[Haskell-cafe] ML 2013: last call for presentations

2013-06-19 Thread Daan Leijen
- Daan Leijen (chair) (Microsoft Research, US) Jesse A. Tov(Harvard University, US) Derek Dreyer(MPI-SWS, Germany) Atsushi Ohori (Univ. of Tohoku, Japan) Lars Bergstrom (Univ. of Chicago, US) Jean Yang (MIT CSAIL, US) Gavin Bierman

[Haskell] ML 2013: last call for presentations

2013-06-18 Thread Daan Leijen
- Daan Leijen (chair) (Microsoft Research, US) Jesse A. Tov(Harvard University, US) Derek Dreyer(MPI-SWS, Germany) Atsushi Ohori (Univ. of Tohoku, Japan) Lars Bergstrom (Univ. of Chicago, US) Jean Yang (MIT CSAIL, US) Gavin Bierman

[Haskell] ML workshop 2013: Call for presentations

2013-06-07 Thread Daan Leijen
process, please contact the program chair (daan at microsoft.com). IMPORTANT DATES --- * Friday, June 21 : Submission * Monday, July 22 : Notification * Sunday, September 22: Workshop PROGRAM COMMITTEE - Daan Leijen (chair) (Microsoft Research, US

RE: [Haskell-cafe] implementing a csv reader

2006-08-22 Thread Daan Leijen
2. I am looking for a parser, but I don't know Haskell parsers. Is Parsec a good choice? Parsec is definitely a good choice, but beware that it parses the whole input before returning, thus it may consume a huge batch of memory. As CSV is a line oriented format, you should make your

FW: Reviving wxHaskell (was: Re: [wxhaskell-users] [Haskell-cafe] Troublecompiling wxhaskell)

2006-08-01 Thread Daan Leijen
and packaging correctly). All the best, -- Daan Leijen. Ps. Include me on the reply list as I am not subscribed properly to either mailing list at the moment. From: Simon Peyton-Jones Sent: Tuesday, August 01, 2006 4:46 AM To: Daan Leijen Subject: FW: Reviving wxHaskell (was: Re

Re: [Haskell] why don't we have const Ptrs?

2005-11-02 Thread Daan Leijen
Hi David, One could pretty easily create a ConstPtr type which one could peek into, but not poke to, but then you'd have to explicitely convert a Ptr into a ConstPtr when passing it as an argument. That feels a bit silly. One way of dealing with constant pointer is to introduce (yet

Re: [Haskell] Excessive sharing and GHC

2005-10-18 Thread Daan Leijen
John Meacham wrote: On Tue, Oct 18, 2005 at 08:31:19AM +0100, Simon Peyton-Jones wrote: GHC tries not to create space leaks, but does not guarantee not to. In particular, the full laziness transformation is so beneficial most of the time that, even though it can create a space leak GHC still

Re: [Haskell] combining IntMaps

2005-07-30 Thread Daan Leijen
:-) ) I hope this helps, All the best, Daan Leijen But this is no good, because IntMap.update only affects those keys where lookup succeeds, so IntMap.update (maybeAdd 3) 8 IntMap.empty returns IntMap.empty, rather than a map with 8 - 3 as I had hoped. What would you suggest to help addMaps run

[Haskell] Haskell workshop 2005 -- Call for participation.

2005-07-22 Thread Daan Leijen
website at http://www.cs.uu.nl/~daan/hw2005 and is appended in plain text to this section. This year, David Roundy gives an invited talk about Darcs: a popular distributed version control system written Haskell. 8:45 Welcome by Daan Leijen 9:00 - 10:30 Invited talk: Lessons from Darcs

[Haskell] Haskell workshop 2005: final call for papers

2005-05-30 Thread Daan Leijen
submit papers in postscript or portable document format (pdf), formatted for A4 paper, to Daan Leijen ([EMAIL PROTECTED]). The length should be restricted to 12 pages in standard ACM SIG proceedings format. In particular, LaTeX users should use the most recent sigplan proceedings style available from

