Re: [Haskell] Treatment of unknown pragmas
Hi all,
I've just released HLint 2.1.11 which supports three different forms
of pragma as per https://github.com/ndmitchell/hlint#ignoring-hints,
so you can write:
* {-# ANN module "HLint: ignore Eta reduce" #-}
* {-# HLINT ignore "Eta reduce" #-}
* {- HLINT ignore "Eta reduce" -}
The last two are new to this version of HLint. ANN is a serious
performance penalty, {-# HLINT #-} triggers a GHC warning, and {-
HLINT -} gets highlighted as a comment - so people get to pick their
downside. I will probably remove documentation of the ANN variant at
some point, since it's got serious the most serious downsides.
I have no intention to support a {-@ HLINT @-} or similar syntax,
because everything that might sensibly be used is taken, and even if
it gets adopted universally, I suspect HLINT will account for 80%+
instances, making it still the "weird HLINT syntax".
My preference is still to have GHC not give warnings on HLINT, but
assuming that's still infeasible, I'll probably see about getting all
the Haskell syntax highlighters to add special support for {- HLINT
-}...
Thanks, Neil
On Sun, Oct 28, 2018 at 3:04 PM Artem Pelenitsyn wrote:
>
> Hello Daniel,
>
> Annotations API was discussed earlier in this thread. Main points against are:
>
> Neil:
> Significant compilation performance penalty and extra recompilation. ANN
> pragmas is what HLint currently uses.
>
> Brandon:
> The problem with ANN is it's part of the plugins API, and as such does things
> like compiling the expression into the program in case a plugin generates
> code using its value, plus things like recompilation checking end up assuming
> plugins are in use and doing extra checking. Using it as a compile-time
> pragma is actually fairly weird from that standpoint.
>
> --
> Best, Artem
> On Sat, 27 Oct 2018 at 22:12 Daniel Wagner wrote:
>>
>> I don't have a really strong opinion, but... isn't this (attaching string-y
>> data to source constructs) pretty much exactly what GHC's annotation pragma
>> is for?
>> ~d
>>
>> On Tue, Oct 16, 2018 at 3:14 PM Ben Gamari wrote:
>>>
>>> Vladislav Zavialov writes:
>>>
>>> > What about introducing -fno-warn-pragma=XXX? People who use HLint will
>>> > add -fno-warn-pragma=HLINT to their build configuration.
>>> >
>>> A warning flag is an interesting way to deal with the issue. On the
>>> other hand, it's not great from an ergonomic perspective; afterall, this
>>> would mean that all users of HLint (and any other tool requiring special
>>> pragmas) include this flag in their build configuration. A typical
>>> Haskell project already needs too much such boilerplate, in my opinion.
>>>
>>> I think it makes a lot of sense to have a standard way for third-parties
>>> to attach string-y information to Haskell source constructs. While it's
>>> not strictly speaking necessary to standardize the syntax, doing
>>> so minimizes the chance that tools overlap and hopefully reduces
>>> the language ecosystem learning curve.
>>>
>>> Cheers,
>>>
>>> - Ben
>>> ___
>>>
>>> Haskell mailing list
>>> Haskell@haskell.org
>>> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell
>>
>> ___
>> Haskell mailing list
>> Haskell@haskell.org
>> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell
>
> ___
> ghc-devs mailing list
> ghc-d...@haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
___
Haskell mailing list
Haskell@haskell.org
http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell
Re: [Haskell-community] 2018 state of Haskell survey
Hi Taylor, What does official support look like? I don't think there's anything above and beyond what you're already doing. Thanks, Neil On Sun, 14 Oct 2018 at 3:49 pm, Taylor Fausak wrote: > (I have CCed because the haskell-community > mailing list seems relatively quiet and I want to make sure this is seen.) > > Hello! My name is Taylor Fausak. I run the Haskell Weekly newsletter. Last > year I published a survey [1] for the Haskell community. I collected and > reported [2] on about 1,335 responses. I plan on publishing another survey > this year on the same date, November 1st. I am developing it in the open > again [3] and would love to hear from any interested parties. Please let me > know if you have any ideas about the survey! > > This year I am interested in making the survey official by seeking support > from Haskell.org. Is such a thing possible and desirable? > > Thanks for your consideration! I hope to hear from you soon. > > [1]: https://haskellweekly.news/surveys/2017.html > [2]: > https://taylor.fausak.me/2017/11/15/2017-state-of-haskell-survey-results/ > [3]: https://github.com/haskellweekly/haskellweekly.github.io/issues/206 > ___ > Haskell-community mailing list > Haskell-community@haskell.org > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-community > ___ Haskell-community mailing list Haskell-community@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-community
Re: ANNOUNCE: GHC 7.10.1 Release Candidate 3
All of the mingw links give me 403 forbidden errors. Do they have permission issues? Thanks, Neil On Mon, Mar 16, 2015 at 8:30 PM, Austin Seipp aus...@well-typed.com wrote: We are pleased to announce the third release candidate for GHC 7.10.1: https://downloads.haskell.org/~ghc/7.10.1-rc3 https://downloads.haskell.org/~ghc/7.10.1-rc3/docs/html/ This includes the source tarball and bindists for Windows and Debian Linux. FreeBSD, CentOS and Mac OS X binary distributions will follow soon. These binaries and tarballs have an accompanying SHA256SUMS file signed by my GPG key id (0x3B58D86F). We plan to make the 7.10.1 final release at the end of this week - so please test as much as possible; bugs are much cheaper if we find them before the release! The list of issues we plan on fixing can always be found in an up-to-date form here: https://ghc.haskell.org/trac/ghc/wiki/Status/GHC-7.10.1 -- Regards, Austin Seipp, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/ ___ ghc-devs mailing list ghc-d...@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
Re: ANNOUNCE: GHC 7.10.1 Release Candidate 3
Confirmed, thanks a lot! On Tue, Mar 17, 2015 at 1:47 PM, Austin Seipp aus...@well-typed.com wrote: Neil, this has been fixed. On Tue, Mar 17, 2015 at 7:52 AM, Neil Mitchell ndmitch...@gmail.com wrote: All of the mingw links give me 403 forbidden errors. Do they have permission issues? Thanks, Neil On Mon, Mar 16, 2015 at 8:30 PM, Austin Seipp aus...@well-typed.com wrote: We are pleased to announce the third release candidate for GHC 7.10.1: https://downloads.haskell.org/~ghc/7.10.1-rc3 https://downloads.haskell.org/~ghc/7.10.1-rc3/docs/html/ This includes the source tarball and bindists for Windows and Debian Linux. FreeBSD, CentOS and Mac OS X binary distributions will follow soon. These binaries and tarballs have an accompanying SHA256SUMS file signed by my GPG key id (0x3B58D86F). We plan to make the 7.10.1 final release at the end of this week - so please test as much as possible; bugs are much cheaper if we find them before the release! The list of issues we plan on fixing can always be found in an up-to-date form here: https://ghc.haskell.org/trac/ghc/wiki/Status/GHC-7.10.1 -- Regards, Austin Seipp, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/ ___ ghc-devs mailing list ghc-d...@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs -- Regards, Austin Seipp, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/ ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
Re: [Haskell-cafe] Hoogle vs Hayoo
Hi, Hoogle is definitely not deprecated. The reason you can't yet search all packages simultaneously is that it consumes too many resources - the number of Haskell packages exploded at a time when I wasn't able to spend enough time to allow Hoogle to keep up. It's definitely something on the todo list! The FP complete guys are helping with the work required to get there. Be careful what you wish for though. I can't almost guarantee that every type you search for is available in the lens package as a hylo-zygote-para-poly-morphism if you instantiate the Bazaar applicative to the right type. I agree that sorting the platform packages to the top of the list is likely to help make this more manageable. Thanks, Neil On Fri, Aug 23, 2013 at 3:53 PM, Mateusz Kowalczyk fuuze...@fuuzetsu.co.uk wrote: On 23/08/13 14:57, jabolo...@google.com wrote: It's a bit pointless, if I have to know the package, where I want to search in. Yeah! It does sound a bit pointless. Hoogle should search everything by default, and then you can refine your search by clicking on the '+' or '-' on the packages that appear on the left menu. Jose +1 to this, I never even knew this functionality existed. Why not have a checkbox or something along these lines to enable the search in all packages? This wouldn't change the old behaviour by default and it would allow for a wider search. -- Mateusz K. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Hoogle problems?
Hoogle has returned to live, thanks to the efforts to the new haskell.org admins. Thanks, Neil On Tue, Jul 16, 2013 at 4:33 PM, Neil Mitchell ndmitch...@gmail.com wrote: No idea why it has gone down, my guess is that the Apache rule that says treat it as a CGI script got changed to serve it as a file. In the meantime you can use a copy of Hoogle at: https://www.fpcomplete.com/hoogle Thanks, Neil On Mon, Jul 15, 2013 at 5:19 PM, Niklas Hambüchen m...@nh2.me wrote: OK, but why does it need to go down for migration? On Mon 15 Jul 2013 23:52:02 SGT, Daniel F wrote: The web site is migrating. IRC says: Topic for #haskell: haskell.org in the middle of migration; expect turbulence; use www.haskell.org ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Hoogle problems?
No idea why it has gone down, my guess is that the Apache rule that says treat it as a CGI script got changed to serve it as a file. In the meantime you can use a copy of Hoogle at: https://www.fpcomplete.com/hoogle Thanks, Neil On Mon, Jul 15, 2013 at 5:19 PM, Niklas Hambüchen m...@nh2.me wrote: OK, but why does it need to go down for migration? On Mon 15 Jul 2013 23:52:02 SGT, Daniel F wrote: The web site is migrating. IRC says: Topic for #haskell: haskell.org in the middle of migration; expect turbulence; use www.haskell.org ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Uniplate and rewriting with different types
Hi Chris, With the following type, and transformation functions: data Odd = OddOne Even | OddZero Even deriving (Data,Typeable,Show) data Even = EvenOne Odd | EvenZero Odd | Nil deriving (Data,Typeable,Show) t1,t2,t3 :: Even - Maybe Even But if one of the transformations has a different type, you can't do it this way. For instance, redefine t2 to have a different type: t2 :: Odd - Maybe Odd t2 (OddZero (EvenOne x)) = Just $ OddZero (EvenZero x) t2 x = Nothing and you are stuck because the functions of different types can't be combined into a single transformation. My question is: is there a good way to combine the transformation functions if they have different types? Currently, no. Although there is something definitely related, with transformBis: http://hackage.haskell.org/packages/archive/uniplate/1.6.10/doc/html/Data-Generics-Uniplate-Data.html#v:transformBis That takes a list of transformation functions of different types and acts as though you did transform on each one in turn. You could certainly imagine adding rewriteBis in the same style, and with your version you almost have. The transformBis function is particularly efficient because it knows which traversals or parts of traversals can be fused without changing the semantics. rewriteBis could certainly do the same trick. If you provided a patch for rewriteBis I'd certainly apply it! Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [Haskell] Well-Typed and Skills Matter offer Haskell courses in London in October
Hi Claude, I have a promo code which gives £50 off to make the Haskell Exchange £175. HASKELLX-2012-TE1. Note that this cost isn't profiteering - unfortunately running a conference (just getting a venue) is expensive. There will probably be some social aspect afterwards, I'll certainly go to a pub if anyone wants. I would love to see London HUG revived, I know people have tried (including in the very recent past, a few months ago), but as yet no one has managed to get any meetings going. Perhaps soon though. Hoodlums is a great event, more teaching and less talk based, but very well run and I highly recommend it! Thanks, Neil On Mon, Sep 24, 2012 at 9:11 PM, Claude Heiland-Allen cla...@mathr.co.uk wrote: Hi Andres, list, On 19/09/12 09:41, Andres Löh wrote: Oops, I hit send too prematurely, sorry for the seeming bluntness (but it is still a blunt message, can't apologize for that I suppose): No need to apologize. There's a need for informal meetings as much (or even more) as there is for courses and conferences. Thank you. Regarding London, I know there's the Haskell Hoodlums meetup (http://www.meetup.com/hoodlums/) Thanks, I wasn't aware of this one. I have signed up. Claude ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: Error while installing new packages with GHC 7.4.1
Hi Antoras, The darcs version of Hoogle has had a more permissive dependency for a few weeks. Had I realised the dependency caused problems I'd have released a new version immediately! As it stands, I'll release a new version in about 4 hours. If you can't wait that long, try darcs get http://code.haskell.org/hoogle Thanks, Neil On Thursday, March 1, 2012, Antoras wrote: Ok, interesting info. But how to solve the problem now? Should I contact the author of Hoogle and ask him about how solving this? On 03/01/2012 02:02 AM, Albert Y. C. Lai wrote: On 12-02-29 06:04 AM, Antoras wrote: I don't know where the dependency to array-0.3.0.3 comes from. Is it possible to get more info from cabal than -v? hoogle-4.2.8 has Cabal = 1.8 1.13, this brings in Cabal-1.12.0. Cabal-1.12.0 has array = 0.1 0.4, this brings in array-0.3.0.3. It is a mess to have 2nd instances of libraries that already come with GHC, unless you are an expert in knowing and avoiding the treacherous consequences. See my http://www.vex.net/~trebla/**haskell/sicp.xhtmlhttp://www.vex.net/~trebla/haskell/sicp.xhtml It is possible to fish the output of cabal install --dry-run -v3 hoogle for why array-0.3.0.3 is brought in. It really is fishing, since the output is copious and of low information density. Chinese idiom: needle in ocean (haystack is too easy). Example: selecting hoogle-4.2.8 (hackage) and discarding Cabal-1.1.6, 1.2.1, 1.2.2.0, 1.2.3.0, 1.2.4.0, 1.4.0.0, 1.4.0.1, 1.4.0.2, 1.6.0.1, 1.6.0.2, 1.6.0.3, 1.14.0, blaze-builder-0.1, case-insensitive-0.1, We see that selecting hoogle-4.2.8 causes ruling out Cabal 1.14.0 Similarly, the line for selecting Cabal-1.12.0 mentions ruling out array-0.4.0.0 __**_ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/**mailman/listinfo/glasgow-**haskell-usershttp://www.haskell.org/mailman/listinfo/glasgow-haskell-users __**_ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/**mailman/listinfo/glasgow-**haskell-usershttp://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: Error while installing new packages with GHC 7.4.1
Hi Antoras, I've just released Hoogle 4.2.9, which allows Cabal 1.15, so hopefully will install correctly for you. Thanks, Neil On Thu, Mar 1, 2012 at 5:02 PM, Neil Mitchell ndmitch...@gmail.com wrote: Hi Antoras, The darcs version of Hoogle has had a more permissive dependency for a few weeks. Had I realised the dependency caused problems I'd have released a new version immediately! As it stands, I'll release a new version in about 4 hours. If you can't wait that long, try darcs get http://code.haskell.org/hoogle Thanks, Neil On Thursday, March 1, 2012, Antoras wrote: Ok, interesting info. But how to solve the problem now? Should I contact the author of Hoogle and ask him about how solving this? On 03/01/2012 02:02 AM, Albert Y. C. Lai wrote: On 12-02-29 06:04 AM, Antoras wrote: I don't know where the dependency to array-0.3.0.3 comes from. Is it possible to get more info from cabal than -v? hoogle-4.2.8 has Cabal = 1.8 1.13, this brings in Cabal-1.12.0. Cabal-1.12.0 has array = 0.1 0.4, this brings in array-0.3.0.3. It is a mess to have 2nd instances of libraries that already come with GHC, unless you are an expert in knowing and avoiding the treacherous consequences. See my http://www.vex.net/~trebla/haskell/sicp.xhtml It is possible to fish the output of cabal install --dry-run -v3 hoogle for why array-0.3.0.3 is brought in. It really is fishing, since the output is copious and of low information density. Chinese idiom: needle in ocean (haystack is too easy). Example: selecting hoogle-4.2.8 (hackage) and discarding Cabal-1.1.6, 1.2.1, 1.2.2.0, 1.2.3.0, 1.2.4.0, 1.4.0.0, 1.4.0.1, 1.4.0.2, 1.6.0.1, 1.6.0.2, 1.6.0.3, 1.14.0, blaze-builder-0.1, case-insensitive-0.1, We see that selecting hoogle-4.2.8 causes ruling out Cabal 1.14.0 Similarly, the line for selecting Cabal-1.12.0 mentions ruling out array-0.4.0.0 ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: Error while installing new packages with GHC 7.4.1
