Re: [Haskell-cafe] Building 'text-icu-0.1' on Windows

On Thu, May 14, 2009 at 10:18 AM, Bryan O'Sullivan wrote: > > If one of you has the time to dig into this and send a patch that corrects > the problem, I'd welcome the help. As I'm sure you can tell, I developed > text-icu on Unix, and I don't have regul

Re: [Haskell-cafe] Building 'text-icu-0.1' on Windows

On Wed, May 13, 2009 at 4:46 PM, Alexander Dunlap < alexander.dun...@gmail.com> wrote: > This isn't really helpful, but I received similar errors when trying > to build icu-text on Windows If one of you has the time to dig into this and send a patch that corrects the problem, I'd welcome the he

Re: [Haskell-cafe] Problem with text and text-icu packages

On Tue, May 12, 2009 at 7:16 AM, David Carter wrote: > Specifically, a1.txt contains bytes 97 and 10, while a2.txt contains > bytes 224 160 139 237 144 164. > > Have I misconstrued things, or is this a bug? > It's probably a bug, and it has (I hope) already been found and fixed. Please try the da

Re: [Haskell-cafe] How difficult would creating a collaborative multi-user online virtual world application be in Haskell?

On Thu, May 7, 2009 at 3:28 AM, Benjamin L.Russell wrote: > One question that has been coming up at the back of my mind for the > past several weeks has been how difficult would it be to create a > collaborative multi-user online virtual world application in Haskell. > It should be easier than in

Re: [Haskell-cafe] Is Haskell a Good Choice for Web Applications? (ANN: Vocabulink)

On Wed, May 6, 2009 at 4:12 PM, Jason Dagit wrote: > > While I'm thinking out loud, it would be very cool if someone wrote > some articles, say for the monad reader, that follow the formula of > the Effective C++ books. The last couple of times I've wanted a book like that, I wrote the book mys

Re: [Haskell-cafe] name for monad-like structure?

On Tue, Apr 28, 2009 at 3:54 PM, Michael Vanier wrote: > I've stumbled upon a structure that is like a weaker version of a monad, > one that supports return and >> but not >>=. Has anyone seen this before, > and if so, does it have a standard name? > That's similar to Applicative, which suppor

Re: [Haskell-cafe] Data.Binary, Data.Text and errors

On Sun, Mar 15, 2009 at 8:40 PM, Alexander Dunlap < alexander.dun...@gmail.com> wrote: > > I have noticed that in both Data.Binary and Data.Text (which is still > experimental, but still), the "decode" functions can be undefined > (i.e. bottom) if they encounter malformed input. > For decoding Un

Re: [Haskell-cafe] How to compare PortNumbers or Bug in Network.Socket?

On Thu, Mar 12, 2009 at 8:45 PM, Antoine Latter wrote: > So the Ord instance is wrong for the PortNumber type? Well, maybe not > wrong. It's out and out wrong. You get different results on machines of different endianness. Now, this begs the question of why not just simply use an unwrapped Wor

Re: [Haskell-cafe] How to compare PortNumbers or Bug in Network.Socket?

On Thu, Mar 12, 2009 at 2:44 PM, Stefan Schmidt < stefanschmid...@googlemail.com> wrote: > As a work around, I could convert two PortNumbers back to Int-Values before > comparing them, but I think the ordering functions for the PortNumber-Type > do not work as expected. Or am I wrong? > You're ri

Re: [Haskell-cafe] ByteString in patterns

On Tue, Mar 10, 2009 at 3:28 PM, Manlio Perillo wrote: > This seems impossible, since ByteString data constructor is not available. > You can use view patterns, per http://www.serpentine.com/blog/2009/01/11/fun-with-haskell-view-patterns/ ___ Haskell-Ca

Re: [Haskell-cafe] bytestring vs. uvector

On Sat, Mar 7, 2009 at 10:23 PM, Alexander Dunlap < alexander.dun...@gmail.com> wrote: > Hi all, > > For a while now, we have had Data.ByteString[.Lazy][.Char8] for our > fast strings. Now we also have Data.Text, which does the same for > Unicode. These seem to be the standard for dealing with lis

Re: [Haskell-cafe] Re: MPI

On Thu, Mar 5, 2009 at 10:43 AM, FFT wrote: > > > Are MPI bindings still the best way of using Haskell on Beowulf > > clusters? It's my feeling that the bindings stagnated, or are they > > just very mature? > MPI itself hasn't changed in 14 years, so it's not exactly a moving target. (There's an