Re: [Haskell] Using Haddock

2005-05-14 Thread Daan Leijen
offended by your artistic depiction of improper virtues within the enlightning pureness of Haskell ;-) On the other hand, it could also be that Haddock expects a space between the comment sign and the bar: -- | This is a proper haddock comment Cheers, -- Daan Leijen. {-| The 'square' function squares

[Haskell] announce: wxHaskell 0.9.4, windows bug fix release

2005-05-08 Thread Daan Leijen
problems. Thanks to Sigbjorn Finne for fixing this bug. As always, first uninstall before re-installing: - click on wxhaskell-0.9.4\bin\wxhaskell-unregister.bat - remove the wxhaskell-0.9.4 directory - unzip the new release - click on wxhaskell-0.9.4\bin\wxhaskell-register.bat Have fun, Daan

[Haskell] announce: wxHaskell 0.9.4

2005-05-03 Thread Daan Leijen
are provided for MacOS X, Linux (RPM), and Windows. Unfortunately, GHCi-6.4 does not work with wxHaskell. For Windows platforms I still recommend GHC 6.2.2 since GHCi-6.2.2 works great with wxHaskell (on Windows). All the best, Daan Leijen

Re: [darcs-users] RE: [Haskell-cafe] fptools in darcs now available

2005-05-03 Thread Daan Leijen
a potentially important one. All the best, -- Daan Leijen. 2. Create separate repositories for GHC, Happy, Haddock etc., and duplicate the shared fptools structure in each project. Each time we modify something in the shared part of the tree, we pull the patch into the other trees

[Haskell] Haskell workshop 2005: second call for papers.

2005-05-01 Thread Daan Leijen
in postscript or portable document format (pdf), formatted for A4 paper, to Daan Leijen ([EMAIL PROTECTED]). The length should be restricted to 12 pages in standard ACM SIG proceedings format. In particular, LaTeX users should use the most recent sigplan proceedings style available from

[Haskell] Haskell Workshop 2005: Call for papers

2005-04-08 Thread Daan Leijen
in postscript or portable document format (pdf), formatted for A4 paper, to Daan Leijen ([EMAIL PROTECTED]). The length should be restricted to 12 pages in standard ACM SIG proceedings format. In particular, LaTeX users should use the most recent sigplan proceedings style available from the Haskell

Re: [Haskell] announce: wxhaskell 0.9

2005-03-14 Thread Daan Leijen
Benjamin Franksen wrote: On Friday 25 February 2005 19:14, Daan Leijen wrote: Announcement: wxHaskell version 0.9 Could you (or anyone else) please give me a summary on how exactly I have to patch the makefile[.lib] so that I can compile this ghc-6.4? I found

[Haskell] announce: wxhaskell 0.9

2005-02-25 Thread Daan Leijen
control. Binary installers are provided for MacOS X, Linux (RPM), and Windows, for use with ghc 6.2.2. Have fun, Daan Leijen. -- wxHaskell is a portable GUI library for Haskell. The goal of the project is to provide an industrial

Re: [Haskell] Proposal: Allow \= for field update in record update syntax

2005-02-20 Thread Daan Leijen
Benjamin Franksen wrote: This library class defines the operations on a record: class RecordField r l t | r l - t where getField :: l - r - t putField :: l - t - r - r I have once written a short note about how Haskell'98 records could be made more useful using a

Re: ghc-cvs-snapshot with wxHaskell

2005-02-18 Thread Daan Leijen
Georg Martius wrote: Hi, Patrick and I found some answers to the questions/problems we encountered. Finally got the thing to work. (patches appended) Great! I have a possible fix: add -odir out/... to the call of ghc -M. This produces correct paths for the .o files. Ok, this makes sense and,

Re: ghc-cvs-snapshot with wxHaskell

2005-02-18 Thread Daan Leijen
The original code in the makefile.lib replaced (basename input.hs) with (basename output.o) and *.hi with *.o which is a quite weird approach to the problem. I'am not sure but I think the new approach is better: let the .o files be correct through the -odir flag replace (dir

stdout handle is finalized

2004-11-29 Thread Daan Leijen
? Anyone any idea for a workaround? All the best, Daan Leijen. (ps. I am not on this list, so please cc) ___ Glasgow-haskell-bugs mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs

