class String
  def self.random(size)
    s = ""
    d = ("a".."z").to_a + ("A".."Z").to_a + ("0".."9").to_a
    size.times {
      s << d[rand(d.size)]
    }
    return s
  end
end

# From : http://www.geekmade.co.uk/2008/09/ruby-tip-normalizing-hash-keys-as-symbols/
class Hash
  def symbolize_keys
    inject({}) do |options, (key, value)|
      options[(key.to_sym rescue key) || key] = value
      options
    end
  end
  
  # x = {
  #   :none => String,
  #   :png => "file.png",
  #   :svg => "file.svg"
  # }
  # 
  # x.each_except( :key => [:none], :value => [/\.png$/] ) do |k, v|
  #   puts "#{k} -> #{v}"
  # end
  #
  # => svg -> file.svg
  def each_except( e, &b )
    key_table = (e[:key]||[]).clone.delete_if {|i| i.kind_of? Regexp }
    key_regexp = (e[:key]||[]).clone.delete_if {|i| key_table.include? i }.map {|i| i.to_s }.join("|")

    value_table = (e[:value]||[]).clone.delete_if {|i| i.kind_of? Regexp }
    value_regexp = (e[:value]||[]).clone.delete_if {|i| value_table.include? i }.map {|i| i.to_s }.join("|")

    self.each do |k, v|
      yield( k, v ) unless (key_table.size > 0 and key_table.include?(k)) or (key_regexp.size > 0 and k.to_s.match(key_regexp)) or (value_table.size > 0 and value_table.include?(v)) or (value_regexp.size > 0 and v.to_s.match(value_regexp))
    end
  end
end
