Re: [Haskell] Re: Marketing Haskell

G'day all. Quoting "Benjamin L.Russell" : Actually, according to the Wikipedia entry for "octopus" (see http://en.wikipedia.org/wiki/Octopus), I probably should have written the plural as either "octopuses" or "octopodes": Ah, but "octopodes" is only the _nominative_ plural. You really shoul

Re: [Haskell] Re: [Haskell-cafe] Haskell Weekly News: Issue 111 - March 28, 2009

G'day all. Quoting Krzysztof Skrzętnicki : This paper from 1994: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.36.5611 begins point 1.1 with exactly that sentence. It doesn't seem to be quoted there, so one can assume this is the original source of that sentence. I'm not sure dough.

Re: [Haskell] Re: Teach theory then Haskell as example

G'day all. Quoting Max Rabkin : Good to have a recommendation -- my future CT lecturer has a hard time recommending anything not written by Mac Lane. One more suggestion: "Conceptual Mathematics" by Lawvere and Schanuel is the gentlest introduction that you're going to find. Cheers, Andrew B

Re: [Haskell] Re: on starting Haskell-Edu, a new education-related Haskell-related mailing list

G'day all. Quoting Abhay Parvate <[EMAIL PROTECTED]>: [EMAIL PROTECTED] [EMAIL PROTECTED] Cheers, Andrew Bromage ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell

Re: [Haskell] Empty instance declaration

G'day all. Quoting Isaac Dupree <[EMAIL PROTECTED]>: I know! I said so! My question is whether anyone has an example of doing either of those in mutually-recursive DEFAULT METHOD definitions? class (Eq a) => StupidEqList a where eqList :: [a] -> [a] -> Bool neqList :: [a] -> [a] ->

Re: [Haskell] Empty instance declaration

G'day all. Quoting Hugo Macedo <[EMAIL PROTECTED]>: After checking the Haskell98 grammar I found out that this is allowed syntactically and probably semantically too. Is there any reason to do that? One thing that hasn't come up yet is that empty instance declarations are the only decent opti

Re: [Haskell] Announce: generating free theorems, online and offline

[Ccing to haskell-cafe; please direct any replies there instead of haskell] G'day all. First of all, once again well done to Sascha on a great tool. Just a few comments. Quoting Janis Voigtlaender <[EMAIL PROTECTED]>: - support for type classes (e.g., enter "elem" and note the generated re

Re: [Haskell] View patterns in GHC: Request for feedback

G'day all. Quoting Claus Reinke <[EMAIL PROTECTED]>: > different =/= wrong !-) [...] > but that is not what you're saying there at all! you're saying that -within > view 'view' of Typ- Typ is mapped to either Unit or Arrow, if the mapping > is successfull. there can be other views of Typ, and t

Re: [Haskell] Re: View patterns in GHC: Request for feedback

G'day all. "Claus Reinke" <[EMAIL PROTECTED]> schrieb im Newsbeitrag news:[EMAIL PROTECTED] > >type Typ > > > >unit :: Typ -> Maybe () > >arrow :: Type -> Maybe (Typ,Typ) > >size :: Typ -> Integer > >size (unit -> ()) = 1 > >size (arrow -> (t1,t2)) = size t1 + size t2 The

Re: [Haskell] View patterns in GHC: Request for feedback

G'day all. On Mon, Jul 23, 2007 at 05:09:01AM -0400, Dan Licata wrote: > Simon PJ and I are implementing view patterns, a way of pattern matching > against abstract datatypes, in GHC. Our design is described here: > > http://hackage.haskell.org/trac/ghc/wiki/ViewPatterns I have to agree. Great

Re: [Haskell] boilerplate boilerplate

G'day all. Quoting Alex Jacobson <[EMAIL PROTECTED]>: > It seems really unnecessarily verbose. Having to add the OPTION header ...which you don't need; this could go on the command line... > It is even more of a beat-down to have to add a deriving > clause for every newtype to make this all wo

Re: [Haskell] HaWiki closing in one month; migrate content to HaskellWiki now!

