Re: [Haskell-cafe] HaskellWiki images disappeared

Should be fixed now. The wiki was recently transferred to a new server and this got unfortunately broken in the process. On 18 Jul 2013 22:45, "Henk-Jan van Tuyl" wrote: > > > L.S., > > It looks like the HaskellWiki images have disappeared; can anybody repair > this? (See for example http://www.h

Re: [Haskell-cafe] Two GHC-related GSoC Proposals

[I'll be the mentor for this GSoC project.] I used the MVar approach a while ago and so did Simon Marlow's original solution. Using MVars and Threads for this should scale well enough (1000s of modules) and be relatively straightforward. Error/exception handling could be a bit tricky, but you cou

Re: [Haskell-cafe] Parallel ghc --make

To have a single-process ghc --make -j you first of all need internal thread-safety: GHC internally keeps a number of global caches that need to be made thread-safe: - table of interned strings (this is actually written in C and accessed via FFI) - cache of interface files loaded, these are a

Re: [Haskell-cafe] ghc-heap-view now with recursive pretty-printing

On 21 December 2012 11:16, Joachim Breitner wrote: > Prelude> :script /home/jojo/.cabal/share/ghc-heap-view-0.4.0.0/ghci > Prelude> let x = [1..10] > Prelude> x > [1,2,3,4,5,6,7,8,9,10] > Prelude> :printHeap x > _bh [S# 1,S# 2,S# 3,S# 4,S# 5,S# 6,S# 7,S# 8,S# 9,S# 10] > > Note that the tools shows

Re: [Haskell-cafe] How to correctly benchmark code with Criterion?

On 18 October 2012 13:15, Janek S. wrote: >> Something like this might work, not sure what the canonical way is. >> (...) > > This is basically the same as the answer I was given on SO. My concerns about > this solutions are: > - rnf requires its parameter to belong to NFData type class. This is

Re: [Haskell-cafe] How to correctly benchmark code with Criterion?

Yes, Criterion always discards the time of the first evaluation. On 18 October 2012 15:06, Janek S. wrote: >> So the evaluation will be included in the benchmark, but if "bench" is >> doing enough trials it will be statistical noise. > When I intentionally delayed my dataBuild function (using del

Re: [Haskell-cafe] object file cannot be loaded.

Does `ghc-pkg check` report any issues? On 6 October 2012 15:24, Magicloud Magiclouds wrote: > Hi, > I am installing postgres hackage (cannot remember the exact name > right now). When it compiling the template haskell part I got the > following error message. > I tried to clear all user spac

Re: [Haskell-cafe] Panic loading network on windows (GHC 7.6.1)

Just to explain what's going on. It looks like you are compiling a module that uses template haskell, which in turn relies on GHCi bits. In particular, GHCi has a custom linker for loading compiled code. This linker is very fragile and tends to break whenever the platform GCC/linker changes. Simil

Re: [Haskell-cafe] Haskell Wiki News

It's a wiki. I went ahead and fixed it, this time. To paraphrase Bryan O'Sullivan: Whenever you think "why hasn't anyone done ...", or "why doesn't somebody fix ...", you should ask yourself "Why don't *I* do ..." or "Why don't *I* fix ...". That's how open source works. (Not trying to be offens

Re: [Haskell-cafe] A first glimps on the {-# NOUPDATE #-} pragma

On 30 August 2012 09:34, Joachim Breitner wrote: > but from a first glance it seems that you are not using that part of GHC > in your project, right? > No, I don't think I can make use of your work directly. Lambdachine uses GHC up until the CorePrep phase (the last phase before conversion to ST

Re: [Haskell-cafe] A first glimps on the {-# NOUPDATE #-} pragma

On 29 August 2012 15:21, Joachim Breitner wrote: > Hi Facundo, > > Am Mittwoch, den 29.08.2012, 10:26 -0300 schrieb Facundo Domínguez: > > > upd_noupd n = > > > let l = myenum' 0 n > > > in last l + length l > > > > This could be rewritten as > > > > > upd_

Re: [Haskell-cafe] Platform Versioning Policy: upper bounds are not our friends

My thoughts on the matter got a little long, so I posted them here: http://nominolo.blogspot.co.uk/2012/08/beyond-package-version-policies.html On 17 August 2012 12:48, Heinrich Apfelmus wrote: > Brent Yorgey wrote: > >> Yitzchak Gale wrote: >> >>> For actively maintained packages, I think the >

Re: [Haskell-cafe] Haskell Platform - BSD License?

