Rust: Running Code & Tools

Compiling and running

rustc main.rs                # compile directly (rarely used)
cargo new my_project         # create a new project with Cargo
cd my_project
cargo run                   # compile and run
cargo build --release        # optimized release build

Cargo is Rust's build system and package manager. Almost everyone uses it instead of rustc directly.

Editors

• VS Code -- install the rust-analyzer extension (the official Rust language server)
• CLion + IntelliJ Rust plugin -- JetBrains IDE for Rust
• Vim/Neovim with rust-analyzer LSP server

Cargo essentials

cargo add serde              # add a dependency from crates.io
cargo remove serde           # remove a dependency
cargo test                   # run all tests
cargo test -- --nocapture    # run tests with stdout visible
cargo check                  # fast type-check without producing a binary
cargo clippy                 # run lints
cargo fmt                    # auto-format code

Project structure

A Cargo project:

my_project/
  Cargo.toml         # manifest (name, deps, metadata)
  src/
    main.rs          # entry point for binary
    lib.rs           # entry point for library

Testing

Tests go in the same file, inside a #[cfg(test)] module:

pub fn add(a: i32, b: i32) -> i32 { a + b }

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_add() {
        assert_eq!(add(2, 3), 5);
    }
}

Common resources

• The Rust Book -- official, comprehensive, free
• Rust by Example -- learn by doing
• crates.io -- the Rust package registry
• docs.rs -- documentation for every crate

Quick check below!