G'day all. Quoting "Brett G. Giles" <[EMAIL PROTECTED]>: > There are a lot of pages that look like they would be great to move - > but either no indication of who put them up or no license info on the > persons page if we do know who put them up. I hereby give permission to redistribute anything

[Haskell] Homework help (was: 2 programs VERY URGENT)

G'day all. Quoting Thomas Davie <[EMAIL PROTECTED]>: > Also of note, this channel is in large part made up of university > lecturers, researchers, and PhD students. I really wouldn't be > surprised if one of them were to notice the assignment they set > cropping up here. This and more, covered

Re: [Haskell] Haskell as a disruptive technology?

G'day all. Quoting Immanuel Litzroth <[EMAIL PROTECTED]>: > I have created programs that fill an array with the first 100 > prime numbers using erathostenes sieve. > I have done this in lisp, c++, ocaml and haskell. Lisp and c++ win > hands down, being approximately 5x faster than ocaml, hask

Re: [Haskell] Trying to get a Composite design pattern to work

G'day all. Quoting Asfand Yar Qazi <[EMAIL PROTECTED]>: > Actually, I'm trying to avoid library functions, so I can learn the > language and the functional way of thinking. How would one implement > the concatMap function? See if you can work how how this one works. No library functions, apart

Re: [Haskell] Long live Edison

G'day all. Quoting Cale Gibbard <[EMAIL PROTECTED]>: > One thing which I found odd about the NotJustMaybe pattern is that not > much is really gained apart from a small amount of convenience. That's not the whole truth. It buys you abstraction, in that the library function can signal an error w

Re: [Haskell] Long live Edison

G'day again. Quoting Robert Dockins <[EMAIL PROTECTED]>: > There are a number of methods which take a monad context and call > 'fail' (rather than error) under some conditions, usually when the > data structure is empty [...] > I am considering moving to a MonadPlus context and calling 'mzero'

Re: [Haskell] Long live Edison

G'day all. Quoting Robert Dockins <[EMAIL PROTECTED]>: > Although I am not a data structures expert, several weeks ago I > decided that I would try my hand at maintaining Edison and see if I > could overcome these barriers. Toward this end I have taken the most > recent Edison codebase I could f

Re: [Haskell] Modelling languages for FP (like UML for OO)

G'day all. Quoting Benjamin Franksen <[EMAIL PROTECTED]>: > However, not everyone in the OO camp thinks that UML is really useful: > > http://archive.eiffel.com/doc/manuals/technology/bmarticles/uml/page.html Having actually used it (once), the consensus seems to be: 1. It only applies to a "pu

Re: [Haskell] Re: haskell.org Public Domain

G'day all. Quoting Ashley Yakeley <[EMAIL PROTECTED]>: > What about this one? > > > > "I, the creator of this work, hereby release it into the public domain. > This applies worldwide. > > "In case this is not legally possible

Re: [Haskell] Re: haskell.org Public Domain

G'day all. Quoting Wolfgang Jeltsch <[EMAIL PROTECTED]>: > Yes, BSD might be too "restrictive". So let's put every wiki content under a > very permissive license like the one Udo proposed. Opinions? I agree. Does such a licence already exist? If not, I'd suggest taking the Creative Commons "

Re: [Haskell] haskell.org Public Domain

G'day all. Quoting Ashley Yakeley <[EMAIL PROTECTED]>: > Does anyone have any objections to putting everything in the public > domain? No, with the proviso that individual page authors can override that on the page itself. There is a disincentive for authors to do this, because their material m

Re: [Haskell] Re: License for haskell.org content

G'day all. Quoting Simon Marlow <[EMAIL PROTECTED]>: > I agree - can we please use BSD or public domain? Creative Commons "by" might be an appropriate alternative: http://creativecommons.org/licenses/by/2.5/ Cheers, Andrew Bromage ___ Haskell mai