You may concatenate the licenses of all the packages you are using. GHC includes the LGPL libgmp. The license file for each package is mentioned in the .cabal file. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/list

Re: [Haskell-cafe] Logging pure code

On 27 July 2012 14:52, Marco Túlio Gontijo e Silva wrote: > thread blocked indefinitely in an MVar operation IIRC, that means that a thread is blocked on an MVar and the MVar is only reachable by that thread. You said you tried adding NOINLINE, which is usually required for unsafePerformIO. Did

Re: [Haskell-cafe] Current state of garbage collection in Haskell

GHC does not provide any form of real-time guarantees (and support for them is not planned). That said, it's not as bad as it sounds: - Collecting the first (young) generation is fast and you can control the size of that first generation via runtime system (RTS) options. - The older generation

Re: [Haskell-cafe] Criterion setup/teardown functions?

On 17 July 2012 20:45, tsuraan wrote: > Is there anything in Criterion that allows for a benchmark to run some > code before or after the thing that it's timing? As an example, I'd > like to time a bunch of database inserts, but beforehand I want to > create the target table, and afterwards I'd l

Re: [Haskell-cafe] Memory corruption issues when using newAlignedPinnedByteArray, GC kicking in?

I think you should ask this question on the glasgow-haskell-users mailing list: http://www.haskell.org/mailman/listinfo/glasgow-haskell-users On 10 July 2012 18:20, Nicolas Trangez wrote: > All, > > While working on my vector-simd library, I noticed somehow memory I'm > using gets corrupted/overw

Re: [Haskell-cafe] not enough fusion?

It's described in Andy Gill's PhD thesis (which describes the foldr/build fusion). http://ittc.ku.edu/~andygill/paper.php?label=GillPhD96 Section 4.4 describes the basic ideas. There aren't any further details, though. Max's Strict Core paper also describes it a bit (Section 6): http://www.cl.cam

Re: [Haskell-cafe] attoparsec double precision, quickCheck and aeson

Bryan, do you remember what the issue is with C++ in this case? I thought, adding a wrapper with extern "C" definitions should do the trick for simpler libraries (as this one seems to be). Is the interaction with the memory allocator the issue? Linker flags? On 11 June 2012 06:38, Bryan O'Sulli

Re: [Haskell-cafe] High memory usage with 1.4 Million records?

On 8 June 2012 01:39, Andrew Myers wrote: > Hi Cafe, > I'm working on inspecting some data that I'm trying to represent as records > in Haskell and seeing about twice the memory footprint than I was > expecting. That is to be expected in a garbage-collected language. If your program requires X by

Re: [Haskell-cafe] for = flip map

On 29 March 2012 22:03, Sjoerd Visscher wrote: > Some more bikeshedding: > > Perhaps ffor, as in > >    ffor = flip fmap > > or perhaps > >    infixr 0 <$$> >    (<$$>) = flip (<$>) > >    xs <$$> \x -> ... I don't think it makes sense to add a whole new operator for that. You can just use sectio

Re: [Haskell-cafe] haskell-platform vs macports

If you're not otherwise attached to MacPorts, you might want to check out Homebrew [1]. Its integration with the rest of OS X is generally more smoothly and I haven't come across any missing packages yet. [1]: http://mxcl.github.com/homebrew/ On 22 March 2012 16:34, Warren Harris wrote: > I ass

Re: [Haskell-cafe] Are there arithmetic composition of functions?

I don't understand this discussion. He explicitly said "If you are willing to depend on a recent version of base". More precisely, he meant GHC 7.4 which includes the latest version of base. Yes, this is incompatible with the Haskell2010 standard, but it did go through the library submission pro

Re: [Haskell-cafe] Using multiplate to get free variables from a syntax tree

>>>> (EVar "x") (EVar "y"))) (EVar "x") > (["y","x"],[]) > > I.e. free variables y and x, no bound variables. Is that not correct? > > Sjoerd > > On Feb 25, 2012, at 7:15 PM, Thomas Schilling wrote: > >> That wil

Re: [Haskell-cafe] Using multiplate to get free variables from a syntax tree

That will give you the wrong answer for an expression like: (let x = 1 in x + y) + x Unless you do a renaming pass first, you will end up both with a bound "x" and a free "x". On 25 February 2012 16:29, Sjoerd Visscher wrote: > > On Feb 24, 2012, at 10:09 PM, Stephen Tetley wrote: > >> I'm no

