Re: Gratification (was: libraries, support status, ..)
Jan Skibinski wrote, about Claus Reinke's examples of library status information..] > They are all fine and useful. But I do not see any clear > incentives for authors for doing so, apart from their > desire to make libraries perfect .. in their spare time, > if any, of course. If the develepment of good libraries > had similar gratifying effects as publishing scientific > papers the situation could have looked quite differently, > I guess. The gratifying effect of writing a scientific paper is that one gets across a worthwhile idea, and light-bulbs go on in a few heads; as a side-effect, one may enhance one's reputation and career. > But what kind of gratification one gets from writing > a library, good or bad? Don't ask me, I have not seen > any so far, unless when I do something strictly commercially. In my case, the payoff has been of learning something +ve or -ve from the process, and on rare occasions of having made something worth using; it is very gratifying indeed if people then actually start using it and getting its benefit, after a modest "sales campaign". (But I've only written libraries in industry.) There is a very general cultural problem about building biggish, robust systems in universities; it's discussed in On the importance of being the right size Simon Peyton-Jones, pp 321-335 in Computing Tomorrow, ed. Wand and Milner, CUP 1996 Maybe it's the sort of thing that is more likely to happen in research labs (eg. Microsoft Cambridge, INRIA,...) than universities. Peter Hancock
RE: Where do I start ?
Title: RE: Where do I start ? Rather than give advice, let me tell you how I got started and perhaps it will help. I was a C++ and Java programmer. Then I took a class in the logic on computation, where part two was lambda calculus. Part of the class was an evaluation machine that we built manually on paper. I just happened to be playing a bit with ML at the time, and suddenly it just sank into me deeply and I built some fairly large prototypes in ML. I used Harlequin's compiler and debugger. Then I had something I wanted to build that needed some lazy lists. I got the GCH compiler installed on my Windows laptop and I have never looked back at ML. I have also looked at Milner's process calculus for inspiration. So I guess I started with theory first, then practice. As for books, by both books recommend in one of the responses and ML for the working programmer by Paulson. Hope that helps. Mike > -Original Message- > From: Nicolas Tremblay [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, July 19, 2000 8:15 AM > To: [EMAIL PROTECTED] > Subject: Where do I start ? > > > Hi all, > > I am very interested by the Haskell language. > > I'm not at any faculty, I just heard about this language > on the internet. > > I work in a QA departement in Montreeal, I don't have a lot > of experience in programming; exept for Bourne shell scripting > which I became fairly confortable with. > > I just started to read a bit about Haskell and so far, > I'm very much impressed with the possibilities. > > I setted myself personnal objectives a while ago, to learn > a multiplatform compilable language. In short words C++. > Well, C++ was the answer until I heard about Haskell. > > I Feel it would be a good thing for me, since I don't have > to program something, or work with it very quickly. > It would be just, let's say, a knowledge investment based > on an intuission. I seriously think that this thing has > serious application in a very close future, and I want to > be part of it, in my own way. > > The problem is, I'm this type of guy who would need a book like: > "Learn Haskell in 21 days" ... hehehe or "Haskell for Dummies" > > Tell me, where to start ? > Or where is the best place to start... > (am I crasy to even think about starting ?) > > I just installed this: > nhc98-1.0pre19-1.i386.rpm > > uname -rm > 2.2.14-5.0 i586 > > Thanks a lot. > > -- > > N i c o l a s T r e m b l a y > Product Tester, Infrastructure > D I S C R E E T INC. >
The type of zip
