#+title: hands On system Programming
#+STARTUP: visual-line-mode

* Info about Cargo
+ Cargo is the Rust package manager
+ ~cargo new~ creates a new project
+ ~cargo new lib~ creates a new library
    - Unlike a binary, a library doesn't have a ~main~ function
    - And makes a lib.rs file instead of a main.rs file
+ We can use ~cargo doc~ to generate documentation for the project
** Manipulation
+ ~cargo build~ builds the project
+ ~cargo run~ builds and runs the project
+ ~cargo check~ checks the project for errors
+ ~cargo test~ runs the tests
* Generating Projects
** Gits
*** Gitignore
Its best to add ~/target/~ and ~**/*.rs.bk~ to gitignore in order to reduce redundant files
*** Pre Commit Hook
It runs a code before comitting code.
Put under ~.git/hooks/pre-commit~. It runs as shell code
* Rust
** Errors
+ For returning errors to console, we can use a ~?~. Which is equivalent to:
  #+begin_src rust
    if let Err(e) = io::stdout(){ 
                return Err(e);
            };
  #+end_src
  - The Easier way being:
  #+begin_src rust
    io::stdout()?;
  #+end_src
** dbg!()
Can be used to print out debug logs, not for actual printing
** lib.rs
A lot like a header file.
Every file thats mentioned gets a ~pub~ as a pre name
** Documentation
+ ~//!~ means documenting the enclosing item.
+ ~///~ Documents the item below it
+ It utilizes usual markdown syntax.\
+ The Code written in the markdown runs outside the library.
** Semantic Versioning
X.Y.Z = major.minor.patch
*** Rules
+ When < 1.0.0
  - 1.y is a breaking change
  - 1.0.z is a whatever change
+ WHen >= 1.0.0
  Uses [[https:semver.org/][Normal Semantic Versions]]
  - Major = Breaking Change
  - Minor = Adding Functionality
  - Patch = Bug Fixes