Re: stdout handle is finalized

2004-11-29 Thread Daan Leijen
Daan Leijen wrote: I have a rather large program, and suddenly, after no changes related to output, my program crashes with the message: Fail: stdout: hPutStr: illegal operation (handle is finalized) It does (probably) happen when using ioError and Ex.catch to catch the exception -- maybe the gc

Re: [Haskell] A puzzle and an annoying feature

2004-11-25 Thread Daan Leijen
explicit in the program. Since it would solve the puzzle in a rather elegant and explicit way, I thought that it was interesting to mention. All the best, -- Daan. Keean. Daan Leijen wrote: Lennart Augustsson wrote: [snip] So in what sense is this really ambiguous? I think it would be quite

Re: [Haskell] A puzzle and an annoying feature

2004-11-25 Thread Daan Leijen
Lennart Augustsson wrote: Daan Leijen wrote: A closed class directive however is an explicit specification that makes the intention of the designer explicit in the program. Since it would solve the puzzle in a rather elegant and explicit way, I thought that it was interesting to mention. Indeed

Re: [Haskell] A puzzle and an annoying feature

2004-11-24 Thread Daan Leijen
) or improve a type variable to a certain type (in case the set of instances is a singleton). All the best, -- Daan Leijen. [1] http://www.cs.uu.nl/~bastiaan/papers.html#typeclassdirectives (to appear in PADL 2005) -- Lennart ___ Haskell

Re: [Haskell] Create a List

2004-11-17 Thread Daan Leijen
Hi Jose, Jose manuel Hernando Cobeña wrote: -hello, I need to create a list of Colors, and I like do this: list_colors - varGet vColors color_red - checkBox p [text := Red, checked := False, on command := do aux red list_colors ] where aux one_color list_colors = if (elem

Re: Using GHC and wxHaskell; ik weet niet of je dit ook leest

2004-09-11 Thread Daan Leijen
Ivan Boldyrev wrote: On 8861 day of my life Mike Thomas wrote: | Is that a good option? How can I use the wxHaskell libraries with GHC? | I´m working under Windows XP. Check out wxHaskell: http://wxhaskell.sourceforge.net/ Does it work under Windows? One of my friends tried it under Windows, but

Re: [Haskell] image writing library

2004-08-05 Thread Daan Leijen
Ketil Malde wrote: I would like to write an (Array (Int,Int) Int) to a file in some kind of image format. I implemented (quick and very dirty) XBM output, [snip] So, before I start, does anybody know any other libraries or programs that could be used? Hi Ketil, You could use wxHaskell to write

[Haskell] Announce: wxHaskell 0.8

2004-07-27 Thread Daan Leijen
), and Windows. The webpage has a screenshot of a heap profile viewer for GHC written in wxHaskell by Wei Tan. There is also a *draft* version of an article about the design of wxHaskell. I have to submit a final version this Friday and any comments are very welcome. All the best, Daan Leijen

[Haskell] Announce: wxHaskell 0.8

2004-07-27 Thread Daan Leijen
), and Windows. The webpage has a screenshot of a heap profile viewer for GHC written in wxHaskell by Wei Tan. There is also a *draft* version of an article about the design of wxHaskell. I have to submit a final version this Friday and any comments are very welcome. All the best, Daan Leijen

Re: [Haskell] Memo function help

2004-07-27 Thread Daan Leijen
Tom Hofte wrote: I want to use the memo function for implementing a dynamic programming algorithm in Haskell. This is needed to cache intermediate results. Can anyone tell me where I can find some examples that use the memo function or even a tutorial. Hi Tom, I like Byron Cook's paper about

Re: [Haskell] Re: Initialisation without unsafePerformIO

2004-06-04 Thread Daan Leijen
On Fri, 04 Jun 2004 00:35:14 -0700, Ashley Yakeley [EMAIL PROTECTED] wrote: In article [EMAIL PROTECTED], John Meacham [EMAIL PROTECTED] wrote: I am a fan of allowing top level declarations of the form: foo - newIORef foo which would behave as an initializer, with the semantics being that it be

Re: [wxhaskell-users] RE: [Haskell] Dynamically loading wxhaskell?