Fellow Haskellers, Please forgive my lack of brevity here. It has always seemed to me that having multiple zip functions with different names (zip, zip3, zip4, etc..) was unfortunate, and a single zip that handled all possible tuples would be better. Now, with Multi-Parameter Type Classes and Functional Dependencies, we have an opportunity to make zip more sensible. Note: I am not proposing this as a "typo" for the current report, but for a future version of standard Haskell. Obviously, this would only be valid if MPTC's and FD's become part of the future standard. I would propose: o zip be renamed to zip2 and zipWith to zipWith2 o zip be changed to map tuples-of-lists to lists-of-tuples (the "opposite" of unzip) o A Zippable class be created, defining zip and unzip for all tuple types (or at least the first few) o (optional) a ZipFunctor class (subclass of Functor) defining a function which applies a collection of functions to a collection of values giving a collection of results. The list type ([]) would of course be a member of this class. The advantages I see: o zip . unzip === id o types of zip & unzip are consistent with each other o zip could be extended via the class mechanism to work with non-list collections, and non-tuple elements Disadvantages: o Existing code using zip would break o Implementation might be less efficient than current zip & unzip Sample implementation: > module Zip (zip, unzip, Zippable, ZipFunctor, zip2, zip3, zip4, zipWith2, zipWith3, >zipWith4) where > import Prelude hiding (zip, unzip, zipWith3, zip3) > > class (Functor f) => ZipFunctor f where >($$) :: f (a->b) -> f a -> f b > > instance ZipFunctor [] where >(f:fs) $$ (x:xs) = (f x):(fs $$ xs) >_ $$ _ = [] > > zipWith2 :: (ZipFunctor f) => (a->b->c) -> f a -> f b -> f c > zipWith2 f xs ys = f `fmap` xs $$ ys > > zipWith3 :: (ZipFunctor f) => (a->b->c->d) -> f a -> f b -> f c -> f d > zipWith3 f xs ys zs = f `fmap` xs $$ ys $$ zs > > zipWith4 :: (ZipFunctor f) => (a->b->c->d->e) -> f a -> f b -> f c -> f d -> f e > zipWith4 f xs1 xs2 xs3 xs4 = f `fmap` xs1 $$ xs2 $$ xs3 $$ xs4 > > zip2 :: ZipFunctor f => f a -> f b -> f (a,b) > zip2 = zipWith2 (,) > zip3 :: ZipFunctor f => f a -> f b -> f c -> f (a,b,c) > zip3 = zipWith3 (,,) > zip4 :: ZipFunctor f => f a -> f b -> f c -> f d -> f (a,b,c,d) > zip4 = zipWith4 (,,,) > > class Zippable a f b | a -> f b, f b -> a where >zip :: a -> f b >unzip :: f b -> a > > instance (ZipFunctor f) => Zippable (f a,f b) f (a,b) where >zip (xs,ys) = zip2 xs ys >unzip xys = (fmap fst xys, fmap snd xys) > > instance (ZipFunctor f) => Zippable (f a,f b,f c) f (a,b,c) where >zip (xs,ys,zs) = zip3 xs ys zs >unzip xyzs = ( fmap (\(x,_,_)->x) xyzs, > fmap (\(_,y,_)->y) xyzs, > fmap (\(_,_,z)->z) xyzs ) > > instance (ZipFunctor f) => Zippable (f a,f b,f c,f d) f (a,b,c,d) where >zip (xs1,xs2,xs3,xs4) = zip4 xs1 xs2 xs3 xs4 >unzip xs = ( fmap (\(x,_,_,_)->x) xs, > fmap (\(_,x,_,_)->x) xs, > fmap (\(_,_,x,_)->x) xs, > fmap (\(_,_,_,x)->x) xs ) Question: is there a problem with defining unzip in terms of fmap, as opposed to the current definition in the prelude, which uses foldr? Best regards, Matt Harden
Re: Haskell libraries, support status, and range of applicability(was: Haskell jobs)
On Wed, 19 Jul 2000, Claus Reinke wrote: [List of some examples of library status information..] They are all fine and useful. But I do not see any clear incentives for authors for doing so, apart from their desire to make libraries perfect .. in their spare time, if any, of course. If the develepment of good libraries had similar gratifying effects as publishing scientific papers the situation could have looked quite differently, I guess. I just read "Heath B.O'Connell, Physicists thriving with paperless publishing", e-print physics/0007040, (on "xxx.lanl.gov"), and I was amazed to learn how well this paperless revolution works there, notwithstanding all sorts of extra efforts needed for this to work as smoothly as it does. But there _is_ a strong incentive to be quickly read, and in the same token, to access information as quickly as possible. But what kind of gratification one gets from writing a library, good or bad? Don't ask me, I have not seen any so far, unless when I do something strictly commercially. Secondly, I have not seen any real peer review on this level. I cannot speak for others, but the feedback I receive does not count; sporadic encouragement is not what is important here and web access statistics is useless too. Long time ago ISE Eiffel had so-called EifellShelf, where contributions from third parties were carefully scrutinized by a group at ISE in order to assure quality and conformance to standards. I do not know whether this model is still in operation, but I really liked it then, even though I had to put my commas and blank spaces just right, or put assertions where I had considered them unncecessary at first. It did not harm my pride at all, and it really helped everyone on a long run. Jan
Haskell libraries, support status, and range of applicability (was: Haskell jobs)
> On Wed, 19 Jul 2000, George Russell wrote:
> > What you need for that is SUPPORT, for example, to ensure that things
> > still work when Haskell changes. This is difficult to guarantee in
> > an academic environment.
