how to use ruby methods in Vagrantfiles?

[Maurizio Vitale]

I don't know the first thing about ruby, but I'd like to transform values in a hash.

The following works in pure ruby:

def replace(hash)

  hash.inject({}) do |h,(k,v)|

    if v.kind_of? String

      h[k] = v.upcase

    elsif v.kind_of? Fixnum

      h[k] = v

    else

      h[k] = replace(v)

    end

    h

  end      

end

but when I try to use it inside a Vagrantfile, I get errors about inject being undefined:

/home/mav/Workspaces/i2/new/vagrant_functions/utility.rb:141:in `replace': undefined method `inject' for nil:NilClass (NoMethodError)

is there any documentation on how to use ruby in vagrantfiles?

Thanks a lot!