steveklabnik

require 'flog'
require 'flog_task'
require 'flay'
require 'flay_task'
require 'roodi'
require 'roodi_task'

FlogTask.new :flog, SOME_NUMBER_HERE, %w[app lib]
FlayTask.new :flay, OTHER_NUMBER_HERE, %w[app lib]
RoodiTask.new 'roodi', ['app/**/*.rb', 'lib/**/*.rb']

steveklabnik

My summary of https://www.youtube.com/watch?v=IqrwPVtSHZI

TL;DR:

Rails has a library, ActiveSupport, which adds methods to Ruby core classes. One of those methods is String#blank?, which returns a boolean (sometimes I miss this convention in Rust, the ?) if the whole string is whitespace or not. It looks like this: https://github.com/rails/rails/blob/b3eac823006eb6a346f88793aabef28a6d4f928c/activesupport/lib/active_support/core_ext/object/blank.rb#L99-L117

It's pretty slow. So Discourse (which you may know from {users,internals}.rust-lang.org) uses the fast_blank gem, which provides this method via a C implementation instead. It looks like this: https://github.com/SamSaffron/fast_blank/blob/master/ext/fast_blank/fast_blank.c

For fun, Yehuda tried to re-write fast_blank in Rust. Which looks like this:

steveklabnik

#![feature(lang_items, start)]
#![no_std]

#[link(name = "c")]
extern {
      fn puts(s: *const u8) -> isize;
        fn abort() -> !;
}

#[lang = "panic_fmt"]

steveklabnik

use std::rc::Rc;

fn main() {
    let x = Rc::new(5i);
    
    for _ in range(0, 10u) {
        println!("{}", x)
    }
}

steveklabnik

global start

section .text
bits 32
start:
    ; Point the first entry of the level 4 page table to the first entry in the
    ; p3 table
    mov eax, p3_table
    or eax, 0b11 ; 
    mov dword [p4_table + 0], eax

steveklabnik

   Compiling sparkles v0.1.0 (file:///C:/Users/steve/src/sparkles)
time: 0.003; rss: 17MB  parsing
time: 0.000; rss: 17MB  recursion limit
time: 0.000; rss: 17MB  crate injection
time: 0.000; rss: 17MB  plugin loading
time: 0.000; rss: 17MB  plugin registration
time: 0.241; rss: 89MB  expansion
time: 0.000; rss: 89MB  maybe building test harness
time: 0.000; rss: 89MB  maybe creating a macro crate
time: 0.000; rss: 89MB  checking for inline asm in case the target doesn't support it

steveklabnik

pub fn sum_loop(nums: &[i32]) -> i32 {
    let mut s = 0;

    for i in nums {
        s = s + i;
    }

    s
}

steveklabnik

fn add_to_mutable_reference(x: &mut i32) {
  *x +=1;
}

#[test]
fn mutable_reference_test() {
  let mut x = 5;
  let y = &mut x;

  mutable_reference(y);

steveklabnik

9:05- 9:25 1. Welcome and Introduction (20min)

• Operational Stuff (10min) [Ashley]

  • Introduction to instructors
  • Where are all the materials
  • Explain the schedule, when are breaks
  • Code of Conduct
  • What to do if you need help

• What is the intermezzOS project? (10min) [Steve]

steveklabnik

extern crate rand;
extern crate byteorder;

use std::io::{ Write };
use byteorder::{LittleEndian, WriteBytesExt};

const SAMPLE_RATE: u32 = 44100;
const CHANNELS: u32 = 1;
const HEADER_SIZE: u32 = 36;
const SUBCHUNK1_SIZE: u32 = 16;