> But the success of a language will depend on the quality of the libraries,
> too. If we cannot figure out a way to supply Haskell with working
> libraries, the language itself won't reach outside the academic world. It
> even takes a long time to figure out what a specific library is up to and
> if it's complete etc. Even if the academic staff can only give marginal
> support for their libraries due to their lack of time, it still might be
> sensible to mark libraries as "complete" (Is this a candidate for our
> application?) or even "Haskell 98 compliant" (Will the library compile
> with future versions of GHC/HBC?).
>
> Cheers,
> Axel.
I think the version/flag-documentation problem was addressed elsewhere
(was it last Haskell workshop?).
As George points out, it is hardly possible to make any guarantees
concerning the future of software developed as a by-product of academic
work. The situation is slightly better if the software constitutes the main
deliverable of an ongoing project, but even then guesses about the future
are just that - guesses. And the only complete pieces of software seem
to be those that are no longer in use.
As long as we work on a library, we are usually interested in feedback
and interaction, but if we get dragged away by other commitments, it
usually happens in such a way that the library is long out of date before
we concede defeat and add a comment that it is no longer supported.
I guess there is no disagreement about the general problem and that it
would be useful if the libraries-collection could be split into two
sections,
according to status. So I would propose to base the sections on current
and past information instead of predictions and promises.
Have one group of libraries in "is supported"-status (including date of last
successful communication with the authors for each entry), and simply
move everything that hasn't been updated for six months (at least by
an email saying "I'm still here - please keep my library listed"), but is
still available, into a second group, in "exists"-status. Potential users
can
then judge from the last-contact-date and the application area whether
a library might still be relevant to their project. A "once upon a time.."-
section with old infos and broken links might still be of historical
interest for other researchers, and perhaps helpful as a starting point
for new attempts on related libraries.
Libraries in the "is supported" section should have additional info about
development plans ("no further work planned/needed", "will work on this
when I find the time","a new release addressing the following issues is in
the works and will be released in month/year","helpers needed for the
following:..", ..) and suggested range of applicability ("just something I
did to learn the concepts", "this was a part of my thesis work", "this has
been used in project X, now terminated", "this is being used in the
following ongoing projects", "the following groups are committed to
support this for the next X years",...). Also, evaluations such as "does
these things: .., but is incomplete in the following respects: .." seem
more reliable than "complete".
I would really be interested to see this kind of information added to the
brief descriptions of all the wonderful libraries listed on haskell.org.
Just
wondering what the state of the art really is..
Claus
Re: Where do I start ?
> >I just installed this: > >nhc98-1.0pre19-1.i386.rpm > > Download Hugs it's somewhat nicer to work with. Different people have different preferences, but don't forget that you can always wrap a Hugs-like environment around any Haskell compiler - have a look at 'hi' (hmake interactive) for instance. > there is not debugger available for Haskell AFAIK The next release of nhc98 will feature not just one, but _two_ debuggers for Haskell. This compiler has hosted the Redex Trails tracer/debugger for several years now, and this tracing system is currently being developed further, with many significant improvements already in the pipeline. In addition, Andy Gill's HOOD library is very impressive, quite easy to install and use, is already available for Hugs and Ghc, and will be a standard package in nhc98 from the next release. (See http://www.cse.ogi.edu/~andy/debugging/ for a wider survey of the field of debugging in Haskell.) Regards, Malcolm
Re: Where do I start ?
