[plt-scheme] dots

Thanks Jos for sharing that explanation with the group.

On 6/10/07, Jos Koot <jos.koot at telefonica.net> wrote:
> Hi,
> Jens Axel Soegaard pointed me to the idea. Like he did, I first tried to do all
> the work during expansion time. This is not possible however, as shown in an
> earlier thread on this subject. The hard part was getting loose of my fixation
> on expansion time solutions. Once I relaxed from this fixation, it was just a
> matter of develloping the idea. Initially I made a simple module with none or
> one super-type only, but then I saw that a relatively simple extension allows
> derivation from more than one supertype. The drawback of transferring the main
> part of the solution to run time is slower execution, of course.
>
> I have to say that the module does not only add. It also strips: it prohibits
> the use of variables containing periods. In the most recent version of the
> module, all binding forms are adapted such as to refuse such variables (assuming
> I did not forget some).  That may cause trouble when using libraries that
> provide such variables (as a lucky circumstance, mzscheme does not (as at this
> moment)) A one character change of the source code allows choosing another
> character in stead of the period. The central idea is that when variables with
> periods are prohibited, the dot notation appears to mzscheme as an undefined
> variable and therefore is wrapped as (#%top . dot-notation). Redefining #%top
> does the main part of the job during expansion. Syntaxes set! and set!-values
> are redefined too, of course.
> Hope this answers your question. Thanks for your interest.
> Jos Koot
> (http://www.telefonica.net/web2/koot/records.zip (40 kb, source code plus
> documentation (msword)))
>
> ----- Original Message -----
> From: "Grant Rettke" <grettke at acm.org>
> To: "Jos Koot" <jos.koot at telefonica.net>
> Cc: "Chongkai Zhu" <czhu at cs.utah.edu>; "PLT-list" <plt-scheme at list.cs.brown.edu>
> Sent: Sunday, June 10, 2007 6:03 PM
> Subject: Re: [plt-scheme] dots
>
>
> > Interesting. How difficult was it to add dot notation?
> >
> > On 6/9/07, Jos Koot <jos.koot at telefonica.net> wrote:
> >> ----- Original Message -----
> >> From: "Chongkai Zhu" <czhu at cs.utah.edu>
> >> To: "Jos Koot" <jos.koot at telefonica.net>; "PLT-list"
> >> <plt-scheme at list.cs.brown.edu>
> >> Sent: Sunday, June 10, 2007 12:39 AM
> >> Subject: Re: [plt-scheme] dots
> >>
> >>
> >> > This looks cool. Why don't you submit it to PLaneT?
> >>
> >> Thanks, I might after I am sure it does not contain too many bugs. Of course
> >> I
> >> did many tests, but my experience is that other people always find tests that
> >> expose other bugs. Kind regards, Jos Koot
> >>
> >> >
> >> > Chongkai
> >> >
> >> > ----- Original Message -----
> >> > From: Jos Koot
> >> > To: PLT-list
> >> > Sent: Saturday, June 09, 2007 4:41 PM
> >> > Subject: [plt-scheme] dots
> >> >
> >> >
> >> > Interested in structs with multiple supertypes and dot-notation? I call
> >> > them
> >> > 'records'. Be my guest at:
> >> > http://www.telefonica.net/web2/koot/records.zip (40 kb, source code plus
> >> > documentation (msword))
> >> > Kind regards, Jos Koot
> >> >
> >>
> >> _________________________________________________
> >>   For list-related administrative tasks:
> >>   http://list.cs.brown.edu/mailman/listinfo/plt-scheme
> >>
> >
>
>