Hi Antoras, My suspicion is you've ended up with corrupted packages in your package database - nothing to do with Hoogle. I suspect trying to install parsec-3.1.2 directly would give the same error message. Can you try ghc-pkg list, and at the bottom it will probably say something like: The following packages are broken, either because they have a problem listed above, or because they depend on a broken package. warp-1.1.0 I often find ghc-pkg unregister warp --force on all the packages cleans them up enough, but someone else may have a better suggestion. Thanks, Neil On Fri, Mar 2, 2012 at 12:02 AM, Antoras m...@antoras.de wrote: Hi Neil, thanks for your effort. But it still does not work. The old errors disappeared, but new ones occur. Maybe I have not yet the most current versions: $ ghc --version The Glorious Glasgow Haskell Compilation System, version 7.4.1 $ cabal --version cabal-install version 0.10.2 using version 1.10.1.0 of the Cabal library This seems to be the most current version of Cabal. The command 'cabal info cabal' brings: Versions installed: 1.14.0 but not 1.15 An extract of the error messages: [...] Configuring parsec-3.1.2... Preprocessing library parsec-3.1.2... Building parsec-3.1.2... command line: cannot satisfy -package-id text-0.11.1.13-9b63b6813ed4eef16b7793151cdbba4d: text-0.11.1.13-9b63b6813ed4eef16b7793151cdbba4d is unusable due to missing or recursive dependencies: deepseq-1.3.0.0-a73ec930018135e0dc0a1a3d29c74c88 (use -v for more information) command line: cannot satisfy -package Cabal-1.14.0: Cabal-1.14.0-5875475606fe70ef919bbc055077d744 is unusable due to missing or recursive dependencies: array-0.4.0.0-59d1cc0e7979167b002f021942d60f46 containers-0.4.2.1-cfc6420ecc2194c9ed977b06bdfd9e69 directory-1.1.0.2-07820857642f1427d8b3bb49f93f97b0 process-1.1.0.1-18dadd8ad5fc640f55a7afdc7aace500 (use -v for more information) [...] On Thu 01 Mar 2012 11:06:43 PM CET, Neil Mitchell wrote: Hi Antoras, I've just released Hoogle 4.2.9, which allows Cabal 1.15, so hopefully will install correctly for you. Thanks, Neil On Thu, Mar 1, 2012 at 5:02 PM, Neil Mitchellndmitch...@gmail.com wrote: Hi Antoras, The darcs version of Hoogle has had a more permissive dependency for a few weeks. Had I realised the dependency caused problems I'd have released a new version immediately! As it stands, I'll release a new version in about 4 hours. If you can't wait that long, try darcs get http://code.haskell.org/hoogle Thanks, Neil On Thursday, March 1, 2012, Antoras wrote: Ok, interesting info. But how to solve the problem now? Should I contact the author of Hoogle and ask him about how solving this? On 03/01/2012 02:02 AM, Albert Y. C. Lai wrote: On 12-02-29 06:04 AM, Antoras wrote: I don't know where the dependency to array-0.3.0.3 comes from. Is it possible to get more info from cabal than -v? hoogle-4.2.8 has Cabal= 1.8 1.13, this brings in Cabal-1.12.0. Cabal-1.12.0 has array= 0.1 0.4, this brings in array-0.3.0.3. It is a mess to have 2nd instances of libraries that already come with GHC, unless you are an expert in knowing and avoiding the treacherous consequences. See my http://www.vex.net/~trebla/haskell/sicp.xhtml It is possible to fish the output of cabal install --dry-run -v3 hoogle for why array-0.3.0.3 is brought in. It really is fishing, since the output is copious and of low information density. Chinese idiom: needle in ocean (haystack is too easy). Example: selecting hoogle-4.2.8 (hackage) and discarding Cabal-1.1.6, 1.2.1, 1.2.2.0, 1.2.3.0, 1.2.4.0, 1.4.0.0, 1.4.0.1, 1.4.0.2, 1.6.0.1, 1.6.0.2, 1.6.0.3, 1.14.0, blaze-builder-0.1, case-insensitive-0.1, We see that selecting hoogle-4.2.8 causes ruling out Cabal 1.14.0 Similarly, the line for selecting Cabal-1.12.0 mentions ruling out array-0.4.0.0 ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: parallelizing ghc
Hi Simon, I have found that a factor of 2 parallelism is required on Linux to draw with ghc --make. In particular: GHC --make = 7.688 Shake -j1 = 11.828 (of which 11.702 is spent running system commands) Shake full -j4 = 7.414 (of which 12.906 is spent running system commands) This is for a Haskell program which has several bottlenecks, you can see graph of spawned processes here: http://community.haskell.org/~ndm/darcs/shake/academic/icfp2012/profile.eps - everything above the 1 mark is more than one process in parallel, so it gets to 4 processes, but not all the time - roughly an average of ~ x2 parallelism. On Windows the story is much worse. If you -j4 then the time spent executing system commands shoots up from ~15s to around ~25s, since even on a 4 core machine the contention in the processes is high. I tried investigating this, checking for things like a locked file (none I can find), or disk/CPU/memory contention (its basically taking no system resources), but couldn't find anything. If you specify -O2 then the parallel performance also goes down - I suspect because each ghc process needs to read inline information for packages that are imported multiple times, and ghc --make gets away with doing that once? This looks a bit suspicious. The Shake build is doing nearly twice as much work as the --make build, in terms of CPU time, but because it is getting nearly 2x parallelism it comes in a close second. How many processes is the Shake build using? Shake uses a maximum of the number of processes you specify, it never exceeds the -j flag - so in the above example it caps out at 4. It is very good at getting parallelism (I believe it to be perfect, but the code is 150 lines of IORef twiddling, so I wouldn't guarantee it), and very safe about never exceeding the cap you specify (I think I can even prove that, for some value of proof). The profiling makes it easy to verify these claims after the fact. Thanks, Neil ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: [Haskell-cafe] lost in generics
Hi Rustom, I tend to find that I use Uniplate for most stuff, and SYB for very complex stuff (SYB is quite a bit more complicated to do the simple things, but can do things out of reach for Uniplate). The example of manipulating AST's is very common, and using a generics library is a very good idea. One way to start would be to read the Uniplate manual: http://community.haskell.org/~ndm/darcs/uniplate/uniplate.htm - it even uses a simple expression type as the example. It has examples of all the functions, and also little exercises to try - even if you don't use Uniplate the exercises might give you practice figuring out what functions you're likely to end up using in your generics library. Thanks, Neil On Thu, Oct 20, 2011 at 6:12 PM, Rustom Mody rustompm...@gmail.com wrote: I need some help finding my way around the various generics libraries. My usage scenario is -- at least to start with -- the ASTs of programming languages. It appears to me that there are two generations of generics -- earlier there was generic haskell and strafunski Now there is uniplate and kure (and syb? -- not sure of its generation...) I get this impression because I saw a comment somewhat along these lines. And also the very first reference link on the strafunski webpage: http://www.haskell.org/haskellwiki/Applications_and_libraries/Generic_programming/Strafunski viz http://www.cs.vu.nl/Strafunski/ seems to be dead. So I am wondering whether strafunski is still under development or is it defunct? The following paras from http://www.cs.uu.nl/research/techreps/repo/CS-2008/2008-010.pdf The current status of generic programming in Haskell is comparable to the lazy Tower of Babel preceding the birth of Haskell in the eighties [Hudak et al., 2007]. We have many single-site languages or libraries, each individually lacking critical mass in terms of language/library-design effort, implementations, and users. Although generic programming has been used in several applications, it has few users for real-life projects. This is understandable. Developing a large application takes a couple of years, and choosing a particular approach to generic programming for such a project involves a risk. Few approaches that have been developed over the last decade are still supported, and there is a high risk that the chosen approach will not be supported anymore, or that it will change in a backwards-incompatible way in a couple of years time. sound omninous :-) In general my question is: What is alive/active and what is alive/active and what is -- um -- moved-on-from. And of course which are easier and which more difficult to dig into. Thanks Rusi ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] hledger subcommand detection, RFC
* an option to all commands that lists out all its available options, to aid with shell completion. See the link I posted above about the oggz tools for an example usage and a link to a bash completion file. Note that the next version of CmdArgs will include command line flag completion automatically, so you might want to leave that feature a little while and see if you can make use of the CmdArgs feature. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] extending and reusing cmdargs option specs ?
Hi,
You're asking for:
http://code.google.com/p/ndmitchell/issues/detail?id=291 - it's
something I'm already aware of, and what to do at some point.
Unfortunately, it probably won't be anytime in the next few months,
but it will happen eventually.
Thanks, Neil
On Tue, Aug 9, 2011 at 3:08 AM, wren ng thornton w...@freegeek.org wrote:
On 8/8/11 1:59 PM, Simon Michael wrote:
And, I may have made things worse for myself in the reuse/avoiding
boilerplate department: I'm not sure how to reuse a cmdargs options data
structure, extending it with a few more options.
This is a big problem I'm dealing with too lately. In particular, what I
would like is if cmdargs could do flattening of structures, either
automatically or with a new annotation combinator. With this it would be
easy to have a basic FooBar program:
data FooBar = FooBar
{ foo :: Foo
, bar :: Bar
}
deriving (Data, Typeable,...)
getFooBarMode :: IO (Mode (CmdArgs FooBar))
getFooBarMode = ...
and then extend it to a FooBarBaz program:
data FooBarBaz = FooBarBaz
{ fooBar :: FooBar
, baz :: Baz
}
deriving (Data, Typeable,...)
getFooBarBazMode :: IO (Mode (CmdArgs FooBarBaz))
getFooBarBazMode = ...
The big trick is that I should be able to call getFooBarMode from
getFooBarBazMode equivalently to if I had defined,
data FooBarBaz = FooBarBaz
{ foo :: Foo
, bar :: Bar
, baz :: Baz
}
deriving (Data, Typeable,...)
and copied over getFooBarMode inline into getFooBarBazMode. The problem is
that the bulk of the code is in the Mode-generating functions, and it's also
the sort of code that's hardest to keep in sync documentation-wise.
I don't mind the extra indirection in the Mode structures since I don't
actually use them in the program itself; I have an internal configuration
type that I compile the FooBarBaz down to, so that I can perform additional
semantic consistency checks before execution, as well as precomputing what
the commandline arguments dereference into (e.g., functions).
As always, thanks a lot for cmdargs!
-Simon
Indeed. Aside from this feature request I've been quite pleased :)
--
Live well,
~wren
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Package descriptions on hackage
There are several problems here: 1) Not everyone can write beautiful clear English descriptions, it takes a certain skill. 2) The person writing the description is the author, who knows all the details, but the person reading the description doesn't - writing for a different audience is an even harder skill to master. 3) It's easy to miss something when updating a package. 4) Quality documentation places an ongoing maintenance burden on the package, and while test suites etc. make code maintenance easy, I don't know any way to automatically check documentation! Why not email the maintainers of packages you think need a better description - ideally giving suggestions? I'd welcome that for any of my packages. Thanks, Neil On Mon, Sep 5, 2011 at 11:22 PM, Ivan Lazar Miljenovic ivan.miljeno...@gmail.com wrote: On 5 September 2011 23:59, Joachim Breitner m...@joachim-breitner.de wrote: Dear hackage package authors, this is a short message from your distribution package creators: Please, if possible, write good, not too short descriptions, and also keep them up to date. Of course, users browsing hackage will benefit as well. Also for potential users trying to work out what your library does! Something that I find particularly frustrating is all the libraries of the form hFoo: Haskell bindings to the Foo library; well, what _is_ the Foo library? -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Code critique - Was [Maybe Int] sans Nothings
Hi Michael,
You've used quite a few entirely redundant brackets. The tool HLint (
http://community.haskell.org/~ndm/hlint) will tell you which ones.
Thanks, Neil
On Wed, May 25, 2011 at 12:09 AM, michael rice nowg...@yahoo.com wrote:
The input file: http://dl.dropbox.com/u/27842656/psalms
The Markov chain exercise from The Practice of Programming,
Kermighan/Pike. Sample runs at the end.
Michael
import System.Environment(getArgs)
import System.Random
import Control.Applicative
import Control.Monad.Reader
import Control.Monad.State
import Data.Maybe
import Data.Map
type Prefix = (String,String)
type GeneratorState1 = State ((Map Prefix [String]),Prefix,[String])
type GeneratorState2 = StateT (Prefix,StdGen) (Reader (Map Prefix
[String]))
non_word = \n
f key new old = new ++ old
buildMap :: GeneratorState1 (Map Prefix [String])
buildMap = do (mp,(pfx1,pfx2),words) - get
if (Prelude.null words)
then {- No more words. Return final map (adding non_word
for final prefix). -}
return (insertWithKey' f (pfx1,pfx2) [non_word] mp)
else do {- Add word to map at prefix continue. -}
put (insertWithKey' f (pfx1,pfx2) [head words] mp,
(pfx2,(head words)), tail words)
buildMap
generate :: GeneratorState2 (Maybe String)
generate = do ((pfx1,pfx2),gen) - get
mp - ask
let suffixList = mp ! (pfx1,pfx2)
let (index,newGen) = randomR (0, (length suffixList)-1) gen
let word = suffixList !! index
if (word == non_word)
then
return Nothing
else do
put ((pfx2,word),newGen)
return (Just word)
rInt :: String - Int
rInt = read
main = do (seed:nwords:_) - (Prelude.map rInt) $ getArgs
contents - getContents
putStrLn $ unwords $ catMaybes $ runReader (evalStateT (sequence
$ replicate nwords generate) ((non_word,non_word),mkStdGen seed))
(evalState buildMap
(singleton (non_word,non_word) [], (non_word,non_word), words contents))
{-
[michael@hostname ~]$ ghc --make markov.hs
[1 of 1] Compiling Main ( markov.hs, markov.o )
Linking markov ...
[michael@hostname ~]$ cat psalms | ./markov 111 100
Blessed is the LORD, in thine own cause: remember how the foolish people
have blasphemed thy name. In the courts of the righteous: The LORD taketh
pleasure in the desert. And he led them with the wicked, and with the whole
earth, is mount Zion, on the sides of thine only. O God, and was troubled: I
complained, and my God. My times are in thy praise. Blessed be God, which is
full of the LORD is good: for his wondrous works. Now also when I am small
and despised: yet do I put my trust: how say ye to
[michael@hostname ~]$ cat psalms | ./markov 666 100
Blessed is the LORD, and cried unto thee, Thy face, LORD, will I remember
thee from the beginning: and every one that is weaned of his heart to any
wicked transgressors. Selah. They return at evening: they make ready their
arrow upon the people; and thou hast destroyed all them that fight against
them that trust in thee: and let my tongue cleave to the heavens by his
power for ever; and thy lovingkindnesses; for they have laid a snare before
them: and that my ways were directed to keep thy word. Mine eyes fail while
I have said that
[michael@hostname ~]$
--- On *Tue, 5/24/11, Alexander Solla alex.so...@gmail.com* wrote:
From: Alexander Solla alex.so...@gmail.com
Subject: Re: [Haskell-cafe] [Maybe Int] sans Nothings
To: Haskell Cafe haskell-cafe@haskell.org
Date: Tuesday, May 24, 2011, 5:01 PM
Personally, I find non-functional values without Eq instances to be
degenerate. So I really do not mind superfluous Eq constraints. I
would not hesitate to use filter ((/=) Nothing) in a function whose type
has no free type variables. It's just a bit of plumbing inside of a
more complex function.
Sometimes it seems to be better to not allow Eq on Float and Double.
Since most algebraic laws do not hold for those types, it is more often
an error than an intention to compare two Float values. And how to
compare (IO a) values?
Floats, Doubles, and IO are all degenerate types, for the reasons you
outline. (Admittedly, Float and Double have Eq instances, but invalid Eq
semantics) Notice how their value semantics each depend on the machine your
runtime runs on, as opposed to merely the runtime. Bottom is another one of
these degenerate types, since comparisons on arbitrary values are
undecidable.
Also, by thinking about function types, you often
get interesting use cases. Thus I would not assume too quickly that a
type will always be instantiated by types other than a function type.
Thus I would stick to (filter isJust) and use this
Re: [Haskell-cafe] uniplate (was: code review?)
Hi John, While I'm on the topic, I recently wrote a tool that wanted to traverse deep data structures as produced by haskell-src-exts. ?I wound up with about 50 lines of case expressions and around the time my hands were literally beginning to hurt decided that enough was enough and I should try a generic approach. ?I heard uniplate was pretty easy to use, and was pretty pleased to turn the entire thing into a single line. ?It took me a little longer to figure out I needed to use universeBi since all the examples were monotyped, but once I did it Just Worked. ?Amazing. ?So thanks again! ?And maybe you could mention universeBi in the instant introduction? Yes, I probably should - I'll try and get to that. Of course, I'd also happily accept a patch against http://community.haskell.org/~ndm/darcs/uniplate I use Uniplate inside HLint, and it's invaluable - there are a lot of times when List Comp + universeBi really hits the spot. Does Uniplate include an instance for: instance Uniplate a = Biplate [a] a No, it only includes: instance Biplate [Char] Char where biplate (x:xs) = plate (:) |* x ||* xs biplate x = plate x I am slightly curious why I didn't include the more general a instead of Char version, but perhaps it doesn't quite work - polymorphic versions of the Direct instances can have problems if you pick weird types. I'll have a think, and if it does always work, I'll include it. Note that if you use the Typeable or Data versions this instance is automatically available. In practice I almost always end up using the Data versions of Uniplate, they require no instance definitions are are good to get started with - you can switch to Direct only if you need the additional performance. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] code review?
