#                                                                          
# File 'hash.rb' created on 09 ott 2007 at 15:59:11.                    
#
# See 'dokkit.rb' or LICENSE for licence information.                      
#                                                                          
# (c)2006, 2007 Andrea Fazzi <andrea.fazzi@alca.le.it> (and contributors). 
#                                                                          

class Hash
  # Set the default values for keyword arguments.
  # See http://www.lukeredpath.co.uk/2006/7/27/using-ruby-hashes-as-keyword-arguments-with-easy-defaults
  # for a complete discussion.
  def with_defaults!(defaults)
    self.merge!(defaults) { |key, old, new| old.nil? ? new : old }
  end
  # Non-desctructive version of Hash#with_defaults method.
  def with_defaults(defaults)
    self.merge(defaults) { |key, old, new| old.nil? ? new : old } 
  end
  # Hash#recursive_merge merges two arbitrarily deep hashes into a single hash. 
  # The hash is followed recursively, so that deeply nested hashes that are at 
  # the same level will be merged when the parent hashes are merged.
  def recursive_merge!(other_hash)
    merge!(other_hash) do |key, value, other_value|
      if(value.class == Hash && other_value.class == Hash)
        value.recursive_merge other_value
      elsif(value.class == Array && other_value.class == Array)
        value.concat(other_value)
      else
        store(key, other_value)
      end
    end
  end
  # Non-destructive version of Hash#recursive_merge method.
  def recursive_merge(other_hash)
    dup.recursive_merge!(other_hash)
  end
end