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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Comparing version numbers
Date: Mon, 13 Nov 2017 09:10:50 +0100
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Xref: feeder.eternal-september.org comp.lang.ada:48845
Date: 2017-11-13T09:10:50+01:00
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On 13/11/2017 03:39, Victor Porton wrote:
> Not sure if it is quite on-topic, because it is more about general
> programming ideas rather than about Ada. (However, a solution in Python or
> Ruby or JavaScript would more likely used regexps than Ada.)

I doubt regular expressions would help here, or any other kind of text 
patterns language. It is not a pattern matching problem.

> Suppose I have two version numbers of a software. I need to check which of
> the two is greater.
> 
> Lexical order string comparison does not work:
> 
> "2.3" vs "11.4".
> 
> I could split it by "." and compare the numbers. But a component of a
> version numbers may be nonnumeric like:
> 
> "1.2beta".
> 
> What to do?

Is it what you are looking for:

    http://www.dmitry-kazakov.de/ada/strings_edit.htm#11

> It should work for example for all Debian packages containing interpreters
> (for example, "2.7" for "python" package).

AFAIK, Debian's dh-make has somewhere an operation to compare versions 
the way apt does. I don't remember where. but it is there.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de