Hi Niklas, I use Uniplate inside HLint, and it's invaluable - there are a lot of times when List Comp + universeBi really hits the spot. +1 on that, I use uniplate for pretty much all my haskell-src-exts tasks these days, works like a charm! I'd love to include some standard traversal functionality in haskell-src-exts that depends on uniplate, but hesitate to do so because of HP aspirations for haskell-src-exts. Neil, what do you reckon the chances of getting uniplate in the HP are? :-) I'm happy to have it included. The only likely change is that I currently have basically two versions of all modules (Data.Generics.PlateData and Data.Generics.Uniplate.Data). I'll upload a version 1.7 of Uniplate marking those deprecated, then a 1.8 removing them, and then I'd love to get included in the Platform. Of course, whether it goes in the platform is not really up to me, it's up to the community - but if someone proposes it I'll back it. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] lambdabot hoogle
Hi Jacek, Which works swimmingly on Ubuntu, but fails on OS X, because wget seems to be hard-wired. I seem to recall that at least one of the packages that I installed over the last 2 days, automatically selected wget on Ubuntu, and curl on OS X. I see someone raised a bug for this: http://code.google.com/p/ndmitchell/issues/detail?id=434 - it's a very reasonable idea, which I'll include in the next version. Then if you have either wget or curl it will work. Any pointers to the least painful way of getting 'hoogle data' to work on OS X? Set up a shell alias so wget just calls curl? Install wget on OS X? If neither of these is feasible let me know and I'll rush out a new version of Hoogle. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] code review?
Before doing a code review I always demand that the author runs over the code with HLint (http://community.haskell.org/~ndm/hlint) - they Very good point. In fact you just inspired me to finally download it and run it on my own code. Thanks for the great tool! Glad you like it. While I'm on the topic, I recently wrote a tool that wanted to traverse deep data structures as produced by haskell-src-exts. I wound up with about 50 lines of case expressions and around the time my hands were literally beginning to hurt decided that enough was enough and I should try a generic approach. I heard uniplate was pretty easy to use, and was pretty pleased to turn the entire thing into a single line. It took me a little longer to figure out I needed to use universeBi since all the examples were monotyped, but once I did it Just Worked. Amazing. So thanks again! And maybe you could mention universeBi in the instant introduction? Yes, I probably should - I'll try and get to that. Of course, I'd also happily accept a patch against http://community.haskell.org/~ndm/darcs/uniplate I use Uniplate inside HLint, and it's invaluable - there are a lot of times when List Comp + universeBi really hits the spot. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] code review?
'if all == False then return False else return True' is a pretty confusing way to say 'return all'. In fact, any time you see 'x == True' you can just remove the '== True'. The whole postAll thing would be clearer as Before doing a code review I always demand that the author runs over the code with HLint (http://community.haskell.org/~ndm/hlint) - they don't have to necessarily apply all the suggestions, but they do have to at least be aware of obvious alternatives. A code review takes a reasonable amount of time, and it's best to use that for things that machines can't yet figure out - rather than the simpler stuff like the above. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Functional dependencies and Peano numbers (and hoogle-bug?)
Hi Oscar, Sorry for the seriously late reply. I only just found this message in the bottom of my inbox: On an unrelated note: I hoogled to (i.e. http://haskell.org/hoogle/?hoogle=to) and just got a blank page. Nothing. Nil (not even html.../html). Is this a bug or a feature? :) It was a bug, fixed in hoogle-4.2.1. I had an incomplete pattern match on to, which crashed Hoogle. The reason to is treated specially is that when people search for a to b, they usually mean a - b, and my code to detect this was incorrect. All fixed now. Thanks for the report. In future, if you find a bug in Hoogle can you please email me directly, or raise it on my bug tracker: http://code.google.com/p/ndmitchell/issues/ Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] wrong backquote in haskell 2010 report Prelude
Hi Albert, Thanks for spotting this, it definitely looks wrong. On the line above I also see the ^ characters have got corrupted. I've emailed it onwards to the current report editor (Malcolm Wallace) Thanks, Neil On Thu, Mar 17, 2011 at 4:57 PM, Albert Y. C. Lai tre...@vex.net wrote: Haskell 2010 report chapter 9 Standard Prelude uses a wrong backquote, e.g., infixl 7 ⋆, /, ‘quot‘, ‘rem‘, ‘div‘, ‘mod‘ Those are U+2018. The grammar (Chapter 3) requires U+0060 and accepts no substitutes, e.g., varop → varsym | ` varid ` ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: hoogling GHC
Hi Ranjit, Is there a command line option that allows one to change the default prefix for the URL returned by searches? No command line option, but you can change the .txt file itself by doing: @url http://www.haskell.org/ghc/docs/7.0.1/html/libraries/ghc-7.0.1/ @package ghc That should cause all the URL's in the GHC package that aren't explicit to have the above URL prepended to them. If there's demand, I can add a flag. Thanks, Neil On Mar 9, 2011, at 1:59 PM, Neil Mitchell wrote: Hi Ranjit, It sounds like you've got quite far. Sadly the manual is a bit out of date with respect to generating databases, but generally you need to produce ghc.txt on your own (using tools such as GHC's make system), then you can do: hoogle convert ghc.txt default.hoo Then you can run the local server with: hoogle server --databases=. That will find databases from the current directory, and serve them. Alternatively, if you put ghc.hoo (or default.hoo) in $DATADIR/databases it will pick them up automatically (where $DATADIR is whatever Cabal configured it to be). If you name the database as default.hoo it will be searched by default, if you name it ghc.hoo then foo +ghc will search for foo in the GHC database. If a copy of ghc.txt was publicly available somewhere (and updated on some schedule), I'd be happy to make the official Hoogle server search it. Usually I just grab databases off Hackage, but I'll happily make an exception for GHC. Thanks, Neil On Sun, Mar 6, 2011 at 7:52 AM, Malcolm Wallace malcolm.wall...@me.com wrote: The final stumbling block is getting the local webserver (hoogle server) to also search the above database. I'm sure there must be some simple way I can pass the name of the database as an argument when I boot up the server, but I can't seem to find it... Have you found the various versions of the web deployment procedure yet? deploy.txt: instructions to follow manually (seems to be up-to-date) deploy.sh: a shell script version to run locally (may be old) Deploy.hs: a haskell version to run remotely (may also be old) Obviously those scripts are tailored to the official installation, but there are some clues in there, for instance the steps cabal configure --datadir=/srv/web/haskell.org/hoogle/ --datasubdir=datadir -O2 and Upload datadir/resources to /srv/web/haskell.org/hoogle/datadir/resources Upload datadir/databases/* to /srv/web/haskell.org/hoogle/datadir/databases Regards, Malcolm ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: [Haskell-cafe] Cmdargs and common flags
{-# OPTIONS_GHC -fno-warn-missing-fields #-}
That's what I did in my CmdArgs test suite - if you have all your
CmdArgs bit in a separate file then missing this warning will be fine.
I don't know of any way to rewrite the code to indicate to GHC that
you know what you are doing.
Thanks, Neil
On Sat, Mar 12, 2011 at 8:02 AM, Magnus Therning mag...@therning.org wrote:
On Mon, Feb 14, 2011 at 19:11, Neil Mitchell ndmitch...@gmail.com wrote:
Hi Magnus,
Finally, you can switch to the pure annotations. I will document them
shortly and give an example in System.Console.CmdArgs.Implicit, but
for now the details can be found at
http://hackage.haskell.org/packages/archive/cmdargs/0.6.7/doc/html/System-Console-CmdArgs-Annotate.html
I've added more details in:
http://hackage.haskell.org/packages/archive/cmdargs/0.6.8/doc/html/System-Console-CmdArgs-Annotate.html
http://hackage.haskell.org/packages/archive/cmdargs/0.6.8/doc/html/System-Console-CmdArgs-Implicit.html
The first link includes comparisons for pure/impure, and the second
gives a set of equivalences for converting between the two forms.
Thanks, Neil
I noticed that the form record Ctor {} [...] leads to a warning that
Ctor isn't initialised. The obvious way to remove the warning is to
call the constructor with all the arguments, but is there a more
convenient/terse way of achieving the same?
/M
--
Magnus Therning OpenPGP: 0xAB4DFBA4
email: mag...@therning.org jabber: mag...@therning.org
twitter: magthe http://therning.org/magnus
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: hoogling GHC
Hi Ranjit, It sounds like you've got quite far. Sadly the manual is a bit out of date with respect to generating databases, but generally you need to produce ghc.txt on your own (using tools such as GHC's make system), then you can do: hoogle convert ghc.txt default.hoo Then you can run the local server with: hoogle server --databases=. That will find databases from the current directory, and serve them. Alternatively, if you put ghc.hoo (or default.hoo) in $DATADIR/databases it will pick them up automatically (where $DATADIR is whatever Cabal configured it to be). If you name the database as default.hoo it will be searched by default, if you name it ghc.hoo then foo +ghc will search for foo in the GHC database. If a copy of ghc.txt was publicly available somewhere (and updated on some schedule), I'd be happy to make the official Hoogle server search it. Usually I just grab databases off Hackage, but I'll happily make an exception for GHC. Thanks, Neil On Sun, Mar 6, 2011 at 7:52 AM, Malcolm Wallace malcolm.wall...@me.com wrote: The final stumbling block is getting the local webserver (hoogle server) to also search the above database. I'm sure there must be some simple way I can pass the name of the database as an argument when I boot up the server, but I can't seem to find it... Have you found the various versions of the web deployment procedure yet? deploy.txt: instructions to follow manually (seems to be up-to-date) deploy.sh: a shell script version to run locally (may be old) Deploy.hs: a haskell version to run remotely (may also be old) Obviously those scripts are tailored to the official installation, but there are some clues in there, for instance the steps cabal configure --datadir=/srv/web/haskell.org/hoogle/ --datasubdir=datadir -O2 and Upload datadir/resources to /srv/web/haskell.org/hoogle/datadir/resources Upload datadir/databases/* to /srv/web/haskell.org/hoogle/datadir/databases Regards, Malcolm ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: [Haskell-cafe] Cmdargs and common flags
Hi Magnus, Finally, you can switch to the pure annotations. I will document them shortly and give an example in System.Console.CmdArgs.Implicit, but for now the details can be found at http://hackage.haskell.org/packages/archive/cmdargs/0.6.7/doc/html/System-Console-CmdArgs-Annotate.html I've added more details in: http://hackage.haskell.org/packages/archive/cmdargs/0.6.8/doc/html/System-Console-CmdArgs-Annotate.html http://hackage.haskell.org/packages/archive/cmdargs/0.6.8/doc/html/System-Console-CmdArgs-Implicit.html The first link includes comparisons for pure/impure, and the second gives a set of equivalences for converting between the two forms. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Cmdargs and common flags
Hi Magnus,
What you want is actually easier than you think!
To quote from
http://hackage.haskell.org/packages/archive/cmdargs/0.6.7/doc/html/System-Console-CmdArgs-Implicit.html:
Missing Fields: If a field is shared by multiple modes, it may be
omitted in subsequent modes, and will default to the previous value.
Therefore you can just do:
cmd1 = Cmd1 { foo = def = help .., ...}
cmd2 = Cmd2 { ...} -- never mention foo in Cmd2
cmdArgs [cmd1,cmd2]
And foo in Cmd2 will act exactly like you duplicated the definition
from foo in Cmd1. I use this feature regularly - it's a big time
saver.
Alternatively, you can use the tricks described by Kevin.
Finally, you can switch to the pure annotations. I will document them
shortly and give an example in System.Console.CmdArgs.Implicit, but
for now the details can be found at
http://hackage.haskell.org/packages/archive/cmdargs/0.6.7/doc/html/System-Console-CmdArgs-Annotate.html
To translate your cmd1/cmd2:
cmd1 = record Cmd1{} [foo := def += help .., ...]
cmd2 = record Cmd2{} [foo := def += help .., ...]
And then call cmdArgs_ instead. Now you can do anything that
equational reasoning supports without any danger:
cmd1 = record Cmd1{} [myfoo, ...]
cmd2 = record Cmd2{} [myfoo, ...]
myfoo = foo := def += help ..
Even when using the pure annotations, you can still use missing fields:
cmd1 = record Cmd1{} [foo := def += help .., ...]
cmd2 = record Cmd2{} [...]
Thanks, Neil
On Mon, Jan 24, 2011 at 8:50 PM, Kevin Quick qu...@sparq.org wrote:
Magnus,
I used the following technique, but it was a couple of iterations of CmdArgs
ago:
data UIMode = Normal | Batch | Query deriving (Data,Typeable,Show,Eq)
uimode_arg :: forall t. t - UIMode
uimode_arg _ = enum Normal
[ Batch = flag B text batch mode (no interaction)
group grp
, Query = flag Q
text query mode (user verification solicited)
group grp
]
where grp = Operating Mode
data Globalargs = CMD1 { ... , uimode :: UIMode , ... }
| CMD2 { ... , uimode :: UIMode , ... }
cmd1mode :: Mode Globalargs
cmd1mode = mode $ CMD1 { ... , uimode = uimode_arg cmd1 }
= text (usage ...)
cmd2mode :: Mode Globalargs
cmd2mode = mode $ CMD1 { ... , uimode = uimode_arg cmd2 }
= text (usage ...)
modes :: [ Mode Globalargs ]
modes = [ cmd1mode, cmd2mode ]
main = do cmdArgs progSummary modes
...
I've cut and pasted from my usage and perhaps pasted too little, so let me
know if the above is unuseably brief. And again, cmdargs has changed
somewhat since this code was written and I haven't tried a recent
compilation.
-KQ
P.S. This often required {-# OPTIONS_GHC -fno-full-laziness -fno-strictness
#-} because GHC (6.12? 6.10?) would complain about my uimode_arg type
otherwise.
On Thu, 20 Jan 2011 01:48:35 -0700, Magnus Therning mag...@therning.org
wrote:
I'm looking for a good way of dealing with common flags in cmdargs.
Currently what I do requires a bit of repetition that I'd really like
to get rid of:
1. Data types
data Modes = Cmd1 { foo :: String, ... } | Cmd2 { foo :: String, ... }
2. Mode specifications
cmd1 = Cmd1 { foo = def = help .., ...}
cmd2 = Cmd2 { foo = def = help .., ...}
I have no idea how to deal with the repetition in the data types, so
all suggestions are welcome.
For the repetition in the mode specifications I attempted to factor
the common bits into a variable:
flagFoo = = help ..
but that resulted in only the first command getting the proper
specification. I suppose this comes down to the impurity, but how do
I work around that? (Especially, are there any good examples of using
the pure part of the API?)
