From 64d95837e9813541cf5b357de13865ce687ae98d Mon Sep 17 00:00:00 2001 From: Adam Brewer Date: Mon, 16 Oct 2023 07:37:12 -0400 Subject: Update Exercises Directory Names to Reflect Order --- exercises/smart_pointers/README.md | 12 ----- exercises/smart_pointers/arc1.rs | 45 ---------------- exercises/smart_pointers/box1.rs | 58 -------------------- exercises/smart_pointers/cow1.rs | 78 --------------------------- exercises/smart_pointers/rc1.rs | 105 ------------------------------------- 5 files changed, 298 deletions(-) delete mode 100644 exercises/smart_pointers/README.md delete mode 100644 exercises/smart_pointers/arc1.rs delete mode 100644 exercises/smart_pointers/box1.rs delete mode 100644 exercises/smart_pointers/cow1.rs delete mode 100644 exercises/smart_pointers/rc1.rs (limited to 'exercises/smart_pointers') diff --git a/exercises/smart_pointers/README.md b/exercises/smart_pointers/README.md deleted file mode 100644 index d56d2b6..0000000 --- a/exercises/smart_pointers/README.md +++ /dev/null @@ -1,12 +0,0 @@ -# Smart Pointers - -In Rust, smart pointers are variables that contain an address in memory and reference some other data, but they also have additional metadata and capabilities. -Smart pointers in Rust often own the data they point to, while references only borrow data. - -## Further Information - -- [Smart Pointers](https://doc.rust-lang.org/book/ch15-00-smart-pointers.html) -- [Using Box to Point to Data on the Heap](https://doc.rust-lang.org/book/ch15-01-box.html) -- [Rc\, the Reference Counted Smart Pointer](https://doc.rust-lang.org/book/ch15-04-rc.html) -- [Shared-State Concurrency](https://doc.rust-lang.org/book/ch16-03-shared-state.html) -- [Cow Documentation](https://doc.rust-lang.org/std/borrow/enum.Cow.html) diff --git a/exercises/smart_pointers/arc1.rs b/exercises/smart_pointers/arc1.rs deleted file mode 100644 index 3526ddc..0000000 --- a/exercises/smart_pointers/arc1.rs +++ /dev/null @@ -1,45 +0,0 @@ -// arc1.rs -// -// In this exercise, we are given a Vec of u32 called "numbers" with values -// ranging from 0 to 99 -- [ 0, 1, 2, ..., 98, 99 ] We would like to use this -// set of numbers within 8 different threads simultaneously. Each thread is -// going to get the sum of every eighth value, with an offset. -// -// The first thread (offset 0), will sum 0, 8, 16, ... -// The second thread (offset 1), will sum 1, 9, 17, ... -// The third thread (offset 2), will sum 2, 10, 18, ... -// ... -// The eighth thread (offset 7), will sum 7, 15, 23, ... -// -// Because we are using threads, our values need to be thread-safe. Therefore, -// we are using Arc. We need to make a change in each of the two TODOs. -// -// Make this code compile by filling in a value for `shared_numbers` where the -// first TODO comment is, and create an initial binding for `child_numbers` -// 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 mut joinhandles = Vec::new(); - - for offset in 0..8 { - let child_numbers = // TODO - joinhandles.push(thread::spawn(move || { - let sum: u32 = child_numbers.iter().filter(|&&n| n % 8 == offset).sum(); - println!("Sum of offset {} is {}", offset, sum); - })); - } - for handle in joinhandles.into_iter() { - handle.join().unwrap(); - } -} diff --git a/exercises/smart_pointers/box1.rs b/exercises/smart_pointers/box1.rs deleted file mode 100644 index 513e7da..0000000 --- a/exercises/smart_pointers/box1.rs +++ /dev/null @@ -1,58 +0,0 @@ -// box1.rs -// -// At compile time, Rust needs to know how much space a type takes up. This -// becomes problematic for recursive types, where a value can have as part of -// itself another value of the same type. To get around the issue, we can use a -// `Box` - a smart pointer used to store data on the heap, which also allows us -// to wrap a recursive type. -// -// The recursive type we're implementing in this exercise is the `cons list` - a -// data structure frequently found in functional programming languages. Each -// item in a cons list contains two elements: the value of the current item and -// the next item. The last item is a value called `Nil`. -// -// Step 1: use a `Box` in the enum definition to make the code compile -// Step 2: create both empty and non-empty cons lists by replacing `todo!()` -// -// Note: the tests should not be changed -// -// Execute `rustlings hint box1` or use the `hint` watch subcommand for a hint. - -// I AM NOT DONE - -#[derive(PartialEq, Debug)] -pub enum List { - Cons(i32, List), - Nil, -} - -fn main() { - println!("This is an empty cons list: {:?}", create_empty_list()); - println!( - "This is a non-empty cons list: {:?}", - create_non_empty_list() - ); -} - -pub fn create_empty_list() -> List { - todo!() -} - -pub fn create_non_empty_list() -> List { - todo!() -} - -#[cfg(test)] -mod tests { - use super::*; - - #[test] - fn test_create_empty_list() { - assert_eq!(List::Nil, create_empty_list()) - } - - #[test] - fn test_create_non_empty_list() { - assert_ne!