class Temple::Engine

def call_chain
  @call_chain ||= @chain.map do |e|
    name, filter, option_filter, local_options = e
    case filter
    when Class
      filtered_options = Hash[*option_filter.select {|k| options.include?(k) }.map {|k| [k, options[k]] }.flatten]
      filter.new(ImmutableHash.new(local_options, filtered_options))
    when UnboundMethod
      filter = filter.bind(self)
      filter.arity == 1 ? filter : filter.call
    else
      filter
    end
  end.compact
end