Session1/bewisesh

exercises/enums/enums1.rs

@@ -1,11 +1,13 @@
 // enums1.rs
 // 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/enums/enums2.rs

@@ -1,11 +1,13 @@
 // enums2.rs
 // 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: i32, y: i32},
+    Echo(String),
+    ChangeColor(i32, i32, i32),
+    Quit
 }
 
 impl Message {

exercises/enums/enums3.rs

@@ -2,10 +2,12 @@
 // Address all the TODOs to make the tests pass!
 // 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 {
@@ -37,7 +39,12 @@ impl State {
     }
 
     fn process(&mut self, message: Message) {
-        // TODO: create a match expression to process the different message variants
+        match message {
+            Message::ChangeColor(color) => self.change_color(color),
+            Message::Echo(string) => self.echo(string),
+            Message::Move(position) => self.move_position(position),
+            Message::Quit => self.quit()
+        }
     }
 }
 

exercises/error_handling/errors1.rs

@@ -5,14 +5,13 @@
 // construct to `Option` that can be used to express error conditions. Let's use it!
 // 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/error_handling/errors2.rs

@@ -17,16 +17,17 @@
 // one is a lot shorter!
 // 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>();
-
-    Ok(qty * cost_per_item + processing_fee)
+    match qty 
+    {
+        Ok(value) => Ok(value * cost_per_item + processing_fee), _ => qty
+    }
+
 }
 
 #[cfg(test)]

exercises/error_handling/errors3.rs

@@ -4,11 +4,9 @@
 // Why not? What should we do to fix it?
 // 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";
 
@@ -20,6 +18,7 @@ fn main() {
         tokens -= cost;
         println!("You now have {} tokens.", tokens);
     }
+    Ok(())
 }
 
 pub fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {

exercises/error_handling/errors4.rs

@@ -1,7 +1,6 @@
 // errors4.rs
 // Execute `rustlings hint errors4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
 
 #[derive(PartialEq, Debug)]
 struct PositiveNonzeroInteger(u64);
@@ -14,7 +13,11 @@ enum CreationError {
 
 impl PositiveNonzeroInteger {
     fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
-        // Hmm...? Why is this only returning an Ok value?
+        if value < 0 {
+            return Err(CreationError::Negative)
+        } else if value == 0 {
+            return Err(CreationError::Zero)
+        }
         Ok(PositiveNonzeroInteger(value as u64))
     }
 }

exercises/error_handling/errors5.rs

@@ -23,7 +23,7 @@ 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/error_handling/errors6.rs

@@ -23,16 +23,16 @@ impl ParsePosNonzeroError {
     fn from_creation(err: CreationError) -> 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: i64 = s.parse().map_err(ParsePosNonzeroError::from_parseint)?;
     PositiveNonzeroInteger::new(x)
         .map_err(ParsePosNonzeroError::from_creation)
 }

exercises/intro/intro2.rs

@@ -2,8 +2,7 @@
 // Make the code print a greeting to the world.
 // Execute `rustlings hint intro2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 fn main() {
-    println!("Hello {}!");
+    let greeting = "World";
+    println!("Hello {}!", greeting);
 }

exercises/move_semantics/move_semantics1.rs

@@ -6,7 +6,7 @@
 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

@@ -7,7 +7,7 @@
 fn main() {
     let vec0 = Vec::new();
 
-    let mut vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec(&vec0);
 
     // Do not change the following line!
     println!("{} has length {} content `{:?}`", "vec0", vec0.len(), vec0);
@@ -17,8 +17,8 @@ fn main() {
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 }
 
-fn fill_vec(vec: Vec<i32>) -> Vec<i32> {
-    let mut vec = vec;
+fn fill_vec(vec: &Vec<i32>) -> Vec<i32> {
+    let mut vec = vec.to_vec();
 
     vec.push(22);
     vec.push(44);

exercises/move_semantics/move_semantics3.rs

@@ -17,7 +17,7 @@ fn main() {
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 }
 
-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

@@ -7,9 +7,8 @@
 // I AM NOT DONE
 
 fn main() {
-    let vec0 = Vec::new();
 
-    let mut vec1 = fill_vec(vec0);
+    let mut vec1 = fill_vec();
 
     println!("{} has length {} content `{:?}`", "vec1", vec1.len(), vec1);
 
@@ -20,7 +19,7 @@ fn main() {
 
 // `fill_vec()` no longer takes `vec: Vec<i32>` as argument
 fn fill_vec() -> Vec<i32> {
-    let mut vec = vec;
+    let mut vec = Vec::new();
 
     vec.push(22);
     vec.push(44);

exercises/move_semantics/move_semantics5.rs

@@ -8,8 +8,9 @@
 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/move_semantics/move_semantics6.rs

@@ -7,19 +7,19 @@
 fn main() {
     let data = "Rust is great!".to_string();
 
-    get_char(data);
+    get_char(&data);
 
-    string_uppercase(&data);
+    string_uppercase(data);
 }
 
 // Should not take ownership
-fn get_char(data: String) -> char {
+fn get_char(data: &str) -> 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/standard_library_types/arc1.rs

@@ -18,19 +18,18 @@
 // where the second TODO comment is. Try not to create any copies of the `numbers` Vec!
 // Execute `rustlings hint arc1` or use the `hint` watch subcommand for a hint.
 
-// 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 = // TODO
+        let child_numbers = shared_numbers.clone();
         joinhandles.push(thread::spawn(move || {
             let sum: u32 = child_numbers.iter().filter(|n| *n % 8 == offset).sum();
             println!("Sum of offset {} is {}", offset, sum);

exercises/strings/strings1.rs

@@ -2,13 +2,11 @@
 // Make me compile without changing the function signature!
 // Execute `rustlings hint strings1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 fn main() {
     let answer = current_favorite_color();
     println!("My current favorite color is {}", answer);
 }
 
 fn current_favorite_color() -> String {
-    "blue"
+    return "blue".to_string();
 }

exercises/strings/strings2.rs

@@ -2,8 +2,6 @@
 // Make me compile without changing the function signature!
 // 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) {
@@ -13,6 +11,6 @@ fn main() {
     }
 }
 
-fn is_a_color_word(attempt: &str) -> bool {
+fn is_a_color_word(attempt: String) -> bool {
     attempt == "green" || attempt == "blue" || attempt == "red"
 }

exercises/strings/strings3.rs

@@ -1,21 +1,16 @@
 // strings3.rs
 // 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!
-    ???
+    return input.trim().to_string();
 }
 
-fn compose_me(input: &str) -> String {
-    // TODO: Add " world!" to the string! There's multiple ways to do this!
-    ???
+fn compose_me(input: &str) -> String {    
+    return input.to_string() + " world!";
 }
 
 fn replace_me(input: &str) -> String {
-    // TODO: Replace "cars" in the string with "balloons"!
-    ???
+    return input.replace("cars", "balloons");
 }
 
 #[cfg(test)]

exercises/strings/strings4.rs

@@ -6,8 +6,6 @@
 // before the parentheses on each line. If you're right, it will compile!
 // No hints this time!
 
-// I AM NOT DONE
-
 fn string_slice(arg: &str) {
     println!("{}", arg);
 }
@@ -16,14 +14,14 @@ 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());
 }