OnRails.org

The conference is about to start in 30 minutes, the room starts to buzz. The confreaks guys have their camera and video recording equipment all setup. So you will be able to catch up the conference online soon. Somehow I really like single track conferences and the sessions seem really great and will be fast passed, 30 to 45 minutes. Check out the schedule. So I will sit back and enjoy the show.

Follow it live on Justin TV!!

Salt Lake City is definitively a beautiful city, surrounded by it’s mountains…

After the release of 10.5, I published an article about building RMagick from source on Leopard. I won’t rehash the why, you can read the original article for that. My clean install necessitated updating the RMagick script, so here’s what worked for me to install from source on Snow Leopard! For the impatient, here’s the download link: rmagick-build.sh

First, we start with installing wget, as it seems to be a bit more clever than curl about dealing with mirrors, etc. Then, we compile and install each prerequisite package. Finally, we install the gem.

All the links in the script worked for me, but, depending on your location, network, conditions, etc, your mileage may vary. Enjoy!

#!/bin/sh

# install wget, which is cleverer than curl
curl -O http://ftp.gnu.org/gnu/wget/wget-1.11.tar.gz
tar zxvf wget-1.11.tar.gz 
cd wget-1.11
./configure --prefix=/usr/local
make
sudo make install
cd /usr/local/src

# prerequisite packages
wget http://nongnu.askapache.com/freetype/freetype-2.3.9.tar.gz
tar zxvf freetype-2.3.9.tar.gz
cd freetype-2.3.9
./configure --prefix=/usr/local
make
sudo make install
cd /usr/local/src

wget http://superb-west.dl.sourceforge.net/sourceforge/libpng/libpng-1.2.39.tar.gz
tar zxvf libpng-1.2.39.tar.gz
cd libpng-1.2.39
./configure --prefix=/usr/local
make
sudo make install
cd /usr/local/src

wget ftp://ftp.uu.net/graphics/jpeg/jpegsrc.v6b.tar.gz
tar xzvf jpegsrc.v6b.tar.gz
cd jpeg-6b
ln -s `which glibtool` ./libtool
export MACOSX_DEPLOYMENT_TARGET=10.6
./configure --enable-shared --prefix=/usr/local
make
sudo make install
cd /usr/local/src

wget ftp://ftp.remotesensing.org/libtiff/tiff-3.9.1.tar.gz
tar xzvf tiff-3.9.1.tar.gz
cd tiff-3.9.1
./configure --prefix=/usr/local
make
sudo make install
cd /usr/local/src

wget http://superb-west.dl.sourceforge.net/sourceforge/wvware/libwmf-0.2.8.4.tar.gz
tar xzvf libwmf-0.2.8.4.tar.gz
cd libwmf-0.2.8.4
make clean
./configure
make
sudo make install
cd /usr/local/src

wget http://www.littlecms.com/lcms-1.17.tar.gz
tar xzvf lcms-1.17.tar.gz
cd lcms-1.17
make clean
./configure
make
sudo make install
cd /usr/local/src

wget ftp://mirror.cs.wisc.edu/pub/mirrors/ghost/GPL/gs870/ghostscript-8.70.tar.gz
tar zxvf ghostscript-8.70.tar.gz
cd ghostscript-8.70
./configure  --prefix=/usr/local
make
sudo make install
cd /usr/local/src

wget ftp://mirror.cs.wisc.edu/pub/mirrors/ghost/GPL/gs860/ghostscript-fonts-std-8.11.tar.gz
tar zxvf ghostscript-fonts-std-8.11.tar.gz
sudo mv fonts /usr/local/share/ghostscript

# Image Magick
wget ftp://ftp.fifi.org/pub/ImageMagick/ImageMagick.tar.gz
tar xzvf ImageMagick.tar.gz
cd `ls | grep ImageMagick-`
export CPPFLAGS=-I/usr/local/include
export LDFLAGS=-L/usr/local/lib
./configure --prefix=/usr/local --disable-static --with-modules --without-perl --without-magick-plus-plus --with-quantum-depth=8 --with-gs-font-dir=/usr/local/share/ghostscript/fonts --disable-openmp
make
sudo make install
cd /usr/local/src

# RMagick
sudo gem install rmagick

UPDATE There is a bug with libgomp that breaks the convert utility (See comments below). the --disable-openmp configure option has been added to the script to fix this.

