almost done

REVISITS.md

@@ -30,6 +30,11 @@ return results to new Vec<i32> vector
 31) box.rs for smart pointer to allocate memory in recursive types
 32) arc.rs for atomic reference counters, moving ownershup to thread::spawn.
 33) rc.rs Rc::strong_count, Rc::new and Rc::clone, and drop(). Also note "In summary, if you need shared ownership in a single-threaded context, you can use Rc. If you need shared ownership across multiple threads, you should use Arc." Rc is faster and smaller than Arc
+34) Cow
+35) All threads exercises :(. handles and join methods for thread completion wait in the main thread.
+36) threads2 exercises important for understanding synchorization primitize Mutex
+37) threads3  - again - all threads exercises.
+38) all macros exercises
 
-clippy conversions macros threads
+conversions
 

exercises/clippy/clippy1.rs

@@ -6,12 +6,10 @@
 // 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 pi = f32::consts::PI;
     let radius = 5.00f32;
 
     let area = pi * f32::powi(radius, 2);

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 +1,27 @@
 // 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();
     }
 
     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 my_empty_vec = vec![1, 2, 3, 4, 5].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;
-    value_b = value_a;
+    std::mem::swap(&mut value_a, &mut value_b);
+    // value_a = value_b;
+    // value_b = value_a;
     println!("value a: {}; value b: {}", value_a, value_b);
 }

exercises/conversions/from_into.rs

@@ -35,10 +35,27 @@ 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.to_string().len() == 0 {  
+            Person::default()  
+        } else {
+            let person_attr: Vec<&str> = s.split(",").collect();
+            match person_attr.len() {
+                2 => match person_attr[0] {
+                    "" => Person::default(),
+                    _ => match person_attr[1] {
+                        "" => Person::default(),
+                        _ => match person_attr[1].parse::<usize>() {
+                            Ok(person_age) => Person{name: person_attr[0].to_string(), age: person_age},
+                            Err(_) => Person::default()
+                        }
+                    }
+                },
+                _ => Person::default()
+            }
+            
+        }
     }
 }
 

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 +1,7 @@
 // macros1.rs
 // Execute `rustlings hint macros1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
+#[macro_export]
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
@@ -10,5 +9,5 @@ macro_rules! my_macro {
 }
 
 fn main() {
-    my_macro();
+    my_macro!();
 }

exercises/macros/macros2.rs

@@ -1,12 +1,11 @@
 // macros2.rs
 // Execute `rustlings hint macros2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 fn main() {
     my_macro!();
 }
 
+#[macro_export]
 macro_rules! my_macro {
     () => {
         println!("Check out 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;
 
@@ -12,15 +10,16 @@ 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().unwrap();
         completed_threads += 1;
     }
 

exercises/threads/threads2.rs

@@ -3,25 +3,25 @@
 // 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;
 use std::thread;
 use std::time::Duration;
+use std::sync::Mutex;
 
 struct JobStatus {
     jobs_completed: u32,
 }
 
 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 = Arc::clone(&status);
         let handle = thread::spawn(move || {
             thread::sleep(Duration::from_millis(250));
             // TODO: You must take an action before you update a shared value
-            status_shared.jobs_completed += 1;
+            let mut status = (*status_shared).lock().unwrap(); //do a deref so you can do lock on Mutex sync primitive
+            status.jobs_completed += 1;
         });
         handles.push(handle);
     }
@@ -29,6 +29,6 @@ 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

@@ -1,10 +1,8 @@
 // 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::sync::{Arc, Mutex};
 use std::thread;
 use std::time::Duration;
 
@@ -24,23 +22,29 @@ impl Queue {
     }
 }
 
-fn send_tx(q: Queue, tx: mpsc::Sender<u32>) -> () {
+fn send_tx(q: Queue, mytx: Arc<Mutex<mpsc::Sender<u32>>>) -> () {
     let qc = Arc::new(q);
     let qc1 = Arc::clone(&qc);
     let qc2 = Arc::clone(&qc);
 
+    let tx1 = Arc::clone(&mytx);
+
     thread::spawn(move || {
         for val in &qc1.first_half {
             println!("sending {:?}", val);
-            tx.send(*val).unwrap();
+            let mytx = tx1.lock().unwrap();
+            mytx.send(*val).unwrap();
             thread::sleep(Duration::from_secs(1));
         }
     });
 
+    let tx2 = Arc::clone(&mytx);
+
     thread::spawn(move || {
         for val in &qc2.second_half {
             println!("sending {:?}", val);
-            tx.send(*val).unwrap();
+            let mytx = tx2.lock().unwrap();
+            mytx.send(*val).unwrap();
             thread::sleep(Duration::from_secs(1));
         }
     });
@@ -51,7 +55,8 @@ fn main() {
     let queue = Queue::new();
     let queue_length = queue.length;
 
-    send_tx(queue, tx);
+    let newtx = Arc::new(Mutex::new(tx));
+    send_tx(queue, newtx);
 
     let mut total_received: u32 = 0;
     for received in rx {