Rust for Rubyist

I'm learning basic Rust. As a veteran Rubyist with OOP skill, Rust is like another world to me. So I'll try to list the key differences and terminalogies in each language side by side.

Ruby	Rust	Note
Class/Module	Type/Trait	Traits are more like Interfaces
`rake`	`cargo`
Gems	Crates
-	Macros	Ruby has Metaprogramming, but I don't think it's the same.
`def`	`fn`
`print "#{var}"`	`println!("{}", var)`	Does Rust have string interpolation within quotes?
String	Char / String / String Slices
`#`	`//`	Comments in Rust are like in JavaScript/C
Array	Array / Vector	Array in Rust mostly be immutable, Vector can be mutable with `mut`
`nil`	`Option<Some, None>`	I like the `Option` thing in Rust
`case when`	`match`	Better pattern matching in Rust!
block { \|x\| x }	closure ( \|x\| x )
No semicolons	Semicolons (almost)
Duck Typing	Static Typing	Wait for Ruby 3!

I will add more when I read all essential docs and start making something with Rust.

(This page is still work in progress)