rustlings solutions

exercises/clippy/clippy1.rs

@@ -4,12 +4,10 @@
 //
 // Execute `rustlings hint clippy1` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
     let x = 1.2331f64;
     let y = 1.2332f64;
-    if y != x {
+    if (y - x).abs() > 0.0 {
         println!("Success!");
     }
 }

exercises/clippy/clippy2.rs

@@ -1,12 +1,10 @@
 // clippy2.rs
 // Make me compile! Execute `rustlings hint clippy2` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
     let mut res = 42;
     let option = Some(12);
-    for x in option {
+    if let Some(x) = option {
         res += x;
     }
     println!("{}", res);

exercises/enums/enums1.rs

@@ -1,11 +1,12 @@
 // enums1.rs
 // Make me compile! Execute `rustlings hint enums1` for hints!
 
-// 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/enums/enums2.rs

@@ -1,11 +1,12 @@
 // enums2.rs
 // Make me compile! Execute `rustlings hint enums2` for hints!
 
-// I AM NOT DONE
-
 #[derive(Debug)]
 enum Message {
-    // TODO: define the different variants used below
+    Quit,
+    Echo(String),
+    Move { x: i32, y: i32 },
+    ChangeColor(i32, i32, i32)
 }
 
 impl Message {

exercises/enums/enums3.rs

@@ -1,10 +1,11 @@
 // enums3.rs
 // Address all the TODOs to make the tests pass!
 
-// I AM NOT DONE
-
 enum Message {
-    // TODO: implement the message variant types based on their usage below
+    Quit,
+    Echo(String),
+    Move { x: i32, y: i32 },
+    ChangeColor(i32, i32, i32)
 }
 
 struct Point {
@@ -36,7 +37,12 @@ impl State {
     }
 
     fn process(&mut self, message: Message) {
-        // TODO: create a match expression to process the different message variants
+        match message {
+            Message::ChangeColor(r,g,b) => self.change_color((r as u8, g as u8, b as u8)),
+            Message::Echo(s) => self.echo(s),
+            Message::Move{x,y} => self.move_position(Point{ x: x as u8, y: y as u8 }),
+            Message::Quit => self.quit()
+        }
     }
 }
 

exercises/error_handling/errors1.rs

@@ -6,14 +6,12 @@
 // this function to have.
 // Execute `rustlings hint errors1` for hints!
 
-// 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.len() > 0 {
-        Some(format!("Hi! My name is {}", name))
+        Ok(format!("Hi! My name is {}", name))
     } else {
         // Empty names aren't allowed.
-        None
+        Err(format!("`{}` was empty; it must be nonempty.", "name"))
     }
 }
 
@@ -28,7 +26,7 @@ mod tests {
     fn generates_nametag_text_for_a_nonempty_name() {
         assert_eq!(
             generate_nametag_text("Beyoncé".into()),
-            Some("Hi! My name is Beyoncé".into())
+            Ok("Hi! My name is Beyoncé".into())
         );
     }
 

exercises/error_handling/errors2.rs

@@ -16,14 +16,12 @@
 // There are at least two ways to implement this that are both correct-- but
 // one is a lot shorter! Execute `rustlings hint errors2` for hints to both ways.
 
-// 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/error_handling/errors3.rs

@@ -4,21 +4,19 @@
 // Why not? What should we do to fix it?
 // Execute `rustlings hint errors3` for hints!
 
-// I AM NOT DONE
-
 use std::num::ParseIntError;
 
-fn main() {
+fn main() -> Result<String, ParseIntError> {
     let mut tokens = 100;
     let pretend_user_input = "8";
 
     let cost = total_cost(pretend_user_input)?;
 
     if cost > tokens {
-        println!("You can't afford that many!");
+        Ok(format!("You can't afford that many!"))
     } else {
         tokens -= cost;
-        println!("You now have {} tokens.", tokens);
+        Ok(format!("You now have {} tokens.", tokens))
     }
 }
 

exercises/error_handling/errorsn.rs

@@ -15,19 +15,17 @@
 //
 // Execute `rustlings hint errorsn` for hints :)
 
-// I AM NOT DONE
-
 use std::error;
 use std::fmt;
 use std::io;
 
 // PositiveNonzeroInteger is a struct defined below the tests.
-fn read_and_validate(b: &mut dyn io::BufRead) -> Result<PositiveNonzeroInteger, ???> {
+fn read_and_validate(b: &mut dyn io::BufRead) -> Result<PositiveNonzeroInteger, Box<dyn error::Error>> {
     let mut line = String::new();
-    b.read_line(&mut line);
-    let num: i64 = line.trim().parse();
-    let answer = PositiveNonzeroInteger::new(num);
-    answer
+    b.read_line(&mut line)?;
+    let num: i64 = line.trim().parse()?;
+    let answer = PositiveNonzeroInteger::new(num)?;
+    Ok(answer)
 }
 
