Ryman

Help the docs!

So! The new tutorial will be focused on building several small projects in Rust. This example is the first one: a classic 'guessing game.' This was one of the first programs I wrote when I first learned C. 😄

I'd like the feedback of the community before I actually start writing the guide. So this code will be the final code of the first real example Rust programmers see. So I want it to be good. I don't claim this code is good, I just worked something out real quick.

The idea is that I will slowly build from hello world to this final code in steps, introducing one concept at a time. Here are the concepts I'd like a Rust programmer to understand by the time they're done:

Concepts

Ryman

Latency Comparison Numbers
--------------------------
L1 cache reference                            0.5 ns
Branch mispredict                             5   ns
L2 cache reference                            7   ns             14x L1 cache
Mutex lock/unlock                            25   ns
Main memory reference                       100   ns             20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy              3,000   ns
Send 1K bytes over 1 Gbps network        10,000   ns    0.01 ms
Read 4K randomly from SSD*              150,000   ns    0.15 ms

Ryman

Things that programmers don't know but should

(A book that I might eventually write!)

Gary Bernhardt

I imagine each of these chapters being about 2,000 words, making the whole book about the size of a small novel. For comparison, articles in large papers like the New York Times average about 1,200 words. Each topic gets whatever level of detail I can fit into that space. For simple topics, that's a lot of space: I can probably walk through a very basic, but working, implementation of the IP protocol.

Ryman

#[macro_use] extern crate nickel;
extern crate rustc_serialize;

use nickel::{Nickel, MediaType};
use rustc_serialize::json;

#[derive(RustcEncodable)]
struct Fruit<'a> {
    name: &'a str
}

Ryman

Sublime Text 2 – Useful Shortcuts (Mac OS X)

General

⌘T	go to file
⌘⌃P	go to project
⌘R	go to methods
⌃G	go to line
⌘KB	toggle side bar
⌘⇧P	command prompt

Ryman

Windstad to Heljarchen = 379
Windstad to Riverwood = 65
Windstad to Ivarstead = 43
Windstad to Helgen = 101
Windstad to Whiterun = 229
Windstad to Riften = 445
Windstad to Windhelm = 334
Windstad to Markarth = 384
Windstad to Solitude = 195
Windstad to Falkreath = 100

Ryman

Types

A type is a collection of possible values. An integer can have values 0, 1, 2, 3, etc.; a boolean can have values true and false. We can imagine any type we like: for example, a HighFive type that allows the values "hi" or 5, but nothing else. It's not a string and it's not an integer; it's its own, separate type.

Statically typed languages constrain variables' types: the programming language might know, for example, that x is an Integer. In that case, the programmer isn't allowed to say x = true; that would be an invalid program. The compiler will refuse to compile it, so we can't even run it.

Ryman

*~

Ryman

require 'octokit'

username     = ''
password     = ''
org_name     = 'honeypotio'
board_name   = 'The Agile Bear'
column_name  = 'Live/Done'
client = Octokit::Client.new(login: username, password: password)

user = client.user

Ryman

# This file extends and overrides parts of the ActiveAdmin DSL and internals
# in order to provide support for automatically displaying and editing images,
# which in our infrastructure are stored as URLs whose column names end in "img".
# Since this file will be reloaded frequently in the development environment,
# all operations done at load time (class_eval's, etc.) MUST be idempotent.

ActiveAdmin::Views::TableFor.class_eval do

  def img_column(col_sym=:img, title="Image")
    column title, sortable: false do |obj|