Re: [Haskell-cafe] Undocumented cost-centres (.\) using auto-all, and SCC pragma not being honored

On 15 February 2012 16:17, Dan Maftei wrote: > > 1 When profiling my code with -auto-all, my .prof file names some > sub-expressions with a backslash. Cf. below. What are these? > >      e_step >       e_step.ewords >       e_step.\ >        e_step.\.\ >         e_step.update_counts >       e_ste

Re: [Haskell-cafe] Google Summer of Code 2012 Announced

As Heinrich said, write a proposal. It's a good idea to write one (or more) before the actual deadline since that will leave enough time for discussion. The proposal is not just between you and the mentors -- it's a good thing to have a public discussion about this, and it's a good way to find a

Re: [Haskell-cafe] How do I get official feedback (ratings) on my GSoC proposal?

It's usually the (potential) mentors who do the rating. I know we did that two years ago; can't remember last year, though. On 13 February 2012 23:45, Greg Weber wrote: > http://hackage.haskell.org/trac/summer-of-code/report/1 > There is a column 'Priority'. And there are now several unrated pr

Re: [Haskell-cafe] ghc-api Static Semantics?

is before the ICFP deadline (and only very little afterwards), but Scion is not dead (just hibernating). > > JP > > > On Thu, Jan 26, 2012 at 2:31 PM, Thomas Schilling > wrote: > > > > > > On 26 January 2012 09:24, Christopher Brown > wrote: > >&

Re: [Haskell-cafe] ghc-api Static Semantics?

On 26 January 2012 09:24, Christopher Brown wrote: > Hi Thomas, > > By static semantics I mean use and bind locations for every name in the AST. Right, that's what the renamer does in GHC. The GHC AST is parameterised over the type of identifiers used. The three different identifier types are:

Re: [Haskell-cafe] ghc-api Static Semantics?

I assume by static semantics you mean the renamed Haskell source code. Due to template Haskell it (currently) is not possible to run the renamer and type checker separately. Note that the type checker output is very different in shape from the renamed output. The renamed output mostly follows the

Re: [Haskell-cafe] Code generation and optimisation for compiling Haskell

wrote: > On Tue, Jan 10, 2012 at 9:25 AM, Steve Horne > wrote: > >> Also, what papers should I read? Am I on the right lines with the ones I've >> mentioned above? > > Thomas Schilling gave you a good response with papers so I will give > you a different perspec

Re: [Haskell-cafe] Code generation and optimisation for compiling Haskell

Based on your stated background, the best start would be the (longer) paper on the Spineless Tagless G-machine [1]. It describes how graph reduction is actually implemented efficiently. Since then there have been two major changes to this basic implementation: Use of eval/apply (a different calli

Re: [Haskell-cafe] Type checker for haskell-src-exts (was: Typechecking Using GHC API)

On 17 December 2011 05:39, Gregory Crosswhite wrote: > > On Dec 17, 2011, at 9:58 AM, Thomas Schilling wrote: > > Wll... I've gotten a little bit of a different perspective on this > since working at a company with very high code quality standards (at > least f

Re: [Haskell-cafe] Type checker for haskell-src-exts (was: Typechecking Using GHC API)

On 16 December 2011 17:44, Niklas Broberg wrote: > With all due respect, the sentiments you give voice to here are a large part > of what drives me to do this project in the first place. Haskell is not GHC, > and I think that the very dominant position of GHC many times leads to ill > thought-thro

Re: [Haskell-cafe] [Haskell] Proposal to incorporate Haskell.org

On 16 December 2011 13:36, Ganesh Sittampalam wrote: >> Would a donation to haskell.org include a fee to SPI?  I couldn't find >> any information on their website. > > Yes - 5% goes to SPI to cover their overheads. It's detailed in > http://www.spi-inc.org/projects/associated-project-howto/ but n

Re: [Haskell-cafe] [Haskell] Proposal to incorporate Haskell.org

On 16 December 2011 11:10, Ganesh Sittampalam wrote: > On 16/12/2011 10:59, Giovanni Tirloni wrote: >> On Fri, Dec 16, 2011 at 7:08 AM, Ganesh Sittampalam > > wrote: >> >>     > Q: If an umbrella non-profit organisation "The Haskell Foundation" was >>     >     created, wou

Re: [Haskell-cafe] How to get a file path to the program invoked?

