# File lib/ruote/exp/ro_attributes.rb, line 173
    def lval (vals, vars, flds, att_options)

      if k = has_att(*vals)

        attribute(k, h.applied_workitem, att_options)

      elsif k = has_att(*vars)

        k = attribute(k, h.applied_workitem, att_options)
        lookup_variable(k)

      elsif k = has_att(*flds)

        #k = attribute(k, @applied_workitem, att_options)

        #@applied_workitem.attributes[k.to_s] ||
        #@applied_workitem.attributes[k.to_s.to_sym]

        k = attribute(k, h.applied_workitem, att_options)
        h.applied_workitem['fields'][k]

        # TODO : what about leveraging workitem#lookup ?

      else

        nil
      end
    end