Re: [Haskell] A collection of related proposals regarding monads

G'day all. I wrote: > > My feeling is that do { p <- xs; return e } should behave identically > > (modulo the precise error message if the pattern match fails) to > > map (\p -> e) xs. Your proposal would make it into a map/filter > > hybrid. Which, of course, it is now. I blame lack of caffei

Re: [Haskell] A collection of related proposals regarding monads

G'day Cale. Quoting Cale Gibbard <[EMAIL PROTECTED]>: > I personally feel that the inclusion of 'fail' in the Monad class is > an ugly solution to the problem of pattern matching, and gives the > incorrect impression that monads should have some builtin notion of > failure. So do I. > We ought

RE: [Haskell] PROPOSAL: class aliases

G'day all. Quoting Simon Peyton-Jones <[EMAIL PROTECTED]>: > I've considered this before, but never done anything about it because > superclasses are so close. Specifically, what is the difference between > > (i) class (C a, D a) => CD a > and > (ii) class alias CD a = (C a, D a) > > Note tha

Re: [Haskell] pros and cons of static typing and side effects ?

G'day all. Quoting John Meacham <[EMAIL PROTECTED]>: > I find pretty much completly the opposite is true. for random hacking > and evolving code, static typing is essential. I agree with that. While you can't be certain that once your code typechecks, it's bug-free (though that does often happe

Re: Re[2]: [Haskell] Dynamic binding

G'day all. Thursday, June 23, 2005, 5:38:03 AM, you wrote: > To handle the problem of drawing all shapes, in c++, I would have a list > of shape pointers: > struct shape{ virtual void draw(...);}; > struct circle : public shape {...}; > struct square : public shape {...}; > std::list shapes; > f

Re: [Haskell] A MonadPlusT with fair operations and pruning

G'day all. Quoting [EMAIL PROTECTED]: : Since Andrew Bromage wished for that interesting monad, perhaps he has : in mind a good example of its use. We are particularly interested in a : short example illustrating soft-cut (and, perhaps, `once'). No obvious small examples of soft cut spring to m

Re: [Haskell] [Newbie] Data structure for Dijkstra's algorithm

G'day all. Quoting robert dockins <[EMAIL PROTECTED]>: > This algorithm relies pretty fundamentally on mutability, which makes it > a less than wonderful fit for a functional language. Right, which makes me wonder if this is the algorithm that you really want. Does it have to be Dijkstra's al

Re: [Haskell] monad transformers

G'day all. Quoting John Meacham <[EMAIL PROTECTED]>: > However, now we come to the crux, I want > the various interesting monad operations (MonadReader, MonadWriter, > etc.. ) to be able to pass through StatT [...] Why do you want to do that? Think carefully before you answer. I've never liked

Re: [Haskell] A puzzle and an annoying feature

G'day all. Quoting Lennart Augustsson <[EMAIL PROTECTED]>: > Here is a small puzzle. You can understand this one because the closed world hypothesis doesn't apply to type context inference. However, this seems as good a time as any to mention one of my pet peeves again: module FD where class

Re: [Haskell] Re: Global Variables and IO initializers

G'day all. Quoting George Russell <[EMAIL PROTECTED]>: > No. I mean by the "Haskell language" what is described in > the Haskell 98 Report. unsafePerformIO is not part of the language, > it is a value defined by one of the standard hierarchical libraries. unsafePerformIO is part of the FFI ad

Re: [Haskell] Re: sizeFM type

G'day all. Quoting "S. Alexander Jacobson" <[EMAIL PROTECTED]>: > I'll cite that hoary Hoare quotation here. > "Premature optimization is the root of all evil." Agreed! In particular, functions meant for general use, especially in the standard library, should not optimise for a specific case an