/M
--
-KQ
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: Release/git plans
Hi Austin, The compiler plugins work is a great, and I'd be a likely user. The original version wasn't supported on Windows, because GHC on Windows lacked various forms of dynamic linking. Does the current patch you've prepared work on Windows? Thanks, Neil On Sat, Jan 22, 2011 at 10:29 AM, Max Bolingbroke batterseapo...@hotmail.com wrote: On 21 January 2011 23:59, austin seipp a...@hacks.yi.org wrote: Perhaps Max can elaborate on why this design was rejected in favor of the current one, so we can see how and where it falls down, and what we really want. The only reason really is that it added a lot of mechanism. From the top of my head: * Parsing etc for PHASE pragmas that declared phase objects * A new namespace for phases * Stuff to gather declared phases from all imported modules during compilation * A built-in phase for each core pass * A solver that ordered core passes and plugin passes according to the phases So it was a lot of trouble for relatively little gain. In an effort to keep the delta against GHC small I threw it out in favour of the much, much simpler design we have today. Thomas pointed out the Scala compiler plugin design document, so I'll be sure to read over it this weekend when I get the chance to cook up ideas. The Scala plugins project was just starting when I was working on GHC plugins so there was no design doc I could refer to at that time. Shame :-( Thanks for taking the lead on resurrecting plugins, Austin! Cheers, Max ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
[Haskell-cafe] Community.haskell.org is down
http://www.downforeveryoneorjustme.com/http://community.haskell.org Currently community is down for me. I remember some infrastructure/website strike team was set up, but I couldn't find where to get in contact with them? Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] parsec2 vs. parsec3... again
This isn't completely without basis. For instance, I made some big speed improvements to attoparsec's very performance-sensitive takeWhile function just the other day, thanks to -auto-all. I might, though, see if there's a way I could enable that flag only for myself (in a way that I wouldn't routinely forget). See ~/.cabal/config - I use that to make sure all my packages are installed globally with profiling, and I think it might have enough options to force -auto-all in some way. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] hoogle command line program on Linux
On Mon, Jan 10, 2011 at 10:17 PM, Neil Mitchell ndmitch...@gmail.com wrote: If so, I'll make a new release that just changes the file creation mask to the above during hoogle data (and sets it back after). Thanks to Erik's help testing preview versions I've now released Hoogle 4.1.4 that sets the file creation mask appropriately. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] hoogle command line program on Linux
Thanks to Erik's help testing preview versions I've now released Hoogle 4.1.4 that sets the file creation mask appropriately. Shouldn't data like this really go in /var rather than /usr ? To quote Wikipedia [1]: /var/: Variable files—files whose content is expected to continually change during normal operation of the system—such as logs, spool files, and temporary e-mail files. The Hoogle databases are expected to change very rarely - most users will install them when they install Hoogle. A small number will update them occasionally as the packages update. I'm using the Cabal datadir to store the databases, but does Cabal provide a more sensible place to put them? As a Windows user, I'm happy to defer to what Posix system users want. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Needed: A repeatable process for installing GHC on Windows
Earlier today I was trying to set up a Windows build bot for the 'network' package. That turned out to be quite difficult. Too much playing with PATHs, different gcc versions, etc. Does anyone have a repeatable, step-by-step process to install GHC and get a build environment (where I could build network) going? No, but I used to (and sadly can't find it any more). I used to have a script called ghcsetup which built GHC on Windows, and importantly validated the setup was correct (the right gcc was first in the path etc) and took actions to correct it. I am sure there used to be a great web page on the GHC wiki, saying the exact steps to build (written by Claus), but I can't find it any more. Perhaps Claus knows where it has gone? Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] hoogle command line program on Linux
Hi Joachim, The Hoogle databases are expected to change very rarely - most users will install them when they install Hoogle. A small number will update them occasionally as the packages update. I'm using the Cabal datadir to store the databases, but does Cabal provide a more sensible place to put them? As a Windows user, I'm happy to defer to what Posix system users want. shouldn’t they change with every library update? In that case, maybe that should be managed by cabal, similar to how cabal can update your haddock index at ~/.cabal/share/doc/index.html. Yes, that's exactly how it should work. All we need is someone to do the work :-) There is a bug tracking the progress on this issue here: http://code.google.com/p/ndmitchell/issues/detail?id=80 - but its a reasonable amount of work, touching lots of different parts of the Haskell infra. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: RFC: migrating to git
As another non-GHC contributor, my opinion should probably also count for little, but my experience with git has been poor. I have used git daily in my job for the last year. Like Simon PJ, I struggle to understand the underlying model of git, despite reading quite a few tutorials. I have a high failure rate with attempting anything beyond the equivalents of darcs record, push, and pull. I'm in exactly the same camp as Malcolm. I don't understand git, and I end up deleting the entire repo and starting again every time I try and do anything clever - something I've never needed to do with darcs. I consider the git equivalent of darcs unrecord to be rm -rf, but I'm sure that's a lack of knowledge/intuition on my part. All my git dislike aside, I wouldn't worry about git and Windows. GHC on Windows already drags in plenty of dependencies from Cygwin or Mingw, both of which provide workable git binaries, and none of which ever seem to have caused a problem. The standard gui's (gitk and git gui) both work on Windows, and I certainly miss them when using darcs. Thanks, Neil ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: [Haskell-cafe] hoogle command line program on Linux
If so, I'll make a new release that just changes the file creation mask to the above during hoogle data (and sets it back after). That makes sense. If you have a darcs repo of the code (or even a tarball), I can check it before create a package. That would be very useful. I'll try and update the darcs version tomorrow and let you know when it's done. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] hoogle command line program on Linux
Hi Erik, I'll release Hoogle 4.1.3 with a fix later today. Thanks, Neil On Sun, Jan 9, 2011 at 5:07 AM, Erik de Castro Lopo mle...@mega-nerd.com wrote: Hi all, I'm testing out hoogle 4.1.2 on Debian Linux and getting the following when trying to update the local hoogle databases: erik sudo hoogle data Starting default Starting keyword hoogle: keyword.txt: commitAndReleaseBuffer: invalid argument (Invalid or incomplete multibyte or wide character) My LANG related envorinment variables are set as follows: erik env | grep LANG LANG=en_AU.UTF-8 GDM_LANG=en_AU.UTF-8 LANGUAGE=en_AU.UTF-8 LC_LANG=en_AU.UTF-8 When faced with a similar problem while working on Ben Lippmeier's compiler, I fixed this by replacing all instances of readFile with readUtf8File which is defined as: readUtf8File :: FilePath - IO String readUtf8File filePath = do h - openFile filePath ReadMode hSetEncoding h utf8 hSetEncoding stdout utf8 hGetContents h Is it possible to fix this without hacking the hoogles sources? I'd like to package hoogle for Debian, but first I need to get it working. Cheers, Erik -- -- Erik de Castro Lopo http://www.mega-nerd.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] hoogle command line program on Linux
Hi Erik, Hoogle 4.1.3 is now released, which reads and writes Hoogle input files in UTF8 throughout. Please let me know if this doesn't fix your problem. Thanks, Neil On Sun, Jan 9, 2011 at 11:22 AM, Neil Mitchell ndmitch...@gmail.com wrote: Hi Erik, I'll release Hoogle 4.1.3 with a fix later today. Thanks, Neil On Sun, Jan 9, 2011 at 5:07 AM, Erik de Castro Lopo mle...@mega-nerd.com wrote: Hi all, I'm testing out hoogle 4.1.2 on Debian Linux and getting the following when trying to update the local hoogle databases: erik sudo hoogle data Starting default Starting keyword hoogle: keyword.txt: commitAndReleaseBuffer: invalid argument (Invalid or incomplete multibyte or wide character) My LANG related envorinment variables are set as follows: erik env | grep LANG LANG=en_AU.UTF-8 GDM_LANG=en_AU.UTF-8 LANGUAGE=en_AU.UTF-8 LC_LANG=en_AU.UTF-8 When faced with a similar problem while working on Ben Lippmeier's compiler, I fixed this by replacing all instances of readFile with readUtf8File which is defined as: readUtf8File :: FilePath - IO String readUtf8File filePath = do h - openFile filePath ReadMode hSetEncoding h utf8 hSetEncoding stdout utf8 hGetContents h Is it possible to fix this without hacking the hoogles sources? I'd like to package hoogle for Debian, but first I need to get it working. Cheers, Erik -- -- Erik de Castro Lopo http://www.mega-nerd.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] hoogle command line program on Linux
Hi Erik, The next problem is that hoogle installed as a Debian package would install as root as /usr/bin/hoogle. Then, when I run hoogle data it wants to install the database at /usr/share/hoogle/hoogle-4.1.3/databases which fails because I'm not running as root. So, to install the databases I need to run sudo hoogle data (which is acceptable), but then an unprivelidge user can't run hoogle because they don't have read permission on the database. The solution would be to set the umask before writing the databases. Something like (untested): import System.Posx -- Set umask to world read/execute. Save old umask for -- restoration later. oldumask - setFileCreationMask 0o022 Should all files created by hoogle data always have world read/execute? I'm not sure what the Unix conventions are - would that be reasonable? If so, I'll make a new release that just changes the file creation mask to the above during hoogle data (and sets it back after). Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] A question regarding cmdargs package
Hi Sönke, helpArg [groupname Something] should work, but it sounds like it doesn't. I've raised a bug: http://code.google.com/p/ndmitchell/issues/detail?id=392 I'll probably have this fixed in about a week. Thanks, Neil On Thu, Dec 30, 2010 at 4:05 PM, Sönke Hahn sh...@cs.tu-berlin.de wrote: That i18n is a fantastic argument - and one that really means cmdargs has no choice but to support all the attributes on help/version. Is it possible to change the groupname for the implicit help and version options? I have defined some options with groupname development flags, but I would want to have another groupname for help and version. (Or -- even better -- have them included in the Common flags section. I toyed around with something like 'helpArg [groupname Something]', but without success. Thanks, Sönke (Using System.Console.CmdArgs.Implicit from cmdargs-0.6.5.) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] A question regarding cmdargs package
Hi Sönke, I've just released cmdargs-0.6.6 which supports helpArgs [groupname Something] Thanks, Neil On Thu, Dec 30, 2010 at 5:09 PM, Neil Mitchell ndmitch...@gmail.com wrote: Hi Sönke, helpArg [groupname Something] should work, but it sounds like it doesn't. I've raised a bug: http://code.google.com/p/ndmitchell/issues/detail?id=392 I'll probably have this fixed in about a week. Thanks, Neil On Thu, Dec 30, 2010 at 4:05 PM, Sönke Hahn sh...@cs.tu-berlin.de wrote: That i18n is a fantastic argument - and one that really means cmdargs has no choice but to support all the attributes on help/version. Is it possible to change the groupname for the implicit help and version options? I have defined some options with groupname development flags, but I would want to have another groupname for help and version. (Or -- even better -- have them included in the Common flags section. I toyed around with something like 'helpArg [groupname Something]', but without success. Thanks, Sönke (Using System.Console.CmdArgs.Implicit from cmdargs-0.6.5.) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] OT: Monad co-tutorial: the Compilation Monad
Er, it works for me. Maybe *your* DNS has been hijacked? I know lots of Windows viruses play tricks like this... No, the DNS for haskell.org was down yesterday - if you try again today (after the DNS caches have cleared) it will work. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Rendering of hask in new wiki (MSIE6)
Hi In general I'd say that MSIE should be avoided and updated to newer version like 7 or 8 (according to wikipedia they should be avaible for Windows XP - or at least they were available when Windows XP was supported) - IE6 have technology from 2001. I understand however that it may be outside your control (maybe portable Fx would be solution?) I strongly agree that MSIE 6 should be avoided, but for many company networks it's required. The big problem isn't that 16% (or whatever) of people use it, it's that while technical people will use a modern and powerful browser, many non-technical managers will just use the default settings/systems, and it gives a bad impression if when told that Haskell is a great tool a manager looks up haskell.org and sees a messy splat. For reference, the new Haddock style also gives various rendering issues in IE6. I reported these a while back (to Mark) but never got any response. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Weird error during derive-2.3.0.2 build
Hi Alex, The latest version of derive is 2.4.1, which has a number of compile fixes for newer compilers. Any package I maintain is tested on GHC 6.10.4, 6.12.3 and 7.0.1 - so this bug should not be present in 2.4.1. Thanks, Neil On Sun, Dec 12, 2010 at 10:07 PM, Alex alex.s...@gmail.com wrote: Hi all. I am trying to install the yi editor using cabal-install, which in turns installs the package 'derive-2.3.0.2'. I get the following error during derive's compilation: [53 of 58] Compiling Data.Derive.Internal.Traversal ( Data/Derive/Internal/Traversal.hs, dist/build/Data/Derive/Internal/Traversal.o ) Data/Derive/Internal/Traversal.hs:34:0: Illegal instance declaration for `Applicative (Writer w)' (All instance types must be of the form (T t1 ... tn) where T is not a synonym. Use -XTypeSynonymInstances if you want to disable this.) In the instance declaration for `Applicative (Writer w)' cabal: Error: some packages failed to install: derive-2.3.0.2 failed during the building phase. The exception was: ExitFailure 1 Of course, I tried to build it with --ghc-option=-XTypeSynonymInstances, which in turn gives another compilation error. I am using ubuntu maverick 32-bit, with ghc-6.12.1 and cabal-install 0.8.2. The ghc was installed from the package repository. Cabal was installed using: cabal-install cabal Alex. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Question about TagSoup
Hi David,
I see no reason not to use TagSoup for this, assuming it does what you
want. It wasn't really designed for either modification or round
tripping, so be careful that things like entities don't become
corrupted. Also note that this won't replace all the contents of the
Content tag, only the first text node, so if someone writes
ContentiText/i/Content you won't hit it. But if it works, I'd
stick with it - it's light weight and easy to get to grips with.
Also your use of recursion seems perfectly reasonable. I often find
the easiest way to encode some kind of multiple element search (i.e.
for the Content tag and it's following text) is with direct
recursion - although I'm certain some kind of fold would also work.
Thanks, Neil
On Fri, Dec 3, 2010 at 1:45 PM, Alex Rozenshteyn rpglove...@gmail.com wrote:
I really wouldn't use tag soup for this. Haskell has libraries specifically
for XML processing which might be better suited to your needs.
On Fri, Dec 3, 2010 at 5:59 AM, David Virebayre dav.vire+hask...@gmail.com
wrote:
Hello café,
I have seen tutorials about extracting information from a tag soup, but I
have a different use case:
I want to read a xml file, find a tag, change its content, and write the
xml file back.
This is an example of the files
?xml version=1.0 encoding=UTF-8 standalone=yes?
idPkg:Story
xmlns:idPkg=http://ns.adobe.com/AdobeInDesign/idml/1.0/packaging;
DOMVersion=7.0
Story Self=ub9fad AppliedTOCStyle=n TrackChanges=false
StoryTitle=$ID/ AppliedNamedGrid=n
StoryPreference OpticalMarginAlignment=false
OpticalMarginSize=12 FrameType=TextFrameType
StoryOrientation=Horizontal StoryDirection=LeftToRightDirection/
InCopyExportOption IncludeGraphicProxies=true
IncludeAllResources=false/
ParagraphStyleRange
AppliedParagraphStyle=ParagraphStyle/prix
CharacterStyleRange
AppliedCharacterStyle=CharacterStyle/$ID/[No character style]
Contentzzznba5/Content
/CharacterStyleRange
/ParagraphStyleRange
/Story
/idPkg:Story
Assuming I want to change the content of the Content tag, this is what I
came up with (simplified), I'm using direct recursion. Is there a better way
?
ts = do
soup - parseTags `fmap` readFile idml/h00/Stories/Story_ub9fad.xml
writeFile test $ renderTagsOptions renderOptions{optMinimize = const
True}
$ modif soup
modif [] = []
modif (x@(TagOpen Content []):TagText _m : xs) = x : TagText modified
: modif xs
modif (x:xs) = x : modif xs
David.
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
--
Alex R
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell] haskell.org downtime: Tuesday Nov 30th
Hi Bas, Neil will be working on developing Hoogle all this weekend, but without Internet access. He expects to get it set up on the new server sometime during next week, but probably not before Weds. Ok thanks for the heads up! We get a new developer at work next week who needs to read through some of our Haskell code. It really helps to have Hoogle around for this type of thing. I'll tell him to install one locally. (Of course there's also Hayoo which is great also) With the darcs version of Hoogle running a local hoogle server is now trivial - just type hoogle server. With that you can build a version of Hoogle that indexes both hackage, along with whatever codebase you might use. Thanks, Neil ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
Re: [Haskell] haskell.org downtime: Tuesday Nov 30th
Thanks to a large portion of help from Ian, I now have Hoogle working at http://new-www.haskell.org/hoogle/ The old Hoogle seems to have broken with a configuration error - not sure if that's related to the move, or just the old server being flakey, but come tomorrow it won't matter. Thanks, Neil On Mon, Nov 29, 2010 at 10:01 PM, Bas van Dijk v.dijk@gmail.com wrote: On Mon, Nov 29, 2010 at 10:02 PM, Neil Mitchell ndmitch...@gmail.com wrote: Hi Bas, Neil will be working on developing Hoogle all this weekend, but without Internet access. He expects to get it set up on the new server sometime during next week, but probably not before Weds. Ok thanks for the heads up! We get a new developer at work next week who needs to read through some of our Haskell code. It really helps to have Hoogle around for this type of thing. I'll tell him to install one locally. (Of course there's also Hayoo which is great also) With the darcs version of Hoogle running a local hoogle server is now trivial - just type hoogle server. With that you can build a version of Hoogle that indexes both hackage, along with whatever codebase you might use. Thanks, Neil Nice, thanks! ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
Re: Add haskell-src as an official machine-readable component of the Haskell standard
There is nothing to stop an library author doing exactly this, and it might even be useful for some people (personally I'm going to stick to haskell-src-exts, because it's a brilliant library). However, I don't think we should make it official or part of the standard. I've found plenty of HSE/GHC parsing differences in my work, and my suspicion is that several of them are probably also present in haskell-src. I also don't want the Haskell Prime Committee to take on the jobs of library maintainership or implementation, those are best kept elsewhere. Thanks, Neil On Tue, Nov 16, 2010 at 9:13 AM, Yitzchak Gale g...@sefer.org wrote: I propose that the haskell-src package be renamed haskell20nn-src for each revision Haskell 20nn of the standard, and be made an official machine-readable component of the standard. This has the following advantages: 1. It would require almost no extra work, because haskell-src already exists, and syntax changes, if any, will be very minimal for each revision. 2. For the portion of the standard that it covers, any ambiguity that might creep into the human-readable standard document would be resolved. 3. It would serve as a basic machine-verification tool which is easily extensible. 4. As a side-effect, the haskell-src package would be continually maintained. The package is useful in its own right as a much lighter-weight version of haskell-src-exts. It is much easier to use when an application does not require full support of all of Haskell's syntax. This proposal is a natural extension of a proposal raised on the libraries mailing list in the context of the Haskell Platform: Ian Lynagh proposed that the current haskell-src-exts be renamed haskell-src (and included in the Haskell Platform, as suggested by Sterling Clover), and that the current haskell-src be renamed to haskell98-src (and removed from the Platform). The libraries subthread is here: http://www.haskell.org/pipermail/libraries/2010-November/015018.html Thanks, Yitz ___ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime ___ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime
[Haskell-cafe] Space not reclaimed by GC
Hi,
I have a program which runs, then calls performGC multiple times. I'd
expect all (or nearly all) of the memory to be freed by that point.