Nicolas Tremblay <[EMAIL PROTECTED]> writes: My few suggestions (I have starting looking at Haskell just a year or so ago and never used it very intensivly) Download Hugs it's somewhat nicer to work with. There are two books available for Haskell Haskell The Craft of Functional Programming (author: Simon Thompson) and The Haskell School of Expression (learning functional prorgramming through Multimedia Paul Hudak. I tend to recommend the later. It's IMHO a bit better written, but of course YMMV. > > The problem is, I'm this type of guy who would need a book like: > "Learn Haskell in 21 days" ... hehehe or "Haskell for Dummies" AFAIK not available > > Tell me, where to start ? > Or where is the best place to start... > (am I crasy to even think about starting ?) see above > > I just installed this: > nhc98-1.0pre19-1.i386.rpm > > uname -rm > 2.2.14-5.0 i586 all the Haskell compilers and/or Intepreters work more on Linux, at lest I was able to get install them here ;-) Other languages woth a look OCAML (too a functional language) but comes with more utilities (e.g with a debugger, there is not debugger available for Haskell AFAIK) Common Lisp (nice development environements, extremly flexible) Smalltalk (off topic here, I think) Regards Friedrich -- for e-mail reply remove all after .com
Re: hugs98 download and installation
Dear Cuong Nguyen, I just downloaded and unpacked the latest version of Hugs98, and it worked just fine. You first need to download hugs98-Feb2000.zip into your C: drive and unzip it there. This will create a directory called "hugs98" directly under your C: drive. Then, you need to download win32exes.zip (although I used win32exes-pre.zip to avoid the potentially fatal type checker error in win32exes.zip listed on the Hugs98 download page at http://www.cse.ogi.edu/PacSoft/projects/Hugs/pages/downloading.htm) into your new C:\hugs98 directory. This will create a new subdirectory, win32exes (win32exes-pre in my case), under C:\hugs98. Then, you need to copy or cut the files in that win32exes (or win32exes-pre) subdirectory back into C:\hugs98. After that, you just run Hugs.exe, and this will start the February 2000 version of Hugs98. Hope this helps. Benjamin L. Russell [EMAIL PROTECTED] [EMAIL PROTECTED] On Wed, 19 Jul 2000 18:16:03 +1000 "cqnguyen" <[EMAIL PROTECTED]> wrote: > Dear Sir/Madam, > I am a student in Computer Sciences. I have just > successfully downloaded > Hugs98 but having trouble of using it. My question is > that if I need to > download both files : hugs98-Feb2000.zip and > win32exes.zip into C:\Hugs98 to > get it running or just either one of them. > I have tried different alternative such as downloaded > either one or both > files but none of the methods is working. > Could you please tell me how to download and install it > correctly. > I thank you very much and hope to receive your response > soon. > My E-mail address is [EMAIL PROTECTED] > Best regards, > Cuong Nguyen > >
Re: Haskell jobs (fwd)
On Wed, 19 Jul 2000, George Russell wrote: > What you need for that is SUPPORT, for example, to ensure that things > still work when Haskell changes. This is difficult to guarantee in > an academic environment. But the success of a language will depend on the quality of the libraries, too. If we cannot figure out a way to supply Haskell with working libraries, the language itself won't reach outside the academic world. It even takes a long time to figure out what a specific library is up to and if it's complete etc. Even if the academic staff can only give marginal support for their libraries due to their lack of time, it still might be sensible to mark libraries as "complete" (Is this a candidate for our application?) or even "Haskell 98 compliant" (Will the library compile with future versions of GHC/HBC?). Cheers, Axel.
Where do I start ?
Hi all, I am very interested by the Haskell language. I'm not at any faculty, I just heard about this language on the internet. I work in a QA departement in Montreeal, I don't have a lot of experience in programming; exept for Bourne shell scripting which I became fairly confortable with. I just started to read a bit about Haskell and so far, I'm very much impressed with the possibilities. I setted myself personnal objectives a while ago, to learn a multiplatform compilable language. In short words C++. Well, C++ was the answer until I heard about Haskell. I Feel it would be a good thing for me, since I don't have to program something, or work with it very quickly. It would be just, let's say, a knowledge investment based on an intuission. I seriously think that this thing has serious application in a very close future, and I want to be part of it, in my own way. The problem is, I'm this type of guy who would need a book like: "Learn Haskell in 21 days" ... hehehe or "Haskell for Dummies" Tell me, where to start ? Or where is the best place to start... (am I crasy to even think about starting ?) I just installed this: nhc98-1.0pre19-1.i386.rpm uname -rm 2.2.14-5.0 i586 Thanks a lot. -- N i c o l a s T r e m b l a y Product Tester, Infrastructure D I S C R E E T INC.
Re: Haskell jobs (fwd)
Axel Simon wrote: > One for industrial-strength and > complete libraries that will remain stable as long as Haskell lives and > one for the rest. What you need for that is SUPPORT, for example, to ensure that things still work when Haskell changes. This is difficult to guarantee in an academic environment.