UPDATE 2 A new patchlevel of ImageMagick has been released that supersedes the original one referenced in this script, and the original has been removed from the server. Thanks to Sebastian for this update that will grab the latest release.

The Confreaks guys did setup their cameras, sound and lights, so you will certainly be able to see all the talks in a few weeks.

The conference takes place in Salt Lake City, the scenery is impressive as the city is surrounded by high mountains…even for someone living in Denver. The picture above was taken just before the conference starts and shows the atrium we gonna spend the next two days in. The talks looks really cool and tonight the Engine Yard’s Hackfest 2.0 in suite next to mine at the Hilton Salt Lake City Center.

The first two days of the training were really excellent. Great pace, clear explanations and samples, very technical, Chad and Dave really rock at Ruby.

Making Domain-Specific Languages

We start with a discussion on DSL versus an API.

Meat-and-Potato DSLs

• Block based API.
• Directly manipulating domain model classes
• Defining classes and methods
• Manually typing repetitive, low-level code

Example is Rake. Rake is a dependency oriented programming language.

Eexample from Dhaka (a paraser generator)

for_pattern("\n") do
 create_token("newline")
end

method_missing Trick

require 'pp'

class CommandListener
  def initialize
    @commands = []
  end

  def method_missing(*args)
    @commands << args
    self
  end
end

listener = CommandListener.new

listener.instance_eval do
  this object accepts whatever you type and stores it
end
pp listener

outputs:

#<CommandListener:0x80264
 @commands=
  [[:you, CommandListener],
   [:whatever, #<CommandListener:0x80264 ...>],
   [:accepts, #<CommandListener:0x80264 ...>],
   [:object, #<CommandListener:0x80264 ...>],
   [:this, #<CommandListener:0x80264 ...>],
   [:it],
   [:stores, #<CommandListener:0x80264 ...>]]>

listener = CommandListener.new
listener.instance_eval do
  this.object.accepts.whatever.commands.and.stores.it
end  

pp listener

outputs:

#<CommandListener:0x712b4
 @commands=
  [[:this],
   [:object],
   [:accepts],
   [:whatever],
   [:commands],
   [:and],
   [:stores],
   [:it]]>

Note any keyword can be used with method_missing…E.g. freeze is not a missing method.

Now by using a BlankSlate object we can avoid this issue:

class BlankSlate
  instance_methods.each do |method|
    undef_method(method) unless method =~ /^__/ || method == 'instance_eval'
   end
end

We can now create a command listener that can use any commands:

require 'pp'

class CommandListener < BlankSlate
  def initialize
    @commands = []
  end

  def method_missing(*args)
    @commands << args unless [:inspect, :to_s].include? args.first 
    self
  end

  def pretty_print(pp)
    pp.output.write @commands.inspect
  end

end

listener = CommandListener.new

listener.instance_eval do
  You can even type freeze!
end
pp listener

And we get the following output:

[[:freeze!], [:type, #<CommandListener:0x7ee28>], [:even, #<CommandListener:0x7ee28>], [:can, #<CommandListener:0x7ee28>], [:You, #<CommandListener:0x7ee28>]]

On the same principals we just create a morse encoder, and of course Dave had to show off and interface with the speech function of OSX and another version that interfaces with the MIDI controller.

