2025-04-25

• Replaced Arch's rust-package with Arch's rustup package in WSL on home-laptop.

• Started (again) on The Rust Programming Language.

• https://gitlab.com/tevaughan/learning-rust
• Made hello_word subdirectory.
• What looks like function-call but with function-name terminating in '!' is a macro call, such as

  println!("Hello, world!");
  

• But I do not know what "macro call" means in rust.
  • For now, book suggests that knowing that a call is a macro is good because a real function obeys rules, and a macro might not obey those rules.
• Running cargo new project_name will usually make a new directory project_name and initialize it as a git-repository.
  • But this will not happen if the upper directory in which cargo is run is itself a git-repository.
  • Anyway, in project_name/src/main.rs will be the standard hello-world programe.
• Inside the project_name directory, running cargo build will build the project.
  • The executable will be target/debug/program_name.
• Inside project_name, running cargo run will (if necessary) build and (always) execute target/debug/program_name.
• cargo check is faster than cargo build and verifies that build will work but does not generate an executable.
• cargo build --release build the release-version instead of the debug-version.