Re: [Haskell-cafe] ANNOUNCE: text and text-icu, fast and comprehensive Unicode support using stream fusion

On Sun, Mar 1, 2009 at 5:05 AM, Manlio Perillo wrote: > > This is interesting. > Any plans to write a pure Haskell package, using Unicode CLDR data? > http://unicode.org/cldr/ > Foundational l10n work, however important it may be, is an unrewarding slog, so it's the kind of work I'd do under cont

Re: [Haskell-cafe] ANNOUNCE: text and text-icu, fast and comprehensive Unicode support using stream fusion

On Fri, Feb 27, 2009 at 7:27 AM, minh thu wrote: > I mean it is straightforward to rewrite attoparsec to use Text instead of > (Lazy and Strict) Bytestring, but is it the way to go ? > My first priority is to write Data.Text.Lazy, since I don't think that it makes sense to layer a parsing libra

Re: [Haskell-cafe] ANNOUNCE: text and text-icu, fast and comprehensive Unicode support using stream fusion

On Fri, Feb 27, 2009 at 12:57 AM, George Pollard wrote: > Unfortunately it doesn’t build for me. I have libicu-dev 3.8.1 installed. > Yes, as the README states, the text-icu package needs ICU 4.0. The basic text library has no such external dependencies. _

[Haskell-cafe] ANNOUNCE: text and text-icu, fast and comprehensive Unicode support using stream fusion

Harper Duncan Coutts Bryan O'Sullivan ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Coming up with a better API for Network.Socket.recv

On Thu, Feb 26, 2009 at 1:45 PM, Johan Tibell wrote: > I find it quite inconvenient to use the `recv` function in > Network.Socket as it throws an exception when reaching EOF and there's > no way to check whether EOF has been reached before calling `recv`. I agree, the current behaviour is quite

Re: [Haskell-cafe] memory-efficient data type for Netflix data - UArray Int Int vs UArray Int Word8

2009/2/23 Kenneth Hoste > Does anyone know why the Word8 version is not significantly better in terms > of memory usage? > Yes, because there's a typo on line 413 of Data/Array/Vector/Prim/BUArr.hs. How's that for service? :-) ___ Haskell-Cafe mailin

Re: [Haskell-cafe] Re: speed: ghc vs gcc

On Fri, Feb 20, 2009 at 12:44 PM, Achim Schneider wrote: > Bulat, you are right in every aspect. You never did anything wrong. > Back when you debugged your code all night long, you were only > dreaming. Achim, this doesn't seem like a constructive way to respond. Bulat's already been taken to

Re: [Haskell-cafe] Hoogle and Network.Socket

On Wed, Feb 18, 2009 at 6:50 PM, Thomas DuBuisson < thomas.dubuis...@gmail.com> wrote: > I recall that Niel made sure hoogle doesn't search through > non-portable libraries (a shame), but I thought Network.Socket could > be used on Windows and yet Hoogle does not give any results for > 'socket' or

Re: [Haskell-cafe] Race condition possible?

2009/2/14 Peter Verswyvelen > If you have two streams of time/value pairs - using MVars as write-once > sampling variables - and both streams are fed from another thread (e.g. > timers firing), and you want to merge these two streams into a single stream > with monotonic time stamps, then you wan

Re: [Haskell-cafe] Re: Why binding to existing widget toolkits doesn't make any sense

Hi, Antony - It's good to see you active on here. > It's not clear to me if the Cairo API in its current form supports > vector-level clipping or constructive area geometry, [...] The Cairo clipping API is very PostScripty; you set up a path and then turn it into a clip region instead of filli

Re: [Haskell-cafe] Re: Why binding to existing widget toolkits doesn't make any sense

On Fri, Jan 30, 2009 at 1:11 PM, Antony Courtney wrote: > A 2-D vector graphics library such as Java2D ( or Quartz on OS/X or > GDI+ on Windows ) supports things like computing tight bounding > rectangles for arbitrary shapes, hit testing for determining whether a > point is inside or outside a sh

Re: [Haskell-cafe] How outdated is Hugs?

On Wed, Jan 28, 2009 at 3:42 PM, Duncan Coutts wrote: > The way I've tested it recently is to build the Setup.hs with ghc and > use that to install Cabal for hugs. From then on one can use runhugs to > run other Setup scripts. > That's good to know, thanks. __

Re: [Haskell-cafe] How outdated is Hugs?

