Re: Generics vs. O-O?

[Alan Jump <alan.jump@gmail.com>]

On Friday, August 2, 2013 8:08:38 AM UTC-7, Shark8 wrote:
> > Yet another language design
> > problem that there is no simple way to declare such singleton types in Ada.

> Really?
> In Ada 2012 I can say the following:
>     package Test is
> 	Type K is Private;
> 	J : Integer := 12;
>     private
> 	use type System.address;
> 	type K is new integer with TYPE_INVARIANT => K'Address = J'Address;
>     end test;
>
> Type K sure looks like a singleton to me.

This is going off on a bit of a tangent, but as a new student of the language, I  think a case could be made that many stand-alone packages or procedures in Ada are singletons, simply because of Ada's inherent strong typing. After all, what's a singleton? By definition, to be a singleton pattern, two criteria must be met: one and only one instance with a global point of access, and initialization on first use. (Source: http://sourcemaking.com/design_patterns/singleton)

With that said, and again being a new student of the language, I find myself in favor of generic use, simply from a standpoint of code reuse. A well-designed algorithm that finds itself applied several times within a given procedure, which varies only in parameter types, should only have to be coded once.

Just my 2p worth...save up the change for a pack of monitor wipes or something.

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73 de N5ILN
Alan