Re: Issues with the logical consistency of The Third Manifesto

Martha Stewart called it a Good Thing when "Ja Lar" <ingen_at_mail.her> wrote:
> "Alfredo Novoa" <anovoa_at_ncs.es> ...
> <snip>
>
>> Tuples are objects, relations are objects, classes are objects,
>> variables are objects, operators are objects, I am an object,
>> everything is an object.
>>
>> A good definition of object is this:
>>
>> Object: Something intelligible or perceptible by the mind.
>
> With such a definition you exclude yourself from commenting on what
> OO means. For you it obviously means everything, i.e. in fact
> nothing in particular.

Ah, but the problem is that those are all virtually equally legitimate answers as to what OO "means."

I am only aware of two works that try to put together a theory-based presentation of what "objects" are:

1. _A Theory of Objects_ by Martin Abadi, Luca Cardelli and
2. _Types and Programming Languages_ by Benjamin C. Pierce

Aside from those fairly obscure references, "OO" generally seems to mean "whatever programming model they put into my favorite language that they decided to call 'object oriented.'"

Thus, to some, "OO" means the things you can express using C++ classes.

To others, it represents the things expressible using Java classes.

To still others, it is about creating function methods to allow Smalltalk objects to invoke the right bits of code in order to pass messages to other Smalltalk objects.

Those are just three particular sets of dogma; probably the most flexible object system is in Common Lisp, where CLOS combined aspects of LOOPS, Flavors, as well as other "object models" of the 1980s. (And that's not to imply any obsolescence; I can't see that there have been any honest-to-goodness new developments since then...)

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