RE: Haskell jobs (fwd)
On Wed, 19 Jul 2000, S. Alexander Jacobson wrote: > * the codebase needs to be production qualty (handle millions of hits > per day) > * there should be a network of users (or a support organization) running > and supporting the software Hi, I think most of the Haskell libraries found on www.haskell.org have this "experimental" flavour which makes serious application development a risky undertaking. Beyond that you need the always evolving extentions in GHC to write real world applications. The latter will hopefully change with a new Haskell standard, but the libraries will always suffer from being prototype implementations of good ideas. My suggestion is to divide the library section into two distinct areas: One for industrial-strength and complete libraries that will remain stable as long as Haskell lives and one for the rest. This might even motivate people to complete their libraries in order that it might move into the "industrial" section. Greetings, Axel Simon.
RE: Haskell jobs (fwd)
Folks, I have seen a few answers here. Let me add a few other constraints: * we are unix shop so win32 solutions don't work well here * the codebase needs to be production qualty (handle millions of hits per day) * there should be a network of users (or a support organization) running and supporting the software * we are largely running Java as our platform so easier Java integration is important. > S. Alexander Jacobson writes: > > Off the top of my head here are some Haskell specific things that we need: > > > * HSP pages (like ASP or JSP or PHP) > > Erik Meijer has done this. Can't find the preprint online, though. (Erik?) Is this production quality. Proof-of-concept implementations don't cut it. > > * in memory Haskell server analogous to JServ that talks to apache > > mod_haskell? > http://losser.st-lab.cs.uu.nl:8080/ Same question. It appears to be 0.1. > > * Haskell access to a pool of database connections > > Daan Leijen's HaskellDB? > http://haskell.cs.yale.edu/haskellDB/ Windows Only. > > * Haskell access to Java classes > > Erik's Lambada > http://www.cs.uu.nl/people/erik/Lambada.html I know about lambada. It is experimental. According to the homepage: "The current release does not offer much tool support to access Java classes from Haskell yet" It is also windows only. Is anyone here using it? > > * Encapsulation of Haskell as Java classe > > I don't know what that means, exactly. You mean a Hugs-like implementation in > Java? Not a bad idea... do you need that, though, now that GHC can produce > Java bytecode? Anyway, once the Java backend stabilizes, you would (in > principle, at least :) be able to cross-compile GHC into a Java binary, and > then use its upcoming interactive frontend. You still wouldn't have > programmatic hooks (i.e., a Java-level rather than console-level interface) to > the front-end, but it would become much easier to add. Actually, the ability generate Java bytecode would be a BIG win here if GHC generated code could smoothly cal Java classes as well. (then you get dbpools from java!) > > And all of this has to be relatively zipless and compatible with an > > existing JServ/JSP/Apache installation. > > Eh? "zipless"? It has to be relatively easy to configure and install. Overall, Haskell has a lot of promise. It is just not there. Perhaps when I get the right people, we will take a look and discover that the hurdles aren't so great. Mainly I need developers who would explore this. If I get that, the rest is easy. -Alex- ___ S. Alexander Jacobson Shop.Com 1-212-420-7700 voiceThe Easiest Way To Shop (sm)
RE: Haskell jobs (fwd)
Frank Atanassow <[EMAIL PROTECTED]> wrote, > Manuel M. T. Chakravarty writes: > > Frank Atanassow <[EMAIL PROTECTED]> wrote, > > > > > Chris Angus writes: > > > > Aren't most of these "java additions" MS J++ or MS specific > > > > rather than java/jdbc "run-anywhere" though? > > > > > > Not as far as I know, but maybe Erik and Daan will clarify. > > > > HaskellDB is Win-specific as it is based on COM - at least > > that is what Daan told me last week. (Otherwise, it looks > > super-cool.) > > There is a non-Windows distribution at > > http://haskell.cs.yale.edu/haskellDB/download.html > > so I thought it supported Unix, but the page also says, "no driver is yet > available for these platforms but it should be quite easy to create a general > ODBC driver." Maybe it can be extended to work with NDBM/GDBM/MySQL? That would be cool. > (Sorry, I am a DB moron.) Me too :-) Manuel
Re: Precision problem
Tue, 18 Jul 2000 14:48:36 +0200 (MET DST), Wilhelm B. Kloke
<[EMAIL PROTECTED]> pisze:
> If you mind that this could be exploited to create side-effects,
> you have to wrap FP into a monad.