On Tue, Jan 27, 2009 at 1:18 PM, Duncan Coutts wrote: > Not since then, no. However a lot of things work fine, especially if you > use a newer Cabal version. I've been unable to figure out how to build Cabal with Hugs 2006.09.04: $ *runhugs -98 Setup configure --hugs --prefix=/usr* runhugs: Err

Re: [Haskell-cafe] Haskell not ready for Foo [was: Re: Hypothetical Haskell job in New York]

On Thu, Jan 8, 2009 at 1:07 PM, Manlio Perillo wrote: > Another example is the multipart parser: > > -- | Read a multi-part message from a 'Handle'. > -- Fails on parse errors. > hGetMultipartBody :: String -- ^ Boundary > -> Handle > -> IO MultiPart > hGetMult

Re: [Haskell-cafe] Haskell not ready for Foo [was: Re: Hypothetical Haskell job in New York]

On Thu, Jan 8, 2009 at 10:06 AM, Don Stewart wrote: > Note that there even exists an FFI binding to Erlang for Haskell, so > that Haskell nodes can seamlessly interact with other nodes speaking > Erlang's protocol format. > Actually, the erlang package doesn't use the FFI: it speaks the Erlang w

Re: [Haskell-cafe] Will GHC finally support epoll in 2009?

On Wed, Dec 31, 2008 at 11:42 AM, Levi Greenspan wrote: > Hence my question - is it likely that GHC will support epoll in 2009? Yes. I'm working on a patch at the moment. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mai

Re: [Haskell-cafe] Missing Network Functions

On Sun, Dec 28, 2008 at 1:38 AM, Thomas DuBuisson < thomas.dubuis...@gmail.com> wrote: > getNthWord n bs@(PS ptr off len) = > inlinePerformIO $ withForeignPtr ptr $ \ptr' -> do > let p = castPtr $ plusPtr ptr' off > peekElemOff p n > > But even this

Re: [Haskell-cafe] Missing Network Functions

2008/12/27 John Van Enk > > Currently this only has: > >- htons >- htonl >- ntohs >- ntohl > > This is all subsumed by the binary package (Data.Binary), where it makes a lot more sense in any instance. ___ Haskell-Cafe mailing list Haske

[Haskell-cafe] ANN: "Real World Haskell", now shipping

Good evening - John Goerzen, Don Stewart and I are delighted to announce the availability of our book, "Real World Haskell". It is 710 pages long, and published by O'Reilly Media. This is the first book to comprehensively cover modern Haskell programming. From an introduction to functional progra

Re: [Haskell-cafe] Can't figure out source of race condition when using System.Process

2008/11/2 Rafal Kolanski <[EMAIL PROTECTED]> > > Unfortunately, it also segfaults once in a while, probably indicating I > have some kind of race condition ... but I can't figure out why. What is the "it" that segfaults? The Haskell program shouldn't, at least. That said, your code for reading

Re: [Haskell-cafe] An irritating Parsec problem

On Wed, Oct 15, 2008 at 12:20 PM, Jonathan Cast <[EMAIL PROTECTED]>wrote: > This is a bit > easier if you supply the missing Applicative instance: > > const <$> parser <*> eof > > Too verbose. parser <* eof ___ Haskell-Cafe mailing list Haskell-Cafe@ha

Re: [Haskell-cafe] Network trouble: what to do?

On Wed, Oct 15, 2008 at 6:54 AM, Creighton Hogg <[EMAIL PROTECTED]> wrote: > Is there a way around this that I just haven't seen, or should I write > a patch to Network to add an extra constructor to SockAddr and code to > handle it? Linux and Windows support Bluetooth sockets, but they have diff

Re: [Haskell-cafe] Restricted file reading monad

2008/10/1 George Pollard <[EMAIL PROTECTED]>: > Since the ID3 tag as a whole has size information, I need to pass that > into the frame-reading functions to ensure that I never read past the > end of the total header. What you want for this is the environment monad, also known as the Reader monad

[Haskell-cafe] Notes on the future of Haskell from ICFP

Here's a writeup I posted from the conference floor this afternoon: http://www.serpentine.com/blog/2008/09/26/some-notes-on-the-future-of-haskell-and-fp/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haske

Re: [Haskell-cafe] Doing something constructive. [Was: Climbing up the shootout...]

