Re: Scalars & atomic values & variables
Date: Sat, 3 Jan 2004 15:06:53 -0800
Message-ID: <1073171406.113620_at_news-1.nethere.net>
"Bob Badour" <bbadour_at_golden.net> wrote in message <news:eICdnT6fXqHX2Gqi4p2dnA_at_golden.net>...
> "Adrian Kubala" <adrian_at_sixfingeredman.net> wrote in message
> news:slrnbvebrd.ta3.adrian_at_sixfingeredman.net...
> > The definition I proposed elsewhere (for types the values of which are
> > atomic), is that subtypes are non-atomic. What constitutes a subtype
> > depends on the type system, I guess. Using the "set of values and
> > associated functions" definition, my original guess is that A is a
> > subtype of B if its values and functions are supersets of those of B.
>
> Nope. A is a subtype of B if its values are a subset and its operations are
> a superset. A is a proper subtype of B if its values are a proper subset and
> its operations are a proper superset.
And then there's Liskov's notion of subtypes:
URL:http://en2.wikipedia.org/wiki/Liskov_substitution_principle
Perhaps the notions of "subtype" and "derived type" should be distinct.
-- Joe Foster <mailto:jlfoster%40znet.com> Sacrament R2-45 <http://www.xenu.net/> WARNING: I cannot be held responsible for the above They're coming to because my cats have apparently learned to type. take me away, ha ha!Received on Sun Jan 04 2004 - 00:06:53 CET