Re: [Haskell-cafe] deepSeq vs rnf

Interesting, I hadn't thought of the SYB approach. I still need to get through those papers. Actually, I wonder if this idea would help with something else I was looking into. It seems like it might occasionally be useful to have a monad that is the identity, except that it forces evaluation as

Re: Parallel GC

Sounds great, thanks! -Chad On 10/16/06, Simon Marlow [EMAIL PROTECTED] wrote: GHC 6.6 does run code in parallel on SMP hardware, but the GC is still single threaded. We have a prototype parallel GC, and I'm planning to work on it some more in the next few months... you'll probably see it in

Re: [Haskell] Classes with no data type

-- ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell End of Haskell Digest, Vol 38, Issue 6 ** -- Chad Scherrer Time flies like an arrow; fruit flies like a banana -- Groucho Marx

[Haskell] ByteString tokens

interactive:1:0: Not in scope: `tokens' Any idea where it went? Thanks, -- Chad Scherrer Time flies like an arrow; fruit flies like a banana -- Groucho Marx ___ Haskell mailing list

Re: [Haskell] ByteString tokens

) - ByteString - [ByteString] tokens f = List.filter (not.null) . splitWith f Duncan Ok, I'll just do it that way. Thanks! -- Chad Scherrer Time flies like an arrow; fruit flies like a banana -- Groucho Marx ___ Haskell mailing list Haskell@haskell.org http

Re: [Haskell-cafe] cumulative sum

Tamas, try scanl (+) 0 for the cumulative sum From there the zipWith idea you mentioned seems like the way to go. -Chad Hi, I have two lists, p and lambda (both are finite). I would like to calculate 1) the cumulative sum of lambda, ie if lambda = [lambda1,lambda2,lambda3,...] then

[Haskell-cafe] DiffTime in Data.Time

I'm trying to use Data.Time, and I'm totally confused. DiffTime is abstract, and I don't see anything that maps into it. How do I construct one? I would like to then use the result to create a value of type UTCTime, but it seems (currently) like this might be easier. Thanks, -- Chad Scherrer

[Haskell-cafe] Re: DiffTime in Data.Time

Ok, that's much simpler than I was making it. fromIntegral or fromRational does the trick. Obvious in hindsight, I guess. Thanks! -Chad On 10/2/06, Ashley Yakeley [EMAIL PROTECTED] wrote: Chad Scherrer wrote: I'm trying to use Data.Time, and I'm totally confused. DiffTime is abstract, and I

Re: [Haskell-cafe] smallest double eps

Hang on, hang on, now I'm getting confused. First you asked for the smallest (positive) x such that 1+x /= x which is around x=4.5e15. Then Joachim wondered if you wanted 1+x /= 1 which is around x=2.2e-16. But not you claim to be looking for the smallest positive number that a Double

Re: [Haskell-cafe] smallest double eps

-- Chad Scherrer Time flies like an arrow; fruit flies like a banana -- Groucho Marx ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

[Haskell-cafe] Expressing seq

not just do something like this (in ghci)? Prelude let sq x y = if x == x then y else y Prelude 1 `sq` 2 2 Prelude (length [1..]) `sq` 2 Interrupted. There must be a subtlety I'm missing, right? -- Chad Scherrer Time flies like an arrow; fruit flies like a banana -- Groucho Marx

Re: [Haskell-cafe] Expressing seq

There must be a subtlety I'm missing, right? What if the types are not instances of Eq? Jason Thanks, I figured it was something simple. Now I just to convince myself there's no way around that. Is there a proof around somewhere? -- Chad Scherrer Time flies like an arrow; fruit flies

Re: [Haskell-cafe] REALLY simple STRef examples

! Of course there is no problem if you don' use the higher order function $. Use parens instead x = runST (return 1) Simon | -Original Message- | From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of | Chad Scherrer | Sent: 19 July 2006 23:02 | To: haskell-cafe@haskell.org

Re: Re[4]: [Haskell-cafe] REALLY simple STRef examples

The IO monad hasn't given me too much trouble, but I want to be sure to structure things the way they should be. If I get everything running using IO first and then have type-checking problems with ST, it will be tempting to just slap on an unsafePerformIO and call it good. Sure, it's really

loop problems

! -- Chad Scherrer Time flies like an arrow; fruit flies like a banana -- Groucho Marx ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users

Re: loop problems

depends on the value of x. Hence you get a circular problem, which would non-terminate, but the compiler can spot this self-dependance and says loop instead. Maybe one of your two other functions have this problem? Thanks Neil -- Chad Scherrer Time flies like an arrow; fruit flies like a banana

[Haskell-cafe] REALLY simple STRef examples

maybe I needed to replace 1 with (1 :: Int) so the state representation didn't force the type, but it still gives the same result. Can someone point me to the simplest possible runST example that actually works? Thanks! -- Chad Scherrer Time flies like an arrow; fruit flies like a banana

Re: [Haskell-cafe] REALLY simple STRef examples

Whoa. That changes everything I thought I knew about ($). Come to think of it, one of the examples that does work it written main = print $ runST f where f is defined separtely. So that's consistent. I'll take a look at the references. Thanks! Indeed. The short answer: use runST (long

Re: [Haskell-cafe] REALLY simple STRef examples

mapM_ (x0 +=) xs x0 -- Chad Scherrer Time flies like an arrow; fruit flies like a banana -- Groucho Marx ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: Re[2]: [Haskell-cafe] REALLY simple STRef examples

Are the types of (result x) and result' not exactly the same? -- Chad Scherrer Time flies like an arrow; fruit flies like a banana -- Groucho Marx ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

[Haskell-cafe] deepSeq vs. rnf?

