gistfile1.rb

require "yajl"
parser = Yajl::Parser.new
encoder = Yajl::Encoder.new

regex = /(.*)asdf(\w+)\s+{3}/

regex_json = encoder.encode(regex)
r = Regexp.new(parser.parse(regex_json))
 => /(?-mix:.*asdf\w+\s+{3})/
"fooasdfblah argasdfbuh    wowasdfderp" =~ r
 => 0 

## END

require "yajl/json_gem"

regex = /(.*)asdf(\w+)\s+{3}/
regex_json = regex.to_json
Regexp.new(JSON.parse(regex_json))
JSON::ParserError: lexical error: inside a string, '\' occurs before a character which it may not.
                      "(?-mix:(.*)asdf(\w+)\s+{3})"
                     (right here) ------^

        from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/yajl-ruby-0.8.2/lib/yajl/json_gem/parsing.rb:16:in `rescue in parse'
        from /usr/local/rvm/gems/ruby-1.9.2-p180/gems/yajl-ruby-0.8.2/lib/yajl/json_gem/parsing.rb:13:in `parse'
        from (irb):5
        from /usr/local/rvm/rubies/ruby-1.9.2-p180/bin/irb:16:in `<main>'