pauldix/sax-machine — pull request #61 by aderyabin (2014-12-15 09:58:59+00:00)
Title: Add Blocks support

I suggest to handle values using blocks.
Less words - more examples:
```ruby
element :title do |title|
"#{title}!!!"
end

attribute :id do |id|
id.to_i
end

element :link, value: :foo do |link|
link.downcase
end
```