On Wed, Sep 24, 2008 at 12:31 PM, Don Stewart <[EMAIL PROTECTED]> wrote: >> Twisted (a Python asynchronous framework) is a confortable environment, >> but I feel concurrent Haskell is superior. > > Should be a lot faster, given there's compiled native code, and no > global locks. The concurrent H

Re: [Haskell-cafe] performance of map reduce

On Fri, Sep 19, 2008 at 2:31 PM, Manlio Perillo <[EMAIL PROTECTED]>wrote: > > By the way, this phrase: > "We allow multiple threads to read different chunks at once by supplying > each one with a distinct file handle, all reading the same file" > here: > > http://book.realworldhaskell.org/read/con

Re: [Haskell-cafe] A round of golf

On Thu, Sep 18, 2008 at 10:02 AM, Creighton Hogg <[EMAIL PROTECTED]> wrote: > > If this makes anyone cringe or cry "you're doing it wrong", I'd > actually like to hear it. Yes, that made me cry :-) Your code seems very convoluted, and quite successfully hides what it's really trying to do. Here

Re: [Haskell-cafe] readFile and closing a file

On Wed, Sep 17, 2008 at 6:21 AM, David Roundy <[EMAIL PROTECTED]> wrote: > > Eventually the garbage collector should close the file, I believe. > That's true, but "eventually" could be long enough to mean "never" in practice. It's safest to assume that finalizers will not run at all, never mind i

Re: [Haskell-cafe] Float instance of 'read'

On Tue, Sep 16, 2008 at 5:29 AM, Mauricio <[EMAIL PROTECTED]> wrote: > > Do you think 'read' (actually, > 'readsPrec'?) could be made to also > read the international convention > (ie., read "1,5" would also work > besides read "1.5")? No, as read is really intended to be a language-level tool,

Re: the real world of Haskell books (Re: [Haskell-cafe] Online RealWorld Haskell, problem with Sqlite3 chapters)

On Fri, Sep 5, 2008 at 7:50 PM, Derek Elkins <[EMAIL PROTECTED]> wrote: > To make what (I believe) Claus is saying more explicit and direct, add a > note to the beginning of the book (or somewhere reasonably prominent) > that states something along the lines [...] We will add a link to an errata

Re: [Haskell-cafe] Online Real World Haskell, problem with Sqlite3 chapters

On Fri, Sep 5, 2008 at 3:45 AM, david48 <[EMAIL PROTECTED]> wrote: > In the online version of Real world Haskell, there's a problem with > examples in ghci when the module Database.HDBC.Sqlite3 is imported. Oops, should be fixed now. ___ Haskell-Cafe mai

Re: the real world of Haskell books (Re: [Haskell-cafe] Online Real World Haskell, problem with Sqlite3 chapters)

On Fri, Sep 5, 2008 at 5:04 AM, Claus Reinke <[EMAIL PROTECTED]> wrote: > Seriously, though, what is the RWH authors' plan for tackling > the eternal frustration of Haskell book authors, a moving target? Other tech books face the same problem, which, if they sell successfully and the authors have

Re: [Haskell-cafe] Linux version of ghc-6.8.3 won't intall or run for me: "Floating point exception".

On Thu, Sep 4, 2008 at 2:24 PM, Don Stewart <[EMAIL PROTECTED]> wrote: >> I've downloaded the ghc-6.8.3-i386-unknown-linux.tar.bz2 tarball, which >> I expected to work on my GNU/Linux box (1.2 GHz Athlon, Debian Sarge). > > Was there a problem installing GHC from the Debian package system with apt

Re: [Haskell-cafe] Re: [Haskell] Top Level <-

On Fri, Aug 29, 2008 at 4:33 PM, Dan Weston <[EMAIL PROTECTED]> wrote: > C++ faced this very issue by saying that with global data, uniqueness of > initialization is guaranteed but order of evaluation is not. In C++ circles, this is referred to as the "static initialization order fiasco", and it i

Re: [Haskell-cafe] two problems with Data.Binary and Data.ByteString

On Tue, Aug 26, 2008 at 3:04 PM, Don Stewart <[EMAIL PROTECTED]> wrote: > No, since I can get whnf with `seq`. However, that does sound like a > good idea (a patch to the parallel library? ) I suspect that patching parallel doesn't scale. It doesn't have a maintainer, so it will be slow, and the

Re: [Haskell-cafe] two problems with Data.Binary and Data.ByteString

On Mon, Aug 25, 2008 at 2:28 PM, Don Stewart <[EMAIL PROTECTED]> wrote: > I've pushed a decodeFile that does a whnf on the tail after decoding. Does this mean that there are now NFData instances for bytestrings? That would be handy. ___ Haskell-Cafe mai

