Solutions 4

exercises/clippy/clippy1.rs

@@ -6,15 +6,12 @@
 // check clippy's suggestions from the output to solve the exercise.
 // Execute `rustlings hint clippy1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 use std::f32;
 
 fn main() {
-    let pi = 3.14f32;
     let radius = 5.00f32;
 
-    let area = pi * f32::powi(radius, 2);
+    let area = f32::consts::PI * f32::powi(radius, 2);
 
     println!(
         "The area of a circle with radius {:.2} is {:.5}!",

exercises/clippy/clippy2.rs

@@ -1,12 +1,10 @@
 // clippy2.rs
 // Execute `rustlings hint clippy2` or use the `hint` watch subcommand for a hint.
 
-// 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/clippy/clippy3.rs

@@ -1,28 +1,26 @@
 // clippy3.rs
 // Here's a couple more easy Clippy fixes, so you can see its utility.
 
-// I AM NOT DONE
-
 #[allow(unused_variables, unused_assignments)]
 fn main() {
     let my_option: Option<()> = None;
-    if my_option.is_none() {
+    if let Some(x) = my_option {
-        my_option.unwrap();
+        x
     }
 
     let my_arr = &[
-        -1, -2, -3
+        -1, -2, -3,
         -4, -5, -6
     ];
     println!("My array! Here it is: {:?}", my_arr);
 
-    let my_empty_vec = vec![1, 2, 3, 4, 5].resize(0, 5);
+    let mut my_empty_vec = vec![1, 2, 3, 4, 5];
+    my_empty_vec.clear();
     println!("This Vec is empty, see? {:?}", my_empty_vec);
 
     let mut value_a = 45;
     let mut value_b = 66;
     // Let's swap these two!
-    value_a = value_b;
+    std::mem::swap(&mut value_a, &mut value_b);
-    value_b = value_a;
     println!("value a: {}; value b: {}", value_a, value_b);
 }

exercises/conversions/as_ref_mut.rs

@@ -3,24 +3,22 @@
 // and https://doc.rust-lang.org/std/convert/trait.AsMut.html, respectively.
 // Execute `rustlings hint as_ref_mut` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 // Obtain the number of bytes (not characters) in the given argument
 // Add the AsRef trait appropriately as a trait bound
-fn byte_counter<T>(arg: T) -> usize {
+fn byte_counter<T: AsRef<str>>(arg: T) -> usize {
     arg.as_ref().as_bytes().len()
 }
 
 // Obtain the number of characters (not bytes) in the given argument
 // Add the AsRef trait appropriately as a trait bound
-fn char_counter<T>(arg: T) -> usize {
+fn char_counter<T: AsRef<str>>(arg: T) -> usize {
     arg.as_ref().chars().count()
 }
 
 // Squares a number using AsMut. Add the trait bound as is appropriate and
 // implement the function body.
-fn num_sq<T>(arg: &mut T) {
+fn num_sq<T: AsMut<u32>>(arg: &mut T) {
-    ???
+    *arg.as_mut() = arg.as_mut().pow(2);
 }
 
 #[cfg(test)]

exercises/conversions/from_into.rs

@@ -35,10 +35,32 @@ impl Default for Person {
 // If while parsing the age, something goes wrong, then return the default of Person
 // Otherwise, then return an instantiated Person object with the results
 
-// I AM NOT DONE
-
 impl From<&str> for Person {
     fn from(s: &str) -> Person {
+        if s.len() == 0 {
+            return Default::default();
+        }
+
+        let mut person: Person = Default::default();
+        let parts: Vec<&str> = s.split(",").collect();
+
+        if parts.len() != 2 {
+            return Default::default();
+        }
+
+        if parts[0].len() > 0 {
+            person.name = parts[0].to_string();
+        } else {
+            return Default::default();
+        }
+
+        if let Ok(n) = parts[1].parse::<usize>() {
+            person.age = n;
+        } else {
+            return Default::default();
+        }
+
+        person
     }
 }
 

exercises/conversions/from_str.rs

@@ -28,8 +28,6 @@ enum ParsePersonError {
     ParseInt(ParseIntError),
 }
 
-// I AM NOT DONE
-
 // Steps:
 // 1. If the length of the provided string is 0, an error should be returned
 // 2. Split the given string on the commas present in it
@@ -46,6 +44,24 @@ enum ParsePersonError {
 impl FromStr for Person {
     type Err = ParsePersonError;
     fn from_str(s: &str) -> Result<Person, Self::Err> {
+        if s.len() == 0 {
+            return Err(ParsePersonError::Empty)
+        }
+
+        let parts: Vec<&str> = s.split(",").collect();
+
+        if parts.len() != 2 {
+            return Err(ParsePersonError::BadLen)
+        }
+
+        if parts[0].len() < 1 {
+            return Err(ParsePersonError::NoName)
+        }
+
+        match (parts[1].parse::<usize>()) {
+            Ok(age) => Ok(Person { name: parts[0].to_string(), age }),
+            Err(x) => Err(ParsePersonError::ParseInt(x))
+        }
     }
 }
 

exercises/conversions/try_from_into.rs

@@ -23,8 +23,6 @@ enum IntoColorError {
     IntConversion,
 }
 
-// I AM NOT DONE
-
 // Your task is to complete this implementation
 // and return an Ok result of inner type Color.
 // You need to create an implementation for a tuple of three integers,
@@ -38,6 +36,13 @@ enum IntoColorError {
 impl TryFrom<(i16, i16, i16)> for Color {
     type Error = IntoColorError;
     fn try_from(tuple: (i16, i16, i16)) -> Result<Self, Self::Error> {
+        let range = 0..=255;
+
+        if !range.contains(&tuple.0) || !range.contains(&tuple.1) || !range.contains(&tuple.2) {
+            return Err(IntoColorError::IntConversion);
+        }
+
+        Ok(Color { red: tuple.0 as u8, green: tuple.1 as u8, blue: tuple.2 as u8 })
     }
 }
 
