Day 1

Opening

JEREMY WALKER @iHiD

MonoRail - one huge app that tries to do everything
Propono (https://github.com/meducation/propono)
- Pub/Sub pattern
- SNS to n SQS

require 'propono'

Propono.config do |config|
  config.access_key = "AKIAIPE2MSOM5ZFGQBCQ"
  config.secret_key = "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"
  config.queue_region = "eu-west-1"
end

require 'twitter'
@twitter = Twitter::REST::Client.new do |config|
  config.consumer_key = ""
  config.consumer_secret = ""
  config.access_token = ""
  config.access_token_secret = ""
end

# publisher.rb
require_relative 'config'
...
# subscribers.rb
require_relative 'config'
...

mruby: AltRuby

YUKIHIRO MATSUMOTO (@yukihiro_matz)

You-Key-Hero Matz-Motor
Varioius Ruby VMs
- MRI - Matz’s Ruby Interpreter
- Opal - Ruby to JS
- mruby (https://github.com/mruby/mruby)
  - 2-year project granted by METI
  - Matsumoto’s, eMbedded, Minimalistic (generational incremental GC), Modular
    - MRB_USE_FLOAT, MRB_NAN_BOXING, MRB_USE_IV_SEG?
    - Will work on any environment that can run a C99 compiler
    - mrbgems - gem install mgem (https://github.com/mruby/mgem-list)
      - mruby-arduino
      - etc.
    - API design is something between Ruby & Lua

Standard Library, Uncommon Uses

PIOTR SZOTKOWSKI @chastell http://talks.chastell.net/baruco-2014/

Signore (https://github.com/chastell/signore)
- signore prego [topic]
- yaml/store - transaction-based
- gserver (TCP server)
- Tom Dale - Rails Node Perl Lisp
- abbrev (https://github.com/rubysl/rubysl-abbrev)
- Levenshtein Distance - levenshtein gem
- drb/drb
- typo_finder?
Summary
- use a few more bits of core ruby
- persist with pstore
- serve with webrick
- …
- do play around with Enumerable
- use stdlib (WeakRef!) and contribute to its docs
- check out the levenshtein gem
- End of Line (stdlib posts)
- stop reinventing the wheel and come to ArrrCamp
- …

# code snippets
module_function?
threads.flat_map(&:value)?

“One does not simply tag-complete to Mordor”

Twenty Thousand Leagues Under ActiveRecord

PAT SHAUGHNESSY @pat_shaughnessy http://patshaughnessy.net/2014/9/17/20000-leagues-under-activerecord http://patshaughnessy.net/2014/9/23/how-arel-converts-ruby-queries-into-sql-statements

Jules Verne - Vingt Mille Lieues sous Les Mers
http://en.wikipedia.org/wiki/Captain_Nemo
ActiveRecord
Agenda
- ActiveRecord::Relation
- all > where > order > limit

User.all.where(name: “Captain Nemo”)
    .order(arel_table[primary_key].asc)
    .limit(1).to_a

Generating SQL
- https://github.com/rails/arel
- Visitor pattern
- PostgreSQL
  - parse > Analyze and Rewrite > ? > ?
- Executing SQL
  - byson (new version of yak?)
- The B-Tree Algorithm
  - Balanced Tree Algorithm

Dive into the tools that you’re using

Release Responsibly

EMILY STOLFO @emstolfo http://www.slideshare.net/emstolfo/release-responsibly-maintaining-backwards-compatibility

Innovation and Stability are in conflict in Ruby community
Backwards compatibility
- Simple API
  - Configurability and Stability are at odds
  - Do
    - Add arguments with default values, so old method calls still work
    - Add methods
    - Add subclasses
  - Don’t
    - Add arguments without default values
    - …
  - Have a Compatibility module
  - Use Polymorphism instead of conditionals
  - Backport only when necessary
Clear communication
- Compatible with?
  - Define the scope of what you support
  - Test everything you support - MongoDB uses Jenkins to do this!
  - Changelog is important (http://keepachangelog.com/)
  - User trust should be a priority
  - Have a deprecation strategy (http://www.mongodb.com/support-policy)
  - Anticipate deprecations when designing
Semantic versioning

How I built my own Twitch-Plays-Pokémon

JOSÉ TOMÁS ALBORNOZ @eljojo http://ajipirijou.com/

Used Sinatra
Problems
- simulating keystrokes
- requires desktop environment
- latency
Built his own Gameboy emulator in Ruby
Conference Driven Development

Keep Software Weird

LEON GERSING @rubybuddha

Dominant culture, subculture, etc.
- We simulate reality and we know it.
- We lose touch with our actual reality.
- The simulated reality becomes real.
Scrum as an example
- Waterfall - dominant culture...
Invent reality
Perception is Reality

Morality is temporary, Wisdom is permanent Code is the representation of your current self at a point in time

A Dangerous Game: Safety in Ruby

RYAN LEVICK @itchyankles https://speakerdeck.com/rylev/a-dangerous-game-safety-in-ruby

Static typing

Redis.fetch(key: String): String
 Either...

What is the best testing library ever invented?
- compiler?
- puts?
- Math!
- Curry-Howard correspondence (http://en.wikipedia.org/wiki/Curry%E2%80%93Howard_correspondence)
  - For all inputs a valid and correct output is given
  - Always present and cannot be forgotten
  - Cannot be erased
  - The compiler is far less likely to be buggy than your tests
  - Test business logic

def head(list)
  if list.empty?
    # argument error!
  else
    list.first
  end
end

Idris

  # haskell
  head : Vect (S n) a -> a
  head (h::tail) = h
  # ruby
  x,y = [1,2]

No more runtime errors!
Erlang has this
Ruby is a tool, not the end solution to every problem

Lightning Talks

Oga XML/HTML parser written in Ruby

https://github.com/yorickpeterse/oga

91% Ruby
Supports MRI, Rubinius, Jruby
Thread-safe
XML/HTML parsing
XMl namespaces
XPath
CSS selectors (planned)
No system libraries

$ gem install oga

Let's Sketch Note

@malweene

works at DaWanda (http://en.dawanda.com/)
material/s - paper & pen
done is better than perfect

Shoes4 - Ruby for GUI

Tobias Pfeiffer @PragTob

GUI toolkit/DSL
cross-platform
packaging
all Ruby all the time
simple
JRuby + SWT

My Favourite Algorithm

@tomstuart

** Burrows-wheeler transform ** BANANA ANANAB NANABA ... ABANAN

sort then get last character
reversible

My Code Is More Popular Than Me

@philnash twilio

@GuyBrushPirate
Twitter bot?
https://github.co/philnash/guybot
@chuck_facts, @vindieselfacts
Write code, have fun, beware

Nomadic Programmer

@arnvald

Lesson No. 1: Don't get burned out Lesson No. 2: You can do everything Lesson No. 3: You can work anywhere

juanpaulo/gist:db59b0a8377b3065c8cd