Re: [Haskell-cafe] "Real World Haskell" hits a milestone

On Fri, Aug 22, 2008 at 1:46 PM, Daryoush Mehrtash <[EMAIL PROTECTED]> wrote: > Are the book's sample code available for download? Not yet. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

[Haskell-cafe] "Real World Haskell" hits a milestone

Hi, all - I'm proud to report that John, Don and I have finished the draft manuscript of our book. It is now available online in its entirety. For more details, see here: http://www.realworldhaskell.org/blog/2008/08/22/our-writing-is-now-complete/ We expect the final book to be published around

Re: [Haskell-cafe] two problems with Data.Binary and Data.ByteString

On Wed, Aug 13, 2008 at 3:02 PM, Tim Newsham <[EMAIL PROTECTED]> wrote: > However, I think probably the real blame here should probably go > to Data.Binary which doesn't attempt to check that it has consumed > all of its input after doing a "decode". If "decode" completes > and there is unconsume

Re: [Haskell-cafe] two problems with Data.Binary and Data.ByteString

On Wed, Aug 13, 2008 at 5:39 PM, Tim Newsham <[EMAIL PROTECTED]> wrote: > So am I understanding you correctly that you believe this is not > a bug? That the use Data.Binary.decodeFile function leaks a file > descriptor and this is proper behavior? I think he might be saying that decodeFile is not

Re: [Haskell-cafe] two problems with Data.Binary and Data.ByteString

On Tue, Aug 12, 2008 at 6:01 PM, Tim Newsham <[EMAIL PROTECTED]> wrote: > (my keys are dates, which are Enum). This should look at > every key in every inner map. Shouldn't that be sufficient to > force the entire data set (or do I have to touch the fields in the > data elements too?) You might

Re: [Haskell-cafe] Dealing with heterogeneously-typed lists?

2008/8/12 Leif Warner <[EMAIL PROTECTED]>: > I know in a language like Java or C++ I might do some sort of run-time type > identification, which would detect the type of each element in the list, and > output it appropriately. I think I've missed a step. Why do you want to break the fields of an

Re: [Haskell-cafe] two problems with Data.Binary and Data.ByteString

On Tue, Aug 12, 2008 at 5:34 PM, Tim Newsham <[EMAIL PROTECTED]> wrote: > I tried to force the data with: > >loadState db = do >d <- decode <$> B.readFile stateFile >let force = sum $ M.elems $ M.size `fmap` d >force `seq` atomically $ writeTVar db d > > and I get the s

Re: [Haskell-cafe] two problems with Data.Binary and Data.ByteString

On Tue, Aug 12, 2008 at 5:13 PM, Tim Newsham <[EMAIL PROTECTED]> wrote: > The data type I'm storing is a Map (of maps): > > type DailyDb = M.Map Date Daily > type InstrsDb = M.Map String DailyDb > > What's going on here? The default marshalling scheme that Binary uses for lists and maps (whic

Re: [Haskell-cafe] ANN: Tutorial on information visualization and visual analytics in Haskell

On Sat, Aug 9, 2008 at 11:30 AM, Jefferson Heard <[EMAIL PROTECTED]> wrote: > I'll be > building a site around it until then, complete with compilable code > examples, but I thought I would let everyone get a sneak peek at the > long version of the tutorial before I'm done with it. That's a beaut

Re: [Haskell-cafe] code review? store server, 220loc.

On Sat, Aug 2, 2008 at 10:13 PM, Tim Newsham <[EMAIL PROTECTED]> wrote: > Anyone interested in critiquing some code? I'm looking for ideas > for making it faster and/or simpler: > > http://www.thenewsh.com/%7Enewsham/store/Server5.hs The code looks fairly reasonable, although most of your stric

Re: [Haskell-cafe] Re: www.haskell.org is currently very slow in responding to HTTP requests

On Wed, Jul 30, 2008 at 2:54 AM, Ashley Yakeley <[EMAIL PROTECTED]> wrote: > Other software versions: > > Linux 2.4.21 (latest is 2.6.26) > Apache 2.0.46 (latest is 2.2.9) > MySQL 3.23.58 (latest is 5.0.51a) > PHP 4.3.2 (latest is 5.2.6) > MediaWiki 1.5.4 (latest is 1.12) >

Re: [Haskell-cafe] Re: Bit Streams

On Wed, Jun 18, 2008 at 11:00 AM, Adam Langley <[EMAIL PROTECTED]> wrote: > On Wed, Jun 18, 2008 at 10:52 AM, Don Stewart <[EMAIL PROTECTED]> wrote: >> Would you recommend binary-strict over bitsyntax now? >> Or are none yet entirely satisfactory > > Probably, yes. Bitsyntax was, after all, the fir