Exotic Control Flow

Creating a loop with continuations

def start_loop
  callcc{|c|c }
end

def end_loop(c)
  c.call(c)
end

i = 0
again = start_loop

  puts i
  i += 1

end_loop(again) unless i > 5

Moving on…

We voted on what to cover next as we won’t have time to cover every thing…and the winners are:

* Concurrency                  ..................
* Debugging/Profiling          ................
* JRuby                        ......
* Ruby Extras                  ...........
* Distributed Programming      ......................

Distributed Programming

DRb

Marshaling

>> h = {:x => 1} >> Marshal.dump(h) => ”\004\b{\006:\006xi\006” >> Marshal.load(_) => {:x=>1}

DRB Server

require 'drb/drb'
require 'ostruct'

DRb.start_service("druby://localhost:4321", OpenStruct.new)
DRb.thread.join

DRb Client

DRB.start_service
o = DRbOject.new_with_url("druby:''localhost:4321")
o.last_accessed = Time.now
o.some_other_arbitrary_method = "Set this on the open struct"

By default Pass-by-value, but can be Pass-by-reference can be enabled by including DRbUndumped.

• Rinda
• Ring

...

That’s all Folk! ...my hands/brain where running tired during the last hour :-)

That was an incredible 3 days thanks to Chad and Dave. So if you want to dive deeper in Ruby, the Advanced Ruby is the best way to get there!

Enjoy! Daniel

 
1.class.ancestors
=> [Fixnum, Integer, Numeric, Comparable, Object, Kernel, BasicObject]

1.class.instance_methods(false)
=> [:to_s, :-@, :+, :-, :*, :/, :div, :%, :modulo, :divmod, :fdiv, :**, :abs, :magnitude, :==, :<=>, :>, :>=, :<, :<=, :~, :&, :|, :^, :[], :<<, :>>, :to_f, :size, :zero?, :odd?, :even?, :succ]

m = 1.method(:inspect)
=> #<Method: Fixnum(Kernel)#inspect>

...make it fast.

Benchmarking

require 'benchmark'
puts Benchmark.measure {(1..1000000).map{|num| ""+num.to_s}}
  0.940000   0.050000   0.990000 (  1.001714)

puts Benchmark.measure {(1..1000000).map{|num| ""+num.to_s}}
  1.800000   0.050000   1.850000 (  1.850319)

require 'benchmark'
Benchmark.bm do |b|
  b.report("map") {(1..1000000).map{|num| ""+num.to_s}}
  b.report("inject") {(1..1000000).inject(""){|accum, num| ""+num.to_s}}
end
      user     system      total        real
map  1.970000   0.070000   2.040000 (  2.077786)
inject  1.910000   0.010000   1.920000 (  1.978541)

Don't Use Ruby

require 'dl/import'
require 'dl/struct'

memoization

def fib(n)
 @k||={}
 n<=2 ? 1 : (@k[n-1]||=fib(n-1))+(@k[n-2]||=fib(n-2))
end

puts fib(200)
280571172992510140037611932413038677189525

Program exited with code #0 after 0.02 seconds

def fib(n)
  if n <= 2 
      1
  else
     fib(n-1) + fib(n-2)
  end
end

alias :pre_memoized_fib :fib

def fib(n)
  @cache ||= {}
  @cache[n] ||= pre_memoized_fib(n)
end

The Ruby Object Model

class << str   # << opens up the singleton class. Arrows seem to go wrong way.
  p self  # ghost class: <Class:#<String:0x1d0ec>> - class of the class String
  def speak
    puts "miaow"
  end
end

puts str.speak

class Dave
  class << self   # puts the methods into the singleton class and becomes class methods
    def do_something      
    end
  end
end

class Person < Struct.new(:name, :age)
  def greet
      puts "Hello #{self.name}"
  end
end

f = Person.new("Chad", 28)

module Logger
  def log(msg)
    puts msg
  end
end

class Album
  include Logger
end


Album.ancestors # => [Album, Logger, Object, Kernel]
# Note that Logger becomes ancestor of Album...It's insert a generated class named after the module that shares the method table.

