- Haskell-Cafe - Haskell.org

Re: [Haskell-cafe] Fractional sqrt
by Novák Zoltán 19 Jan '07

19 Jan '07

Hi, Thanks for the answers. The best solution would be a general purpose arbitrary precision math library for Haskell. I found two: http://medialab.freaknet.org/bignum/ http://r6.ca/FewDigits/ I think both uses power series and have trigonometric functions too. (I only need sqrt, so probably I will not use them, just the simple Newton alg.) It would be great, if a fast implementation of arbitrary precision real arithmetic Class would be part of the Standard libraries. Because Haskell is so great for numerical computations already (functions, composing functions, higher order f. with typechecking), a good math library would make Matlab obsolete. :) Zoltan Novak ps. Call me Zoltan (that is my first name), just we write it in different order in Hungary. (Names are in hungarian notation here: the type description precedes the actual name)

3 2

for loops and 2d arrays in haskell
by Fernan Bolando 19 Jan '07

19 Jan '07

hi all Since I am very new to haskell and still learning, I hope I will not annoy poeple by asking the following question. what is the simplest way to implement the following code in haskell? it's just printing the contents of 2D array. for(i = 0; i < imax; i++){ for(n = 0; n < nmax; n++){ printf("%i:%i = %f\n", array[i][n]); } } ,Fernan -- Public PGP/GnuPG key (http://www.fernski.com) pub 1024D/3576CA71 2006-02-02 Fernan Bolando Key fingerprint = FDFE C9A8 FFED C1A5 2F5C EFEB D595 AF1C 3576 CA71

4 5

hs-plugins on ghc6.6?
by Adam Megacz 19 Jan '07

19 Jan '07

Has anybody been able to get hs-plugins to work with ghc6.6? http://www.nabble.com/Re%3A-hs-plugins-runtime-error-with-GHC-6.6%3A-index-… - a -- PGP/GPG: 5C9F F366 C9CF 2145 E770 B1B8 EFB1 462D A146 C380

3 2

X11
by Philippe de Rochambeau 18 Jan '07

18 Jan '07

Hello, does anyone know where I can find examples that use the Graphics.X11.Xlib.Window module. Thanks. phiroc

1 0

Tracing a list comprehension
by Philippe de Rochambeau 18 Jan '07

18 Jan '07

Hello, is there a way to trace a list comprehension such as concat1 :: [[a]] -> [a] concat1 xss = [ x | xs <- xss, x <- xs ] I would like to see what gets stored in xs. Cheers, phiroc

2 1

New (simple) Lazy Evaluation tutorial
by Andrew Wagner 18 Jan '07

18 Jan '07

Hi all, An interesting question came up in #haskell the other day, and I took the resulting discussion and wrapped it up into a simple tutorial for the wiki. Since I'm quite a newbie to haskell myself, I'd appreciate any double-checking of my logic and, of course, any other comments/suggestions. Thanks to Cale for his efforts on this problem, and to the original asker, whose name I can't recall. http://www.haskell.org/haskellwiki/Haskell/Lazy_Evaluation

2 1

Re: [Haskell-cafe] Article review: Category Theory
by David House 18 Jan '07

18 Jan '07

On 18/01/07, Daniel Fischer <daniel.is.fischer(a)web.de> wrote: > Since I don't know whether I would have to register to modify the wiki or > something (and don't know what markup to use either), I just send you a few > corrections by e-mail. Thanks; I've corrected them all, with the exceptions of the ones shown below. http://en.wikibooks.org/w/index.php?title=Haskell/Category_theory&diff=7231… > perhaps index join/unit with the appropriate objects, e.g. > join_X . M(join_X) = join_X . join_M(X), to aid the newcomers? > the picture's left is the text's right. -- -David House, dmhouse(a)gmail.com

1 0

re: Simple HTTP lib for Windows?
by brad clawsie 18 Jan '07

18 Jan '07

there is a Network.HTTP module, but it is not easy to use what you want is the equivalent of perl's LWP::Simple, which provides get() and head() functions i have heard that this is being worked on, in the meantime i personally use this wrapper: http://www.b7j0c.org/content/haskell-http.html that i wrote myself to provide simple get and head functionality with some trivial redirect support i use this module routinely so it should work, although i have only tested it on freebsd and linux no one else has ever looked at this so feel free to send critiques, it is mostly a hack of the get() example script distributed with the Network.HTTP module

1 1

Announce: piggybackGHC 0.1
by Martin Grabmueller 18 Jan '07

18 Jan '07

Hello fellow Haskell Hackers, I announce release 0.1 of piggybackGHC, a small utility package for using GHC for lexing and parsing Haskell source code. Description: The modules in this package provide several functions for conveniently lexing and parsing Haskell modules. The library uses the GHC library for all the hard stuff, so all supported GHC extensions are available. Homepage: http://uebb.cs.tu-berlin.de/~magr/projects/piggybackGHC/doc/ Darcs: darcs get --partial http://uebb.cs.tu-berlin.de/~magr/projects/piggybackGHC/ Feedback appreciated! Have fun, Martin

1 0

Currying
by phiroc＠free.fr 18 Jan '07

18 Jan '07

Hello, what is so great about "currying"? What are its uses, apart from letting one define functions with less parentheses? Many thanks. Phiroc

6 5