(1) Chapter 743, Oregon Laws 1971, shall govern the construction of and punishment for any offense defined in chapter 743, Oregon Laws 1971, and committed after January 1, 1972, as well as the construction and application of any defense to a prosecution for such an offense.
(2) Except as otherwise expressly provided, or unless the context requires otherwise, the provisions of chapter 743, Oregon Laws 1971, shall govern the construction of and punishment for any offense defined outside chapter 743, Oregon Laws 1971, and committed after January 1, 1972, as well as the construction and application of any defense to a prosecution for such an offense.
(3) Chapter 743, Oregon Laws 1971, shall not apply to or govern the construction of and punishment for any offense committed before January 1, 1972, or the construction and application of any defense to a prosecution for such an offense. Such an offense shall be construed and punished according to the law existing at the time of the commission of the offense in the same manner as if chapter 743, Oregon Laws 1971, had not been enacted.
(4) When all or part of a criminal statute is amended or repealed, the criminal statute or part thereof so amended or repealed remains in force for the purpose of authorizing the accusation, prosecution, conviction and punishment of a person who violated the statute or part thereof before the effective date of the amending or repealing Act.