Greg, I have heard you talk repeatedly about Haskell, so I finally broke down and read about it. I wasn't very hopeful that I would be interested.
I looked here: http://www.haskell.org/aboutHaskell.html But instead, it is a very interesting concept. I like the analagy to a spreadsheet funcionality where one specifies what the end result wanted it, rather than the steps needed to get a result. I had thought that someone said that M was a functional language. And I thought that ment that the spacing after the function names is important (i.e. else has to have two spaces after it). But either I am remembering wrong, or it is a name being used another way. So are are you trying to integrate a language like Haskell with the concept of Globals like M? Thanks for the Haskell link. I don't think I will try to learn it right now, but it sounds cool. Kevin On 11/22/05, Greg Woodhouse <[EMAIL PROTECTED]> wrote: > > > --- Kevin Toppenberg <[EMAIL PROTECTED]> wrote: > > > > > Greg, I'm glad we have people like you to think about these > > things...., because right now this is over my head! > > > > :-) > > > > Kevin > > Basically, it's about generalizing relations withing the context of > type theory (which caught my attention because it's something I've been > thinking about, even if I haven't talked about it much on Hardhats). It > also has some interesting criticisms of the relational model. > > Domain theory is kind of like a structured set theory that allows you > to "solve" equations representing recursive relationships. I put > "solve" in quotes, because the solutions turn out to be fixed points of > an operator that can be realized through a series of approximations at > the domain level, and that sequence of approximations is essentially > the unfolding of a recursive definition into iterative form. I know I'm > only offering hints here, but a domain is basically a special kind of > partially ordered set where the partial order is represents > computational approximation. > > I don't know if anyone read my little post about "counting to > infinity", but it provides an interesting hint here. The following > Haskell program > > fix f = f (fix f) > g f n = n : f n > h f = 1 : map (+1) f > > provides a recursive definition of the infinite list [1, 2, 3 ..] as > the fixed point of the function that operates on this list by adding 1 > to each element (to obtain [2, 3, 4 ..] and then sticking a 1 at the > head of the list (to obtain [1, 2, 3 ..]). This is one method of > expressing recursion, but the point is that it illustrates how the > fixpoint operator (also called the paradoxical operator!) can be used > to define recursive *structures*, thus giving you a mathematical > framework for introducing such things as trees and lists as data types. > > But there's more to the story, too. This framework makes it easy to > translate recursive definitions into a framework known as lambda > calculus (introduced by Alonzo Church), and lambda expressions can be > mechanically evaluated. I've spoken to a few people off-line about the > possibility of a "Functional MUMPS" or "Functional Fileman". The > question is whether very large shared data structures (like globals) > can *efficiently* be dealt with in the context of lambda calculus. If > the answer turns out to be yes, that opens up the door to a > referentially transparent (no indirection, no dangling pointers and > more) method of reasoning about globals and programs, even the > possibility of proving correctness of VistA code. > > So, if it seems like I've fallen off the map a bit, well, perhaps the > above examples will give some hints as to the nature of my little > research project. > > > === > Gregory Woodhouse <[EMAIL PROTECTED]> > > > "Interaction is the mind-body problem of computing." > > --Philip Wadler > > > > > > > > > > > > > > ------------------------------------------------------- > This SF.Net email is sponsored by the JBoss Inc. Get Certified Today > Register for a JBoss Training Course. Free Certification Exam > for All Training Attendees Through End of 2005. For more info visit: > http://ads.osdn.com/?ad_id=7628&alloc_id=16845&op=click > _______________________________________________ > Hardhats-members mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/hardhats-members > ------------------------------------------------------- This SF.Net email is sponsored by the JBoss Inc. Get Certified Today Register for a JBoss Training Course. Free Certification Exam for All Training Attendees Through End of 2005. For more info visit: http://ads.osdn.com/?ad_idv28&alloc_id845&op=click _______________________________________________ Hardhats-members mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/hardhats-members