But it isn't.
Given this program:
import Language.Haskell.Exts.Annotated -- from haskell-src-exts
import System.Mem
main :: IO ()
main = do
let src = fromParseResult $ parseFileContents $ data C = C {a ::
F {- ++ replicate 40 'd' ++ -} }
putStrLn $ Total length is: ++ show (length $ show $ src)
performGC
performGC
performGC
I run with: ghc --make Temp.hs -rtsopts Temp.exe +RTS -G1 -S (the
use of 1 generation is to make sure all GC's clear up everything, the
leak still happens without it). I am using GHC 7.0.1
I get the output:
AllocCopied LiveGCGC TOT TOT Page Flts
bytes bytes bytes user elapuserelap
... lots of values ...
16187336 9598808 9600428 0.05 0.060.470.6600 (Gen: 0)
19513288 11571104 11572724 0.06 0.070.550.7700 (Gen: 0)
23519176 13948292 13949912 0.09 0.080.670.8900 (Gen: 0)
Total length is: 4226
24645752 548 2091128 0.00 0.000.750.9800 (Gen: 0)
20 540 2091120 0.00 0.000.750.9900 (Gen: 0)
0 540 2091120 0.00 0.000.751.0000 (Gen: 0)
1288 844 3028 0.00 0.000.751.0100 (Gen: 0)
0 0.00 0.00
162,592,312 bytes allocated in the heap
81,004,756 bytes copied during GC
13,949,912 bytes maximum residency (30 sample(s))
226,344 bytes maximum slop
63 MB total memory in use (6 MB lost due to fragmentation)
Generation 0:30 collections, 0 parallel, 0.48s, 0.51s elapsed
INIT time0.02s ( 0.02s elapsed)
MUT time0.25s ( 0.47s elapsed)
GCtime0.48s ( 0.51s elapsed)
EXIT time0.00s ( 0.00s elapsed)
Total time0.75s ( 1.01s elapsed)
%GC time 64.6% (50.6% elapsed)
Alloc rate613,093,182 bytes per MUT second
Productivity 33.3% of total user, 24.7% of total elapsed
QUESTION 1: My reading of this report is that performGC leaves 2091120
of live data. However, the program seems to run a GC on termination,
when only 3028 bytes of data are left. Why is all the data not
released on performGC?
QUESTION 2: It seems that the haskell-src-exts parser has some kind of
space leak in data C = C {a :: F {- d -} }, but not in data C =
C {a :: F} {- d -}. That's fair enough, but is it because it's a
space leak that performGC doesn't get the data? If I change to the
second form then the in use memory after performGC is about 3Kb.
I found that if I did the parseFileContents/print bit once I get 2Mb
of leak, if I do it twice I get 2Mb, and if I do it three times I get
1Mb of leak, which really confused me.
Thanks, Neil
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] RegEx versus (Parsec, TagSoup, others...)
I've been working on a project that requires me to do screen scraping. If you are screen scraping HTML I think tagsoup is a very good choice. The use of tagsoup means that you have a real HTML 5 compliant parser underneath, and then you can use whatever technique you wish to split up the page text - and regular expressions/parsec might be a reasonable choice. I've written lots of screen scraping stuff with tagsoup, and it's usually very easy - the manual even walks you through a couple of examples: http://community.haskell.org/~ndm/darcs/tagsoup/tagsoup.htm He's very experienced, and comes from a Perl perspective. I let him into what I was doing, and he opined I should be using pcre. When all you have is a hammer, everything looks like a thumb. Structured manipulation of algebraic data types is trivial in Haskell, and much less natural in Perl, so they use different techniques in different places. So now I'm second guessing my choices. Why do people choose not to use regex for uri parsing? If you mean HTML parsing, then it's because it's a nightmare to get right, and people on the web do all kinds of crazy stuff. A correct regular expression to match an HTML tag is lots of work. Given that it's a solved problem, why go to all that effort. It is possible to do with regular expressions, but not pleasant. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] xml packages
First question. As I saw in sources, both hxt and haxml uses [Char]'s. this is very inefficient. I want to know, does any effective parser for haskell, written in haskell, exists. The TagSoup parser can generate ByteString syntax trees - but they're quite a bit slower than [Char] versions. I am planning to speed up the ByteString version in the future: http://code.google.com/p/ndmitchell/issues/detail?id=290 Efficient means using ByteString to store strings and possibly building representations that shares one string for all similiary named elements. If there is no, is anyone interested in writing one? I intend to do that in TagSoup, and it can even be done now by running a Map state over the available strings with fmap. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: MonoLocalBinds and darcs
Hi Ganesh, Make sure you are using RC2 of the compiler, from what I remember RC1 required signatures it shouldn't have, or enabled MonoLocalBinds more than it should - RC2 required less signatures. However, your code could well just be heavily using the relevant features. Thanks, Neil On Tue, Nov 2, 2010 at 1:28 PM, Sittampalam, Ganesh ganesh.sittampa...@credit-suisse.com wrote: Simon Marlow wrote: On 02/11/2010 07:37, Sittampalam, Ganesh wrote: I've just been updating darcs 2.5 for GHC 7.0. I had to add about 40 signatures for MonoLocalBinds in about 140 files/30K LOC. Is that about normal? darcs does make fairly heavy use of rank 2 polymorphism which leads to quite a lot of local definitions needing to be polymorphic. Sounds about right given my experience so far, but as you say it depends a lot on the style of code involved. Some people tend to write a lot more polymorphic local bindings than others :-) In the case of darcs much of the fundamental structure of the code pushes us that way; code that works on repositories is written as withRepository (some polymorphic function) so that it's generic on the specific repository type, and since where clauses generally scope outside the withRepository they get bitten. Similarly our witnesses lists of patches have map operations with rank-2 types. Also, NoMonoLocalBinds didn't help at all, which surprised me a bit - I thought it might at least make some of the signatures unnecessary. I suspect MonoLocalBinds is being turned on again by an option later in the ordering. I had this problem a lot when trying to use NoMonoLocalBinds, it's actually quite hard to make it stick. e.g. if you have LANGUAGE GADTs in the source file, that will override NoMonoLocalBinds on the command line. Ahh. I'd put it as the first option! I'm not sure what (if anything) we should do about this. It intuitively feels like language specifiers should be order-independent, but when you have positive and negative extensions like we do that's not trivial to achieve. Perhaps we could do better if more combinations were errors instead of taking the last selection. Also, perhaps options that imply other options could be decomposed into the underlying pieces, with the high-level options being aliases for baskets of the lower-level ones. So GADTs = GADTsCore + MonoLocalBinds, and then GADTS + NoMonoLocalBinds (in any order) = GADTsCore + MonoLocalBinds + NoMonoLocalBinds = an error. Finally, is NoMonoLocalBinds supposed to imply NPlusKPatterns? The only changes I was able to revert when I enabled it were a couple of those! It certainly is not, if you have evidence to the contrary please submit a bug report. OK, I'll check. Cheers, Ganesh === Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html === ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: [Haskell-cafe] trying to use Tag Soup - fromAttrib
Hi Michael, If you just replace all 'str' with 'String' when reading the signature then that will almost certainly be sufficient for your purposes. So read it as: fromAttrib :: String - Tag String - String Where Tag String can be thought of as just Tag. If you try to parse HTML with regular expressions you'll probably find it much harder than using tagsoup. As one of the previous commenter's guessed, Show is indeed required only for nice error messages. I think it's also probably redundant, since StringLike has a toString style method on it anyway. Thanks, Neil On Tue, Nov 2, 2010 at 10:04 PM, Michael Litchard mich...@schmong.org wrote: Ah thank you. I can go ahead and figure out how to parse that string. Using a regex is tempting but I have a feeling I can get something more maintainable if I use another approach. On Tue, Nov 2, 2010 at 2:52 PM, Daniel Schoepe daniel.scho...@googlemail.com wrote: Excerpts from Michael Litchard's message of Tue Nov 02 22:40:27 +0100 2010: Daniel, Thank you for your reply. I'm still confused. When I see a code sample like this main = do posts - liftM parseTags (readFile posts.xml) print $ head $ map (fromAttrib Id) $ filter (~== (row OwnerUserId= ++ userid ++ )) posts I have no idea how to match that up with what you said. The usage of fromAttrib here doesn't match up with what I htink the type signature is saying. fromAttrib :: (Show str, Eq str, StringLike str) = str - Tag str - str seems to say fromAttrib takes two parameters (I know it doesn't literally take two), one str (with the constraints in parenthesis to the left) and one str of type Tag, giving back a str. Then I look at the above code sample and can't match the two up. In the code sample, the first argument is Id, in which case the concrete type for the type variable str is String, and the second argument are the tags returned by the call to filter, which have type Tag String. The second parameter is not a str of type Tag, but Tag (which is a type constructor) applied to the same concrete type for str its first argument has. So in your case, calling fromAttrib href (TagOpen ...) Would give you /launchWebForward.do?resourceId=4policy=0returnTo=%2FshowWebForwards.do. To get the resourceId you want, you'd have to dissect this string further. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Idea for a tool
Hi Michael, I want this tool. I fake it slightly by using my RSS reader and http://page2rss.com/ to get notified when any packages I depend on change, which basically works - but if you could provide a better service (ideally integrated in to hackage), I'd use it. Thanks, Neil On Wed, Oct 20, 2010 at 8:27 AM, Bas van Dijk v.dijk@gmail.com wrote: On Wed, Oct 20, 2010 at 7:36 AM, Michael Snoyman mich...@snoyman.com wrote: Hi all, I saw a quote from Eric Kow via Neil Mitchell[1] that we don't spend enough time writing tools. Well, I've decided that the most annoying part of package maintainership right now is staying on top of new versions of dependencies. We essentially have two options right now: * Follow the PVP and put an upper bound on all dependencies, and people will be upset when your package only works with the old version of the dependency. * Skip the upper bound, and risk having your code break when there's a new version. I have an idea for a tool: you give it a list of packages you maintain, or even better yet, you give it your email address and it gets that list automatically. Then is looks through all your dependencies and sees if you have any upper bounds preventing newer versions from being used. Bonus points for making it a web service that just gives you an RSS feed. If anyone's interested in writing a tool like that, let me know. Otherwise, next time I'm twiddling my thumbs I'll try to throw it together. I've never dealt directly with the Cabal library, but there's a first time for everything. If someone else wants to write that tool and wants help sticking a web service on it, let me know. Michael [1] http://neilmitchell.blogspot.com/2010/10/enhanced-cabal-sdist.html ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe This would be a nice feature for the new hackage server: http://sparky.haskell.org:8080 Bas ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: un-used record wildcards
Hi Simon,
I've seen this issue with GHC 6.12.3 (and assumed it was by design).
It occurs with a slight modification of your example:
{-# LANGUAGE RecordWildCards #-}
module Test where
data T = MkT { f,g :: Int }
p x = let MkT{..} = x in f
This example warns about Defined but not used: `g' on the line
defining p. I've raised a GHC bug:
http://hackage.haskell.org/trac/ghc/ticket/4411 about this warning.
Thanks, Neil
Which version of GHC are you using? GHC 6.12 does not complain about unused
variables bound by ... Try this, which complains about y, but not g.
Simon
{-# LANGUAGE RecordWildCards #-}
module Test where
data T = MkT { f,g :: Int }
p (MkT { .. }) y = f
| -Original Message-
| From: glasgow-haskell-users-boun...@haskell.org
[mailto:glasgow-haskell-users-
| boun...@haskell.org] On Behalf Of Serge D. Mechveliani
| Sent: 14 October 2010 11:01
| To: Antoine Latter
| Cc: glasgow-haskell-users@haskell.org
| Subject: Re: un-used record wildcards
|
| On Wed, Oct 13, 2010 at 01:47:11PM -0500, Antoine Latter wrote:
| On Wed, Oct 13, 2010 at 1:02 PM, Serge D. Mechveliani mech...@botik.ru
| wrote:
| Dear GHC developers,
|
| I use the language extension of RecordWildcards, for example,
| f (Foo {foo1 = n, foo2 = m, ..}) = ...
|
| But the complier warns about un-used values of foo3, foo4,
| probably, due to the extension of
| Foo {foo1 = n, foo2 = m, foo3 = foo3, foo4 = foo4}.
|
| In such cases, these warnings look as unneeded.
| Is it possible to have an un-used binding warnings with exception for
| wildcards in records?
| If not, then has it sense to introduce an option?
|
|
| If you're not using foo3 and foo4, can you not put it the ellipsis?
| that won't cover every case (such as where you're using foo3 but not
| foo4).
|
| Antoine
|
|
| Indeed, thank you.
| It occurs that under RecordWildcards the compiler allows to skip some
| record fields in a pattern.
| ___
| Glasgow-haskell-users mailing list
| glasgow-haskell-us...@haskell.org
| http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
___
Glasgow-haskell-users mailing list
Glasgow-haskell-users@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
___
Glasgow-haskell-users mailing list
Glasgow-haskell-users@haskell.org
http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: [Haskell-cafe] a couple of cabal related questions
I do this using a .ghci file. For Hoogle I have a file called Paths.hs with the module name Paths_hoogle and stub exports. I then have my .ghci file as: :load Main.hs Paths.hs Now Paths.hs will never interfere, or be picked up in ghc --make, because it has the wrong name - but is used in ghci. Thanks, Neil On Wed, Oct 13, 2010 at 6:45 AM, Antoine Latter aslat...@gmail.com wrote: On Tue, Oct 12, 2010 at 10:41 PM, Ivan Lazar Miljenovic ivan.miljeno...@gmail.com wrote: On 13 October 2010 02:00, Magnus Therning mag...@therning.org wrote: On Tue, Oct 12, 2010 at 15:34, Dmitry V'yal akam...@gmail.com wrote: By the way, the 'version' variable doesn't mentioned in Cabal user guide, or at least I missed it. Is it documented somewhere? I don't know, I think I found it in the source more or less by mistake :-) Yeah, I think that's the common consensus; there is _some_ documentation of the Paths_foo module in the Cabal user guide, but it doesn't cover much. One thing I do wish was possible: the ability to use a stub Paths_foo module for testing purposes (as currently you have to have done a cabal configure cabal build to get it), but I couldn't find a way to do so without Cabal packaging the stub version when creating the distribution tarball :s I've used CPP, something like: module MyPaths ( export contents of Paths_magic ) where #ifdef SOME_DEF_SET_BY_CABAL import Paths_magic #else mock implementation of paths magic here #endif Then in your .cabal file declare the define which causes it to use the real magic paths module. When not compiling via cabal, you'll at least have something sensible (like the current directory or something). I'm pretty sure I didn't make this up, but I have used it. It's a bit of a pain to set up, though. Antoine ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: A question regarding cmdargs package
This makes me curious. What's the use case where you want to allow the user to pass arguments on the command line, but you don't want that user to be able to use '--help' to find out what arguments may be passed? When you don't want to bother defining the help options/descriptions? :p (alternatively, you may wish to provide a more full-featured version like what darcs does by using a pager) You can already do this with CmdArgs. If you use cmdArgsMode/process it returns a structure populated to say what to do next (i.e. display a help message), but you are welcome to do something different, or do what it says in a different way. However, I can see some people might want to remove help entirely, so I'll try and find a balance. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Re: A question regarding cmdargs package
The point here was not so much removing --help, but rather that I want to have control over the 'standard' options (help,version,verbosity) in the same way as for the rest. My program might not have a version, so why offer --version? Or maybe I want a different name for it because the -V is already used for something else, which I cannot change for backwards compatibility. I might want another name for --help, for instance -h. The standard -? does not work in all shells/configurations and --help might look strange if all other options are of the one-dash-one-character sort. I would also like to configure the help text for the standard options, for instance for i18n or because I like starting with a lower case letter or... That i18n is a fantastic argument - and one that really means cmdargs has no choice but to support all the attributes on help/version. BTW another cool feature of an auto-magic option parsing lib is the GNU standard -- (arguments after this are not to be treated as options). cmdargs also supports this by default. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: A question regarding cmdargs package
Hi Ben, How can I disable the standard arguments 'help' and 'version'? In general I suggest you email the author of the cmdargs package directly, as well as cc'ing the mailing list (otherwise the author might miss this message, as I did!) In CmdArgs there is currently no way to suppress either --help or --version, but I am currently reviewing a patch (from you!) and expect that the next version will have both these features. The hard part is making sure the defaults match what people expect and that the options to modify the behaviour are discoverable and natural, but I'm sure I'll find something. Thanks, Neil If you're not fully committed to the cmdargs package, you might try my package 'console-program' instead http://hackage.haskell.org/package/console-program. It does not have built-in --help or --version functionality. (There is a function 'showUsage' that takes the description of the command/option structure of your program, and prints --help style usage information, but you use this at your own discretion.) Thanks, looks good. I will certainly try it out. Cheers Ben ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] HTML library with DOM?