Not side effects but "unstable" values. IMHO it would be too pedantic,
although theoretically necessary. A programming language should be
convenient for programming. Given the style of the rest of Haskell,
advantages of having pure floating point operations are bigger than
disadvantages of their "impossible" behavior, assuming that the
operations are unstable anyway and we only consider their interface.
Especially as we have a "correct" alternative implementation.
This impurity is like readFile; maybe a little worse. readFile
should not return a lazy string but read the whole file at once
(because the given value may depend on future I/O actions; at least
it's stable, i.e. is determined once read). readFile can be used to
write "impossible" functions, not possible without it. But readFile
is convenient.
This impurity is like GHC's exceptions. They allow reliable (at
least in practice, I'm not sure about the theory) distinguishing of
'error "string"' values with different arguments passed, although
the language formally states that bottom is simply bottom.
We should be aware and have documented where these shortcuts exist,
but they are useful.
--
__("< Marcin Kowalczyk * [EMAIL PROTECTED] http://qrczak.ids.net.pl/
\__/GCS/M d- s+:-- a23 C+++$ UL++>$ P+++ L++>$ E-
^^W++ N+++ o? K? w(---) O? M- V? PS-- PE++ Y? PGP+ t
QRCZAK5? X- R tv-- b+>++ DI D- G+ e> h! r--%>++ y-
RE: Haskell jobs (fwd)
Manuel M. T. Chakravarty writes: > Frank Atanassow <[EMAIL PROTECTED]> wrote, > > > Chris Angus writes: > > > Aren't most of these "java additions" MS J++ or MS specific > > > rather than java/jdbc "run-anywhere" though? > > > > Not as far as I know, but maybe Erik and Daan will clarify. > > HaskellDB is Win-specific as it is based on COM - at least > that is what Daan told me last week. (Otherwise, it looks > super-cool.) There is a non-Windows distribution at http://haskell.cs.yale.edu/haskellDB/download.html so I thought it supported Unix, but the page also says, "no driver is yet available for these platforms but it should be quite easy to create a general ODBC driver." Maybe it can be extended to work with NDBM/GDBM/MySQL? (Sorry, I am a DB moron.) -- Frank Atanassow, Dept. of Computer Science, Utrecht University Padualaan 14, PO Box 80.089, 3508 TB Utrecht, Netherlands Tel +31 (030) 253-1012, Fax +31 (030) 251-3791
RE: Haskell jobs (fwd)
Frank Atanassow <[EMAIL PROTECTED]> wrote, > Chris Angus writes: > > Aren't most of these "java additions" MS J++ or MS specific > > rather than java/jdbc "run-anywhere" though? > > Not as far as I know, but maybe Erik and Daan will clarify. HaskellDB is Win-specific as it is based on COM - at least that is what Daan told me last week. (Otherwise, it looks super-cool.) Manuel
RE: Haskell jobs (fwd)
Chris Angus writes: > Aren't most of these "java additions" MS J++ or MS specific > rather than java/jdbc "run-anywhere" though? Not as far as I know, but maybe Erik and Daan will clarify. -- Frank Atanassow, Dept. of Computer Science, Utrecht University Padualaan 14, PO Box 80.089, 3508 TB Utrecht, Netherlands Tel +31 (030) 253-1012, Fax +31 (030) 251-3791
Re: Precision problem
Sven Panne wrote: > (As an aside: I *hate* standards which are not freely > available, I've never seen a real IEEE-754 document. A $4000 annual > subscription price for a single person is ridiculous, and I would probably > have slight problems persuade my company to buy the $40.000 enterprise > subscription...) I agree about this. The GHC people based at Cambridge do however have access to a real copy of I754, since there is one in the CL library there, or at any rate was about 2 years ago. But you can probably find out everything you want to know on Kahan's Web page: http://HTTP.CS.Berkeley.EDU/~wkahan/ Fergus Henderson wrote > If all the platforms that GHC target use the same IEEE arithmetic > and representation for Float/Double, why does GHC need to use > Rational to represent floating pointer values? Unfortunately they probably don't. About the only platform I can think of which is fully IEEE-conformant by default is Sparc/Solaris. On Intel things are done in extra precision and can then be rounded (I presume you can construct perverse cases where this rounding goes completely wrong). On Alphas IEEE 754 conformance requires insertion of trap barriers so overflows can be handled properly. cc only does this when you give it an obscure option no-one uses, and as far as I know gcc can't do it at all. So my opinion is that GHC should attempt no FP constant folding at all when cross-compiling. It is probably just as well that the Haskell standard does not insist on IEEE754, as it might be difficult to guarantee.