Now and again I see references to deepSeq, and I've never understood how this could be any different than using rnf from Control.Parallel.Strategies. Is there really any difference? When is it better to use one or the other? Thanks, -- Chad Scherrer Time flies like an arrow; fruit flies like

Re: [Haskell-cafe] Windows PowerShell Monad

yet, and already the mainstream-to-be is taking over the google results. Googling for microsoft monad gives all powershell and no MS Research! -- Chad Scherrer Time flies like an arrow; fruit flies like a banana -- Groucho Marx ___ Haskell-Cafe mailing

[Haskell-cafe] Windows PowerShell Monad

Yep, that's its codename. Now, I'm not much of a Windows person. Is the name just a weird coincidence, or does it have anything to do with monads as we know them? http://en.wikipedia.org/wiki/MSH_(shell) -- Chad Scherrer Time flies like an arrow; fruit flies like a banana -- Groucho Marx

[Haskell-cafe] Hackathon hesitation

Hi, I'm interested in attending the Hackathon, but I don't have any previous experience working on compilers. I think it could be a great learning experience, but I certainly don't want to slow progress on any work by just hanging around asking questions. I'm a mathematician/statistician, and my

Re: [Haskell] Speed of ByteString.Lazy

Findler [EMAIL PROTECTED] wrote: Just out of curiosity, did you try wc -l?RobbyOn Jun 29, 2006, at 1:18 PM, Chad Scherrer wrote: I have a bunch of data files where each line represents a data point. It's nice to be able to quickly tell how many data points I have. I had been using wc, like this: % cat

[Haskell-cafe] Re: Speed of ByteString.Lazy

Then I should be thanking Duncan as well (thanks!). I had seen the array fusion idea before in the NDP work, but I hadn't thought of applying to this area. I wonder where else the concept might apply? Is there a typeclass to be built? -- Chad ScherrerTime flies like an arrow; fruit flies like a

[Haskell-cafe] Re: Learning C after Haskell

Thanks for all the replies - this has helped a lot! ChadOn 6/12/06, Chad Scherrer [EMAIL PROTECTED] wrote: Ok, so I'm doing things somewhat backward. I've been using Haskell for a while now, whenever I get a chance to. But in order to become more involved in high-performance computing projects

[Haskell-cafe] Learning C after Haskell

Ok, so I'm doing things somewhat backward. I've been using Haskell for a while now, whenever I get a chance to. But in order to become more involved in high-performance computing projects at my work, I need to learn C. I've heard a lot of people say that experience in Haskell can improve one's

Re: [Haskell-cafe] Learning C after Haskell

Subject: Re: [Haskell-cafe] Learning C after HaskellTo: Chad Scherrer [EMAIL PROTECTED]hi,C is very different from Haskell.* you'lle have to manage explicitly memory de/allocation. * c programming is a bit like haskell io monad programming (butwithout the functionnal part) :you'lle use = in place

[Haskell-cafe] Re: Newbie request

Philip,you wrote:-I am trying to learn Haskell. As an exercise, I wrote afunction to create a binary tree in level-order. I am attaching the code. I am sure there are a number of places wherethe code could be

[Haskell-cafe] Re: [Haskell] installing streams library

On 5/20/06, Donald Bruce Stewart [EMAIL PROTECTED] wrote: Data.ByteString is in the base libraries now.For a bit of the flavour, see:http://haskell.org/haskellwiki/Wc In this message http://article.gmane.org/gmane.comp.lang.haskell.general/13625 Bulat says, i foresee that Streams + Fast Packed

Re: [Haskell] installing streams library

Thanks, Bulat. I'm looking forward to trying it out this weekend. Is there any indication what fast IO approach might work its way into the standard libraries? It would be nice for idiomatic Haskell to be really fast by default, and I'd love to be able to show off the language shootout

[Haskell] installing streams library

It sounds like Bulat has gotten some impressive I/O speedups with his Streams library. I'd like to try this out, but I'm having some trouble installing it. I'm using GHC on Linux.My first attempt was looking around on this page: http://www.haskell.org/haskellwiki/Library/StreamsThere's a really

[Haskell-cafe] Re: [Haskell] installing streams library

://haskell.org/haskellwiki/Library/Streams and download it as http://freearc.narod.ru/Streams.tar.gzfrom a thread in February entitled:Streams: the extensible I/O library (Feb 21)Googlesite:haskell.org bulat extensible I/O library for the thread, etc. Hope that helps,Jared.On 5/19/06, Chad Scherrer

Re: Parallel GHC on Altix?

On Mon, 2006-05-08 at 12:19 +0100, Simon Marlow wrote: My understanding is that for the 32-bit version, this all works in parallel, but GC is sequential. Is that still the case? Is the 64-bit version in the same state? nested data parallelism: not yet. forkIO, MVars, STM, par, and

[Haskell] Re: Haskell Digest, Vol 33, Issue 3

Phil, thanks for the response. I was thinking about the dynamic behavior of par, and there's something that's a little confusing to me. Am I right in understanding that (x `par` y) evaluates to y, and may or may not evaluate x along the way?The reason that par doesn't necessarily evaluate it's

Parallel GHC on Altix?

Hi, I'd like to get more involved in parallel programming in Haskell, and I have access to an SGI Altix machine (a shared-memory multiprocessor). Can someone tell me, if I download a 64-bit GHC 6.5 snapshot, to what extent will parallelism just work? Specifically, I'm interested in * parallel

[Haskell-cafe] first post

. Or, if you're using ghci, you could just do s - load parse s This is because ghci executes in the IO monad (maybe there are some details of this I'm missing, but that's how I think of it anyway. BTW, your load function could be equivalently written simply as load = readFile parse.hs -Chad

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