 // This is a test helper function that turns a &str into a BufReader.

exercises/error_handling/option1.rs

@@ -4,19 +4,19 @@
 // on `None`. Handle this in a more graceful way than calling `unwrap`!
 // Execute `rustlings hint option1` for hints :)
 
-// I AM NOT DONE
-
 pub fn pop_too_much() -> bool {
     let mut list = vec![3];
 
-    let last = list.pop().unwrap();
-    println!("The last item in the list is {:?}", last);
+    match list.pop() {
+        Some(item) => println!("The last item in the list is {:?}", item),
+        None => println!("Failed"),
+    };
+
+    match list.pop() {
+        Some(item) => println!("The second-to-last item in the list is {:?}", item),
+        None => println!("Failed"),
+    };
 
-    let second_to_last = list.pop().unwrap();
-    println!(
-        "The second-to-last item in the list is {:?}",
-        second_to_last
-    );
     true
 }
 

exercises/error_handling/result1.rs

@@ -1,8 +1,6 @@
 // result1.rs
 // Make this test pass! Execute `rustlings hint result1` for hints :)
 
-// I AM NOT DONE
-
 #[derive(PartialEq, Debug)]
 struct PositiveNonzeroInteger(u64);
 
@@ -14,7 +12,15 @@ enum CreationError {
 
 impl PositiveNonzeroInteger {
     fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
-        Ok(PositiveNonzeroInteger(value as u64))
+        if value > 0 {
+            Ok(PositiveNonzeroInteger(value as u64))
+        } 
+        else if value == 0 {
+            Err(CreationError::Zero)
+        }
+        else {
+            Err(CreationError::Negative)
+        }
     }
 }
 

exercises/functions/functions1.rs

@@ -1,7 +1,9 @@
 // functions1.rs
 // Make me compile! Execute `rustlings hint functions1` for hints :)
 
-// I AM NOT DONE
+pub fn call_me() {
+    println!("test");
+}
 
 fn main() {
     call_me();

exercises/functions/functions2.rs

@@ -1,13 +1,11 @@
 // functions2.rs
 // Make me compile! Execute `rustlings hint functions2` for hints :)
 
-// 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/functions/functions3.rs

@@ -1,10 +1,8 @@
 // functions3.rs
 // Make me compile! Execute `rustlings hint functions3` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
-    call_me();
+    call_me(10);
 }
 
 fn call_me(num: i32) {

exercises/functions/functions4.rs

@@ -4,14 +4,12 @@
 // This store is having a sale where if the price is an even number, you get
 // 10 Rustbucks off, but if it's an odd number, it's 3 Rustbucks off.
 
-// 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: i32) -> i32 {
     if is_even(price) {
         price - 10
     } else {

exercises/functions/functions5.rs

@@ -1,13 +1,11 @@
 // functions5.rs
 // Make me compile! Execute `rustlings hint functions5` for hints :)
 
-// I AM NOT DONE
-
 fn main() {
     let answer = square(3);
     println!("The answer is {}", answer);
 }
 
 fn square(num: i32) -> i32 {
-    num * num;
+    num * num
 }

exercises/if/if1.rs

@@ -1,13 +1,8 @@
 // if1.rs
 
-// 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
-    // Execute `rustlings hint if1` for hints
+    if a > b { a } else { b }
 }
 
 // Don't mind this for now :)

exercises/macros/macros1.rs

@@ -1,14 +1,12 @@
 // macros1.rs
 // Make me compile! Execute `rustlings hint macros1` for hints :)
 
-// I AM NOT DONE
-
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
     };
 }
 
 fn main() {
-    my_macro();
+    my_macro!();
 }

exercises/macros/macros2.rs

@@ -1,14 +1,12 @@
 // macros2.rs
 // Make me compile! Execute `rustlings hint macros2` for hints :)
 
-// I AM NOT DONE
-
-fn main() {
-    my_macro!();
-}
-
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
     };
 }
+
+fn main() {
+    my_macro!();
+}

exercises/macros/macros3.rs

@@ -2,8 +2,7 @@
 // Make me compile, without taking the macro out of the module!
 // Execute `rustlings hint macros3` for hints :)
 
-// I AM NOT DONE
-
+#[macro_use]
 mod macros {
     macro_rules! my_macro {
         () => {

exercises/macros/macros4.rs

@@ -1,12 +1,10 @@
 // macros4.rs
 // Make me compile! Execute `rustlings hint macros4` for hints :)
 
-// I AM NOT DONE
-
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
-    }
+    }; 
     ($val:expr) => {
         println!("Look at this other macro: {}", $val);
     }