module Speak
  def hello
     puts "hello"
  end
end

str = "cat"
str.extend Speak

puts str.hello

Metaprogramming

Library Organization

Let’s get started. I’m at the Advanced Ruby training. Here are the topics we gonna cover

• Blocks, Procs, and Closures
• Ruby 1.9
• Your Own, Private Ruby
• Design in a Dynamic Language
• Messin’ with Types
• ...make it fast.
• The Ruby Object Model
• Metaprogramming
• Making Domains-Specific Languages
• Concurrency
• Exotic Control Flow
• Library Organization
• Debugging and Profiling
• JRuby
• Ruby Extras
• Distributed Programming
• Onward and Upward!

In fact when I saw the topics that will be covered by Dave Thomas and Chad Fowler, and the fact that some of my collogues from Pinnacol where attending I had to join…Oh yea, it’s a 25 minute drive from home too.

cd ruby-1.9.1-p0
autoconf
./configure --prefix=/usr/local/ruby1.9
make
sudo make install

Then you can check the version by

 
$/usr/local/ruby1.9/bin/ruby -v 
ruby 1.9.1p0 (2009-01-30 revision 21907) [i386-darwin9.6.0]
$/usr/local/ruby1.9/bin/irb 
RUBY_VERSION 
=> "1.9.1"

I didn’t add /usr/local/ruby1.9/bin to my path, so the default ruby is still my mack default, 1.8.6 of my mac (ruby 1.8.6 (2008-03-03 patchlevel 114) [universal-darwin9.0]).

Keep on reading to see some of the code we are walking through. This said it’s hard to convey how much value Chad and Dave are passing along with all their deep explanations of each of the examples…

Objectives

Deep The “Why” not just the “How” Explore Ruby’s Lesser-kown Corners Pragmatic, not Dogmatic Discussion for Highest Group Value

Blocks, Procs, and Closures

Blocks

one two {...} # binds to #two, and result of that is passed to one

one two do … end # block bind to #one, and two is passed to as argument.

Built-in support:

• block_given?
• loop
• yield
• break, redo, next, retry

def show_break
  puts "before yield"
  yield
  puts "after yield" # never make it here
end

puts "before call"
result = show_break do
  puts "before break"
  break 123
  puts "after break" # never make it here
end
puts "after call, result = #{result}"

The output of the above code is

before call
before yield
before break
after call, result = 123

Then Dave and Chad explain in details the next, redo, and retry keywords. Note retry is removed in 1.9.

Blocks Into Objects

def show_block_param(&block)
  puts block.inspect  # use the blokc
  [1,2,3].each &block # pass the block along
  puts block.call
  yield
end

show_block_param { puts "in block"}

Using lambda, proc, and Proc.new

• 1.8: proc and lambda are synonyms
• 1.9: proc and Proc.new are synonyms

So don’t use proc. Lambda closer to method calling Proc.new uses parallel assignment rules for parameter passing

Proc.new { |a,b| }.call(1,2,3) # OK
lambda { |a,b| }.call (1)  # ArgumentError: wrong number of args (1 for 2)

Dave goes onto the parameters and yield, followed by Return form blocks.

def meth(&block)
  block.call
end

b = Proc.new { return 99 }
puts meth(&b) # LocalJumpError: unexpected return

Bindings

Encapsulate the context at a point of execution

class A
  attr_writer :ivar
  def initialize
    @ivar = 123
  end
  def get_binding
    ivar = "ivar"
    binding
  end
end

a = A.new
bind = a.get_binding { "block value" }
eval "puts ivar", bind  # => ivar
eval "puts @ivar", bind # => 123

a.ivar = "new value"
eval "puts ivar", bind  # => ivar
eval "puts @ivar", bind # => new value

