Re: Re: Re: OO in Mathematica
- To: mathgroup at smc.vnet.net
- Subject: [mg37709] Re: [mg37664] Re: [mg37648] Re: OO in Mathematica
- From: "Hermann Schmitt" <schmitther at netcologne.de>
- Date: Sat, 9 Nov 2002 00:29:26 -0500 (EST)
- References: <200211080714.CAA07306@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hello,
As you write below:
"Mathematica contains all that is necessary to program in an OO style, but
perhaps lacks tools to make such an endeavor easy."
Therefore I created an OO system for Mathematica as a package. I think, that
it contains all the features, which are considered necessary for an OO
system.
You may find a small example program for my system in my contribution of
Nov. 4, 10.38.
I shall make my package available, soon, on my web site:
www.schmitther.de
Hermann Schmitt
----- Original Message -----
From: "Sseziwa Mukasa" <mukasa at jeol.com>
To: mathgroup at smc.vnet.net
Subject: [mg37709] [mg37664] Re: [mg37648] Re: OO in Mathematica
> This is my last post on this thread I promise ;-)
>
> On Thursday, November 7, 2002, at 06:42 AM, Orestis Vantzos wrote:
>
> > Sseziwa Mukasa <mukasa at jeol.com> wrote in message
> > news:<aqb1dj$mih$1 at smc.vnet.net>...
> >> But what's wrong with defining fields as upvalues of a head indicating
> >> the record type? If you use the model demonstrated by Orestis
> >> (unfortunately due to the change in subject lines this thread seems to
> >> have split into 4 separate ones) you can inherit structure and methods
> >> etc. I know Orestis used downvalues but I think upvalues would be
> >> more
> >> efficient. I'd also change his method to use a symbol without a
> >> definition rather than overloading Dot. If you are using Mathematica
> >> you already have to condition yourself to use Map, Fold et al. rather
> >> than Do, For, While etc. What's wrong with using pattern matching for
> >> structures instead of tuples?
> >
> > The whole idea is going beyond a simple 'record', all the way to a
> > full fledged object, complete with methods. I used DownValues, because
> > I think that the message passing mechanism is best pictured in
> > Mathematica as obj@method[args] rather than as method[obj,args]. What
> > I mean to say is that the object obj receives the message method[args]
> > rather than method is applied on {obj,args}, which would be more
> > functional in style.
> > There is a major implementation issue related with my use of
> > DownValues, instead of UpValues. Although the identity of the object
> > is obvious, the identity of the method is not, given that inheritance
> > and polymorphism can identify several pieces of code with the same
> > 'method'. It is therefore wise to enclose the 'unstable' part of the
> > expression (method[args]) with the definite one (obj), incase some
> > form of processing is needed before the message is actualy evaluated
> > (in which case you would SetAttributes[onj,HoldAll] ).
> >
>
> The UpValues versus DownValues issue is a matter of taste as you seem
> to agree (as is the use of Dot). I was just suggesting the my personal
> preference is to use the UpValues. The post to which you are replying
> was a response to a question about porting code which used C struct
> types to Mathematica, OO issues were not mentioned. I was merely
> suggesting that if you wanted to mechanically port (by which I mean
> substituting a roughly equivalent Mathematica expression for each line
> of C code) C code containing structs then changing the structs to
> expressions with heads sorted by type may be a better idea than
> maintaining them as lists.
>
> That said, I have never had occasion to do this myself and am merely
> speculating about how I would approach such a project. From your posts
> it seems you have had experience in just such a project and I will
> defer to your wisdom on the subject.
>
> Finally to make my own position perfectly clear. I believe that
> Mathematica contains all that is necessary to program in an OO style
> but perhaps lacks tools to make such an endeavor easy. I'm not even
> sure what those tools should be since they would almost necessarily
> enforce some sort of OO policy decisions (ie. delegates as Orestis uses
> or the more static hierarchy using lists of rules presented earlier)
> which would make someone unhappy. In fact it seems that similarly to
> the way X Windows allows the creation of a GUI without specifying the
> rules of the GUI (focus follows mouse, menubar on window or desktop
> etc.) Mathematica allows OO without making decisions about the specific
> form either. To use OO in Mathematica then it would probably be better
> to understand the more general object model of a system such as CLOS
> than a more rigid model such as Java or C++. Anyway, I've already said
> more than I ever intended to on this subject. It seems the best way to
> make any productive contributions to this subject is for people to
> actually implement projects using OO techniques in Mathematica and
> present them. If there is any interest then I'm sure Mathematica users
> will be able to generalize whatever features are necessary to make OO
> programming easy in Mathematica and maybe even get them included as a
> standard package.
>
> Regards,
>
> Ssezi
>
>
- References:
- Re: Re: OO in Mathematica
- From: Sseziwa Mukasa <mukasa@jeol.com>
- Re: Re: OO in Mathematica