def add_expr(src, code, indicator)
      case indicator
      when '='
        @escape ? add_expr_literal(src, code) : add_expr_escaped(src, code)
      when '=='
        @escape ? add_expr_escaped(src, code) : add_expr_literal(src, code)
      when '==='
        add_expr_debug(src, code)
      end
    end
def add_expr(src, code, indicator)
      case indicator
      when '='
        @escape ? add_expr_literal(src, code) : add_expr_escaped(src, code)
      when '=='
        @escape ? add_expr_escaped(src, code) : add_expr_literal(src, code)
      when '==='
        add_expr_debug(src, code)
      end
    end
--
def self.included(klass)
  klass.class_eval <<-END
    alias _add_expr_literal add_expr_literal
    alias _add_expr_escaped add_expr_escaped
    alias add_expr_literal _add_expr_escaped
    alias add_expr_escaped _add_expr_literal
  END
end
++