Closures

Blocks carry with them the binding in which they were created

def block_in_sandbox(param)
  ivar = "local variable"
  lambda do
    puts "param = #{param}"
    puts "ivar = #{ivar}"
  end
end

block = block_in_sandbox(99)
block.call

# param = 99
# ivar = local variable

Then we moved onto an exercise to create a counter with what we just learned:

require 'test/unit'
def counter(start=0, increment=1)
  start -= increment
  lambda do
    start += increment
  end
end

class CounterTest < Test::Unit::TestCase

    def test_counter
      result = counter(0,2)
      assert_equal 0, result.call
      assert_equal 2, result.call
      assert_equal 4, result.call
    end

    def test_another_one
      another_one = counter(10, 3)
      assert_equal 10, another_one.call
      assert_equal 13, another_one.call
      assert_equal 16, another_one.call
    end
end

# 2 tests, 6 assertions, 0 failures, 0 errors

Blocks, closures, and define_method

class Example
  def self.create_multiplier(name, factor)
    define_method(name) do |arg|
      arg * factor
    end
  end
end

Example.create_multiplier(:double, 2)
Example.create_multiplier(:triple, 3)

eg = Example.new
puts eg.double(33) # 66
puts eg.triple(33) # 99

Ruby Internals

Now we are going lower level than we want to…Looking at the source of Ruby:

• Main interpreter in top-level source
• Ruby libraries in lib/
• C libraries in ext/
• Architecture-sepcific stuff in bcc32/, win32/, wince/ and 68k/

Most important files parse.y and eval.c

If you install ruby like I listed at the start of this entry you have all the source files, I have mine under /Users/daniel/Downloads/ruby-1.9.1-p0. Opening in textmate it looks as follows

ParseTree shows the nodes

sudo gem install ParseTree Successfully installed RubyInline-3.8.1 Successfully installed sexp_processor-3.0.1 Successfully installed ParseTree-3.0.3

require 'rubygems'
require 'parse_tree'

class Daniel
 def talk
    "salut"
 end
end

p = ParseTree.new
p.parse_tree(Daniel).to_yaml

--- 
- - :class
  - :Daniel
  - - :const
    - :Object
  - - :defn
    - :talk
    - - :scope
      - - :block
        - - :args
        - - :str
          - salut
=> nil

1. Note, doesn’t work i 1.9
2. In 1.9 can call the interpreter
3. Also ripper library, gives the output of the parse.

parse.y

Chad now explain how the parser works. In the parser.y you’ll find exactly how the parsing works. It’s over 10000 lines for Ruby 1.9

if_tail        : opt_else
        | keyword_elsif expr_value then
          compstmt
          if_tail
            {
            /*%%%*/
            $$ = NEW_IF(cond($2), $4, $5);
            fixpos($$, $2);
            /*%
            $$ = dispatch3(elsif, $2, $4, escape_Qundef($5));
            %*/
            }
        ;

expr_value    : expr
            {
            /*%%%*/
            value_expr($1);
            $$ = $1;
                if (!$$) $$ = NEW_NIL();
            /*%
            $$ = $1;
            %*/
            }
        ;

Naming Conventions

• NODE_XX type of a node
• rb_cXxxx class object for Ruby clas Xxx
• rb_mXxxx module object for Ruby module xxxx
• rb_xxx C-implementation of a Ruby method
• Qxxx immediate value of Qnil
• RXXXXXX

Object Representation

Look in ruby.h for definition

To find Classes and Modules you can search in the c files:

$ grep String *.c | grep rb_define_class
string.c:    rb_cString  = rb_define_class("String", rb_cObject);

If we look in string.c we see how the methods of the String Ruby class are defined in c.

    
void
Init_String(void)
{
#undef rb_intern
#define rb_intern(str) rb_intern_const(str)
    rb_cString  = rb_define_class("String", rb_cObject);
    rb_include_module(rb_cString, rb_mComparable);
    rb_define_alloc_func(rb_cString, str_alloc);
    rb_define_singleton_method(rb_cString, "try_convert", rb_str_s_try_convert, 1);
    rb_define_method(rb_cString, "initialize", rb_str_init, -1);
    rb_define_method(rb_cString, "initialize_copy", rb_str_replace, 1);
    rb_define_method(rb_cString, "<=>", rb_str_cmp_m, 1);
    rb_define_method(rb_cString, "==", rb_str_equal, 1);
    rb_define_method(rb_cString, "eql?", rb_str_eql, 1);
    rb_define_method(rb_cString, "hash", rb_str_hash_m, 0);
    rb_define_method(rb_cString, "casecmp", rb_str_casecmp, 1);
    rb_define_method(rb_cString, "+", rb_str_plus, 1);
...