@@ -45,6 +50,7 @@ impl TryFrom<(i16, i16, i16)> for Color {
 impl TryFrom<[i16; 3]> for Color {
     type Error = IntoColorError;
     fn try_from(arr: [i16; 3]) -> Result<Self, Self::Error> {
+        Color::try_from(&arr[..])
     }
 }
 
@@ -52,6 +58,17 @@ impl TryFrom<[i16; 3]> for Color {
 impl TryFrom<&[i16]> for Color {
     type Error = IntoColorError;
     fn try_from(slice: &[i16]) -> Result<Self, Self::Error> {
+        let range = 0..=255;
+
+        if slice.len() != 3 {
+            return Err(IntoColorError::BadLen)
+        }
+
+        if slice.iter().any(|n| !range.contains(n)) {
+            return Err(IntoColorError::IntConversion)
+        }
+
+        Ok(Color { red: slice[0] as u8, green: slice[1] as u8, blue: slice[2] as u8 })
     }
 }
 

exercises/conversions/using_as.rs

@@ -6,11 +6,9 @@
 // and returns the proper type.
 // Execute `rustlings hint using_as` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 fn average(values: &[f64]) -> f64 {
     let total = values.iter().sum::<f64>();
-    total / values.len()
+    total / values.len() as f64
 }
 
 fn main() {

exercises/macros/macros1.rs

@@ -1,8 +1,6 @@
 // macros1.rs
 // Execute `rustlings hint macros1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
@@ -10,5 +8,5 @@ macro_rules! my_macro {
 }
 
 fn main() {
-    my_macro();
+    my_macro!();
 }

exercises/macros/macros2.rs

@@ -1,14 +1,12 @@
 // macros2.rs
 // Execute `rustlings hint macros2` or use the `hint` watch subcommand for a hint.
 
-// 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` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
+#[macro_use]
-
 mod macros {
     macro_rules! my_macro {
         () => {

exercises/macros/macros4.rs

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

exercises/threads/threads1.rs

@@ -2,8 +2,6 @@
 // Execute `rustlings hint threads1` or use the `hint` watch subcommand for a hint.
 // This program should wait until all the spawned threads have finished before exiting.
 
-// I AM NOT DONE
-
 use std::thread;
 use std::time::Duration;
 
@@ -12,20 +10,20 @@ fn main() {
 
     let mut handles = vec![];
     for i in 0..10 {
-        thread::spawn(move || {
+        handles.push(thread::spawn(move || {
             thread::sleep(Duration::from_millis(250));
             println!("thread {} is complete", i);
-        });
+        }));
     }
 
     let mut completed_threads = 0;
     for handle in handles {
-        // TODO: a struct is returned from thread::spawn, can you use it?
+        handle.join();
         completed_threads += 1;
     }
 
     if completed_threads != 10 {
         panic!("Oh no! All the spawned threads did not finish!");
     }
-    
+
 }

exercises/threads/threads2.rs

@@ -3,9 +3,7 @@
 // Building on the last exercise, we want all of the threads to complete their work but this time
 // the spawned threads need to be in charge of updating a shared value: JobStatus.jobs_completed
 
-// I AM NOT DONE
+use std::sync::{Arc,Mutex};
-
-use std::sync::Arc;
 use std::thread;
 use std::time::Duration;
 
@@ -14,13 +12,14 @@ struct JobStatus {
 }
 
 fn main() {
-    let status = Arc::new(JobStatus { jobs_completed: 0 });
+    let status = Arc::new(Mutex::new(JobStatus { jobs_completed: 0 }));
     let mut handles = vec![];
     for _ in 0..10 {
         let status_shared = status.clone();
         let handle = thread::spawn(move || {
             thread::sleep(Duration::from_millis(250));
             // TODO: You must take an action before you update a shared value
+            let mut status_shared = status_shared.lock().unwrap();
             status_shared.jobs_completed += 1;
         });
         handles.push(handle);
@@ -29,6 +28,6 @@ fn main() {
         handle.join().unwrap();
         // TODO: Print the value of the JobStatus.jobs_completed. Did you notice anything
         // interesting in the output? Do you have to 'join' on all the handles?
-        println!("jobs completed {}", ???);
+        println!("jobs completed {}", status.lock().unwrap().jobs_completed);
     }
 }

exercises/threads/threads3.rs

@@ -1,8 +1,6 @@
 // threads3.rs
 // Execute `rustlings hint threads3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 use std::sync::mpsc;
 use std::sync::Arc;
 use std::thread;
@@ -28,11 +26,13 @@ fn send_tx(q: Queue, tx: mpsc::Sender<u32>) -> () {
     let qc = Arc::new(q);
     let qc1 = qc.clone();
     let qc2 = qc.clone();
+    let tx1 = tx.clone();
+    let tx2 = tx.clone();
 
     thread::spawn(move || {
         for val in &qc1.first_half {
             println!("sending {:?}", val);
-            tx.send(*val).unwrap();
+            tx1.send(*val).unwrap();
             thread::sleep(Duration::from_secs(1));
         }
     });
@@ -40,7 +40,7 @@ fn send_tx(q: Queue, tx: mpsc::Sender<u32>) -> () {
     thread::spawn(move || {
         for val in &qc2.second_half {
             println!("sending {:?}", val);
-            tx.send(*val).unwrap();
+            tx2.send(*val).unwrap();
             thread::sleep(Duration::from_secs(1));
         }
     });