May I ask what the problem is you're trying to solve? If you want to access datafiles in an installed program then Cabal can help you with that. See http://www.haskell.org/cabal/users-guide/#accessing-data-files-from-package-code If you want to do more complicated things, maybe take a look at ho

Re: [Haskell-cafe] Type checker for haskell-src-exts (was: Typechecking Using GHC API)

What exactly are the hopes for such a type checker? I can understand it being interesting as a research project, but as a realistic tools there are two huge issues: 1. It's going to take a LOT of time to reach feature parity with GHC's type checker. 2. Assuming that can be done, how is it goin

Re: [Haskell-cafe] [Alternative] some/many narrative

On 15 December 2011 06:29, Chris Wong wrote: > class (Applicative f, Monoid f) => Alternative f where >    -- | Keep repeating the action (consuming its values) until it > fails, and then return the values consumed. I think this should be "collect" rather than "consume" and you can omit the pare

Re: [Haskell-cafe] Splitting off many/some from Alternative

On 12 December 2011 22:39, Antoine Latter wrote: > But now they look as if they are of equal importance with the other > class methods, which is not really true. Maybe, but something like this is best fixed by improving documentation, not by shuffling things around and needlessly breaking APIs.

Re: [Haskell-cafe] Haskell Summers of Code retrospective (updated for 2011)

I would be interested in what the hold-up is with the two Cabal projects. Does the work need more clean-up or is it just stuck in the Duncan-code-review pipeline? If Duncan is indeed the bottleneck, maybe we should look into ways of taking some of the work off Duncan. On 11 December 2011 02:57,

Re: [Haskell-cafe] Superset of Haddock and Markdown

On 21 November 2011 17:34, Brandon Allbery wrote: >> Haddock carries the same license as GHC. > > More to the point, Haddock uses ghc internals these days; it's not just a > matter of bundling, and the licenses *must* be compatible. No. If the haddock library any program that links against that

Re: [Haskell-cafe] compiler construction

Chalmers University in Gothenburg, Sweden has a master's programme that includes a compiler construction course. For the lectures from last term, see: http://www.cse.chalmers.se/edu/course/TDA282/lectures.html When I took it in 2006 it was a very practical course -- your task was to implement a b

Re: [Haskell-cafe] SMP parallelism increasing GC time dramatically

It would be really useful to see the threadscope output for this. Apart from cache effects (which may well be significant at 12 cores), the usual problems with parallel GHC are synchronisation. When GHC wants to perform a parallel GC it needs to stop all Haskell threads. These are lightweight thr

Re: [Haskell-cafe] Best bit LIST data structure

On 9 October 2011 14:54, Joachim Breitner wrote: > Hi, > > Am Freitag, den 07.10.2011, 10:52 -0400 schrieb Ryan Newton: >> What about just using the Data.Bits instance of Integer?  Well, >> presently, the setBit instance for very large integers creates a whole >> new integer, shifts, and xors: >>

Re: [Haskell-cafe] Much faster complex monad stack based on CPS state

Well, you can get something close with the help of IORefs, but I forgot the details. I believe this is the paper that explains it: "Value recursion in the continuation monad" by Magnus Carlsson http://www.carlssonia.org/ogi/mdo-callcc.pdf On 28 September 2011 15:15, Bas van Dijk wrote: > On 28

Re: [Haskell-cafe] Improvements to Vim Haskell Syntax file - Is anyone the maintainer?

How about moving/adding the repo to https://github.com/haskell? That would be a nice canonical and easy to find location, IMHO. On 9 September 2011 05:03, steffen wrote: > Hi, > check out this one: > https://github.com/urso/dotrc/blob/master/vim/syntax/haskell.vim > > A (not up to date) version o

Re: [Haskell-cafe] Undefined symbol error coming from shared, dynamic library.

stg_newByteArrayzh is defined in the runtime system. Presumably you need to link against the GHC runtime system. If that doesn't help try asking your question on the glasgow-haskell-us...@haskell.org mailing list. On 6 September 2011 16:52, David Banas wrote: > Hi all, > > I'm trying to build a