2004-04-15 Thread Daan Leijen
On Wed, 14 Apr 2004 09:37:02 +0100, Simon Marlow [EMAIL PROTECTED] wrote: What error messages do you get, specifically? Here it is: --- Loading package data ... linking ... done. Loading package wxcore ... ghc-6.2.1: can't load .so/.DLL for: wxc-gtk2.4.2-0.7

Re: Bug in the proof of Data.FiniteMap and DData.Map

2004-03-29 Thread Daan Leijen
On Fri, 26 Mar 2004 09:46:53 +0100, Robert Will [EMAIL PROTECTED] wrote: The precondition-problem is not easy to fix. However, I ackknowledge that your balancing-checks are really good evidence for the correctness of the algorithm. (I didn't notice them first, because you checked via an

Re: Bug in the proof of Data.FiniteMap and DData.Map

2004-03-24 Thread Daan Leijen
On Fri, 19 Mar 2004 09:00:22 +0100, Robert Will [EMAIL PROTECTED] wrote: both of the data structures are based on Adams' balancing algorithm which contains a bug -- at least in its proof. (Perhaps it is correct, but I don't know anyone that knows if.) I have been redoing proofs of Adam's

Re: [Haskell] RFC: DData in hierarchical libraries

2004-03-11 Thread Daan Leijen
Hi Christian, (Some have already replied, but I'll say some more about some issues) On Mon, 08 Mar 2004 12:32:21 +0100, Christian Maeder [EMAIL PROTECTED] wrote: Set.toAscList is not really necessary as it is the same as Set.toList. Not necessarily: the lists from Set.toList will be equal for

Re: [Haskell] definition of intersperse

2004-03-03 Thread Daan Leijen
On Tue, 02 Mar 2004 16:59:48 -0800, Iavor S. Diatchki [EMAIL PROTECTED] wrote: i'd like to suggest that the definition of intersperse from the List module be made more lazy. Good thing, I think that library functions should always be as lazy as possible in their observeable interface (or well

Re: [wxhaskell-users] Re: [Haskell] Announce: wxHaskell 0.6

2004-03-03 Thread Daan Leijen
Dear Gour, On Wed, 3 Mar 2004 12:58:53 +0100, Gour [EMAIL PROTECTED] wrote: (Again), I have one suggestion for wxHaskell: to combine doc src packages into one - wxhaskell-x-xx. The documentation is generated from the source, so there is no need to include it. Furthermore, the binary releases

[Haskell] Announce: wxHaskell 0.6

2004-02-23 Thread Daan Leijen
. And even if you don't intend to write GUI's yourself, it will be fun to check out the screenshots at http://wxhaskell.sourceforge.net. All the best, Daan Leijen. ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell

Re: [Haskell] Impredicative Types?

2004-02-18 Thread Daan Leijen
On Tue, 17 Feb 2004 14:40:18 -0800, Ashley Yakeley [EMAIL PROTECTED] wrote: Ben Rudiak-Gould [EMAIL PROTECTED] wrote: Bear in mind you can't even write IO (forall t. whatever) in Haskell. True, but why is this? Is there a deep reason why we can use nested foralls as the arguments to (-), but

Re: [Haskell] Parsec question: attempted 'notMatching' combinator

2004-02-18 Thread Daan Leijen
On Wed, 18 Feb 2004 01:11:31 -0500, Andrew Pimlott [EMAIL PROTECTED] wrote: After some pondering and fiddling, a version I like: notFollowedBy' :: Show a = GenParser tok st a - GenParser tok st () notFollowedBy' p= join $ do a - try p; return (unexpected (show a))

[Haskell] Announce: wxhaskell 0.5

2004-02-12 Thread Daan Leijen
.x on Windows, MacOS X and Unix systems with GTK. A binary distribution is available for Windows and MacOS X. And even if you don't intend to write GUI's yourself, it will be fun to check out the screenshots at http://wxhaskell.sourceforge.net. All the best, Daan Leijen