Re: [Haskell-cafe] Problem building GHC 6.8.3

On Wed, Jun 18, 2008 at 5:28 AM, Daniel Fischer <[EMAIL PROTECTED]> wrote: > Sorry, probably stupid questions for knowledgeable folks Not stupid at all, but possibly the wrong mailing list. glasgow-haskell-users would usually be a better place to ask. > Setup: Haddock's internal GHC version must

Re: [Haskell-cafe] Bit streams

On Tue, Jun 17, 2008 at 1:05 PM, Andrew Coppin <[EMAIL PROTECTED]> wrote: > Before I sit down and spend 3 months designing my own library from scratch, > does anybody know of an existing library that allows you to do what Binary > does, but with single-bit precision? The binary-strict library inc

Re: [Haskell-cafe] blas bindings, why are they so much slower the C?

On Tue, Jun 17, 2008 at 9:00 PM, Anatoly Yakovenko <[EMAIL PROTECTED]> wrote: > here is the C: > > #include > #include > > int main() { > int size = 1024; > int ii = 0; > double* v1 = malloc(sizeof(double) * (size)); > double* v2 = malloc(sizeof(double) * (size)); > for(ii = 0; ii < siz

Re: [Haskell-cafe] Re: Patrick Perry's BLAS package

Judah Jacobson wrote: > My preference is to use an autoconf script to solve that problem. > ("build-type: Configure" in the cabal file.) That approach would not work well for BLAS. The various BLAS libraries have profoundly different performance characteristics, and you wouldn't want to get the

Re: [Haskell-cafe] [ANN] bloomfilter 1.0 - Fast immutable and mutable Bloom filters

David MacIver wrote: > The Hashable stuff in there looks like it might be independently > useful. Probably, yes. > Any interest in splitting it out into an independent package > or is it really intended to be something fairly specific to the Bloom > filter implementation? I'll split them if the

[Haskell-cafe] [ANN] bloomfilter 1.0 - Fast immutable and mutable Bloom filters

I'm pleased to announce the availability of a fast Bloom filter library for Haskell. A Bloom filter is a probabilistic data structure that provides a fast set membership querying capability. It does not give false negatives, but has a tunable false positive rate. (A false positive arises when th

Re: [Haskell-cafe] Copying Arrays

Ketil Malde wrote: > I guess this is where I don't follow: why would you need more short > strings for Unicode text than for ASCII or 8-bit latin text? Because ByteString is optimised for dealing with big blobs of binary data, its performance when you split a big ByteString into a pile of words i

Re: [Haskell-cafe] Copying Arrays

Tom Harper wrote: > Because I'm writing the Unicode-friendly ByteString =p Perhaps I'm not understanding. Why wouldn't you use ByteString for I/O, even if you're writing a different library? After all, ByteString's own internals use memcpy. http://www.haskell.org/mailman/listinfo/haske

Re: [Haskell-cafe] Copying Arrays

Tom Harper wrote: > I'm trying to implement some file I/O where I can read in a file to an > array, but do so without having to know how much space I will need. Why not just read it into a lazy ByteString? Are you looking to use an array with elements of a different type? You could then convert

Re: [Haskell-cafe] RealFloat constraint on Complex type

Richard A. O'Keefe wrote: >> I think the practice of constraint in type definitions is generally >> discouraged, > > Is this true? If so, why? As a practical matter, a Haskell 98 constraint infects every place you might like to use the type. They're like prion proteins, corrupting everything t

Re: [Haskell-cafe] Re: Write Haskell as fast as C. [Was: Re: GHC predictability]

Andrew Coppin wrote: > On the other hand, this is the anti-theisis of Haskell. We start with a > high-level, declarative program, which performs horribly, and end up > with a manually hand-optimised blob that's much harder to read but goes > way faster. Buh? This is hard to read? mean n m = go

Re: [Haskell-cafe] GHC predictability

Darrin Thompson wrote: > These "tricks" going into Real World Haskell? Some will, yes. For example, the natural and naive way to write Andrew's "mean" function doesn't involve tuples at all: simply tail recurse with two accumulator parameters, and compute the mean at the end. GHC's strictness a

Re: [Haskell-cafe] MonadPlus

Andrew Coppin wrote: > ...so it's a kind of choice operator? Run all actions until you get to > one that succeeds and return the result from that? In the context of Parsec, yes. In the grander scheme of things, the behaviour depends on whatever is appropriate for the particular monad you're work