Writing Extensions

Why?

• Interface to external libraries
• Performance
• Accessing internal
• Showing off

C-api is really nice.

Recipe is: create new directory, create source .c file. Create extconf.rb script and run it (requires ‘mkmf’). make. make install…It just all works.

Practice in your own user-local Ruby copy.

Example wrapping the Tidy library.

And onto lunch and exercise…Back at 1:15pm

• How many build-in classes define a to_i method?
• What’s the difference between Symbol#to_i and Symbol#to_int?

Ruby 1.9

• Encoding support and multinationalization
• Method Calling
• Blocks, Procs, and Iterators
• Regular Expressions
• Fibers
• Lots more…
• Performance

The 1.9 rdoc can be found here

# default argument values not only at end of argument list.

def lunch(spam=false, how_much)
  spam ? puts("no thanks") : puts(how_much)
end

lunch(2)
lunch(true, 2)

#symbol to proc backed in

puts ['daffy', 'donald'].map(&:upcase)

# enumerator

e = [1,2,3].each
p e.next
p e.next
e.rewind
p e.next

# Enumerator halts loops

letters = ('a'..'e').to_enum
loop do 
    puts "STARTING: #{letters.next}"   # .next Stops the loop at the end by raising StopIteration. Can call it your self.
end
puts "DONE"

# Stabby Procs

l = lambda{|x,y| "woo ugly #{x+y}"}.call(1,2) # 1.8
puts l

l =->x,y{"woo ugly #{x+y}"}.(1,2)  # 1.9
puts l

# === is Margic

less_than_one_thousand =-> v{v<1000}
divisible_by_three =->v{v % 3 ==0}

case 909
 when less_than_one_thousand
     puts "#is Less than a thousand"
 when divisible_by_three
     puts "is Divisible by three" 
end   

puts  1005 ===  less_than_one_thousand

# Block paramters always local to block

n = 123
10.times do |n|
end
puts n  

# Can declare block-local varaibles

number_processded = 12
pizza_shop =->(orders; number_processded) do  # ; means use outside scope
  puts "inside:#{number_processded}"
end

pizza_shop[["pepperoni", "anchovies"]]
puts "number_processded:#{number_processded}"

# Curry

adder =->(x,y){x+y}.curry
add_three = adder.(3)
# add_three.(1,2)  ArgumentError: wrong number of arguments (3 for 2)
add_four = adder[4]

#  Reglar Expression - (?<name>pattern)

if /(?<key>\w+)=(?<value>.*)/ =~ "ruby=cool and fun" 
    puts key
    puts value
end

# Reglar Expression  
# see http://pragdave.blogs.pragprog.com/pragdave/2008/10/fun-with-ruby-19-regular-expressions.html

# Fibers

fibs = Fiber.new do
  n1 = n2 = 1
  loop do 
    Fiber.yield n1
    n1, n2 = n2, n1+n2
    puts "n1:#{n1} n2:#{n2}"
  end  
end  

10.times { print fibs.resume}

# Fibers - continuation

require 'continuation'  # basis of continuation
require 'fiber'         # symetrical coroutines

More Ruby 1.9 goodness

• RubyGems now backed in
• BasicObject
• Ripper: access to the parser
• Object#tap and Object#p
• Enumerable#cycle
• Hashes now retina their order
• Hash#select
• Minitest and minispec