Yes, I don't think I've officially announced a version of TagSoup that has had HTML 5 parsing, but it now does as standard for the last few releases. The HTML 5 spec is still changing, so it's entirely possible something is incorrect in a corner case, but please let me know and I'll fix it. Thanks, Neil 2010/10/7 Gregory Collins g...@gregorycollins.net: Michael Snoyman mich...@snoyman.com writes: As far as I know, Neil Mitchel's tagsoup[1] parses according to the HTML 5 parsing rules, but it just generates a list of Tags[2], so you'd have to build the DOM tree up from there. I personally have had great experience with tagsoup. It's even the core of HTML-scraping technology powering searchonce[3]. Yep, someone else wrote me privately to say this (that tagsoup respects the html5 lexing rules). So I'll be using this as the basis of an html5 DOM parser. Stay tuned! G -- Gregory Collins g...@gregorycollins.net ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Notes from Haskell takes over the world BoF at ICFP
Hi Digressing a little, can anyone interested in doing so merge hoogle and Hayoo and make them part of Hackage? I am currently working on this in my spare time. I hope to have something to show in the next month. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: EDSL for Makefile
Hi Telling from the video and the slide, Neil's make system is actually really cool. Indeed something I would really enjoy to use. Thanks :-) So you use want and need to tell the system about the static and dynamic dependencies. The want at the beginning just tells which targets to start. Since you may want to choose your task via command line, you actually would want to do something like: main = do wantDefault file1 = getArgs file1 * ... Yep, that's certainly one way of doing it (and a very natural way of doing it). Since using String everywhere for dependencies can lead to errors, it is always a good idea to replace the strings by constants you can reuse. You can also use wildcards everywhere (i.e. have a rule for *.exe), and then you only give each file once - but anyone duplicating any complex thing like a string more than once should either use a let or write a combinator on top of it - either works just fine. Shake is more kind of a library. If you want a more make-like System you can even write a preprocessor (like the haskell sinatra clone bird), which even looks for your target symbols and then generates a haskell file with target symbols replaced by Strings. It doesn't even need to generate a Haskell file, you can sequence these operations dynamically in a Monad and use Shake as a backend target for anything. Haskell is great :-) I hope the space leaks will be fixed in the future, so one can even write long running processes which automatically detect changes and rerun without user interaction and much more. Yes, although in practice you could probably already do it without issue. I think the space leak is incredibly shallow, and could be fixed in a few hours. I actually wonder about the semantic differences between want and need. Is need used to tell about dynamic dependencies and want for static dependencies? You could always do: PHONY * \_ - do need xs Instead of want xs, and have the system know about PHONY specially. want is a way of kicking off the initial set, and need is doing it after that - the real difference is the monad they run in and nothing else. The semantic idea is that want expresses that you the end user wants to have these files available, while the rules need to have files available before they continue - it's entirely possible they should be overloaded over the two monads. Thanks, Neil On 4 Okt., 05:41, C K Kashyap ckkash...@gmail.com wrote: mention_only_once file action = do want [file] file * action main = mention_only_once file1 $ \x - do need [file2] putStrLn Hello putStrLn World Thanks Bulat I guess even this should work - main = do let file1=file1 want [file1] file1 * \x - do need [file2] putStrLn Hello putStrLn World -- Regards, Kashyap ___ Haskell-Cafe mailing list haskell-c...@haskell.orghttp://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] EDSL for Makefile
I checked out the video - nice - but I think, understandably, since its not open source yet, not much of implementations details were mentioned. Yes, it's unfortunate. So, I have this unanswered question nagging in my head. In the example below, how can I let the makefile writer refer to the target name and dependencies. Likr Emil mentioned, I could use target r1 but I want to avoid having to mention r1. If it helps, written in Shake, this would be: main = do want [file1] file1 * \x - do need [file2] putStrLn Hello putStrLn World Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] EDSL for Makefile
Hi,
What great timing! I will be giving a talk at the Haskell Implementors
Workshop tomorrow about the Make system Shake. It will be video taped
and I can send you the slides after I've given the talk. So wait a
day, and I'll give you all the answers.
Thanks, Neil
On Thu, Sep 30, 2010 at 6:02 AM, Neil Brown nc...@kent.ac.uk wrote:
On 30/09/10 09:41, C K Kashyap wrote:
Hi All,
I was thinking about doing an EDSL for Makefile (as an exercise)
I put down my line of thought here -
http://hpaste.org/40233/haskell_makefile_edsl
I'd appreciate some feedback on the approach. Also, I wanted some idea
on how(in the current approach) I could make the target name and the
dependency available to the action writer - as shown below.
r1 = Rule {
target = file1,
dependsOn = [file2],
action = do
execute (gcc -c ++ dependencyList ++ -o ++
target)
}
Neil Mitchell gave a talk at AngloHaskell 2009 on doing a better make in
Haskell. I've found the abstract on the wiki:
http://www.haskell.org/haskellwiki/AngloHaskell/2009 but, alas, no slides to
be found. My memory was that he had implemented the system successfully for
internal use at a company and it had worked out quite well. Perhaps you can
contact him about the slides.
Thanks,
Neil.
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] EDSL for Makefile
What great timing! I will be giving a talk at the Haskell Implementors Workshop tomorrow about the Make system Shake. It will be video taped and I can send you the slides after I've given the talk. So wait a day, and I'll give you all the answers. Will you publish the tool too? ;-) No :-( [or at least not yet] Wait for the talk, and I'll explain more. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: BlockedIndefinitelyOnMVar exception
I wrote my Chan around the abstraction: data Chan a = Chan (MVar (Either [a] [MVar a])) The Chan either has elements in it (Left), or has readers waiting for elements (Right). To get the fairness properties on Chan you might want to make these two lists Queue's, but I think the basic principle still works. By using this abstraction my Chan was a lot simpler. With this scheme implementing isEmpyChan or unGetChan would both work nicely. My Chan was not designed for performance. (In truth I replaced the Left with IntMap a, and inserted elements with a randomly chosen key, but the basic idea is the same.) I like the idea. But what happens if one of the blocked threads gets killed by a killThread (e.g. a timeout) while it is waiting? Won't we still give it an element of the Chan sometime in the future? Perhaps this doesn't happen in your scenario, but it seems to throw a spanner in the works for using this as a general-purpose implementation. I hadn't thought of that at all - my scenario doesn't have any threads being killed. With the thought of threads dying concurrency abstractions become significantly harder - I hadn't quite realised how hard that must make it. Thanks, Neil ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: BlockedIndefinitelyOnMVar exception
Hi Simon, My suspicion for the root cause of the problem is that Concurrent.Chan is incorrect. In the course of debugging this problem we found 2 bugs in Chan, and while I never tracked down any other bugs in Chan, I no longer trust it. By rewriting parts of the program, including avoiding Chan, the bugs disappeared.I don't think I'll be using Chan again until after someone has proven in correct. Considering Chan is 150 lines of code and has been around for many years, that's amazing! Did you report the bugs? Is it anything to do with asynchronous exceptions? Nothing to do with async exceptions. I found: http://hackage.haskell.org/trac/ghc/ticket/4154 http://hackage.haskell.org/trac/ghc/ticket/3527 Of course, there's also the async exceptions bug still around: http://hackage.haskell.org/trac/ghc/ticket/3160 However, even after having a program with no async exceptions (I never used them), and eliminating unGetChan and isEmpyChan, I still got bugs. I have no proof they came from the Chan module, and no minimal test case was ever able to recreate them, but the same program with my own Chan implementation worked. My Chan had different properties (it queues items randomly) and a subset of the Chan functions, so it still doesn't prove any issue with Chan - but I am now sceptical. You should have more luck with Control.Concurrent.STM.TChan, incedentally. It's much easier to get right, and when we benchmarked it, performance was about the same (all those withMVar/modifyMVars in Chan are quite expensive), plus you get to compose it easily: reading from either of 2 TChans is trivial. The performance of the Haskell is irrelevant - the program spends all its time invoking system calls. Looking at the implementation I am indeed much more trusting of TChan, I'll be using that in future if there is ever a need. Thanks, Neil ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: BlockedIndefinitelyOnMVar exception
http://hackage.haskell.org/trac/ghc/ticket/4154 Yup, that's a bug. Not clear if it's fixable. http://hackage.haskell.org/trac/ghc/ticket/3527 That too. A very similar bug in fact, if there is a fix it will probably fix both of them. The problem is that readChan holds a lock on the read end of the Chan, so neither isEmptyChan nor unGetChan can work when a reader is blocked. I wrote my Chan around the abstraction: data Chan a = Chan (MVar (Either [a] [MVar a])) The Chan either has elements in it (Left), or has readers waiting for elements (Right). To get the fairness properties on Chan you might want to make these two lists Queue's, but I think the basic principle still works. By using this abstraction my Chan was a lot simpler. With this scheme implementing isEmpyChan or unGetChan would both work nicely. My Chan was not designed for performance. (In truth I replaced the Left with IntMap a, and inserted elements with a randomly chosen key, but the basic idea is the same.) own Chan implementation worked. My Chan had different properties (it queues items randomly) and a subset of the Chan functions, so it still doesn't prove any issue with Chan - but I am now sceptical. It's surprising how difficult it is to get these MVar-based abstractions right. Some thorough testing of Chan is probably in order. Agreed! In this project I wrote 8 different concurrency abstractions. I had bugs in most. MVar is a great building block on which to put higher layered abstractions, but using it correctly is tricky. I found that I used MVar's in four ways: 1) MVar's which are always full, and are just locks around data for consistency. Created with newMVar, used with modifyMVar. 2) MVar's which contain unit and are used for locking something other than data (i.e. a file on disk). Created with newMVar, used with withMVar. 3) MVar's which are used to signal computation can begin, created with newMVarEmpty, given to someone who calls putMVar (), and waited on by the person who created them. 4) MVar's which go in a higher-level concurrency operation - CountVars (variables which wait until they have been signaled N times), RandChan (Chan but with randomness), Pool (thread pool) etc. Thanks, Neil ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: BlockedIndefinitelyOnMVar exception
Hi Simon, Thanks for the excellent information. I've now debugged my problem, and think I've got the last of the MVar blocking problems out. * How confident are people that this exception does really mean that it is in a blocked state? Is there any chance the error could be raised incorrectly? There have been one or two bugs in the past that could lead to this exception being raised incorrectly, but I'm not aware of any right now. It's not inconceivable of course. I have no reason to think it's broken. I found at least 3 separate concurrency bugs in various parts (one added the day before, one over a year old, one of which had been introduced while trying to work around the MVar problem). My suspicion for the root cause of the problem is that Concurrent.Chan is incorrect. In the course of debugging this problem we found 2 bugs in Chan, and while I never tracked down any other bugs in Chan, I no longer trust it. By rewriting parts of the program, including avoiding Chan, the bugs disappeared.I don't think I'll be using Chan again until after someone has proven in correct. * Any debugging tips for this problem? I'd use the event log: compile with -debug, run with +RTS -Ds -l, and dump the event log with show-ghc-events (cabal install ghc-events). Or just dump it to stderr with +RTS -Ds, if the log isn't too large. Use GHC.Exts.traceEvent to add your own events to the trace. The event log is fantastic! Thanks, Neil ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: BlockedIndefinitelyOnMVar exception
My understanding was that this error occurred when one thread was blocked, waiting on an MVar, and no other thread in the program has a reference to that MVar (this can be detected during GC). Ergo, the blocked thread will end up waiting forever because no-one can ever wake it up again. That certainly seems a sensible rule - I'll see if that can help me debug my problem. Do you actually have use of MVars in your program directly, or are they being used via a library? And do you at least know which thread is throwing this exception? It should be catchable so you can probably wrap the arguments to your forkIO calls with a catcher than indicates which thread blew up. I use MVar's directly, use Chan/QSem, and have about 5 concurrency data types built on top of MVar's - they're everywhere. I also have a thread pool structure, so tasks move between threads regularly - knowing which thread got blocked isn't very interesting. Thanks for the information, Neil ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: [Haskell-cafe] TagSoup 0.9
Hi, From what I can tell of your example you've managed to get the raw HTTP response in Unicode, which isn't suitable for sending to tagsoup. I've not used the Network.HTTP library for downloading much, but when I did I thought it stripped the headers automatically. Can you just print the first few lines of the output you get from the HTTP library, without passing them through tagsoup. That should show the problem independent of tagsoup. Thanks, Neil On Mon, May 24, 2010 at 3:24 AM, Ralph Hodgson rhodg...@topquadrant.com wrote: Thanks Neil, Using Network.HTTP worked. However something else I have just run into concerns some web pages that start with: ?xml version=1.0 encoding=iso-8859-1? !DOCTYPE html PUBLIC -//W3C//DTD XHTML 1.0 Transitional//EN http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd; I get the following bad result: TagText HTTP/1.1 200 OK\r\nContent-Type: text/html\r\nLast-Modified: Tue, 27 Oct 2009 19:30:40 GMT\r\nETag: \6f248cf73b57ca1:25e2\\r\nDate: Sun, 23 May 2010 22:46:41 GMT\r\nTransfer-Encoding: chunked\r\nConnection: close\r\nConnection: Transfer-Encoding\r\n\r\n4000\r\n\255\254\NUL?\NULx\NULm\NULl\NUL \NULv\NULe\NULr\NULs\NULi\NULo\NULn\NUL=\NUL\\NUL1\NUL.\NUL0\NUL\\NUL \NULe\NULn\NULc\NULo\NULd\NULi\NULn\NULg\NUL=\NUL\\NULi\NULs\NULo\NUL-\NUL8\NUL8\NUL5\NUL9\NUL-\NUL1\NUL\\NUL etc etc Is this an easy thing to fix? I've started to look over the code. -Original Message- From: Neil Mitchell [mailto:ndmitch...@gmail.com] Sent: Wednesday, May 19, 2010 12:19 PM To: Ralph Hodgson Cc: Daniel Fischer; haskell-cafe@haskell.org; Don Stewart Subject: Re: [Haskell-cafe] TagSoup 0.9 Hi Ralph, I was using TagSoup 0.8 with great success. On upgrading to 0.9 I have this error: TQ\TagSoup\TagSoupExtensions.lhs:29:17: `Tag' is not applied to enough type arguments Expected kind `*', but `Tag' has kind `* - *' In the type synonym declaration for `Bundle' Failed, modules loaded: TQ.Common.TextAndListHandling. My change notes have this being a change between 0.6 and 0.8. As Malcolm says, any old uses of Tag should become Tag String. The reason is that Tag is now parameterised, and you can use Tag ByteString etc. However, I should point out that Tag ByteString won't be any faster than Tag String in this version (it's in the future work pile). Forgot to add: I now need to understand the following warnings on this line import Text.HTML.Download: Everyone's comments have been right. I previously included Text.HTML.Download so that it was easy to test tagsoup against the web. Since I first wrote that snippet the HTTP downloading libraries have improved substantially, so people should use those in favour of the version in tagsoup - you'll be able to connect to more websites in more reliable ways, go through proxies etc. I don't intend to remove the Download module any time soon, but I will do eventually. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] No copy XML parser (rough idea only)
Hi Joachim, I have been playing around with this idea myself in TagSoup (http://community.haskell.org/~ndm/tagsoup). The largest conceptual problem I came across was that TagSoup decodes entities (i.e. gt; becomes ). However, I think that's a minor issue, and entity resolution can be turned off in TagSoup to guarantee copy-free parsing. The practical problem is that writing an HTML parser is hard, and that writing it in a way that works on both String/ByteString/LBS and gets the copy-free behaviour in the right places is tricky. I am still working on program optimisation techniques that I think will make this feasible (based around the idea of supercompilation, to expose the underlying structure of the parser, without writing it in too painful a manner). So with any luck your copy-free XML parser will happen sooner or later. Thanks, Neil On Fri, May 14, 2010 at 8:20 PM, Joachim Breitner m...@joachim-breitner.de wrote: Hi, Am Freitag, den 14.05.2010, 15:31 -0300 schrieb Felipe Lessa: On Fri, May 14, 2010 at 08:57:42AM -0700, John Millikin wrote: Additionally, since the original bytestring is shared in your types, potentially very large buffers could be locked in memory due to references held by only a small portion of the document. Chopping a document up into events or nodes creates some overhead due to the extra pointers, but allows unneeded portions to be freed. However, if your bytestring comes from mmap'ed memory this drawback wouldn't apply :D. exactly. Of course such a library would not be a general-purpose tool, but in cases where you know that you need most of the document for most of the time, e.g. when doing statistics on it, this would be acceptable. Also note that even after chopping into nodes, if you don’t make sure you drop the reference to root in a timely manner, the same thing would happen. Am Freitag, den 14.05.2010, 08:57 -0700 schrieb John Millikin: The primary problem I see with this is that XML content is fundamentally text, not bytes. Using your types, two XML documents with identical content but different encodings will have different Haskell values (and thus be incorrect regarding Eq, Ord, etc). The instances could be adapted... but this will be expensive, of course. One could also convert documents that are not utf-8 encoded as a whole and then work on that. If you'd like memory-efficient text storage, using Bryan O'Sullivan's text package[1] is probably the best option. It uses packed Word16 buffers to store text as UTF-16. Probably not as efficient as a type backed by UTF-8, but it's much much better than String. Right. For arbtt, I tried to switch from String to text, and it actually got slower. The reason (I think) was that besides passing strings around, it mainly runs pcre-light on them – which wants utf8-encoded bytestrings. I ended up creating a newtype¹ around utf8-encoded ByteStrings and the result was quite satisfying, both memory- and runtime-wise. I wish we had a package providing a standard type for this type that would become similarly popular. There is at least one more packages on hackage that defines this type: http://hackage.haskell.org/packages/archive/regex-tdfa-utf8/1.0/doc/html/Text-Regex-TDFA-UTF8.html Greetings, Joachim ¹ http://darcs.nomeata.de/arbtt/src/Data/MyText.hs -- Joachim Breitner e-Mail: m...@joachim-breitner.de Homepage: http://www.joachim-breitner.de ICQ#: 74513189 Jabber-ID: nome...@joachim-breitner.de ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] TagSoup 0.9
Hi Ralph, I was using TagSoup 0.8 with great success. On upgrading to 0.9 I have this error: TQ\TagSoup\TagSoupExtensions.lhs:29:17: `Tag' is not applied to enough type arguments Expected kind `*', but `Tag' has kind `* - *' In the type synonym declaration for `Bundle' Failed, modules loaded: TQ.Common.TextAndListHandling. My change notes have this being a change between 0.6 and 0.8. As Malcolm says, any old uses of Tag should become Tag String. The reason is that Tag is now parameterised, and you can use Tag ByteString etc. However, I should point out that Tag ByteString won't be any faster than Tag String in this version (it's in the future work pile). Forgot to add: I now need to understand the following warnings on this line import Text.HTML.Download: Everyone's comments have been right. I previously included Text.HTML.Download so that it was easy to test tagsoup against the web. Since I first wrote that snippet the HTTP downloading libraries have improved substantially, so people should use those in favour of the version in tagsoup - you'll be able to connect to more websites in more reliable ways, go through proxies etc. I don't intend to remove the Download module any time soon, but I will do eventually. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] {-# LANGUAGE DeriveApplicative #-} ?