Re: [Haskell-cafe] MonadPlus

Andrew Coppin wrote: > But here's a > question: what is the purpose of the MonadPlus class? It gives you a way of working with monads as monoids. Consider a Parsec example: metasyntactic = text "foo" `mplus` text "bar" `mplus` text "baz" You'll get back whichever one matched, in left-to-right-o

Re: [Haskell-cafe] runInteractiveProcess and hGetLine on Windows

David Roundy wrote: > This is the correct behavior (although it's debatable whether kpsewhich > should be outputting in text mode). I think it would be more accurate to say that runInteractiveProcess has an inadequate API, since you can't indicate whether the interaction with the other process sh

Re: [Haskell-cafe] letting go of file handles and Data.Binary

Ben wrote: > i played around with all that you suggested, and came to the conclusion > that i don't understand seq! That's certainly possible, but you also got the type of your first forcing function wrong :-) > strictDecodeFile :: Binary a => FilePath -> (a -> b) -> IO () > encodeFile fname

Re: [Haskell-cafe] letting go of file handles and Data.Binary

Doh! For all that I wrote about encodeFile, substitute decodeFile. You'll need to write something to force the value that you're decoding. Something like this ought to do the trick. import Data.Binary (Binary, decode) import Control.Exception (bracket) import qualified Data.ByteString.Lazy as L

Re: [Haskell-cafe] letting go of file handles and Data.Binary

Ben wrote: > this throws a permission denied exception, presumably because the file > is still open when the removeFile is called. Yes. The file handle opened by encodeFile won't be closed until its finalizer is run. There is no guarantee that the finalizer will be run immediately. In fact, yo

Re: [Haskell-cafe] Parallel weirdness [new insights]

Bulat Ziganshin wrote: > yes. multi-threaded GC is planned gor next ghc version, afair To be clear, it'll be a parallel GC, not a concurrent one. The former still stops all threads, but runs the collector on multiple cores at once. The latter performs collection while mutator threads are still

Re: [Haskell-cafe] Ann: Win32-notify 0.1

Niklas Broberg wrote: > So API suggestions would be most welcome! Your challenge will lie in finding an API that can be implemented efficiently on all concerned platforms. I don't know what the characteristics of the Windows or OS X notification APIs are, but if you use inotify on Linux, and you

Re: [Haskell-cafe] announce: Glome.hs-0.3 (Haskell raytracer)

Jim Snow wrote: > The concurrency bug has to do with excessive memory use, and was > discussed earlier here on the mailing list (search for Glome). > http://hackage.haskell.org/trac/ghc/ticket/2185 Interesting. I looked at your test case. I can reproduce your problem when I build with the threa

[Haskell-cafe] [ANN] cabal-rpm 0.4

I've just uploaded version 0.4 of cabal-rpm to Hackage. This is a program that generates an RPM package from a Cabal package. RPM is the package format used by several major Linux distributions. New in this version are support for GHC 6.8.2 and the Cabal 1.2 release series. Download: http://ha

Re: [Haskell-cafe] Lock-Free Data Structures using STMs in Haskell

Pete Kazmier wrote: > data ArrayBlockingQueueSTM e = ArrayBlockingQueueSTM { > [...] > sa :: Array Int (TVar e) > } > > It's unclear to me why the Array's elements must be wrapped in TVars. To allow them to be modified. You can't otherwise modify the elements of an array without goi

Re: [Haskell-cafe] Re: Doing without IORef

Jinwoo Lee wrote: > To summarize, embed IORef inside ReaderT and use that IORef to > read/change the file path info, both in IO monad and MyState monad. Is > this right? Yep. In case you ever want to multithread your program, you might want to use an MVar instead of an IORef. http://www

Re: [Haskell-cafe] Re: HDBC, character encoding

John Goerzen wrote: > I've looked at the Data.ByteString.Internal API, and it looks like > that ought to work. Oddly, the Data.ByteString.Lazy.Internal API does > not seem to export enough to work with it in FFI. It doesn't usually make sense to use lazy ByteStrings directly with the FFI. Most

Re: [Haskell-cafe] Re: Doing without IORef

Jinwoo Lee wrote: > I haven't used ReaderT. What are the advantages when using ReaderT > instead of StateT in this case? A StateT lets you replace one IORef with another, since it gives you mutable state. A ReaderT gives you *immutable* state, so the type system guarantees that you'll always be

Re: [Haskell-cafe] Re: Shouldn't this loop indefinitely => take (last [0..]) [0..]

