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Date: Sun, 2 Aug 2015 14:37:30 -0700 (PDT)
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Subject: Re: Running a preprocessor from GPS?
From: EGarrulo <egarrulo@gmail.com>
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Xref: news.eternal-september.org comp.lang.ada:27339
Date: 2015-08-02T14:37:30-07:00
List-Id: <comp.lang.ada>

On Sunday, August 2, 2015 at 9:21:12 PM UTC+2, Jeffrey R. Carter wrote:
> On 08/02/2015 01:29 AM, EGarrulo wrote:
> > On Sunday, August 2, 2015 at 8:05:21 AM UTC+2, Jeffrey R. Carter wrote:
> >> On 08/01/2015 05:30 PM, EGarrulo wrote:
> >>> I meant: a GUI application that lets the user select its preferred GUI widget
> >>> toolkit (GTK, Motif, etc.) at startup.
> >>
> >> Programming by extension is not needed for this.
> > 
> > How would you solve the problem, then?
> 
> With programming by composition, of course.

And would that decrease complexity, or just move it elsewhere?  I am afraid
that it would increase complexity, and substantially.  Indeed, the "Design 
Patterns" book itself recommends "Favor 'object composition' over 'class 
inheritance'".  And yet the Singleton pattern uses inheritance.  Had the 
authors felt that composition were applicable for the Singleton, they would 
have adopted it, don't you think?  Anyway, if an alternative to Singleton that
uses composition has been documented somewhere, I would gladly peruse it.