Do most of the rustlings

Author: danpetry

exercises/error_handling/errors1.rs

@@ -6,12 +6,12 @@
 // this function to have.
 // Scroll down for hints!!!
 
-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!("`name` was empty; it must be nonempty."))
     }
 }
 
@@ -26,7 +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

@@ -21,9 +21,13 @@ 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)
+    match qty {
+        Ok(qty) => Ok(qty * cost_per_item + processing_fee),
+        Err(e) => Err(e),
+    }
+    //Ok(qty * cost_per_item + processing_fee)
 }
 
 #[cfg(test)]

exercises/error_handling/errors3.rs

@@ -10,14 +10,21 @@ fn main() {
     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!");
-    } else {
-        tokens -= cost;
-        println!("You now have {} tokens.", tokens);
+    let cost = total_cost(pretend_user_input);
+
+    match cost {
+        Ok(cost) => {
+            if cost > tokens {
+                println!("You can't afford that many!");
+            } else {
+                tokens -= cost;
+                println!("You now have {} tokens.", tokens);
+            }
+        }
+        Err(e) => println!("bad input"),
     }
+            
+
 }
 
 pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {

exercises/error_handling/errorsn.rs

@@ -20,12 +20,12 @@ use std::fmt;
 use std::io;
 
 // PositiveNonzeroInteger is a struct defined below the tests.
-fn read_and_validate(b: &mut io::BufRead) -> Result<PositiveNonzeroInteger, ???> {
+fn read_and_validate(b: &mut io::BufRead) -> Result<PositiveNonzeroInteger, Box<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

@@ -7,11 +7,17 @@
 fn main() {
     let mut list = vec![3];
 
-    let last = list.pop().unwrap();
-    println!("The last item in the list is {:?}", last);
-
-    let second_to_last = list.pop().unwrap();
-    println!("The second-to-last item in the list is {:?}", second_to_last);
+    let last = list.pop();
+    match last {
+        Some(el) => println!("The last item in the list is {:?}", el),
+        None     => println!("Nothing in the list!"),
+    }
+
+    let second_to_last = list.pop();
+    match second_to_last {
+        Some(el) => println!("The second-to-last item in the list is {:?}", el),
+        None     => println!("Nothing in the list!"),
+    }
 }
 
 

exercises/error_handling/result1.rs

@@ -12,7 +12,11 @@ enum CreationError {
 
 impl PositiveNonzeroInteger {
     fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
-        Ok(PositiveNonzeroInteger(value as u64))
+        match value {
+            0 => Err(CreationError::Zero),
+            x if x < 0 => Err(CreationError::Negative),
+            _ => Ok(PositiveNonzeroInteger(value as u64)),
+        }
     }
 }
 

exercises/functions/functions1.rs

@@ -8,6 +8,8 @@ fn main() {
 
 
 
+fn call_me() {
+}
 
 
 

exercises/functions/functions2.rs

@@ -5,7 +5,7 @@ fn main() {
     call_me(3);
 }
 
-fn call_me(num) {
+fn call_me(num: i8) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }

exercises/functions/functions3.rs

@@ -2,7 +2,7 @@
 // Make me compile! Scroll down for hints :)
 
 fn main() {
-    call_me();
+    call_me(32);
 }
 
 fn call_me(num: i32) {

exercises/functions/functions4.rs

@@ -9,7 +9,7 @@ fn main() {
     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

@@ -7,7 +7,7 @@ fn main() {
 }
 
 fn square(num: i32) -> i32 {
-    num * num;
+    num * num
 }
 
 

exercises/if/if1.rs

@@ -1,6 +1,7 @@
 // if1.rs
 
 pub fn bigger(a: i32, b:i32) -> i32 {
+    if (a > b) {a} else {b}
     // Complete this function to return the bigger number!
     // Do not use:
     // - return

exercises/macros/macros1.rs

@@ -8,7 +8,7 @@ macro_rules! my_macro {
 }
 
 fn main() {
-    my_macro();
+    my_macro!();
 }
 
 

exercises/macros/macros2.rs

@@ -1,15 +1,15 @@
 // macros2.rs
 // Make me compile! Scroll down for hints :)
 
-fn main() {
-    my_macro!();
-}
-
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
     };
 }
+fn main() {
+    my_macro!();
+}
+
 
 
 

exercises/macros/macros3.rs

@@ -1,6 +1,7 @@
 // macros3.rs
 // Make me compile, without taking the macro out of the module! Scroll down for hints :)
 