Re: [Haskell-cafe] Smarter do notation

On 5 September 2011 15:49, Sebastian Fischer wrote: > > On Mon, Sep 5, 2011 at 10:19 PM, Thomas Schilling > wrote: >>> >>> a >>= \p -> f <$> b -- 'free p' and 'free b' disjoint >>>  --> >>> ((\p -> f) <$&

Re: [Haskell-cafe] Smarter do notation

On 5 September 2011 13:41, Sebastian Fischer wrote: > Hi again, > > I think the following rules capture what Max's program does if applied > after the usual desugaring of do-notation: > > a >>= \p -> return b > --> > (\p -> b) <$> a > > a >>= \p -> f <$> b -- 'free p' and 'free b' disjoint > --

Re: [Haskell-cafe] Smarter do notation

I don't quite understand how this would work. For example, would it work for these examples? do x <- blah let foo = return foo (f x) -- Using an alias of return/pure do x <- Just blah Just (f x) -- another form of aliasing do x <- blah return (g x x) -- could perhap

Re: [Haskell-cafe] GHC API question

suggest you pose this question on the glasgow-haskell-users mailing list. On 28 August 2011 17:57, Chris Smith wrote: > On Sun, 2011-08-28 at 17:47 +0100, Thomas Schilling wrote: >> I don't think you can link GHCi with binaries compiled in profiling >> mode.  You'll hav

Re: [Haskell-cafe] GHC API question

I don't think you can link GHCi with binaries compiled in profiling mode. You'll have to build an executable. On 28 August 2011 16:38, Chris Smith wrote: > Okay, I should have waited until morning to post this... so actually, > things still work fine when I build without profiling.  However, whe

Re: [Haskell-cafe] For class Monoid; better names than mempty & mappend might have been: mid (mident) & mbinop

On 25 July 2011 08:22, Paul R wrote: > Hi Café, > > Thomas> I think (<>) is fairly uncontroversial because: > Thomas> (...) > Thomas> 2. It's abstract. i.e., no intended pronunciation > > How can that be an advantage ? A text flow with unnamed (or > unpronounceable) symbols makes reading, understa

Re: [Haskell-cafe] For class Monoid; better names than mempty & mappend might have been: mid (mident) & mbinop

ibraries. For this reason, I think a larger change would have to come with a larger library re-organization. Johan Tibell suggested something like that a while ago: instead of lots of little cuts (backwards incompatible changes), a working group of activists should redesign a whole new (incompa

Re: [Haskell-cafe] For class Monoid; better names than mempty & mappend might have been: mid (mident) & mbinop

Yes, this has sort-of been agreed upon in a GHC ticket about a year ago: http://hackage.haskell.org/trac/ghc/ticket/3339 I had a patch in Darcs, but then came the switch to Git. I ported it to Git, but didn't iron out all the issues. That was quite a while ago so it's currently a bit bitrotten.

Re: [Haskell-cafe] Automatic Reference Counting

Reference counting usually has much higher overheads than garbage collection and is tricky to parallise. It's main advantage is quicker release of memory. I believe the main feature of ARC is that the user does not need to manually keep reference counts up to date. I heard from people using CPyt

Re: [Haskell-cafe] Toy implementation of the STG machine

Does Bernie Pope's http://www.haskell.org/haskellwiki/Ministg work for you? On 11 June 2011 21:19, Florian Weimer wrote: > I'm looking for a simple implementation of the STG machine to do some > experiments, preferably implemented in something with memory safety. > Performance is totally secondar

Re: [Haskell-cafe] Unbelievable parallel speedup

While I would guess that your superlinear speedup is due to the large variance of your single-core case, it is indeed possible to have superlinear speedup. Say you have a problem set of size 32MB and an L2 cache of 8MB per core. If you run the same program on one CPU it won't fit into the cache,

Re: [Haskell-cafe] ANN: Leksah 0.10.0

My guess is that you're doing all indexing work inside a single GHC API session. When loading external packages GHC caches all .hi files in memory -- and never unloads them. Therefore, if you have a large package DB, that'll consume a lot of memory. For similar reasons you can also run into pro

Re: [Haskell-cafe] Haskell Platform 2011.x - planned release date?

My guess is that they're waiting for the next (and final) stable release of 7.0, which should happen in the next few weeks. On 1 February 2011 08:27, Max Cantor wrote: > January has come and gone and HP 2011 has not come with it.  Is there an > updated timetable for the next version of the HP?  

