Singleton class: what is the purpose?

[Nielson Family]

Simon Burton wrote:

>On Fri, 06 Jun 2003 01:49:42 +0000, Gordon Scott wrote:
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>>Is there any difference between the Borg and the Flyweight?  Sound like the
>>same thing.
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>>Gordo
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>My take:
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>A Flyweight would be an instance shared, where there are many flyweights.
>If there is only one flyweight then it's a singleton.
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>ints (and the other immutables) are flyweights in python.
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>Simon Burton.
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I've found your discussion of patterns quite interesting.

 From what I understand of the Flyweight pattern, it and the singleton 
pattern are different in the underlying strucutre.

I'm not sure it's accurate to say that one flyweight= singleton, though 
it's possible that a singleton might be used _as_ a flyweight.  In other 
words, a flyweight could also be a singleton, but it is not necessarily 
so, and a singleton could function as a flyweight, but a singleton is 
not, by definition a single flyweight.

-- Seth James Nielson