条件分岐: * [[ref:if]] * [[ref:unless]] * [[ref:case]] 繰り返し: * [[ref:while]] * [[ref:until]] * [[ref:for]] * [[ref:break]] * [[ref:next]] * [[ref:redo]] * [[ref:retry]] 例外処理: * [[ref:raise]] * [[ref:begin]] その他: * [[ref:return]] * […