# from http://pragdave.blogs.pragprog.com/pragdave/2008/04/babydoc.html

require 'ripper/filter'
require 'ripper'

# This class handles parser events, extracting
# comments and attaching them to class definitions
class BabyRDoc < Ripper::Filter
  def initialize(*)
    super
    reset_state
  end

  def on_default(event, token, output)
    reset_state
    output
  end

  def on_sp(token, output) output end
  alias on_nil on_sp

  def on_comment(comment, output)
    @comment << comment.sub(/^\s*#\s*/, "    ")
    output
  end

  def on_kw(name, output)
    @expecting_class_name = (name == 'class')
    output
  end

  def on_const(name, output)
    if @expecting_class_name
      output << "#{name}:\n"
      output <<  @comment
    end
    reset_state
    output
  end

  private

  def reset_state
    @comment = ""
    @expecting_class_name = false
  end
end

BabyRDoc.new(File.read(__FILE__)).parse(STDOUT)

Performance

It’s really faster. Chad is showing some benchmarks, but experiencing makes you believe.

How to use 1.9 without blowing up your production version?

• Download or checkout source
• autoconf (if checked out)
• ./configure
• make
• make test
• sudo make install

Install’s it in /usr/local/ruby.

Now you may want to prefer installing it in it’s own directory. Then do

• ./configure—prefix=/usr/local/ruby19
• export PATH=/usr/local/ruby1.9/bin/:$PATH

When you install gems it install them in the ruby version you use to run the gem install.

require 'rbconfig'
puts RbConfig::CONFIG

But wait…you can make it better. Dave installs it in it’s home folder.

• ./configure—prefix=/Users/dave/ruby19

Design in a Dynamic Language

• Can write in Java style, but it’s better to write using ruby.
• Inheritance (is-a) .vs. Composition (has-a)
• Inheritance is the work of the devil
• Inheritance the exception, composition the norm

Composition

  require 'forwardable'
  class Queue
    extend Forwardable

    def initialize
      @q = [ ]    # prepare delegate object
    end

    # setup prefered interface, enq() and deq()...
    def_delegator :@q, :push, :enq
    def_delegator :@q, :shift, :deq

    # support some general Array methods that fit Queues well
    def_delegators :@q, :clear, :first, :push, :shift, :size
  end

I couldn’t make it this year to RubyConf so I am really thankful to see that most of the presentations are online at confreaks. It’s just awesome that these videos are made available online and so quickly after the conference and for free. It’s a real tribute to the Ruby community and it’s open and sharing spirit. Thanks guys! My understanding is that the rubyconf pays Confreaks to take, processes and distribute these videos. Let me know if the arrangement is different, to give credit where credit is due. Thanks RubyConf and the presenters, and good job Confreaks.

Here are the videos I selected for my commute this week.

• Keynote – Dave Thomas
• Questions & Answers – Yukihiro ‘Matz’ Matsumoto

• Introducing Red Sun – Ruby to Flash – Jonathan Branam
• MacRuby: Ruby for your Mac – Laurent Sansonetti
• OS X Application Development with HotCocoa – Rich Kilmer
• Hacking with ruby2ruby – Marc Chung
• Using Git in Ruby Applications – Scott Chacon

• Adrenaline-Driven Development – Bruce Williams
• Fear of Programming – Nahaniel Talbott
• Recovering from Enterprise – Jamis Buck

View the full list of videos available here.

You may wonder why I would watch videos during my commute. Effectively I drive 40 minutes each way to my customers (happen to be both near enough for me to drive and not tele-commute) and this gives me a chance to catch up on many of the excellent screencast and podcast out there. Now when one screencast really sticks out, I watch it again at night…without driving ;-).

This said I converted the confreaks small videos format (640×240) to the iPhone format using Quicktime pro, but I only get the sound…which is fine for my commute. Any hint on how I can convert them to also get the video going would be appreciated?

Enjoy! Daniel