similarly
         // goals scored by team_2 will be the number of goals conceded by
         // team_1.
+
+        let team_1 = scores.entry(team_1_name).or_insert(Team {
+            goals_scored: 0,
+            goals_conceded: 0,
+        });
+
+        (*team_1).goals_conceded += team_2_score;
+        (*team_1).goals_scored += team_1_score;
+
+        let team_2 = scores.entry(team_2_name).or_insert(Team {
+            goals_scored: 0,
+            goals_conceded: 0,
+        });
+
+        (*team_2).goals_conceded += team_1_score;
+        (*team_2).goals_scored += team_2_score;
     }
     scores
 }

exercises/12_options/options1.rs

@@ -3,8 +3,6 @@
 // Execute `rustlings hint options1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 // This function returns how much icecream there is left in the fridge.
 // If it's before 10PM, there's 5 pieces left. At 10PM, someone eats them
 // all, so there'll be no more left :(
@@ -13,7 +11,13 @@ fn maybe_icecream(time_of_day: u16) -> Option<u16> {
     // value of 0 The Option output should gracefully handle cases where
     // time_of_day > 23.
     // TODO: Complete the function body - remember to return an Option!
-    ???
+    if time_of_day > 23 {
+        return None;
+    }
+    if time_of_day > 21 {
+        return Some(0);
+    }
+    Some(5)
 }
 
 #[cfg(test)]
@@ -33,7 +37,7 @@ mod tests {
     fn raw_value() {
         // TODO: Fix this test. How do you get at the value contained in the
         // Option?
-        let icecreams = maybe_icecream(12);
+        let icecreams = maybe_icecream(12).unwrap_or(0);
         assert_eq!(icecreams, 5);
     }
 }

exercises/12_options/options2.rs

@@ -3,8 +3,6 @@
 // Execute `rustlings hint options2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[cfg(test)]
 mod tests {
     #[test]
@@ -13,7 +11,7 @@ mod tests {
         let optional_target = Some(target);
 
         // TODO: Make this an if let statement whose value is "Some" type
-        word = optional_target {
+        if let Some(word) = optional_target {
             assert_eq!(word, target);
         }
     }
@@ -32,7 +30,8 @@ mod tests {
         // TODO: make this a while let statement - remember that vector.pop also
         // adds another layer of Option<T>. You can stack `Option<T>`s into
         // while let and if let.
-        integer = optional_integers.pop() {
+        while let Some(Some(integer)) = optional_integers.pop() {
+            println!("resulting integer: {}", integer);
             assert_eq!(integer, cursor);
             cursor -= 1;
         }

exercises/12_options/options3.rs

@@ -3,8 +3,6 @@
 // Execute `rustlings hint options3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 struct Point {
     x: i32,
     y: i32,
@@ -14,7 +12,7 @@ fn main() {
     let y: Option<Point> = Some(Point { x: 100, y: 200 });
 
     match y {
-        Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y),
+        Some(ref p) => println!("Co-ordinates are {},{} ", p.x, p.y),
         _ => panic!("no match!"),
     }
     y; // Fix without deleting this line.

exercises/13_error_handling/errors1.rs

@@ -9,14 +9,12 @@
 // Execute `rustlings hint errors1` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
-pub fn generate_nametag_text(name: String) -> Option<String> {
+pub fn generate_nametag_text(name: String) -> Result<String, String> {
     if name.is_empty() {
         // Empty names aren't allowed.
-        None
+        Err("`name` was empty; it must be nonempty.".into())
     } else {
-        Some(format!("Hi! My name is {}", name))
+        Ok(format!("Hi! My name is {}", name))
     }
 }
 

exercises/13_error_handling/errors2.rs

@@ -19,15 +19,12 @@
 // Execute `rustlings hint errors2` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 use std::num::ParseIntError;
 
 pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
     let processing_fee = 1;
     let cost_per_item = 5;
-    let qty = item_quantity.parse::<i32>();
-
+    let qty = item_quantity.parse::<i32>()?;
     Ok(qty * cost_per_item + processing_fee)
 }
 

exercises/13_error_handling/errors3.rs

@@ -7,11 +7,9 @@
 // Execute `rustlings hint errors3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 use std::num::ParseIntError;
 
-fn main() {
+fn main() -> Result<(), ParseIntError> {
     let mut tokens = 100;
     let pretend_user_input = "8";
 
@@ -23,6 +21,7 @@ fn main() {
         tokens -= cost;
         println!("You now have {} tokens.", tokens);
     }
+    Ok(())
 }
 
 pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {

exercises/13_error_handling/errors4.rs

@@ -3,8 +3,6 @@
 // Execute `rustlings hint errors4` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 #[derive(PartialEq, Debug)]
 struct PositiveNonzeroInteger(u64);
 
