def maruku_recover(s, src=nil, con=nil, recover=nil)
      policy = get_setting(:on_error)

      case policy
      when :ignore
      when :raise, :warning
        tell_user create_frame(describe_error(s, src, con, recover))
      else
        raise "Unknown on_error policy: #{policy.inspect}"
      end
    end
def maruku_recover(s, src=nil, con=nil, recover=nil)
      policy = get_setting(:on_error)

      case policy
      when :ignore
      when :raise, :warning
        tell_user create_frame(describe_error(s, src, con, recover))
      else
        raise "Unknown on_error policy: #{policy.inspect}"
      end
    end
This is like {#maruku_error} but will never raise.