Re: [Haskell-cafe] OT: Monad co-tutorial: the Compilation Monad

The haskell.org domain expired. It's being worked on. On 17 December 2010 12:45, Larry Evans wrote: > On 12/17/10 01:32, Max Bolingbroke wrote: > [snip] >> I can't speak for your monad based approach, but you may be interested >> in Neil Mitchell's Haskell DSL for build systems, called Shake: >>

Re: [Haskell-cafe] Behaviour of System.Directory.getModificationTime

Yes, modification times are reported in seconds, so you'll have to wait on average 0.5s for a file change to be visible via the modification date. Due to buffers and filesystem optimisations it might even take longer. On 16 December 2010 16:50, Arnaud Bailly wrote: > actually, IRL the code works

Re: [Haskell-cafe] Rendering of in new wiki (MSIE6)

Yes, the current syntax highligthing plugin (SyntaxHighlight_GeSHi) is quite annoying. It's the version that comes with debian which has the advantage that it will be updated automatically. However, it the surrounding is my attempt at hacking around the fact that it doesn't even support inline-m

Re: [Haskell-cafe] [ANNOUNCE] haskell-mpi-1.0.0

Could you please add your package to the wiki section at http://haskell.org/haskellwiki/Applications_and_libraries/Concurrency_and_parallelism#MPI ? On 9 December 2010 21:40, Dmitry Astapov wrote: > Dear Haskellers, > We are pleased to announce the release of haskell-mpi-1.0.0, a suite of > Haske

Re: [Haskell-cafe] gtk2hs and hmake websites

On 12 December 2010 20:55, Florian Weimer wrote: > > * Joachim Breitner: > > > I get regular error message from some Debian tools that check for new > > upstream versions that it cannot find http://haskell.org/hmake, and > > http://haskell.org/gtk2hs seems to be gone as well since the recent move

Re: [Haskell-cafe] The Monad Reader links are broken

I don't have access to the wordpress site, but here's a quick way to fix the links: - Replace links of the form: - With: / Thomas On 11 December 2010 23:28, Jason Dagit

Re: [Haskell-cafe] haskell2010 and state question.

On 10 December 2010 01:40, Magicloud Magiclouds wrote: > On Wed, Dec 8, 2010 at 6:46 PM, Henk-Jan van Tuyl wrote: >> On Wed, 08 Dec 2010 10:03:40 +0100, Magicloud Magiclouds >> wrote: >> >>> Hi, >>>  Formerly, I had IORef and some state monad to do the task of keeping >>> states. >>>  Now in has

Re: [Haskell-cafe] [Haskell] haskell.org migration complete

On 5 December 2010 08:29, Henning Thielemann wrote: > Thomas Schilling schrieb: >> I created http://www.haskell.org/haskellwiki/MigratingWikiContent to >> list known issues and workarounds.  Please feel free to extend that >> page where needed. > > I liked to add tha

Re: [Haskell-cafe] Most images broken on haskellwiki pages

Should be fixed. PDF previews are currently broken, but images should be fine. 2010/12/3 Eugene Kirpichov : > Hello, > > Any news on this one? > > > > 01.12.2010, в 11:53, Yitzchak Gale написал(а): > >> Eugene Kirpichov wrote: >>> I looked at a couple pages of mine... >>> and looks >>> like the

Re: [Haskell-cafe] Who's in charge of the new Haskell.org server?

On 1 December 2010 18:55, Christopher Done wrote: > If someone will allow me to send them an extension for WikiMedia I will > write one. It shouldn't be complex at all, so code review will be trivial. > Please let me know! I'm sure other people here are interested to know who to > go to to get thi

Re: [Haskell-cafe] Conditional compilation for different versions of GHC?

I think a nicer way to solve that issue is to use Cabal's MIN_VERSION macros. 1. Add CPP to your extensions. This will cause cabal to auto-generate a file with MIN_VERSION_ macros for each in build-depends. 2. GHC 6.12.* comes with template-haskell 2.4, so to test for that use: #ifdef MIN_VE

Re: [Haskell-cafe] Haddock: patch to generate single-index page in addition to perl-letter indexes indices.

For packages with many items in the index, these pages can get a bit huge. How about a permuted index like ? E.g., for your use case, you would go to E and then the row with all the "End" entries, which would contain all the nam

Re: [Haskell-cafe] The Haskell theme

I agree with Mark that we shouldn't try to over-constrain things. However, basic startup-resources are perfectly fine. It gives a good default for people who don't really like (web-)design, and can serve as a baseline for others. I.e., encourage consistency but don't enforce it. On 12 October 20

Re: [Haskell-cafe] Are newtypes optimised and how much?

