Re: PIZZA time again :-)

"mAsterdam" <mAsterdam_at_vrijdag.org> wrote in message news:431777f2$0$11080$e4fe514c_at_news.xs4all.nl...
> Assume
> 1. there is a meaningful (or at least consequential)
> difference between:
>
> toppings([salami, mozarella, onions]).
> and
> toppings([mozarella, onions, salami]).
>
> 2. A, B, C are lists (conforming to the as yet to
> be published Spight LIST grammar in relational context).
>
> What should
> merge ([A,B], C). % merge list of lists into list
> mean ?
>
> I think it should merge A and B into C,
> preserving order, and fail if it can't.
>
> Or, if merge(+, +) just fail if C isn't a merge.
>
> (google for C3, Dylan, Perl)
>
> (clp - sorry for bothering you :-)

Off topic: I have always assumed that the toppings on a pizza form an (unordered) set, that

> toppings([salami, mozarella, onions]).
> and
> toppings([mozarella, onions, salami]).
>

will use exactly the same ingredients, prepare and cook exactly the same way, cost exactly as much, and taste exactly the same. I would be VERY surprised if Domino's had a different opinion.

And that brings me back to the topic:

You can ALWAYS represent a set as if it were a list, by simply presenting the elements in an arbitrary order. You can ALWAYS represent a list as if it were a set, by including an attribute that marks each element's position in the list.

The question is not WHETHER the above can be done. The question is WHEN it SHOULD be done. Received on Wed Sep 07 2005 - 00:08:41 CEST