Re: [Parsec] Extracting line and column numbers

2004-01-14 Thread Daan Leijen
What about these? sourceColumn :: SourcePos - Column sourceLine :: SourcePos - Line These signatures are missing in the source, therefore they are not listed in the documentation generated by haddock. I'll fix this in the Parsec sources, so the GHC 6.2+ will have it. Maybe I'll even get

Re: from array update algorithm to nice Haskell code

2004-01-10 Thread Daan Leijen
Hi Wolfgang, I think that you are mixing up worst case bounds O(..) with some specific case. I guess that you mean by O(1) elements a known and constant number of elements. I mean a constant maximum number of elements. An example would be that the set b is guaranteed to have not more than one

Re: from array update algorithm to nice Haskell code

2004-01-09 Thread Daan Leijen
Now assume that I have a set a with O(n) elements and a set b with O(1) elements. You can't have O(1) elements ... (A bound like O(..) talks about the worst case time/space of an operation.) a `minusSet` b would take O(n) time and so would a `intersect` b. If I'd use foldr (flip delFromSet) a

Re: Combining distinct-thread state monads?

2004-01-08 Thread Daan Leijen
composing monads by Mark Jones and Luc Duponcheel. It specifies precisely what kind of laws should hold before monads can be composed. (and indeed, it also shows that not all monads are symetrical and can be arbitrarily composed!) http://www.cse.ogi.edu/~mpj/pubs/composing.html All the best, Daan

Re: Working haskell/db+hugs set?

2004-01-02 Thread Daan Leijen
Hi Kyra, Trying to play with haskell/db, I've found myself being a little bit stuck. The latest version of hugs haskell/db (as referenced from http://www.haskell.org/haskellDB/download.html) works with seems to be of May 1999. I cannot find any references to this version of hugs except

Re: from array update algorithm to nice Haskell code

2003-12-31 Thread Daan Leijen
On Wed, 31 Dec 2003 12:35:23 +0100, Wolfgang Jeltsch [EMAIL PROTECTED] wrote: The documentation of DData.Map states the following as an advantage of DData.Map over Data.FiniteMap: It uses the efficient hedge algorithm for both union and difference [...]. Does this mean that the Data.FiniteMap

Re: from array update algorithm to nice Haskell code

2003-12-30 Thread Daan Leijen
Hi Wolfgang, is there some documentation about the complexity of the FiniteMap and Set operations? My DData library gives some useful links to papers about this subject, also take a look at the IntSet and IntMap libraries as they have an interesting complexity class. Also, all DData functions

RE: Why are strings linked lists?

2003-12-09 Thread Daan Leijen
Hi Graham, I tried to track that down (for a colleague), but the link at: http://www.cs.uu.nl/helium/documentation.html to: http://www.cs.uu.nl/~daan/papers/lvm.pdf is broken, and I can't find any other references. Sorry for the broken link. The LVM is described in the last chapter

Re: set representation question

2003-11-12 Thread Daan Leijen
Hi Hal, On Tue, 11 Nov 2003 16:45:56 -0800 (PST), Hal Daume III [EMAIL PROTECTED] wrote: i'm looking for a representation for a set of natural numbers. right now, my representation is sorted array, which works well. *all* i care about is being able to quickly calculate the size of the

Announce: wxHaskell 0.4

2003-11-07 Thread Daan Leijen
, MacOS X and Unix systems with GTK. A binary distribution is available for Windows and MacOS X. And even if you don't intend to write GUI's yourself, it will be fun to check out the screenshots at http://wxhaskell.sourceforge.net. All the best, dr. :-) Daan Leijen

Haskell on the cover of a magazine!

