Setting up the first Rust project

1. Prerequisites

On Windows: Install Visual Studio Community

• download from: link
• open installer
• make sure to select Desktop development with C++

On Unixes: Make sure to have a version of gcc or clang installed

• Ubuntu: sudo apt install build-essential
• Mac: brew install llvm (probably)
• BSD: pkg install lang/gcc

2. Download rustup

This is a tool that makes it easy to install the different components of the rust compiler

• on Windows, download the executable and run it
• on other OSes, run the command that begins with curl in a terminal
• type 1 to begin the install

3. Install Visual Studio Code (VSCode)

Go to the extensions page in the menu (a square made from 4 other squares, usually the last button) and install the following extensions

• rust-analyzer (id: rust-lang.rust-analyzer)
• C/C++ (id: ms-vscode.cpptools)
• Even Better TOML (id: tamasfe.even-better-toml)
• CodeLLDB (id: vadimcn.vscode-lldb)

Other optional extensions:

• Error lens (id: usernamehw.errorlens)

4. Create a new project

Cargo is a tool that helps building and packaging Rust applications. The usual workflow is:

• open a terminal
• cargo new hello_world => creates a new project with the name hello_world. This will also create a git repository for the project.
• cd hello_world => changes the directory in the newly created folder
• cargo build => builds the project
• cargo check => prints errors without actually building the application. Is used because it's faster than the build command.
• cargo run => builds and runs the project
• cargo fmt => formats the source code in the community approved code style

Right now, you should see Hello, world! on the terminal.

5. Listen to this at least four times

😃

6. Observe the files created by cargo

• Cargo.toml specifies meta information for our project like the name, the version, and the libraries that it uses
• .gitignore is a file that git checks in order to ignore files that are not needed to be committed.
• src/ is the folder that contains all the source files
• src/main.rs is the file that usually contains the main function ran at the start of the program

7. Open the project in VSCode

Type code . in the terminal

Or open a VSCode instance, go to File/Start=>Open folder=>navigate to the folder that contains Cargo.toml => OK

8. Run the program

Either by pressing the Run near the main, after the initial loading finishes.

Or:

• Go to menu and click the button with a triangle and a bug
• Click create a launch.json file

• Select LLDB
• Press Yes

Now you can use F5/Ctrl+F5 and the other commands to run and debug the application.

9. Debug shortcuts

Print example

#![allow(unused)]
fn main() {
let rabbits = 5;
println!("Hello world! I have {} rabbits.", rabbits);
}

Problems

At the end, upload all the problems below to a GitHub repository under a folder named lab01. Make sure to format (cargo fmt) your code before uploading.

1. Make a function that calculates if a number is prime, and call it with every number from 0 to 100, printing the primes.

2. Make a function that calculates if two numbers are coprime, and call it with pairs of every number between 0 and 100.

3. "Sing" the 99 bottles of beer problem.

Use the debugger after this: put a breakpoint on the first line of main, and run it line by line. Try to get familiar with the shortcuts. Observe the variables in the panel as they change.