# Re: What databases have taught me

From: Bob Badour <bbadour_at_pei.sympatico.ca>

Date: Sat, 01 Jul 2006 18:40:29 GMT

Message-ID: <xkzpg.4699$pu3.108771_at_ursa-nb00s0.nbnet.nb.ca>

> If I understand you correctly (iffy), you are saying that a data type

Date: Sat, 01 Jul 2006 18:40:29 GMT

Message-ID: <xkzpg.4699$pu3.108771_at_ursa-nb00s0.nbnet.nb.ca>

Marshall wrote:

>>But the point is the set of values is not the data type. The data type >>is both the set of values and the set of operations. Making up a new >>operation does not alter the data type because that operation was always >>there even if never previously expressed. >>[...] >>And what I am saying is we don't really define anything that wasn't >>already there and what we choose as defining operations are quite >>arbitrary. The data type existed before we defined anything just as the >>values exist before we ever express them.

*>*> If I understand you correctly (iffy), you are saying that a data type

*> is the set of value, and the set of functions on those values**> *whether those functions are reified or not.***>**> In other words, the type integer includes the function**>**> power: int, int -> int**>**> whether it's in the standard library, or we write it ourselves**> using multiplication, or even if we couldn't actually link**> to it at all at this time.*Exactly. Received on Sat Jul 01 2006 - 20:40:29 CEST