2003-10-09 Thread Daan Leijen
of the relevant pages, see: http://wxhaskell.sourceforge.net/screenshots.html#linformaticien Just think of all those thousands of French O'Caml programmers that will suddenly start to use Haskell ;-) All the best, Daan Leijen. wxHaskell est un outil d'ores et déjà remarquable et d'une grande

RE: implement hash table

2003-10-08 Thread Daan Leijen
which may also please you: http://www.haskell.org/ghc/docs/6.0/html/base/Data.FiniteMap.html And maybe a fast integer finite map may please you even more: http://www.cs.uu.nl/~daan/ddata.html -- Daan Leijen ___ Haskell mailing

Announce: wxHaskell 0.2

2003-09-16 Thread Daan Leijen
and Unix systems with GTK. A binary distribution is available for Windows and MacOS X. And even if you don't intend to write GUI's yourself, it will be fun to check out the screenshots at http://wxhaskell.sourceforge.net. All the best, Daan Leijen. ps. More funny statistics: the wxWindows

RE: Announce: wxHaskell 0.2

2003-09-16 Thread Daan Leijen
Hi Sven, the library documentation says: Portability: portable, but this is not the case at all, wxHaskell uses quite a few extensions (apart from the FFI, which can be considered portable nowadays): wxHaskell consists of two layers: WXCore and WX. The WXCore layer is supposed to be

RE: Announce: wxHaskell 0.2

2003-09-16 Thread Daan Leijen
Hi Sven, (I'll reply to the portability issues in a separate mail) * It would be nice if the directory created by unzipping wxhaskell-src-0.2.zip contained a version number. * It would be even nicer if wxhaskell-doc-0.2.zip unzipped into a *single* directory. * You need

RE: \s at the end of lines and cpp

2003-09-04 Thread Daan Leijen
Thanks Ian for finding this Bug. I have encountered it before with wxHaskell and I had just removed the line :-) Now, that I know what causes this, I'll add an extra space or comment or something. -- Daan. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On

RE: Announce: wxHaskell, a portable GUI library.

2003-07-23 Thread Daan Leijen
I can't seem to download any files for wxHaskell from sourceforge; this is probably a misconfiguration on their part, but I thought it best to let you know as well. Thanks for the info. However, it downloads fine for most people here at the university. Maybe you should try a different mirror

Announce: wxhaskell: macOSX binaries and bugfix.

2003-07-22 Thread Daan Leijen
Two announcements regarding wxHaskell: http://wxhaskell.sourceforge.net 1) I have created a binary release for MacOS X. Installation details can be found on the download page. 2) I have fixed a small bug in the configuration script for Linux. The source release has been updated. (and I

Announce: wxHaskell, a portable GUI library.

2003-07-21 Thread Daan Leijen
, it will be fun to check out the screenshots at http://wxhaskell.sourceforge.net. All the best, Daan Leijen. ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell

Re: FFI Tutorial / Examples

2003-03-10 Thread Daan Leijen
On Sun, 09 Mar 2003 22:13:35 -0500, Matthew Donadio [EMAIL PROTECTED] wrote: I may be being a bit dense about this, but I am having some trouble understanding how to use FFI, especially with respect to interfacing Haskell lists/arrays to C arrays. For example, say I have the C functions void foo

Re: looking for Database Interface in Haskell

2003-03-03 Thread Daan Leijen
On 03 Mar 2003 13:57:06 +, Steffen Mazanek [EMAIL PROTECTED] wrote: Dear all, we want to access a (MySQL) data base, running on a linux server, from a Haskell program. Have a look here: http://haskell.cs.yale.edu/haskellDB/ A word of warning though from the author :-), HaskellDB is somewhat

Re: GUI for Windows

2003-03-03 Thread Daan Leijen
On Mon, 3 Mar 2003 16:21:22 +0100, [EMAIL PROTECTED] wrote: What User Interface Library would you recommend for use under Windows? Unfortunately, there is no official GUI library for Haskell yet (but many people are working toward this goal at the haskell gui mailing list). At the moment, the

Re: Yet another weakly defined bug report

2003-02-13 Thread Daan Leijen
These things are always tricky to understand, which is why I recommend not using lazy I/O. File reading is not a pure operation: running out of file descriptors is a good counter-example. Without saying wether I agree with lazy I/O or not, I suggest that this particular problem may also be

Re: FiniteMap performance

2003-02-08 Thread Daan Leijen
Dear Magnus, I wonder what the performance of the FiniteMap type is in Haskell. Lookup is of course done in O(log n) but is insertion done in O(n) or O(log n)? ... If it belongs to O(n), aren't the maps really really useless? If it belongs to O(log n), how is this achieved? (my guess is

Re: FiniteMap performance WITHOUT any copying?