Re: [Haskell] insufficiently [EMAIL PROTECTED] -- more counterintuitive stuff

G'day all. Quoting Duncan Coutts <[EMAIL PROTECTED]>: > Or finally, the "it's what you want most often" argument. How about the "it's the most natural thing" argument? Pattern matching on the LHS of a function definitions looks, for all the world, like a set of rewrite rules. That's because, i

Re: [Haskell] RFC: DData in hierarchical libraries

G'day all. Quoting JP Bernardy <[EMAIL PROTECTED]>: > Would you prefix the function name with unsafe? I > wonder what is the best way to do such a marking. I would recommend not using that particular prefix. At the moment, I believe that "unsafe" is only used for functions which could potential

RE: [Haskell] System.Random

G'day all. Quoting Simon Marlow <[EMAIL PROTECTED]>: > I suspect that developers requiring a good source of randomness for > security would disagree with you. I would hope that developers requiring a good source of randomness for security would know better than to use System.Random! Cheers, And

Re: [Haskell] Re: performance tuning Data.FiniteMap

G'day all. Quoting [EMAIL PROTECTED]: > If indeed the read performance is at premium and updates are > infrequent, by bother with ternary etc. trees -- why not to use just a > single, one-level array. Given a reasonable hash function, the > retrieval performance is O(1). Ah, but key compar

Re: Use Radix for FiniteMap? (was Re: [Haskell] performance tuning Data.FiniteMap)

G'day all. Quoting "S. Alexander Jacobson" <[EMAIL PROTECTED]>: > Isn't the following more efficient than Data.FiniteMap? [deletia] TernaryTrie is basically this, minus the Radix type class, and using balanced binary trees for each radix levels instead of arrays. Cheers, Andrew Bromage

Re: [Haskell] Re: Data.Set whishes

G'day all. Quoting Koen Claessen <[EMAIL PROTECTED]>: > I think Chris Okasaki did a nice job and made a good data > structure library proposal with Edison (years ago). It uses > both the qualified names trick and type classes. Why nobody > uses it (or even knows about it) is a mystery to me. My

Re: [Haskell] Re: Data.Set whishes

G'day all. Quoting Ketil Malde <[EMAIL PROTECTED]>: > One could possibly argue that the right solution is to put the > operations in classes? One could also argue that the right solution is first-class modules. :-) Cheers, Andrew Bromage ___ Haskell m

Re: no continuations

G'day all. Quoting Tomasz Zielonka <[EMAIL PROTECTED]>: > OK. I think I may be getting it now. The point is that MonadCont takes > care of passing the continuation, so you don't have to do it by hand. Is > that right? Precisely. > Happy New Year, And to you and yours. Cheers, Andrew Bromage _

Re: efficiency of FiniteMap and Set

G'day all. Quoting Wolfgang Jeltsch <[EMAIL PROTECTED]>: > is there some documentation about the complexity of the FiniteMap and Set > operations? More information than you could ever want is here: http://www.swiss.ai.mit.edu/users/adams/BB/ Cheers, Andrew Bromage _

Re: no continuations

G'day all. Quoting Tomasz Zielonka <[EMAIL PROTECTED]>: > BTW, the factorial example on > http://www.haskell.org/hawiki/MonadicContinuationPassingStyle > seems rather pointless to me, because it doesn't use any methods > of MonadCont (like callCC). The only point of the factorial example is to

Re: Haskell naming conventions

G'day all. Quoting Lennart Augustsson <[EMAIL PROTECTED]>: > According to dictionary.com one of the definitions of the word class is: > >A set, collection, group, or configuration containing members regarded >as having certain attributes or traits in common; a kind or category. > > And wh

Re: Annotating Expressions

G'day all. Quoting Fergus Henderson <[EMAIL PROTECTED]>: > Unless I missed something, none of those solve all the problems that > Meacham is trying to solve (numbers 1 and 2 in his original mail). Many of them solve problem number 1, in that an unannotated structure is computationally identical

Re: Annotating Expressions

G'day all. Quoting John Meacham <[EMAIL PROTECTED]>: > Imagine I have a data structure like so: > > data E = EAp E E | ELam Int E | ELetRec [(Int,E)] E | EVar Int > > now, I want to annotate every occurence of E with some pass specific > information, such as free variables or levels for lambda li

Re: Why are strings linked lists?