Hi, If you think you can write an algorithm for deriving Applicative, I'd welcome you to try adding it to Derive: http://community.haskell.org/~ndm/derive The Functor/Foldable/Traversable derivations all started out in Derive, got tested/implemented/refined there, then moved to GHC later. I think that's a reasonable path with any Applicative derivation. Thanks, Neil On Thu, May 6, 2010 at 11:53 AM, Ben Millwood hask...@benmachine.co.uk wrote: On Thu, May 6, 2010 at 8:55 AM, Pavel Perikov peri...@gmail.com wrote: Hi, list!. Now in 6.12.1 we have DeriveFunctor, DeriveFoldable and DeriveTraversable. This greatly simplifies the reuse structure style of programming. Some structure (not just _data_ structure) got captured in ADT and can be reused for various purposes. Wouldn't it be nice to have the ability to derive Applicative as well? It shouldn't be more difficult than deriving Functor but will provide exciting possibilities. Just think about liftA2. The difference is that there is at most one law-abiding instance of Functor for each type, whereas there are in principle multiple possible instances for Applicative for a type. E.g. the following: instance Applicative [] where pure x = [x] fs * xs = concatMap (\f - map f xs) fs instance Applicative [] where pure = repeat (f:fs) * (x:xs) = f x : fs * xs _ * _ = [] are both law-abiding instances (although only one has a corresponding law-abiding Monad, I believe). Which should GHC choose? It's worth noting, though, that there are other derivable classes that don't have a single implementation. It's a question of trading off complexity of the compiler versus saved effort in code versus additional clarity in code, I think. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Would it be evil to add deriving Typeable to newtype Q?
Hi Leonel,
You might want to try Derive
(http://community.haskell.org/~ndm/derive) if DrIFT doesn't work for
you. They do roughly the same jobs, but Derive has more output formats
(it can be spliced in as Template Haskell, generate #include files,
output text etc) more derivations (but not quite overlapping -
although both have Typeable), and is fully cabal-friendly on all
platforms.
Thanks, Neil
On Thu, May 6, 2010 at 3:42 PM, Leonel Fonseca leone...@gmail.com wrote:
Hey, the hint provided by Ben worked like a charm.
I've also tried Ivan suggestions both on my windows and linux installations.
DrIFT-cabalized couldn't install at all at windows since I don't use MinGW.
So, I ghc'ed --make DrIFT.
Both, windows and linux, refused to complete work with this error:
drift: can't find module Control/Monad
Thank you.
{-# LANGUAGE DeriveDataTypeable, StandaloneDeriving #-}
import Data.Typeable
import Language.Haskell.TH
deriving instance Typeable1 Q
--
Leonel Fonseca.
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell XML Parsers
Hi, You might want to take a look at TagSoup (http://community.haskell.org/~ndm/tagsoup) - it parses XML/HTML lazily returning a stream of tags. It doesn't do nesting, but it does have good memory usage. Thanks, Neil On Fri, Apr 30, 2010 at 11:35 AM, R Senington sc06...@leeds.ac.uk wrote: Dear all, I have been looking at using XML for a little program I have been writing. The file I am currently trying to load is about 9MB, and I have now tried to use HaXml and HST. Without any of my own code, just a simple call to the basic parsers, they both use huge amount of memory. HST is the worst and about 7GB and climbing. HaXml uses 1.3Gb. The code I am using is HST xml - readFile file_name_here;k-runX (parseXmlDocument True) xml;print k and for HaXml x-readFile file_name_here let (Document _ _ e _) = xmlParse t x let t = myFilter $ CElem e print $ length t I have seen on previous posts to the cafe that other people have run into this problem with HST. Is this a general problem with XML in Haskell (I know that XML parsing is a slow and bulky process but this seems excessive)? Is there a known solution? Does anyone have any advice? Cheers RS ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell] Latest Haskell Platform for Windows (2010.1.0.0) does not seem to include C++ support
Hi On checking, Haskell Platform\2010.1.0.0\mingw\libexec\gcc\mingw32\3.4.5 does not contain cc1plus.exe. Previous versions of the platform have done so. Is this an accidental change or a deliberate policy decision? ghc-6.12.1 on Windows did not include the mingw C++ compiler. This was a mistake. It is included once more in ghc-6.12.2. ghc-6.12.1 didn't include cc1plus.exe or libstdc++.a. The lack of libstdc++.a caused a failure in something I was building, so I raised a bug and it's now included in 6.12.2. I didn't explicitly compile any C++ code, so it's possible that still doesn't work. It wasn't a policy decision, merely an accident, and I'm sure if you alert people it will be rectified (since otherwise it's a regression). Thanks, Neil ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
Re: [Haskell-cafe] Broken ghc documentation links
Hi, I have recently updated Hoogle so it points at specific documentation. If anyone finds any further bugs, please let me know. I'm hoping to go through Hoogle and revise much of it in the near future, and intend to put things in place to stop this happening again (and keep it up to date). Thanks, Neil On Mon, Apr 26, 2010 at 2:15 PM, Ivan Lazar Miljenovic ivan.miljeno...@gmail.com wrote: Daniel Fischer daniel.is.fisc...@web.de writes: Am Montag 26 April 2010 13:36:22 schrieb Ivan Lazar Miljenovic: So, the problem is that there are broken links _in Hoogle_; No, hoogle just sends you to http://www.haskell.org/ghc/docs/6.12.2/html/libraries/base-4.2.0.1/Prelude.html#t%3AIO , which does exist. It's the 'Source' link in the haddocks that sends you to the 404 Not Found. It's the same with my local docs, I think it's haddock that got confused by the move of the IO definition from base to ghc-prim. Yeah, as I've said I mis-read the initial problem (I've fielded a few queries recently regarding Hoogle not pointing to the 6.12.2 docs and initially thought this was another one). -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: Agata-0.2.0
Hi Jonas, As far as i can tell, derive only works for regular and linear recursive types and Regular uses frequencies to regulate size. (Also Regular doesn't seem to work for QuickCheck-2). Derive will generate instances for all types, but uses a fairly standard formulation (pick between each constructor equally), meaning that in some cases the generators won't be that good, and will tend to generate infinite branches. Another feature of Agata generators is improved scalability compared to other QuickCheck generators, especially for nested collection data types (analog to a and such). The details of how this works in Agata will one day be explained in the documentation, but the principle is explained in my masters thesis[1]. Very neat :-) I'd welcome an instance generator based on your ideas as a patch to Derive. Derive provides 3 things: * Infrastructure - given a definition, it provides tests, ability to run as template haskell, ability to write to files, auto-generated documentation etc. I hope to add more infrastructure, such as the ability to run derivations via a website, so the user need not even install derive. * Derivation inference - a method infer derivations given a single example (explained in this paper: http://community.haskell.org/~ndm/downloads/paper-deriving_a_relationship_from_a_single_example-04_sep_2009.pdf) * Lots of instances, about 34 different ones. I/you/we could replace the Arbitrary instance with one based on your implementation. You don't have to use the derivation inference (and it probably wouldn't be suitable), but you do get to benefit from the rest of the infrastructure. People can then run your program via the command line, integrate easily with preprocessors etc - and still do the Template Haskell bit too. [1] http://gupea.ub.gu.se/bitstream/2077/22087/1/gupea_2077_22087_1.pdf Nice, I'll have a read (if it's in English) Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANNOUNCE: Agata-0.2.0
Hi, Have you seen the derive package? It also generates QuickCheck instances in virtually the same way - plus it can generate source code and do lots of other types of instances. http://community.haskell.org/~ndm/derive/ Thanks, Neil 2010/4/20 Bas van Dijk v.dijk@gmail.com: 2010/4/19 Jonas Almström Duregård jonas.dureg...@gmail.com: If this is to be used with QuickCheck maybe it should be named that way. Certainly worth considering. There seems to be no convenient way of renaming packages on Hackage though, is there? AFAIK hackage has support for deprecating packages in favor of others. This functionality is not exposed to regular users but you could mail one of the maintainers (Ross Paterson) to rename your package. Bas ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: GUI (was: Re: [Haskell-cafe] DLL on Windows)
:-( - it seems that cabal install wx isn't how you install it on Windows, not by a long shot. I'm currently a Gtk2hs user. If wx got to the point where cabal install wx either installed wx, including all it's non-Haskell dependencies, or printed out a message you're a windows user who hasn't installed wxWidgets, here's a handy url for you to click and run then run cabal install wx again I'd be tempted to switch. I realise that the platform differences makes it annoying, but it would be generally handy for Windows users. I do appreciate the work the wx people are doing for Windows users - it is generally going in the right direction :-) Thanks, Neil On Mon, Apr 19, 2010 at 2:54 AM, Jeremy O'Donoghue jeremy.odonog...@gmail.com wrote: On 18/04/2010, Daniel Fischer daniel.is.fisc...@web.de wrote: Am Sonntag 18 April 2010 21:41:06 schrieb Daniel Fischer: wx-config should have been installed as part of the wxWidgets package. Is that not included in the windows-installer of wxWidgets? Seems it's not so. http://www.haskell.org/haskellwiki/WxHaskell/Building says Windows users should also get the Windows port of wx-config. ( http://sites.google.com/site/wxconfig/ Sadly, the Windows port of wxWidgets doesn't contain wx-config (all of the Unix variants have it - it's a shell script), which is a major problem as this by far the simplest way for the build system to work out the options used to build wxWidgets. The Windows port of wx-config is an attempt to fix this problem, but only currently supports gcc, hence the restriction to using MinGW (although I guess Cygwin would probably work). If wxHaskell could be installed with one cabal command that would be incredibly cool :-) Well, it's just one cabal command if you have all non-Haskell requirements installed as needed. An option I am looking at is creating a basic Windows installer for wxHaskell which would contain a compiled copy of wxWidgets and a copy of wx-config, and which would run cabal install wxWidgets out of the box. (basic here means you probably don't get to choose anything at all - not even where the wxWidgets libraries get installed) Provided that I don't need to maintain a source distribution, this might be a good way forward for some Windows users. The installer would be updated for 'significant' wxWidgets updates (you would be able to 'cabal install wx' at any time wxHaskell is updated once you have all of the libraries) Any interest - please let me know. Regards Jeremy ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] GHC vs GCC vs JHC
Hi John, Any chance of seeing the benchmark? You're not the only one with an optimising compiler tucked away somewhere :-) I have one benchmark where I outperform GHC by 21 times, although saying it's artificial is a bit of an understatement... Thanks, Neil On Fri, Mar 26, 2010 at 6:27 PM, John Meacham j...@repetae.net wrote: Here are jhc's timings for the same programs on my machine. gcc and ghc both used -O3 and jhc had its full standard optimizations turned on. jhc: ./hs.out 5.12s user 0.07s system 96% cpu 5.380 total gcc: ./a.out 5.58s user 0.00s system 97% cpu 5.710 total ghc: ./try 31.11s user 0.00s system 96% cpu 32.200 total As you can see, jhc shines at this example, actually beating gcc -O3. It isn't too surprising, this is exactly the sort of haskell code that jhc excels at. John -- John Meacham - ⑆repetae.net⑆john⑈ - http://notanumber.net/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: Plans for GHC 6.12.2
Hi, Could this bug please be added: http://hackage.haskell.org/trac/ghc/ticket/3893 It's a regression against GHC 6.10.4, entirely a packaging issue, and most likely an oversight to remove the file. Thanks, Neil On Tue, Mar 23, 2010 at 6:38 PM, Ian Lynagh ig...@earth.li wrote: Hi all, This is a summary of our plans for GHC 6.12.2. We plan to put out a release candidate 6.12.2-rc1 shortly and, assuming there are no serious regressions found, 6.12.2 will follow soon after. The bugs that we're planning to fix for 6.12.2 are the high priority tickets in the 6.12.2 milestone: http://hackage.haskell.org/trac/ghc/query?status=newstatus=assignedstatus=reopenedpriority=highestpriority=highmilestone=6.12.2order=priority If there is a bug not in that list that is important to you, please let us know. Thanks Ian ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: [Haskell-cafe] Syntax programming with lexemes rather than trees?