@@ -16,7 +14,13 @@ enum CreationError {
 
 impl PositiveNonzeroInteger {
     fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
-        // Hmm... Why is this always returning an Ok value?
+        if value < 0 {
+            return Err(CreationError::Negative);
+        }
+        if value == 0 {
+            return Err(CreationError::Zero);
+        }
+
         Ok(PositiveNonzeroInteger(value as u64))
     }
 }

exercises/13_error_handling/errors5.rs

@@ -22,14 +22,12 @@
 // Execute `rustlings hint errors5` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 use std::error;
 use std::fmt;
 use std::num::ParseIntError;
 
 // TODO: update the return type of `main()` to make this compile.
-fn main() -> Result<(), Box<dyn ???>> {
+fn main() -> Result<(), Box<dyn error::Error>> {
     let pretend_user_input = "42";
     let x: i64 = pretend_user_input.parse()?;
     println!("output={:?}", PositiveNonzeroInteger::new(x)?);

exercises/13_error_handling/errors6.rs

@@ -9,8 +9,6 @@
 // Execute `rustlings hint errors6` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
 use std::num::ParseIntError;
 
 // This is a custom error type that we will be using in `parse_pos_nonzero()`.
@@ -25,13 +23,17 @@ impl ParsePosNonzeroError {
         ParsePosNonzeroError::Creation(err)
     }
     // TODO: add another error conversion function here.
-    // fn from_parseint...
+    fn from_parseint(err: ParseIntError) -> ParsePosNonzeroError {
+        ParsePosNonzeroError::ParseInt(err)
+    }
 }
 
 fn parse_pos_nonzero(s: &str) -> Result<PositiveNonzeroInteger, ParsePosNonzeroError> {
     // TODO: change this to return an appropriate error instead of panicking
     // when `parse()` returns an error.
-    let x: i64 = s.parse().unwrap();
+    let x_opt = s.parse();
+    let x = x_opt.map_err(ParsePosNonzeroError::from_parseint)?;
+
     PositiveNonzeroInteger::new(x).map_err(ParsePosNonzeroError::from_creation)
 }
 

exercises/quiz1.rs

@@ -13,10 +13,15 @@
 //
 // No hints this time ;)
 
-// I AM NOT DONE
 
 // Put your function here!
-// fn calculate_price_of_apples {
+fn calculate_price_of_apples(apples: u64) -> u64 {
+    if apples > 40 {
+        apples
+    } else {
+        apples * 2
+    }
+}
 
 // Don't modify this function!
 #[test]

exercises/quiz2.rs

@@ -20,8 +20,6 @@
 //
 // No hints this time!
 
-// I AM NOT DONE
-
 pub enum Command {
     Uppercase,
     Trim,
@@ -32,11 +30,22 @@ mod my_module {
     use super::Command;
 
     // TODO: Complete the function signature!
-    pub fn transformer(input: ???) -> ??? {
+    pub fn transformer(input: Vec<(String, Command)>) -> Vec<String> {
         // TODO: Complete the output declaration!
-        let mut output: ??? = vec![];
+        let mut output: Vec<String> = vec![];
         for (string, command) in input.iter() {
             // TODO: Complete the function body. You can do it!
+            match command {
+                Command::Trim => output.push(string.trim().to_string()),
+                Command::Uppercase => output.push(string.to_uppercase()),
+                Command::Append(size) => {
+                    let mut buf: String = string.to_owned();
+                    for n in 0..*size {
+                        buf += "bar";
+                    }
+                    output.push(buf)
+                }
+            }
         }
         output
     }
@@ -45,12 +54,12 @@ mod my_module {
 #[cfg(test)]
 mod tests {
     // TODO: What do we need to import to have `transformer` in scope?
-    use ???;
     use super::Command;
+    use crate::my_module;
 
     #[test]
     fn it_works() {
-        let output = transformer(vec![
+        let output = my_module::transformer(vec![
             ("hello".into(), Command::Uppercase),
             (" all roads lead to rome! ".into(), Command::Trim),
             ("foo".into(), Command::Append(1)),

info.toml

@@ -808,7 +808,7 @@ mode = "test"
 hint = """
 Traits can have a default implementation for functions. Structs that implement
 the trait can then use the default version of these functions if they choose not
-implement the function themselves.
+to implement the function themselves.
 
 See the documentation at: https://doc.rust-lang.org/book/ch10-02-traits.html#default-implementations
 """