Here are the notes I took from day 2 of the Ruby Hoedown conference:

Calling Your Code: Gluing Phone Calls to Ruby

• [Troy spoke on how you can use Ruby to write voice applications with phone calls.]
• Asterisk - open source PBX & telephony platform
• Adhearsion - Ruby framework that sits on top of Asterisk.
• Typical flow:  PSTN -> SIP -> Asterisk -> AGI request (Asterisk Gateway Interface) -> Accept call with Adhearsion -> Run call flow
• Instead of administering the PBX manually, can use Asterisk to administer it in Ruby.
• There are various TTS (text to speech) engines (some much better than others).
• [Troy walked through a few live demos using mobile phone. There were problems, but overall it's impressive.]
• Example apps:
  • Yelpvox - call a #, then get surrounding restaurant information
  • SendSign - real estate flyer information service. If flyer box is empty, call the provided # to get information. Can then go to SendSign.com, enter in the phone # that you called from, and see the homes that you looked for.
  • Frucall - do online comparison shopping by calling a number and entering in a barcode of a product while you're in the store.
• What you need to get started:
  • Asterisk or FreeSwitch (available in virtual machine format)
  • Text to speech engine
  • SIP provider
  • DIDs (phone numbers)

Ruleby: The Rule Engine for Ruby

• We're used to imperative programming.
• It's nice, but the programmer should, ideally, understand all of the entire program (which is often impossible with imperative programming).
• Alternative: rules engines, rules-based paradigm
• Write rules declaritively, but don't specify how code runs.
• Ruleby uses a Ruby domain specific language (DSL) to specify rules
• Uses the Rete algorithm. Good, but exchanges memory for speed (be aware of this).

flog << Test.new

• Flog - continuous integration for code complexity.
• Evolution of a programmer:
  1. Lamer
  2. Haxor
  3. Cowboy
  4. Embryo (start to notice testing)
  5. Webelo
  6. Poseur (half-heartedly do testing)
  7. Human
  8. Apprentice
  9. Journeyman
• Test driving code in a greenfield scenario is much more different than testing existing code.
• Technique: don't change existing code without test covereage.
• Legacy code = code without tests (Michael Feather's book Working with Legacy Code)
• [Comments from the audience: This may just unnecessarily confuse the terms "untested code" and "legacy code". What if old code is well tested? Rails 1.0 is well tested, but is still legacy code.]
• So, for an existing app without tests, where do you start? Very basically, on the outside, pealing away layers.

Archaeopteryx: A Ruby Midi Generator

• [Presentation starts with live demo of electronic music driven by a Ruby script and edited live in a text editor to change the music's style.]
• I'm a former DJ.
• A lot of DJs are using laptops now, which should in theory, make computer geeks popular at parties.
• Venture capitalism is like the patronage system for artists and is stifling.
• Programmers are often distracted by shiny toys.
• Be profitable from the start by being small and cheap.
• I'm trying to create my own niche market using Archaeopteryx and MIDI controllers for DJ work.
• This is your brain on music book.
• I'm going to test my program by running it for 7 days at Burning Man.
• Good business is the best art. -Warhol
• [For sure it's an entertaining presentation, but there are too many rat holes and it comes off to me as scatter-brained.]

Lightning Talk: What Can We Learn?

• Ruby can be used in the "enterprise".
• While I don't want to use Rhino or Hibernate, we can learn a lot from Java's experiences.
• Whereas Ralis embraces convention whole-heartedly, Merb has good defaults set on a highly configurable backend.

Keynote: Ghosts of Ruby

• The Ruby language did, in fact, exist before Rails.
• Presently, version 1.8.6 has the highest adoption.
• 1.8.7 is a strange, present/future 1.8.6 with backported 1.9 features.
• 1.9.0 is not in widespread use.
• 1.9 features
  • New Enumerable methods. There are lots.
  • BasicObject - knows nothing, above Kernel in the class heirarchy.
  • New lambda literal constructor
    • -> () { }
    • A way to have blocks with method argument paramter semantics.
    • Ex: -> (a, b=1) { b } is like lambda { |a, b=1| } except that this is kinda invalid because how can you distinguish b=1 from the bitwise or operator.
• [Points out several things he finds personally peculiary in 1.9]