Do we really want to treat every newtype wrappers as a form of 'id'? For example: newtype Nat = Nat Integer -- must always be positive A possible rule (doesn't actually typecheck, but you get the idea): forall (x :: Nat). sqrt (x * x) = x If we ignore newtyping we get an incorrect rew

Re: [Haskell-cafe] Why isn't there a cheaper "split-in-two" operation for Data.Set?

On 20 October 2010 04:05, wren ng thornton wrote: > On 10/19/10 5:47 AM, Ryan Newton wrote: >> >> That sounds good to me.  In any case the parallel map/fold operations by >> themselves shouldn't compromise the abstraction. >> >> Perhaps an eventual solution would be to start including parallel >>

Re: [Haskell-cafe] Re: How to make cabal pass flags to happy?

You probably want to customise Setup.lhs to use defaultMainWithHooks and add your own custom suffix handler to the UserHooks, see: http://hackage.haskell.org/packages/archive/Cabal/1.8.0.6/doc/html/Distribution-Simple.html#t:UserHooks Take a look at PPSuffixHandler (http://hackage.haskell.org/pac

Re: [Haskell-cafe] An interesting paper on VM-friendly GC

On 16 October 2010 10:35, Andrew Coppin wrote: >  On 15/10/2010 11:50 PM, Gregory Crosswhite wrote: >> >>  On 10/15/2010 03:15 PM, Andrew Coppin wrote: >>> >>> On the other hand, their implementation uses a modified Linux kernel, and >>> no sane person is going to recompile their OS kernel with a

Re: [Haskell-cafe] IORef memory leak

Correct, here's a video of Simon explaining the thunk blackholing issue and its solution in GHC 7: http://vimeo.com/15573590 On 15 October 2010 21:31, Gregory Collins wrote: > Evan Laforge writes: > >> The only workaround I could find is to immediately read the value back >> out and 'seq' on it

Re: [Haskell-cafe] can Haskell do everyting as we want?

On 4 August 2010 21:21, Jason Dagit wrote: > Is scion still being developed?  I have the impression it's dead now. Really > a shame, I think it has a good solid design and just needs work/polish. It is: http://github.com/nominolo/scion/network I changed the architecture to use separate processe

Re: [Haskell-cafe] Preview the new haddock look and take a short survey

On 4 August 2010 15:44, aditya siram wrote: > I really like the color scheme and the Javadoc looking frames. > > One suggestion I can make is to have the index show all the functions with > type signatures without having to pick a letter. A lot of times I'll be > looking for a function of a certai

Re: [Haskell-cafe] Preview the new haddock look and take a short survey

On 4 August 2010 10:11, Magnus Therning wrote: > On Wed, Aug 4, 2010 at 06:00, Mark Lentczner wrote: >> The Haddock team has spent the last few months revamping the look of the >> generated output. We're pretty close to done, but we'd like to get the >> community's input before we put it in the

Re: [Haskell-cafe] hsb2hs preprocessor looking for a maintainer

On 4 August 2010 12:05, Ivan Lazar Miljenovic wrote: > Max Bolingbroke writes: > >> On 4 August 2010 11:39, Ivan Lazar Miljenovic >> wrote: >>> Joachim Breitner writes: the problem is that Template Haskell does not work on all architectures, so the Debian people prefer solutions that

Re: [Haskell-cafe] Design for 2010.2.x series Haskell Platform site

ntents can be edited (and probably shoud be). / Thomas On 17 July 2010 13:31, Christopher Done wrote: > On 17 July 2010 13:37, Andrew Coppin wrote: >> Thomas Schilling wrote: >>> Haters gonna hate. >> Well, I don't *hate* it. It just looks a little muddy, that'

Re: [Haskell-cafe] Design for 2010.2.x series Haskell Platform site

Haters gonna hate. The new wiki will have a user preference to switch back to the default monobook style. You can always do that if you want. It doesn't work fully, yet, but that's on my ToDo list. On 17 July 2010 11:53, Andrew Coppin wrote: > Thomas Schilling wrote: >> &

Re: [Haskell-cafe] Design for 2010.2.x series Haskell Platform site

he ETA on getting the site wiki upgraded and to what version >> will it be? If we're looking at another couple of weeks I'll come up >> with a new wiki template this weekend to replace the current one. > >    For haskell.org? Thomas Schilling and Ian Lynagh are worki

Re: [Haskell-cafe] Hot-Swap with Haskell

What would be the semantics of hot-swapping? For, example, somewhere in memory you have a thunk of expression e. Now the user wants to upgrade e to e'. Would you require all thunks to be modified? A similar problem occurs with stack frames. You'd also have to make sure that e and e' have the s

Re: [Haskell-cafe] Docs on the current and future constraint solver?