G'day all. Quoting Wolfgang Jeltsch <[EMAIL PROTECTED]>: > I think, I have already said the following on this list. I would also like to > have different character types for different subsets of Char (e.g., ASCII) > and a class Character which the different character types are instances of. As a

Re: Why are strings linked lists?

G'day all. Quoting John Meacham <[EMAIL PROTECTED]>: > Something I'd like to see (perhaps a bit less > drastic) would be a String class, similar to Num so string constants > would have type > String a => a Interesting that you mention this. I've also been thinking about this lately in the conte

Re: Why are strings linked lists?

G'day all. Quoting Ben Escoto <[EMAIL PROTECTED]>: > Hi, can someone tell me why Haskell strings are linked lists? Because that's the way it was done in Miranda, almost 20 years ago. OK, to be fair, it does make string-to-string operations a bit more convenient. Apart from undergraduate homewo

Re: set representation question

G'day all. Quoting Hal Daume III <[EMAIL PROTECTED]>: > i'm looking for a representation for a set of natural numbers. right now, > my representation is sorted array, which works well. *all* i care about > is being able to quickly calculate the size of the intersection of two > sets. these set

Re: haskell httpd

G'day all. Quoting Paul Graunke <[EMAIL PROTECTED]>: > Right, cooperative multitasking is faster than preemptive multitasking. That's often the case, but it depends. Some OSes have very, very fast thread primitives. It also depends on the application, as I noted, because what you lose in syste

Re: haskell httpd

G'day all. Quoting Peter Simons <[EMAIL PROTECTED]>: > At least in my experience, multiplexing servers _are_ > significantly faster than those relying on the OS (or > whatever library) to do the scheduling. They also tend to be > much more efficient in terms of memory consumption, thus > allowing

RE: Expiring cached data?

G'day all. Quoting Tom Pledger <[EMAIL PROTECTED]>: > It sounds like the term "splay tree" means different things to > different people. I was thinking in particular of one which, whenever > it finds a key it was looking for, does some rotation so that the > key's node's depth is reduced. The o

RE: Expiring cached data?

G'day all. Tom Pledger wrote: > How about adapting splay trees so that their pointers become weak > after a certain depth? The advantage for caching is that the more > frequently used elements move closer to the root, so you wouldn't have > to add much code for tracking recent use, just a depth

Re: Expiring cached data?

G'day all. On Sun, 2 Nov 2003 22:58:41 -0300 (CLST) "andrew cooke" <[EMAIL PROTECTED]> wrote: > > What options do I have in Haskell? I'm interested both in general > > solutions (maybe some compilers do this anyway?) and in approaches > > to structuring the program so that I can control caching

Re: literate comments

G'day all. Quoting Steffen Mazanek <[EMAIL PROTECTED]>: > Would it make sense, to add a xml like code environment > as well, e.g., ...? It's hard to say. The problem is that some Haskell characters are also important for XML (e.g. <, &) and so you can't just cut and paste valid Haskell inside a

Re: IO behaves oddly if used nested

G'day all. Alastair Reid <[EMAIL PROTECTED]> wrote: > I think it is exactly right. I think it's wrong. The return type of IO should be discarded. Even if it isn't, it doesn't make sense for IO to be in Show. Cheers, Andrew Bromage ___ Haskell mailin

An operational semantics for Haskell

I am looking for advice or ideas on the formulation of an operational semantics for studying the behaviour of Haskell programs. What I have in mind is a structured semantics for the unoptimized evaluation of Core Haskell programs (my main interest is in studying space behaviour). By unoptimised I