Don Stewart wrote: >> Which, incidentally, also explains why Don couldn't reproduce it on a 64- >> bit system. There, instead of hanging for about a minute before printing >> out the list, it would hang for about 4 billion minutes. A billion minutes here, a billion minutes there, and pretty soo

Re: [Haskell-cafe] Shouldn't this loop indefinitely => take (last [0..]) [0..]

Olivier Boudry wrote: > main = do > putStrLn $ show $ take (last [0..]) [0..] > > or simply run: > > take (last [0..]) [0..] > > in ghci, it first hang for about one minute and then starts to generate > an infinite list. It's not an infinite list. It's a list of length maxBound:

Re: [Haskell-cafe] [GSoC] Porting HaRe to use the GHC API

Chaddaï Fouché wrote: > My proposal for the SoC is to port HaRe (its parsing and refactoring) > to use the GHC API instead of Programmatica. This is an appealing idea, and it has the kind of tight scope that makes it plausible as a summer project. Excellent! http://www.haskell.org/mailm

Re: [Haskell-cafe] Random Monad

Matthew Pocock wrote: > On Monday 24 March 2008, Henning Thielemann wrote: >> On Mon, 24 Mar 2008, Matthew Pocock wrote: >>> Who currently maintains the Random monad code? I have some patches to >>> contribute. >> Do you refer to the code on the wiki? > > No, to the code in darcs at http://code.ha

Re: [Haskell-cafe] An ugly zip3 problem..

Michael Feathers wrote: > Would Haskell's type system allow you to pass a function of arbitrary > arity, discern its arity, use that information to construct the > appropriate structure for iteration, and then apply it? The answer is probably "yes", because almost every time I've thought that a t

Re: [Haskell-cafe] IO () and IO [()]

Lennart Augustsson wrote: > Yes, I wish Haskell had a 1-tuple. The obvious syntax is already taken, > but I could accept something different, like 'One a'. Python's one-tuple syntax is (1,). The obvious difficulty with adapting this notation to Haskell lies in how one might write the constructor

Re: [Haskell-cafe] [GSoC] A data parallel physics engine

Roman Cheplyaka wrote: > I have not very deep knowledge about both NDP and physics engines. I've done some physics simulation work for games. One could certainly learn enough to be able to write a straightforward implementation in that time. Broadphase collision detection is easy; narrowphase s

Re: [Haskell-cafe] Starting Haskell with a web application

Don Stewart wrote: > Perhaps it is time for a haskell web apps wiki page, if there isn't one, > outlining the approaches, Indeed. In addition to the code you mention, people like Adam Langley and Johan Tibbell are taking on corners of the web app problem space in a more modern context. It's go

Re: [Haskell-cafe] Starting Haskell with a web application

Jonathan Gardner wrote: > Where do I get started in writing a web app with Haskell? I am looking > more for a framework like Pylons and less like Apache, if that helps. The closest we currently have to a web framework is Happs (http://happs.org/), but it uses the kitchen sink of advanced and unus

Re: [Haskell-cafe] Generating a random list

Milos Hasan wrote: > so let's say I want to generate a list of N random floats. The elegant > way of doing it would be to create an infinite lazy list of floats and > take the first N, but for N = 1,000,000 or more, this overflows the > stack. The reason is apparently that the take function is not

[Haskell-cafe] Bay Area talk tomorrow, on concurrent/parallel Haskell

Satnam Singh of Microsoft Research will be speaking about concurrent and parallel programming at Stanford tomorrow. Details here: http://www.realworldhaskell.org/blog/2008/02/28/stanford-haskell-talk-2008-02-28/ http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Stack overflow

On Feb 27, 2008, at 3:02 AM, Grzegorz Chrupala wrote: I was getting stack overflows when using Data.Binary with a few other datastructures so I decided to try this option. I hacked a Data.Binary.Strict module which is basically a copy and paste of Data.Binary, [...] We've recently hit the poin

Re: [Haskell-cafe] Doubting Haskell

Stefan O'Rear wrote: > Well... that's what I meant by break horribly. Buh? That behaviour makes perfect sense to me. http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Doubting Haskell

Stefan O'Rear wrote: > I'll bet that breaks horribly in the not-so-corner case of /dev/tty. Actually, it doesn't. It seems to do a read behind the scenes if the buffer is empty, so it blocks until you type something. http://www.haskell.org/mailman/listinfo/haskell-cafe

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