Intro to Rust Programming Language

Shared on Shanghai Ruby Tuesday

1. Introduction to Rust zete@odigo.jp github.com/luikore
2. Design • No VM, no GC, compile time checks • Trait based, functional • LLVM as compiler backend • Comes with a Package and Build System: cargo
3. Design • Similar to Swift in many aspects • https://lobste.rs/s/mc9rgv/ rust_creator_graydon_hoare_s_thoughts_on_swift
4. History • Graydon Hoare (just left Mozilla) • Failure of ECMAScript4 • Appear from 2010 • Servo: Mozilla’s new browser engine
5. Inspiration • D - better C++ with engineering features • Haskell - pure functional • Ruby - beautiful block syntax • Scala - adding functional to a legacy OO language • Cyclone - a type safe dialect of C (like Nim)
6. Hello World • brew update; brew install rust • rustc hello.rs; ./hello
7. Notes on Basic Syntax • fn is how you declare a function • Statements separate by ; • println! is a macro, first arg must be literal • Entrance is main • Comment with //
8. Notes on Struct
9. Notes on {:fmt}
10. Cargo crates • cargo new foo --bin • cargo build • cargo run
11. Trait Based System • Separate Data and Behavior • trait can act as interface or partial implementation • trait can inherit and form hierarchy
12. Trait Example
13. Generics • Reusing code for static typed language
14. Generics
15. We can Gives Compiler Much Info via Generics
16. Type Inference (why need it) • Verbosity of static typing: need to write down the type twice or more
17. Type Inference Variants • Hindley-Damas-Milner Inference (Haskell is a variant of H-M inference) • Poor man’s type system (only local inference) • Type deduction
18. Type Inference (deduction) • C++ and Golang are only type deductions
19. Type Inference (generic inference) • Rust: generic enhanced inference
20. Pointers (or reference) • Pointer is memory address with type info • By default: pass by value, not by reference • In Rust, usually you don’t need pointers (passing small structs may be more efficient)
21. Pointer Kinds • Managed — reference counted • Owned — not reference counted • Borrowed — borrow from some one else’s owned pointer
22. Null Pointer • params[:photos].each {…} # NoMethodError!
23. Null Pointer (solution) • Forbid use of possibly uninitialized variable • Option with Pattern Match
24. Pattern Match
25. Borrow Pointer • 0 to N references (&T) to a resource • exactly one mutable reference (&mut T)
26. Borrow Pointer Caveats
27. Dangling Pointer • rust forbids dangling pointers like this: Point* foo() { Point point = {.x = 1, .y = 2}; return &point; // bang! }
28. Dangling Pointer (solution) • Lifetime rules
29. http server • hyper (web frameworks: iron and nickel) • mio • redis-rs
30. Caveats • Syntax a bit longer: ->, let mut, … • Complex concept of pointer type and ownership • LLVM package is large, compiling large project is slow • No actor or CSP-style concurrency? • Too late out to compete for the market
31. Rust by Example • http://rustbyexample.com/