Re: Comparing version numbers

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On 2017-11-13 19:54, Victor Porton wrote:
> I don't understand you.
> 
> Dmitry A. Kazakov wrote:
>> On 2017-11-13 16:56, Victor Porton wrote:
>>
>>> But what is the difference between Compare_Textually and
>>> Compare_Lexicographically?
>>
>> Numerals in the text are ordered according to their values. E.g. if you
>> wanted to order files or versions by numbers in their names.
> 
> It is about Compare_Textually or about Compare_Lexicographically?
> 
>>> "This function compares two strings as texts." What does "compares as
>>> text" mean?
>>
>> Numerals in the text are equal. E.g. if you wanted filter out all
>> versions of the same package or all numbered files.
> 
> I don't understand.
> 
> Please elaborate. My Ada project is important, so your minute or two to
> elaborate is important.

Let you have files named as:

    A_1.2.txt
    B_30.txt
    A_100.0.txt
    A_40.1.txt
    B_2.txt

If you wanted to tell A_<n>.<m>.txt from B_<k>.txt that would be 
"textually". If you wanted to sort them in the "natural" order

    A_1.2.txt
    A_40.1.txt
    A_100.0.txt
    B_2.txt
    B_30.txt

that would be "lexicographically".

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