newbie conceptual question [from haskell list]

[Steinitz, Dominic J]

Alex,

The code isn't ready to go public but you can try out a web interface at http://r341-02.king.ac.uk/cgi-bin/ldap.cgi. If you use the search filter objectClass=top you will get the whole tree on our test server. You shouldn't be able to add, modify or delete (let me know if you can!). The web code isn't very resilient. If you specifiy a non-existent attribute or use the wild card character (*), you will get an uninformative error message. Or you can try searching any public ldap server.

Dominic.




alex@shop.com on 01/08/2001 13:30:00
To:	Dominic Steinitz
cc:	hdaume
franka
haskell-cafe
bcc:	
Subject:	Re: newbie conceptual question [from haskell list]

Is the LDAP client available somewhere?

-Alex-

On 1 Aug 2001, Steinitz, Dominic J wrote:

> I don't know about functional dependencies but using an existential type
 turned out to be very useful in writing an LDAP protocol handler. The protocol
 is specified at an abstract level using ASN.1 and could, in theory, be encoded
 using any set of encoding rules. It happens to use the Basic Encoding Rules. We
 used an existential type to "encode" the protocol at an abstract level and the
 encoding rules take this type and produce a concrete representation ready to
 send over a transport mechanism. Thus we get a good separation between the
 abstract protocol and the concrete encoding. So the next time we implement a
 protocol handler we can re-use the encoding code or we could encode LDAP with a
 different set of encoding rules without having to touch the LDAP code itself.
>
> We are presenting a paper which includes this at the Scottish Functional
 Programming workshop.
>
> Dominic.
>
>
>
>
> hdaume@ISI.EDU on 31/07/2001 22:29:00
> To:	franka
> cc:	haskell-cafe
> bcc:	Dominic Steinitz
> Subject:	Re: newbie conceptual question [from haskell list]
>
> Hi,
>
> Frank Atanassow wrote:
> > D. Tweed wrote:
> > > I've never written a Haskell program using functional dependencies, or
> > > existential classes, ...
> >
> > I find them indispensible, and I know for a fact that I am not the only one
> > around our office who feels that way. Though, the people around here
> > (Utrecht's software technology group) are not exactly typical programmers...
> > :)
>
> I've been recently experimenting quite a bit with existential classes
> and somewhat less with functional dependencies, primarily to help my
> understanding of the concepts.  However, I've yet to be able to think of
> an appropriate place to use them in the "real world".  That is, in
> something more than a toy thought-experiment.  Could you give some
> examples of what you are using them for?
>
> --
> Hal Daume III
>
>  "Computer science is no more about computers    | hdaume@isi.edu
>   than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume
>
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