Re: Mixing OO and DB
From: Dmitry A. Kazakov <mailbox_at_dmitry-kazakov.de>
Date: Thu, 14 Feb 2008 17:43:11 +0100
Message-ID: <1vv7flmj27mx5$.1g7562a5h0hf4.dlg_at_40tude.net>
>
> A constant can take on only one value. A variable is called a variable
> because it can be varied. In other words, the value written in it can be
> replaced.
Date: Thu, 14 Feb 2008 17:43:11 +0100
Message-ID: <1vv7flmj27mx5$.1g7562a5h0hf4.dlg_at_40tude.net>
On Thu, 14 Feb 2008 15:17:19 GMT, David Cressey wrote:
> "Dmitry A. Kazakov" <mailbox_at_dmitry-kazakov.de> wrote in message
> news:9mygggm8sikb.98nyv0zywo9z.dlg_at_40tude.net...
>
>> I don't think that it is essential for a variable to be replaceable. >> Consider a type over a set with exactly one value. Can I have a variable >> of? In my view variable is just a mapping of the computational state onto >> the set of values of the type.
>
> A constant can take on only one value. A variable is called a variable
> because it can be varied. In other words, the value written in it can be
> replaced.
Mathematical interpretation (where the term comes from) is different. It is
"a quantity capable of assuming any of a set of values"
This does imply replacement or even variation. It says that the value is unspecified here, can be thought as any from some set of.
-- Regards, Dmitry A. Kazakov http://www.dmitry-kazakov.deReceived on Thu Feb 14 2008 - 17:43:11 CET