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: ADA.STRINGS.INDEX_ERROR : a-strunb.adb:782 Date: Mon, 15 Jan 2018 14:32:53 +0100 Organization: Aioe.org NNTP Server Message-ID: References: <51e64525-b9f1-4ad9-b737-5bb89f84f40f@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 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 Content-Language: en-US X-Notice: Filtered by postfilter v. 0.8.2 Xref: reader02.eternal-september.org comp.lang.ada:49913 Date: 2018-01-15T14:32:53+01:00 List-Id: On 15/01/2018 13:00, Mehdi Saada wrote: >> When deleting elements of a list by position the loop must run positions >> in reverse: >> [...] >> That will keep the positions straight. Position /= index, BTW. >> However, deleting characters from a string almost never has sense. You >> probably should reconsider the algorithm. > > Ah ? Why so ? An empiric fact. > And how come position =/ index ? "IND" is the same, isn't ? Index can start at any number and for a user-defined string type it might be any discrete type, e.g. not a number. When you use 1..X'Length that is position, When you use X'Range or X'First..X'Last that is index. You cannot delete the element at an index, that would make the array non-contiguous. You can do it at a position, which makes indices of the elements slide. Note that in Ada X'Length is of universal integer for all arrays. It is silently converted to Integer which gives a false impression of being an "index". P.S. Unbounded and fixed-length strings are not properly designed due to language limitations, so Length (X) has the result of a wrong type. -- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.de