gistfile1.txt

1.9.3p125 :001 > require 'yajl'
 => true 
1.9.3p125 :002 > y.on_parse_complete = lambda {|msg| p msg}
NameError: undefined local variable or method `y' for main:Object
	from (irb):2
	from /Users/tagomoris/.rvm/rubies/ruby-1.9.3-p125/bin/irb:16:in `<main>'
1.9.3p125 :003 > y = Yajl::Parser.new
 => #<Yajl::Parser:0x007fd2fc92ce90> 
1.9.3p125 :004 > y.on_parse_complete = lambda {|msg| p msg}
 => #<Proc:0x007fd2fc926108@(irb):4 (lambda)> 
1.9.3p125 :005 > y << '{"message":1}'
{"message"=>1}
 => nil 
1.9.3p125 :006 > ^D
tagomoris$ gem list

*** LOCAL GEMS ***

rake (0.8.7)
yajl-ruby (1.1.0)
tagomoris$