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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Simple string template formatter (Dmitry A. Kazakov take note)
Date: Wed, 22 Nov 2017 23:26:17 +0100
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Date: 2017-11-22T23:26:17+01:00
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On 2017-11-22 21:23, Victor Porton wrote:
> I created a simple string template formatter (no if-then-else, no include,
> just substitution of variables).
> 
> Example:
> 
> "First phrase: {1}. Second phrase: {2}."
> 
> This formatter is suitable for short strings, such as phrases for gettext.
> 
> https://github.com/vporton/xml-boiler/blob/master/src/boiler-auxiliary-string_formatter.ads
> https://github.com/vporton/xml-boiler/blob/master/src/boiler-auxiliary-string_formatter.adb
> 
> My code was not tested!
> 
> Dmitry, I ask you to add something like this to your Simple Components.

Thanks, but I specifically avoid this ugly paradigm. String editing in 
Simple Components deploys a different schema of consequent reading input 
/ writing output string:

    Put
    (  Destination : in out String;
       Pointer     : in out Integer; -- Moving update position
       Value       : Something;
       Field       : Natural   := 0;
       Justify     : Alignment := Left;
       Fill        : Character := ' '
    );

Formatting is one of bad ideas FORTRAN gave us. It is necessarily 
untyped, inefficient and unsafe. Microsoft has more than a dozen 
incarnations of sprintf which is a perfect illustration that the idea is 
just beyond any hope.

I also intentionally avoid so-called "global" operations on strings. 
That is operations taking string as a whole as opposed to "local" 
operations dealing with a string slice. Most "global" operations: find, 
index, substitute, split, translate, tokenize, copy etc are bad. Format 
is a "global" operation. For practical purpose of text processing 
nothing of this is required or makes code clean.

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