(create_empty_list(), create_non_empty_list()) - } -} diff --git a/exercises/smart_pointers/cow1.rs b/exercises/smart_pointers/cow1.rs deleted file mode 100644 index fcd3e0b..0000000 --- a/exercises/smart_pointers/cow1.rs +++ /dev/null @@ -1,78 +0,0 @@ -// cow1.rs -// -// This exercise explores the Cow, or Clone-On-Write type. Cow is a -// clone-on-write smart pointer. It can enclose and provide immutable access to -// borrowed data, and clone the data lazily when mutation or ownership is -// required. The type is designed to work with general borrowed data via the -// Borrow trait. -// -// This exercise is meant to show you what to expect when passing data to Cow. -// Fix the unit tests by checking for Cow::Owned(_) and Cow::Borrowed(_) at the -// TODO markers. -// -// Execute `rustlings hint cow1` or use the `hint` watch subcommand for a hint. - -// I AM NOT DONE - -use std::borrow::Cow; - -fn abs_all<'a, 'b>(input: &'a mut Cow<'b, [i32]>) -> &'a mut Cow<'b, [i32]> { - for i in 0..input.len() { - let v = input[i]; - if v < 0 { - // Clones into a vector if not already owned. - input.to_mut()[i] = -v; - } - } - input -} - -#[cfg(test)] -mod tests { - use super::*; - - #[test] - fn reference_mutation() -> Result<(), &'static str> { - // Clone occurs because `input` needs to be mutated. - let slice = [-1, 0, 1]; - let mut input = Cow::from(&slice[..]); - match abs_all(&mut input) { - Cow::Owned(_) => Ok(()), - _ => Err("Expected owned value"), - } - } - - #[test] - fn reference_no_mutation() -> Result<(), &'static str> { - // No clone occurs because `input` doesn't need to be mutated. - let slice = [0, 1, 2]; - let mut input = Cow::from(&slice[..]); - match abs_all(&mut input) { - // TODO - } - } - - #[test] - fn owned_no_mutation() -> Result<(), &'static str> { - // We can also pass `slice` without `&` so Cow owns it directly. In this - // case no mutation occurs and thus also no clone, but the result is - // still owned because it was never borrowed or mutated. - let slice = vec![0, 1, 2]; - let mut input = Cow::from(slice); - match abs_all(&mut input) { - // TODO - } - } - - #[test] - fn owned_mutation() -> Result<(), &'static str> { - // Of course this is also the case if a mutation does occur. In this - // case the call to `to_mut()` in the abs_all() function returns a - // reference to the same data as before. - let slice = vec![-1, 0, 1]; - let mut input = Cow::from(slice); - match abs_all(&mut input) { - // TODO - } - } -} diff --git a/exercises/smart_pointers/rc1.rs b/exercises/smart_pointers/rc1.rs deleted file mode 100644 index 1b90346..0000000 --- a/exercises/smart_pointers/rc1.rs +++ /dev/null @@ -1,105 +0,0 @@ -// rc1.rs -// -// In this exercise, we want to express the concept of multiple owners via the -// Rc type. This is a model of our solar system - there is a Sun type and -// multiple Planets. The Planets take ownership of the sun, indicating that they -// revolve around the sun. -// -// Make this code compile by using the proper Rc primitives to express that the -// sun has multiple owners. -// -// Execute `rustlings hint rc1` or use the `hint` watch subcommand for a hint. - -// I AM NOT DONE - -use std::rc::Rc; - -#[derive(Debug)] -struct Sun {} - -#[derive(Debug)] -enum Planet { - Mercury(Rc), - Venus(Rc), - Earth(Rc), - Mars(Rc), - Jupiter(Rc), - Saturn(Rc), - Uranus(Rc), - Neptune(Rc), -} - -impl Planet { - fn details(&self) { - println!("Hi from {:?}!", self) - } -} - -#[test] -fn main() { - let sun = Rc::new(Sun {}); - println!("reference count = {}", Rc::strong_count(&sun)); // 1 reference - - let mercury = Planet::Mercury(Rc::clone(&sun)); - println!("reference count = {}", Rc::strong_count(&sun)); // 2 references - mercury.details(); - - let venus = Planet::Venus(Rc::clone(&sun)); - println!("reference count = {}", Rc::strong_count(&sun)); // 3 references - venus.details(); - - let earth = Planet::Earth(Rc::clone(&sun)); - println!("reference count = {}", Rc::strong_count(&sun)); // 4 references - earth.details(); - - let mars = Planet::Mars(Rc::clone(&sun)); - println!("reference count = {}", Rc::strong_count(&sun)); // 5 references - mars.details(); - - let jupiter = Planet::Jupiter(Rc::clone(&sun)); - println!("reference count = {}", Rc::strong_count(&sun)); // 6 references - jupiter.details(); - - // TODO - let saturn = Planet::Saturn(Rc::new(Sun {})); - println!("reference count = {}", Rc::strong_count(&sun)); // 7 references - saturn.details(); - - // TODO - let uranus = Planet::Uranus(Rc::new(Sun {})); - println!("reference count = {}", Rc::strong_count(&sun)); // 8 references - uranus.details(); - - // TODO - let neptune = Planet::Neptune(Rc::new(Sun {})); - println!("reference count = {}", Rc::strong_count(&sun)); // 9 references - neptune.details(); - - assert_eq!(Rc::strong_count(&sun), 9); - - drop(neptune); - println!("reference count = {}", Rc::strong_count(&sun)); // 8 references - - drop(uranus); - println!("reference count = {}", Rc::strong_count(&sun)); // 7 references - - drop(saturn); - println!("reference count = {}", Rc::strong_count(&sun)); // 6 references - - drop(jupiter); - println!("reference count = {}", Rc::strong_count(&sun)); // 5 references - - drop(mars); - println!("reference count = {}", Rc::strong_count(&sun)); // 4 references - - // TODO - println!("reference count = {}", Rc::strong_count(&sun)); // 3 references - - // TODO - println!("reference count = {}", Rc::strong_count(&sun)); // 2 references - - // TODO - println!("reference count = {}", Rc::strong_count(&sun)); // 1 reference - - assert_eq!(Rc::strong_count(&sun), 1); -} -- cgit v1.2.3