From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: "Dmitry A. Kazakov" Newsgroups: comp.lang.ada Subject: Re: Fortran 95: How do you write code to do this? Date: Fri, 2 Nov 2018 09:41:13 +0100 Organization: Aioe.org NNTP Server Message-ID: References: <5a59b308-041b-437e-8878-7259870c802a@googlegroups.com> <1d3e2e3e-93a3-492a-8c87-627b6e726be6@googlegroups.com> <87r2g43cgx.fsf@jacob-sparre.dk> <827aada6-ddaa-450d-8458-a815d0fcf5a9@googlegroups.com> NNTP-Posting-Host: MyFhHs417jM9AgzRpXn7yg.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 X-Notice: Filtered by postfilter v. 0.8.3 Content-Language: en-US Xref: reader02.eternal-september.org comp.lang.ada:54750 Date: 2018-11-02T09:41:13+01:00 List-Id: On 2018-11-02 07:33, Petter Fryklund wrote: > Without shift can be: > > -- Counting bits from right to left, starting with zero > generic > type T is mod <>; > function Boolean_Of(Nat : T; Bit_Number : Natural) return Boolean; > > function Boolean_Of(Nat : T; Bit_Number : Natural) return Boolean is > begin > return (Nat and T(2 ** Bit_Number)) = 1; > end Boolean_Of; > > type Ten_Bits is mod 2 ** 10; > > function Boolean_Of_Ten_Bits is new Boolean_Of(Ten_Bits); > > Input : Ten_Bits := 75; > Bool1 : Boolean := Boolean_Of_Ten_Bits(Input, 0); -- will be True > Bool2 : Boolean := Boolean_Of_Ten_Bits(Input, 1); -- will be False BTW, this does not make sense unless T is mod 2**N and the compiler uses a certain representation for T. In general, bit representation can be any. The number could be kept packed-decimal or as an EBCDIC string containing English numerals written right to left... -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de