Re: Value
From: mAsterdam <mAsterdam_at_vrijdag.org>
Date: Sat, 08 Mar 2008 10:14:22 +0100
Message-ID: <47d2589c$0$14361$e4fe514c_at_news.xs4all.nl>
>
> The notion »value« does not have a special connection to
> /object-oriented/ programming.
>
> A value in mathematics or computer science is any object or
> entity.
>
> To test, whether something is a value, one can use the
> following rule:
>
> Something is a value, whenever an assertion can be made
> about it.
>
> For example, »The moon orbits the earth.« is an assertion
> about the moon, so the moon is a value.
>
> In computer programming and also in user interfaces, values
> often appear in a context, where a selection from a set of
> values can be made, to indicate (select) a certain element of
> this set. Insofar, values represent a certain choice from a
> set of possible choices.
>
> When /digital/ computers are used, the set is finite and
> discrete. All values are part of a specific data type and
> eventually are being represented by a tuple of binary values.
> The mapping between such binary tuples and values is given by
> the implementation of the data type.
>
> For example, the data type consisting of the value moon and
> the value earth in Pascal can specified as follows.
>
> type body =( moon, earth );
Date: Sat, 08 Mar 2008 10:14:22 +0100
Message-ID: <47d2589c$0$14361$e4fe514c_at_news.xs4all.nl>
Stefan Ram wrote:
> mAsterdam writes:
>>> "Value" in this context is a CS term. >> Do you have a better reference?
>
> The notion »value« does not have a special connection to
> /object-oriented/ programming.
>
> A value in mathematics or computer science is any object or
> entity.
>
> To test, whether something is a value, one can use the
> following rule:
>
> Something is a value, whenever an assertion can be made
> about it.
>
> For example, »The moon orbits the earth.« is an assertion
> about the moon, so the moon is a value.
>
> In computer programming and also in user interfaces, values
> often appear in a context, where a selection from a set of
> values can be made, to indicate (select) a certain element of
> this set. Insofar, values represent a certain choice from a
> set of possible choices.
>
> When /digital/ computers are used, the set is finite and
> discrete. All values are part of a specific data type and
> eventually are being represented by a tuple of binary values.
> The mapping between such binary tuples and values is given by
> the implementation of the data type.
>
> For example, the data type consisting of the value moon and
> the value earth in Pascal can specified as follows.
>
> type body =( moon, earth );
I apologize for replying this late (busy life). Your rule is very close to my intuitive understanding of 'value'. I am thinking about later picking some of your post for the [Value] entry (in progress) of the c.d.t. glossary. Would you mind? (I know that strictly speaking I don't need yout permission).
-- What you see depends on where you stand.Received on Sat Mar 08 2008 - 10:14:22 CET