Hi Stephen, It actually sounds like your representation has structure, but you dislike structure because it's hard to work with. The solution is a generics library, and I recommend Uniplate: http://community.haskell.org/~ndm/uniplate Imagine you have a ridiculously complex AST, with beam groups under tuplets etc, and you want to delete the first item from every beam group: transform f where f (Beam (x:xs)) = Beam xs f x = x Uniplate moves through tuplets and any other hierarchical syntax, so you just specify the transformation. My guess is if you throw away the structure then you'll need it back for some operations. Thanks, Neil 2010/3/22 Stephen Tetley stephen.tet...@gmail.com: Hi Malcolm Thanks - particularly I don't want to go to an AST because its I'm finding it too convoluted 'shape wise' - processing beam groups inside tuplets etc. is a nightmare - music representations have had at least eight centuries of ad hoc extension. I know Norman Ramsey and colleagues papers on low-level representations - I'll give them a re-reading. Thanks again Stephen ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] installing Network on windows
Hi, I managed this with the following sequence of commands: http://www.haskell.org/pipermail/libraries/2010-February/013038.html Thanks, Neil On Wed, Mar 17, 2010 at 9:44 PM, Niklas Larsson nikl...@ymail.com wrote: Hi! It needs some shell, if you install MSYS from mingw and do the cabal install from there it will work just fine. Here is the download for MSYS: http://sourceforge.net/projects/mingw/files/MSYS%20Base%20System/msys-1.0.11/MSYS-1.0.11.exe/download // Niklas L. From: gladst...@gladstein.com gladst...@gladstein.com To: haskell-cafe@haskell.org Sent: Wed, March 17, 2010 9:11:00 PM Subject: [Haskell-cafe] installing Network on windows I need some advice on the most straightforward way to install the Network package on Windows. I can install Cywgin if that's what it takes. Thanks in advance. cabal install network Resolving dependencies... Configuring network-2.2.1.7... cabal: Error: some packages failed to install: network-2.2.1.7 failed during the configure step. The exception was: sh: runGenProcess: does not exist (No such file or directory) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell platform for GHC 6.12.1?
Hi Han, I uploaded my latest version which works with GHC 6.12.1: http://community.haskell.org/~ndm/temp/cabal.zip Hope it helps, Thanks, Neil On Sun, Mar 7, 2010 at 5:59 PM, Han Joosten han.joos...@atosorigin.com wrote: Is it possible to post the correct cabal binary at http://www.haskell.org/cabal/download.html ? A while ago I gave up on trying to get GHC 6.12.1 working, for I lost the battle building cabal on my windows machine It would help A LOT when cabal.exe could be downloaded somewhere... Thanks Han Joosten Neil Mitchell wrote: Have you tried compiling cabal-install with GHC 6.12.1? I got these stream errors after I compiled it with 6.10.4, but with 6.12.1 it's working flawless. Woohoo, your tip works! Thanks a lot. Neil 2010/3/6 Neil Mitchell ndmitch...@gmail.com That and all Cabal 0.8 binaries on Windows suffer from zlib corrupted stream issues. I've got cabal-install binary, but it's not worth distributing :-( There is a cabal ticket for this. Thanks, Neil On Fri, Mar 5, 2010 at 11:27 PM, Ivan Lazar Miljenovic ivan.miljeno...@gmail.com wrote: Andrew Coppin andrewcop...@btinternet.com writes: Is there a reason why a new precompiled binary can't be put up for download? I would assume because no-one has supplied one (Duncan doesn't use Windows; don't know about the rest of the cabal-install developers). -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- View this message in context: http://old.nabble.com/Haskell-platform-for-GHC-6.12.1--tp27778596p27813226.html Sent from the Haskell - Haskell-Cafe mailing list archive at Nabble.com. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell platform for GHC 6.12.1?
That and all Cabal 0.8 binaries on Windows suffer from zlib corrupted stream issues. I've got cabal-install binary, but it's not worth distributing :-( There is a cabal ticket for this. Thanks, Neil On Fri, Mar 5, 2010 at 11:27 PM, Ivan Lazar Miljenovic ivan.miljeno...@gmail.com wrote: Andrew Coppin andrewcop...@btinternet.com writes: Is there a reason why a new precompiled binary can't be put up for download? I would assume because no-one has supplied one (Duncan doesn't use Windows; don't know about the rest of the cabal-install developers). -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell platform for GHC 6.12.1?
Have you tried compiling cabal-install with GHC 6.12.1? I got these stream errors after I compiled it with 6.10.4, but with 6.12.1 it's working flawless. Woohoo, your tip works! Thanks a lot. Neil 2010/3/6 Neil Mitchell ndmitch...@gmail.com That and all Cabal 0.8 binaries on Windows suffer from zlib corrupted stream issues. I've got cabal-install binary, but it's not worth distributing :-( There is a cabal ticket for this. Thanks, Neil On Fri, Mar 5, 2010 at 11:27 PM, Ivan Lazar Miljenovic ivan.miljeno...@gmail.com wrote: Andrew Coppin andrewcop...@btinternet.com writes: Is there a reason why a new precompiled binary can't be put up for download? I would assume because no-one has supplied one (Duncan doesn't use Windows; don't know about the rest of the cabal-install developers). -- Ivan Lazar Miljenovic ivan.miljeno...@gmail.com IvanMiljenovic.wordpress.com ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: Easily generating efficient instances for classes
Hi Derive generates declarations - they can be instances, classes, data types, functions, type synonyms etc. Thanks, Neil On Mon, Mar 1, 2010 at 10:32 AM, John Lato jwl...@gmail.com wrote: From: Christian H?ner zu Siederdissen Hi, I am thinking about how to easily generate instances for a class. Each instance is a tuple with 1 or more elements. In addition there is a second tuple with the same number of elements but different type. This means getting longer and longer chains of something like (...,x3*x2,x2,0). - template haskell? - CPP and macros? Consider arrays with fast access like Data.Vector, but with higher dimensionality. Basically, I want (!) to fuse when used in Data.Vector code. (shameless plug) You may want to look at my AdaptiveTuple package, which does something very similar to this. I used Template Haskell because AFAIK neither generic approaches nor DrIFT/Derive will generate data decls. If all you need are the instances, then DrIFT or Derive would be my recommendations. Cheers, John ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: Easily generating efficient instances for classes
As Bulat says, the Derive package might be a good way to go. I am happy to accept any new derivations, and you get lots of things for free - including writing your code using the nice haskell-src-exts library, preprocessor support, TH support etc. Thanks, Neil On Thu, Feb 25, 2010 at 8:57 AM, Bulat Ziganshin bulat.zigans...@gmail.com wrote: Hello Christian, Thursday, February 25, 2010, 3:57:44 AM, you wrote: I am thinking about how to easily generate instances for a class. Each it's called generic programing. just a few overviews on this topic: Libraries for Generic Programming in Haskell http://www.cs.uu.nl/research/techreps/repo/CS-2008/2008-025.pdf Comparing Approaches to Generic Programming in Haskell http://www.cs.uu.nl/~johanj/publications/ComparingGP.pdf Derive package is probably the easiest way Template Haskell is also good although a bit too complex. my own pets: http://www.haskell.org/bz/th3.htm http://www.haskell.org/bz/thdoc.htm -- Best regards, Bulat mailto:bulat.zigans...@gmail.com ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ___ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
Re: [Haskell-cafe] DLL on Windows
Hi Serguey, I notice you are using GHC 6.10.3, I suggest you try 6.10.4 which I know does work. I rewrote that section of the manual recently. I haven't had time to merge it back in, but it might give you more help: http://neilmitchell.blogspot.com/2009/11/haskell-dlls-on-windows.html Thanks, Neil On Tue, Feb 16, 2010 at 2:33 PM, Serguey Zefirov sergu...@gmail.com wrote: I tried the way described in http://www.haskell.org/ghc/docs/latest/html/users_guide/win32-dlls.html and i got this error message: ghc -shared -o test.dll --make test.hs [1 of 1] Compiling Test ( test.hs, test.o ) ghc.exe: panic! (the 'impossible' happened) (GHC version 6.10.3 for i386-unknown-mingw32): link: GHC not built to link this way: LinkDynLib Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug How can I fix it? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] What is the meaning of tilde (~) symbol
Hi The symbols that are not specified in a library can be found here: http://www.haskell.org/haskellwiki/Keywords Hoogle used to show links to this page, when a keyword was searched, but not anymore. And that's a bug: http://code.google.com/p/ndmitchell/issues/detail?id=280 (that I only just became aware of). I'll fix this up shortly. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] DLL on Windows
Hi Serguey, A GHC 6.10.4 version of Gtk2hs: http://www.mail-archive.com/gtk2hs-de...@lists.sourceforge.net/msg00340.html I used to recommend Gtk2hs over wxHaskell for GUI development as there was always a version that worked on Windows with the latest GHC release. I think I might have to switch back to recommending C# for GUI development... Thanks, Neil On Tue, Feb 16, 2010 at 5:19 PM, Serguey Zefirov sergu...@gmail.com wrote: I'd like to, but I cannot. My code is tied to gtk2hs, which supports either 6.10.1 or 6.10.3. I put it another way: could I build DLL using ghc 6.12.*? If I can, I'll use 6.10.3 for gtk2hs code and 6.12 for all new stuff. 2010/2/16 Neil Mitchell ndmitch...@gmail.com: Hi Serguey, I notice you are using GHC 6.10.3, I suggest you try 6.10.4 which I know does work. I rewrote that section of the manual recently. I haven't had time to merge it back in, but it might give you more help: http://neilmitchell.blogspot.com/2009/11/haskell-dlls-on-windows.html Thanks, Neil On Tue, Feb 16, 2010 at 2:33 PM, Serguey Zefirov sergu...@gmail.com wrote: I tried the way described in http://www.haskell.org/ghc/docs/latest/html/users_guide/win32-dlls.html and i got this error message: ghc -shared -o test.dll --make test.hs [1 of 1] Compiling Test ( test.hs, test.o ) ghc.exe: panic! (the 'impossible' happened) (GHC version 6.10.3 for i386-unknown-mingw32): link: GHC not built to link this way: LinkDynLib Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug How can I fix it? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] DLL on Windows
Oh no, I just give up on Haskell and use C# entirely - I'd much rather program in Haskell, but if all you are doing is a simple Windows app then a nice GUI is easy in C# with the form designer. Thanks, Neil On Tue, Feb 16, 2010 at 6:01 PM, Serguey Zefirov sergu...@gmail.com wrote: Thank you very much. How do you use C# for GUI development? Do you use hs-dotnet? 2010/2/16 Neil Mitchell ndmitch...@gmail.com: Hi Serguey, A GHC 6.10.4 version of Gtk2hs: http://www.mail-archive.com/gtk2hs-de...@lists.sourceforge.net/msg00340.html I used to recommend Gtk2hs over wxHaskell for GUI development as there was always a version that worked on Windows with the latest GHC release. I think I might have to switch back to recommending C# for GUI development... Thanks, Neil On Tue, Feb 16, 2010 at 5:19 PM, Serguey Zefirov sergu...@gmail.com wrote: I'd like to, but I cannot. My code is tied to gtk2hs, which supports either 6.10.1 or 6.10.3. I put it another way: could I build DLL using ghc 6.12.*? If I can, I'll use 6.10.3 for gtk2hs code and 6.12 for all new stuff. 2010/2/16 Neil Mitchell ndmitch...@gmail.com: Hi Serguey, I notice you are using GHC 6.10.3, I suggest you try 6.10.4 which I know does work. I rewrote that section of the manual recently. I haven't had time to merge it back in, but it might give you more help: http://neilmitchell.blogspot.com/2009/11/haskell-dlls-on-windows.html Thanks, Neil On Tue, Feb 16, 2010 at 2:33 PM, Serguey Zefirov sergu...@gmail.com wrote: I tried the way described in http://www.haskell.org/ghc/docs/latest/html/users_guide/win32-dlls.html and i got this error message: ghc -shared -o test.dll --make test.hs [1 of 1] Compiling Test ( test.hs, test.o ) ghc.exe: panic! (the 'impossible' happened) (GHC version 6.10.3 for i386-unknown-mingw32): link: GHC not built to link this way: LinkDynLib Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug How can I fix it? ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] What is the meaning of tilde (~) symbol
Hi Patrick, The symbols that are not specified in a library can be found here: http://www.haskell.org/haskellwiki/Keywords I noticed that \ is not in that list, should it be? Yes! Add it. If it would help a beginner understand what something means, it should be on that list. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell] Fun in the Afternoon, London, 17th Feb (next Wednesday)
Dear functional programmers, Standard Chartered Bank in London will be hosting the next Fun In The Afternoon event on Wednesday the 17th of February. The program of talks, with abstracts, is at the bottom of this email. Everyone is welcome! If you would like to come, please email me (ndmitchell -AT- gmail -DOT- com) with your name and affiliation by the 15th of Feb (late registrations will probably be accommodated, but we do need to print out name badges). Address: 1 Basinghall Avenue, London EC2V 5DD http://maps.google.co.uk/maps?q=standard+chartered+bankie=UTF8hl=enhq=standard+chartered+bankhnear=London,+UKll=51.517796,-0.091581spn=0.007023,0.01929z=16iwloc=A Moorgate is the nearest tube station, but London Liverpool Street train/tube station and Bank tube station are easily walkable. Time: The event starts at 1:10pm and finishes at 4:30pm. As traditional, there will be beer/food afterwards. Schedule: 12:00-1:10, arrive at Standard Chartered. We'll find lunch somewhere nearby. Tell the reception you are attending Fun in the Afternoon. If you have any difficulties getting there, or can't find anyone when you arrive, phone me on 07876 126 574 1:10-1:15, Introduction 1:15-2:00, Invited talk, TBC 2:00-2:15, break 2:15-2:45, Zhaohui Luo, On Subtyping for Type Theories with Canonical Objects 2:45-3:15, George Giorgidze, Declarative Hybrid Modelling and Simulation in Haskell 3:15-3:30, break 3:30-4:00, Dominic Orchard, Haskell Type Constraints Unleashed 4:00-4:30, Malcolm Wallace, Pointless fusion for pointwise application 4:30-6:00, Pub 6:00, Dinner Abstracts: == Zhaohui Luo, On Subtyping for Type Theories with Canonical Objects Two different notions of subtyping have been studied in the literature: subsumptive subtyping that employs the subsumption rule and coercive subtyping that uses implicit coercions. They are suitable for different kinds of type systems: subsumptive subtyping for type assignment systems such as the polymorphic calculi in programming languages and coercive subtyping for the type theories with canonical objects such as Martin-Lof's type theory implemented in proof assistants. In this talk, we explain that subsumptive subtyping is incompatible with the idea of canonical object and cannot be employed to reflect, for example, structural subtyping for inductive types in a type theory with canonical objects. Coercive subtyping, on the other hand, can be used in such type theories to deal with structural and non-structural subtyping relations satisfactorily and has interesting and useful applications. If time permits, we shall show how the formal relationship between these two notions of subtyping can be studied by demonstrating how a type system of dependent types with subsumptive subtyping can be transformed faithfully into one with coercive subtyping. == George Giorgidze, Declarative Hybrid Modelling and Simulation in Haskell Mathematical modelling and simulation of physical systems plays an important role in design, implementation and analysis of systems in numerous areas of science and engineering, e.g., electrical engineering, astronomy, particle physics, biology, climatology, automotive industry and finance (to mention just few). To cope with ever increasing size and complexity of real-world systems, a number of declarative domain specific languages (DSLs) have been developed for mathematical modelling and simulation. In the first half of the talk, I will give a brief overview of the state-of-the-art languages for modelling and simulation and identify their shortcomings with respect to reusability, composability and hybrid (mixed discrete and continuous time) simulation. Next, I will introduce a Haskell-embedded DSL for declarative modelling and simulation that addresses some of these shortcomings. The DSL features first-class implicitly formulated equational constrains allowing for higher-order modelling and simulation of highly structurally dynamic, hybrid systems that goes beyond what current languages can simulate. In particular, it allows repeated generation and just-in-time (JIT) compilation of updated equational constrains during the simulation, depending on the results thus far. The embedding approach that we use should be of general interest and usable in other domains as well. In the second half of the talk, I will describe the embedding approach in detail. I will show how to use mixed-level (combination of deep and shallow) embedding and LLVM JIT compiler to implement an iteratively staged DSL (characterised by repeated program generation, compilation and execution) efficiently in a host language that does not provide built-in multi-stage programming capabilities. == Dominic Orchard, Haskell Type Constraints Unleashed The popular Glasgow Haskell Compiler extends the Haskell 98 type system with several powerful features, leading to an expressive language of type terms. In contrast, constraints over types have received much less attention, creating
Re: [Haskell-cafe] Anyone up for Google SoC 2010?
Hi Gwern, Please update: haskell-src-exts - haskell-src **Unknown** This project was an unqualified success. haskell-src-exts is now one of the most commonly used Haskell libraries, achieved the goals in the project proposal, and is an essential piece of Haskell infrastructure. I couldn't be more pleased with how this project turned out. Thanks, Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