RE: Haskell jobs (fwd)
Aren't most of these "java additions" MS J++ or MS specific rather than java/jdbc "run-anywhere" though? Hoping that this isnt the case Chris > -Original Message- > From: Frank Atanassow [mailto:[EMAIL PROTECTED]] > Sent: 19 July 2000 10:22 > To: S. Alexander Jacobson > Cc: Manuel M. T. Chakravarty; [EMAIL PROTECTED] > Subject: RE: Haskell jobs (fwd) > > > S. Alexander Jacobson writes: > > Off the top of my head here are some Haskell specific > things that we need: > > > * HSP pages (like ASP or JSP or PHP) > > Erik Meijer has done this. Can't find the preprint online, > though. (Erik?) > > > * in memory Haskell server analogous to JServ that talks to apache > > mod_haskell? > http://losser.st-lab.cs.uu.nl:8080/ > * Haskell access to a pool of database connections Daan Leijen's HaskellDB? http://haskell.cs.yale.edu/haskellDB/ > * Haskell access to Java classes Erik's Lambada http://www.cs.uu.nl/people/erik/Lambada.html > * Encapsulation of Haskell as Java classe I don't know what that means, exactly. You mean a Hugs-like implementation in Java? Not a bad idea... do you need that, though, now that GHC can produce Java bytecode? Anyway, once the Java backend stabilizes, you would (in principle, at least :) be able to cross-compile GHC into a Java binary, and then use its upcoming interactive frontend. You still wouldn't have programmatic hooks (i.e., a Java-level rather than console-level interface) to the front-end, but it would become much easier to add. > And all of this has to be relatively zipless and compatible with an > existing JServ/JSP/Apache installation. Eh? "zipless"? -- Frank Atanassow, Dept. of Computer Science, Utrecht University Padualaan 14, PO Box 80.089, 3508 TB Utrecht, Netherlands Tel +31 (030) 253-1012, Fax +31 (030) 251-3791
RE: Haskell jobs (fwd)
S. Alexander Jacobson writes: > Off the top of my head here are some Haskell specific things that we need: > * HSP pages (like ASP or JSP or PHP) Erik Meijer has done this. Can't find the preprint online, though. (Erik?) > * in memory Haskell server analogous to JServ that talks to apache mod_haskell? http://losser.st-lab.cs.uu.nl:8080/ > * Haskell access to a pool of database connections Daan Leijen's HaskellDB? http://haskell.cs.yale.edu/haskellDB/ > * Haskell access to Java classes Erik's Lambada http://www.cs.uu.nl/people/erik/Lambada.html > * Encapsulation of Haskell as Java classe I don't know what that means, exactly. You mean a Hugs-like implementation in Java? Not a bad idea... do you need that, though, now that GHC can produce Java bytecode? Anyway, once the Java backend stabilizes, you would (in principle, at least :) be able to cross-compile GHC into a Java binary, and then use its upcoming interactive frontend. You still wouldn't have programmatic hooks (i.e., a Java-level rather than console-level interface) to the front-end, but it would become much easier to add. > And all of this has to be relatively zipless and compatible with an > existing JServ/JSP/Apache installation. Eh? "zipless"? -- Frank Atanassow, Dept. of Computer Science, Utrecht University Padualaan 14, PO Box 80.089, 3508 TB Utrecht, Netherlands Tel +31 (030) 253-1012, Fax +31 (030) 251-3791
hugs98 download and installation
Dear Sir/Madam, I am a student in Computer Sciences. I have just successfully downloaded Hugs98 but having trouble of using it. My question is that if I need to download both files : hugs98-Feb2000.zip and win32exes.zip into C:\Hugs98 to get it running or just either one of them. I have tried different alternative such as downloaded either one or both files but none of the methods is working. Could you please tell me how to download and install it correctly. I thank you very much and hope to receive your response soon. My E-mail address is [EMAIL PROTECTED] Best regards, Cuong Nguyen