The latest work is OutsideIn(X): http://www.haskell.org/haskellwiki/Simonpj/Talk:OutsideIn This is quite long paper. It describes a framework for constraint-based type inference and then instantiates it with a constraint solver that supports type families, GADTs and type classes. Constraint-ba

Re: [Haskell-cafe] Why Either = Left | Right instead of something like Result = Success | Failure

It's indeed arbitrary. Other common names are Inl and Inr (presumably standing for "inject left/right"). Some Haskell project do indeed use a more specific name. The advantage of using the generic Left/Right is reusability of library code. The particular name of the datatype and its constructor

Re: [Haskell-cafe] Performance Issue

On 22 May 2010 16:06, Daniel Fischer wrote: > On Saturday 22 May 2010 16:48:27, Daniel Fischer wrote: >> The boxing is due to the use of (^). >> If you write x*x instead of x^2, it can use the primop *## and needn't >> box it. >> As a side effect, the original time leak probably wouldn't have occu

Re: [Haskell-cafe] Performance Issue

Actually, in this case it would be safe to do CSS. Because a) the function is strict in both arguments so GHC creates a worker which only uses unboxed types b) this cannot cause any space leaks (it contains no pointers) The generated Core does look pretty weird, though: $wnewton = \ (ww_s11

Re: [Haskell-cafe] making the GHC Api not write to stderr

You could try changing the log_action[1] member of the DynFlags. A while ago I turned most printed errors into some form of error message, but I wouldn't be surprised if I missed some places. All output should go through log_action, though, so try changing that to intercept any output. [1]: htt

Re: [Haskell-cafe] executeFile failing on macosx

Works fine on 10.6.3. If you run with +RTS -N2, though, you'll get "forking not supported with +RTS -N greater than 1" The reason for this is that forking won't copy over the threads which means that the Haskell IO manager stops working (you'd have to somehow reinitialise the RTS while leaving he

Re: [Haskell-cafe] ghc api renamed source

The difficulty is that renamer and type-checker are mutually recursive because of Template Haskell. I've been looking into this a while ago and I have a basic idea how a better API could look like, but I haven't sorted out the details. One very hacky workaround -- and I'm not sure whether it can

Re: [Haskell-cafe] GHC 6.12 on OS X 10.5

Building from source alone didn't help, but building from source together with the following extra lines to .cabal/config worked: extra-lib-dirs: /usr/lib extra-lib-dirs: /opt/local/lib This is not an ideal solution because this means that any OS X library will shadow the corresponding Macports l

[Haskell-cafe] Re: Is anyone using Haddock's support for frames?

Ok, I think I should clarify. I believe that the framed view with a long list of modules on the left and the haddocks on the right is still useful. What I don't mind getting rid off is the third frame which shows the contents of the mini_* files. I would have preferred to have something similar

[Haskell-cafe] Re: Is anyone using Haddock's support for frames?

I think it will no longer be needed once Haddock outputs table-less layout code. Frames caused problems with the back-button, so they weren't really an improvement. A simple CSS float:right + smaller font on the div containing the index would be a lot better. I think it would be best to keep the

Re: [Haskell-cafe] Haskell (wiki) Logo license

It was posted to the Wiki, IIUC. Anything posted to the wiki is implicitly licensed by the wiki license: http://haskell.org/haskellwiki/HaskellWiki:Copyrights On 23 April 2010 07:10, Jens Petersen wrote: > Hi, > > We use the Haskell Logo in Fedora OS installer for the Haskell packages group: > h

Re: [Haskell-cafe] GHC Api typechecking

Looking at the code for GHC, it turns out that your use case is not supported. It is not allowed to have in-memory-only files. If you specify a buffer it will still try to find the module file on the disk, but it will (or at least should) use the contents from the specified string buffer. I've b

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