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Re: The wisdom of the object mentors (Was: Searching OO Associations with RDBMS Persistence Models)

From: erk <eric.kaun_at_gmail.com>
Date: 2 Jun 2006 13:11:22 -0700
Message-ID: <1149279082.662054.189580@f6g2000cwb.googlegroups.com>


Cimode wrote:
> I am sorry but operators are *not* functions (relation model speaking).

What do you mean, "relation model speaking"? Relational operators, or operators on various types (the values of which can be stored in the attributes of tuples of relations)? Or are you using the term "relational" more loosely in the sense that =, <, >=, etc. are relational operators? Operators of type T -> T -> boolean, right?

> They are a set of symbols (generally mathematical such as =) that can
> be applied to permissible values included in a specific domain.

So you're talking about functions over a single domain, ones of type T -> T, or T -> T -> T, etc. How are these not functions?

> Each specific combination of operators applied help define a data type.
> That's all there's to it.

So you're talking about the algebraic definition of a type, like pop(push(S, x)) = x for a stack?

Received on Fri Jun 02 2006 - 15:11:22 CDT

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