Ruby 2.0 What’s  new? 

About me @gee_forr Internet Solutions #rubyOnBeer I <3 Ruby 

History Big Changes Little Changes Install Deep Changes Eco System 

History 

Feb 24 1993 Dec 21 1995 Start  of  Xmas  Tradi.on Ruby’s History Language  starts  gaining   serious  trac.on I  want  a  language  more   powerful  than  Perl  and   more  OO  than  Python First  public  release 0.95 Dec 25 1996 1.0 1.2 Dec 1998 1.4 Aug 1999 1.6 Sep 2000 1.8 Aug 2003 Dec 13 2005 Rails  arrives  on  the   scene.  Arguably  the   start  of  Ruby’s  rise. Dec 2007 Language  hits  the  big   .me. 1.9 

Start  of  Xmas  Tradi.on Ruby’s History nguage  starts  gaining   rious  trac.on 1.8 Aug 2003 Dec 13 2005 Rails  arrives  on  the   scene.  Arguably  the   start  of  Ruby’s  rise. Dec 2007 Language  hits  the  big   .me. 1.9 Feb 24 2013 2.0 

Install 

The one true way The one true way ✦Update  RVM ✦rvm install ruby-2.0.0 ✦Update  rbenv ✦rbenv install 2.0.0-p0 RVM RBENV 

Deep Changes 

X BItmap Garbage Collection X X X X X 

No content

Heap based M&S Ruby  structures  are  divided  in  2     halves,  data  and  flags.  Each   structure  has  its  own  flag.  Mark   phase  trawls  through  heap  and   updates  FL_MARK  flag  in  every   object 1.9 GC RString diagram from: http://patshaughnessy.net/2012/3/23/why-you-should-be-excited-about-garbage-collection-in-ruby-2-0 

Bitmap marking All  mark  flags  for  heap  move  to   single  dedicated  data  structure.   1  for  In  Use,  0  for  Collectable. Flag  not  wriMen  to  data   structure,  much  more  friendly   to  copy-­‐on-­‐write 2.0 GC Heap diagram from: http://patshaughnessy.net/2012/3/23/why-you-should-be-excited-about-garbage-collection-in-ruby-2-0 

X Backward Compatible With 1.9 X X X X X 

X require() speed improvements X X X X X 

Big Changes 

X Keyword Arguments X X X X X 

Keyword Arguments def foo(foo: ‘bar’, baz: ‘qux’, **rest) # Do something end foo(baz: ‘qux’, foo: ‘frob’) Big Changes 

X Module Prepend X X X X X 

Module Prepend module IncludableModule def something; end end class MyClass prepend IncludableModule end Big Changes 

X Lazy Enumerators X X X X X 

Lazy Enumerators to_infinity = (0..Float::Infinity) beyond = to_infinity.lazy.select do |n| num % 42 == 0 end 100.times do { |n| puts beyond.next } Big Changes 

X Tracepoint X X X X X 

Trace Point Big Changes OO  alterna*ve  to  set_trace_func trace = TracePoint.new(:raise) do |t| puts "Alert: Exception raised!" end trace.enable 

X Refinements X X X X X 

Refinements * Big Changes Localised  and  contained  monkey  patching Module MyString refine String do def palindrome? self == self.reverse end end end using MyString # Monkey patch now active for context 

little Changes 

Literal Symbol lists sym_list = %i{eeny meeny miny moe} # => [:eeny, :meeny, :miny, :moe] Little Changes 

Binary Search haystack = (1..99999999) haystack.bsearch do |needle| needle == 12345 end # => 12345 Little Changes 

UTF-8 On by Default #!/usr/bin/env ruby1.9 #encoding: utf-8 puts “✖ ✹ ✚ ✭” #!/usr/bin/env ruby-2.0 puts “✖ ✹ ✚ ✭” Little Changes 

__Dir__ keyword Little Changes Similar  in  func*onality  to  __FILE__ Shows  absolute  path  to  file’s  directory No  more  clunky  File.dirname(__FILE__) 

.to_h Little Changes Follows  conven*on  started  by  .to_s,  to_i,  to_a,  etc Super  useful  for  conver*ng  Structs 

Little Changes CGI  is  now  HTML5  compa*ble net/hLp  supports  Server  Name  Indica*on  (SNI) Grab Bag Zlib  runs  outside  of  the  Global  Interpreter  Lock Unused  variables  can  be  prepended  with  _  to  avoid  warnings 

Ecosystem 

Ecosystem Start  of  support  for  stdlib  gems No  more  out  of  place  requires!  MOAR  BUNDLAR! RubyGems 2.0 Searching  is  remote  by  default Metadata  through  Gem::Specifica*on#metadata Simplified  --document/--no-document No  more  --no-rdoc --no-ri mantra 

Ecosystem Supports  Ruby  2.0 Supports  Rubygems  2.0 Bundler 1.3(.1) Supports  Rails  4.0 Support  for  signed  gems! install and update up  to  150x  faster 

EcoSystem Ruby  2.0  is  the  official  preferred  ruby  version Beta  released  1  day  a_er  Ruby  2.0 Rails 4.0 beta gem install rails --version 4.0.0.beta1 --no-document gem ‘rails’, ‘4.0.0-beta1’ 

Now what 

Any Questions? @gee_forr [email protected] Thanks Code examples: https://github.com/gee-forr/whats_new_in_ruby_2.0