2003-02-08 Thread Daan Leijen
Magnus wrote (snipped) Now, Haskell has a garbage collector, so Haskell must know how many pointers there are to all objects in the heap (or?). Then, if a finite map for example only has one single pointer to it, then it ought to be all right to modify the finite map (or whatever

Re: Bizarre Haskell Problem

2003-01-27 Thread Daan Leijen
My guess is that you are having an out-of-date .o of .hi file in your working directory. Clean it up and try again. All the best, Daan. - Original Message - From: Matthew Donadio [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, January 27, 2003 10:34 PM Subject: Bizarre Haskell

Re: Parsec: No newline after last line and 'many'

2002-04-08 Thread Daan Leijen
Hi Till, My guess is that you want to break up a text file into a list of lines with Parsec. (ie. lines functionality). A text file consists of non-newline characters seperated by newline characters: import Parsec plines :: Parser [String] plines = (many (noneOf \n)) `sepBy` newline You

Re: hashmap withdrawal and poor haskell style

2002-04-03 Thread Daan Leijen
Hi Michal, Maybe you should use accumArray to get your histogram. accumArray :: Ix a = (b - c - b) - b - (a,a) - [(a,c)] - Array a b This functions takes a function to combine elements with the same index a, an initial element b, and the range of indices (a,a). We can now write a

Re: hashmap withdrawal and poor haskell style

2002-04-03 Thread Daan Leijen
] To: Daan Leijen [EMAIL PROTECTED] Cc: Michal Wallace [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Wednesday, April 03, 2002 5:54 PM Subject: Re: hashmap withdrawal and poor haskell style ons 2002-04-03 klockan 15.51 skrev Daan Leijen: import Array type Histogram = Array Char Int histogram

Haskell puzzles!

2002-03-19 Thread Daan Leijen
Hi all, I have put together some interesting Haskell puzzles! Not many people were able to solve all three puzzles so don't be discouraged you don't know all the answers. Have fun, Daan. - - All three puzzles are Haskell 98; you can solve

Re: Haskell problem

2002-02-22 Thread Daan Leijen
Hi all, There exist a really neat solution to this. I think that it is pioneered by Doaitse Swierstra and Luc Duponcheel in their parser combinators: http://www.cs.uu.nl/~doaitse/Papers/1996/LL1.pdf I'm trying out some combinatorial parsers, and I ran into a slightly inelegant

announce: PARSEC

2001-10-04 Thread Daan Leijen
is distributedwith GHC but GHC 5.02 unfortunately includes an older version. PARSEC can be downloaded from:http://www.cs.uu.nl/people/daan/parsec.html I would like to thank the many(!) people that have writtenme with advice and comments that improved the library. Have fun, Daan Leijen

Re: Strange error in show for datatype

2001-10-04 Thread Daan Leijen
Koen Cleassen wrote: Indeed. And this is a perfect example of the fact that all this bottom-dictionary passing does not work. The type of the list still matters though: Hugs show ([] :: [Char]) \\ Hugs show ([] :: [Int]) [] Koen is absolutely right. A fundamental property of

Re: Strange error in show for datatype

2001-10-04 Thread Daan Leijen
Simon Peyton-Jones wrote: Consider: data T a = T1 Int | T2 a It's clear that (T1 Int) has no a's in it, not even bottom. Mark Shields and ruminated in the corridor about a kind system to make this apparent. That is, T1 would have type T1 :: forall a::Pure . Int - T a Then if we

Re: HScript

2001-01-30 Thread Daan Leijen
Hi Eric, Unfortunately HaskellScript doesn't work with the latest hugs versions. You need the version of Hugs that is explicitly provided on the HaskellScript website. (http://www.cs.uu.nl/~daan/download/hugs98may.exe) Hope this helps, Daan. - Original Message - From: "Eric

