== Argument passing ==
The sanctioned/default/de facto library for this is clap
=== Using arguments on cargo run ===
``` cargo run -- <argument1></argument1> <argument2></argument2> ```
== Comments ==
- The form //! is used to refer to the “current” item, the module that's just been enteredby the compiler
- We can just use it at the top of our files, for instance
- The form /// annotates whatever is immediately following it
== Files, reading ==
``` use std::fs::File; use std::io::BufReader; use std::io::prelude::*;
fn main() {
let f = File::open("readme.md").unwrap();
let reader = BufReader::new(f);
for line_ in reader.lines() {
let line = line_.unwrap();
println!("{} ({} bytes long)", line, line.len());
}
} ```
== Functions ==
- Using ! as a return type indicates to the Rust compiler that this function never returns
== STDIN, read from ==
``` let stdin = io::stdin(); let reader = stdin.lock(); \\ This produces a similar mechanism to the reader on BufReader ```
== Substraction that goes only down to 0 ==
``` let seven: usize = 7; seven.saturating_sub(9); \\ this never goes below 0 and avoids crashing ```
== Types ==
=== Make an Alias of another Type ===
``` type File = String; ```
=== Make a copy of another Type, have it treated as a completely new one ===
``` struct File(String); ``` This is called the newtype pattern