+#[macro_use]
 mod macros {
     macro_rules! my_macro {
         () => {

exercises/macros/macros4.rs

@@ -4,7 +4,7 @@
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
-    }
+    };
     ($val:expr) => {
         println!("Look at this other macro: {}", $val);
     }

exercises/modules/modules1.rs

@@ -2,7 +2,7 @@
 // Make me compile! Scroll down for hints :)
 
 mod sausage_factory {
-    fn make_sausage() {
+    pub fn make_sausage() {
         println!("sausage!");
     }
 }

exercises/modules/modules2.rs

@@ -2,8 +2,8 @@
 // Make me compile! Scroll down for hints :)
 
 mod delicious_snacks { 
-    use self::fruits::PEAR as fruit;
-    use self::veggies::CUCUMBER as veggie;
+    pub use self::fruits::PEAR as fruit;
+    pub use self::veggies::CUCUMBER as veggie;
 
     mod fruits {
         pub const PEAR: &'static str = "Pear";

exercises/move_semantics/move_semantics1.rs

@@ -4,7 +4,7 @@
 fn main() {
     let vec0 = Vec::new();
 
-    let vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec(vec0);
 
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 

exercises/move_semantics/move_semantics2.rs

@@ -2,27 +2,28 @@
 // Make me compile without changing line 10! Scroll down for hints :)
 
 fn main() {
-    let vec0 = Vec::new();
+    let mut vec0 = Vec::new();
 
-    let mut vec1 = fill_vec(vec0);
+    //let mut vec1 = fill_vec(&vec0);
+    fill_vec(&mut vec0);
 
     // Do not change the following line!
     println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0);
 
-    vec1.push(88);
+    //vec1.push(88);
 
-    println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
+    //println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
-    let mut vec = vec;
+fn fill_vec(vec: &mut Vec<i32>)  {
+    //let/letmut vec = vec;
 
     vec.push(22);
     vec.push(44);
     vec.push(66);
 
-    vec
+    //vec
 }
 
 

exercises/move_semantics/move_semantics3.rs

@@ -16,7 +16,7 @@ fn main() {
 
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
+fn fill_vec(mut vec: Vec<i32>) -> Vec<i32> {
     vec.push(22);
     vec.push(44);
     vec.push(66);

exercises/move_semantics/move_semantics4.rs

@@ -4,9 +4,9 @@
 // freshly created vector from fill_vec to its caller. Scroll for hints!
 
 fn main() {
-    let vec0 = Vec::new();
+    //let vec0 = Vec::new();
 
-    let mut vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec();
 
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 
@@ -16,8 +16,8 @@ fn main() {
 
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
-    let mut vec = vec;
+fn fill_vec() -> Vec<i32> {
+    let mut vec = Vec::new();
 
     vec.push(22);
     vec.push(44);

exercises/primitive_types/primitive_types1.rs

@@ -10,7 +10,7 @@ fn main() {
         println!("Good morning!");
     }
 
-    let // Finish the rest of this line like the example! Or make it be false!
+    let is_evening = false; // Finish the rest of this line like the example! Or make it be false!
     if is_evening {
         println!("Good evening!");
     }

exercises/primitive_types/primitive_types2.rs

@@ -14,7 +14,7 @@ fn main() {
         println!("Neither alphabetic nor numeric!");
     }
 
-    let // Finish this line like the example! What's your favorite character?
+    let your_character = '%'; // 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/primitive_types/primitive_types3.rs

@@ -3,7 +3,7 @@
 // Scroll down for hints!
 
 fn main() {
-    let a = ???
+    let a = [3,4,5];
 
     if a.len() >= 100 {
         println!("Wow, that's a big array!");

exercises/primitive_types/primitive_types4.rs

@@ -5,7 +5,7 @@
 fn main() {
     let a = [1, 2, 3, 4, 5];
 
-    let nice_slice = ???
+    let nice_slice = &a[1..5];
 
     if nice_slice == [2, 3, 4] {
         println!("Nice slice!");

exercises/primitive_types/primitive_types5.rs

@@ -4,7 +4,7 @@
 
 fn main() {
     let cat = ("Furry McFurson", 3.5);
-    let /* your pattern here */ = cat;
+    let (name, age) = cat;
 
     println!("{} is {} years old.", name, age);
 }

exercises/primitive_types/primitive_types6.rs

@@ -5,7 +5,7 @@
 
 fn main() {
     let numbers = (1, 2, 3);
-    println!("The second number is {}", ???);
+    println!("The second number is {}", numbers.2);
 }
 
 

exercises/strings/strings1.rs

@@ -7,7 +7,7 @@ fn main() {
 }
 
 fn current_favorite_color() -> String {
-    "blue"
+    "blue".to_string()
 }
 
 

exercises/strings/strings2.rs

@@ -3,7 +3,7 @@
 
 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.");