RE: Singletons and Reflection

1999-12-15 Thread Daan Leijen
What do folk out there think to the idea of having a std module in Haskell which contains dynamic environment info. things I mean are progName :: String args:: String Representing the 'args' as a value in haskell is probably not the right thing to do. For one thing, it is not possible

RE: Singletons and Reflection

1999-12-15 Thread Daan Leijen
If we had implicit parameters then all graphics functions would have types (? context :: Context) = (explicit arguments) = IO (result) and the main function would be something like do context - getContext doBusiness with context=context The catch is off course that

Re: haskell IDE

1999-12-07 Thread Daan Leijen
I heard that Visual Haskell is under development. Do you know when it is released? It will provide Haskell programmer an environment that is similar to Visual J++, Visual Basic, or...? VisualHaskell is indeed under development. However, due to licensing issues the release date is "somewhere

Re: Contexts

1999-09-13 Thread Daan Leijen
(3) OK with GHC, error with Hugs: f = \x - m x x = f() ... - Is GHC's treatment of (3) a bug? At first glance it looks a bit that way to me, but I will leave it for the more knowledgable Haskell experts to give you a definitive answer on that one. IIRC it's a known bug

Re: HaskellScript

1999-09-09 Thread Daan Leijen
Hello, I'm interested in using HaskellScript. Who can tell me where I can find useful infomation about how to use it to build interactive web pages? Thanks in advance! The best place to start is at: http://www.haskell.org/haskellscript All the best, Daan Leijen Regards, Chen Ping

Re: Licenses and Libraries

1999-08-23 Thread Daan Leijen
"Daan Leijen" [EMAIL PROTECTED] wrote, Sigbjorn Finne has done a lot of work to make sure that H/Direct can handle any standard and dialect of IDL that is around, including OMG/Corba IDL's. H/Direct can generate interface code to any C library that is described with

Re: Licenses and Libraries

1999-08-22 Thread Daan Leijen
On Mon, 23 Aug 1999, Manuel M. T. Chakravarty wrote: ``C - Haskell, or Yet Another Interfacing Tool'' http://www.score.is.tsukuba.ac.jp/~chak/papers/Cha99b.html Thanks for making the paper available, I enjoyed it a lot. Bravo! I fully endorse your main motivations from your

Re: Haskell Object

1999-01-29 Thread Daan Leijen
Hi, I'm using HaskellObject inside Visual Basic 6.0. If I create only 1 object (or 2 objects that have the same source), no problem happen. But when I create 2 objects (different source), Visual Basic 6.0 was crashed. Do you know why? Would you please reply as soon as possible ! HaskellObject

preview of HaskellDB

1999-01-12 Thread Daan Leijen
integration makes it possible to do arbitrary computations on the database (like computing the transitive closure) and makes it convenient to combine HaskellDB with other combinator libraries (like Erik Meijer's CGI library or John Hughes pretty printer). All the best, Daan Leijen.

Re: Haskell, CORBA and Java (Was: Re: Current state of GUI...)

1998-08-13 Thread Daan Leijen
From: Daan Leijen [EMAIL PROTECTED] [...] Allthough we have made a binding now for COM, it would indeed be great if we could also have a CORBA binding; it is of vital importance that Haskell can talk with the outside world and the more languages it knows, the better :-) Since

Re: Haskell, CORBA and Java (Was: Re: Current state of GUI...)

1998-08-10 Thread Daan Leijen
I am quite unhappy to see these developments (e.g., H/Direct) being based on some proprietary standards, as it means that they are rather useless to me. Lets clarify some points: - H/Direct is a OSF DCE IDL compiler which can not only generate COM specific bindings but also for example

Re: Felleisen on Standard Haskell

1998-08-04 Thread Daan Leijen
Simon writes: That's just what I intend to do. I don't see Std Haskell as a big deal, but even little deals are worth completing rather than leaving as loose ends... and I'm more optimistic than Paul about the usefulness of Std Haskell. I would be happy to find a name that was less grand and