- Haskell - Haskell.org

Question concerning ftp and GHC binaries for HP-UX
by ADAMS,RICHARD (Non-HP-Roseville,ex1) 21 Mar '01

21 Mar '01

I would like to download the GHC binaries to our HP 9000 machine (HP-UX 11.0), but have access only to ftp (i.e., no Web browser is available). Does anyone know what ftp address to use? Also, does anyone know whether the GHC binaries for the HP-UX operating system will work on HP-UX 11.0? I am not sure whether it is relevant, but I use Reflection terminal emulation to telnet from my PC to the HP 9000 machine. Truly 'hi-tech' :) . Thank you. Sincerely, Richard E. Adams Softmatrix, Inc. Roseville, CA Email: richard_adams(a)non.hp.com

1 0

Re: modules and re-export
by Matthias Fischmann 21 Mar '01

21 Mar '01

Peter Thiemann <thiemann(a)informatik.uni-freiburg.de> writes: > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > module BUG2A (module BUG2A, module Prelude) where > import Prelude hiding (head) > head = "HEAD" > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > module BUG2B where > import qualified Prelude > import BUG2A > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Unfortunately, this does not behave as (I think) it should: > [...] ghc-4.08.1 compiles it without complaining. A Hugs98 bug? -Matthias

1 0

Re: Coroutines
by Richard Uhtenwoldt 21 Mar '01

21 Mar '01

Andreas Gruenbacher writes: >It's not what I had in mind, though. Simon's MVars (in the Awkward Squad) >come pretty close, but they're still not the sort of (cooperative) >multitasking that I'm thinking of. I hope I'm not being too fussy, but seems to me that the CVar is what is needed, not the MVar: >main= > newCVar >>= \l0 -> > newCVar >>= \l1 -> > newCVar >>= \l2 -> > forkIO readInputLineAtATime l0 >> > forkIO printHeader "silly header" l0 l1 >> > forkIO numberLines 0 l1 l2 >> > printOutputLineAtATime l2 (untested code.)

1 0

GHC Mingw32 build
by Mike Thomas 20 Mar '01

20 Mar '01

Hi all.. What is the recommended way of making the Mingw32 build of GHC and all associated tools, eg HDirect, Green-card etc from the CVS? Cheers Mike Thomas

1 0

modules and re-export
by Peter Thiemann 20 Mar '01

20 Mar '01

I have a little question about the following two modules. Suppose you want to write your own variant of the prelude that redefines a couple of names but leaves all the rest unchanged. The Haskell report says that the following should work: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ module BUG2A (module BUG2A, module Prelude) where import Prelude hiding (head) head = "HEAD" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ This overrides the definition of head and should reexport head along with everything imported from the Prelude. Hugs98/feb2001 loads it happily and says head :: [Char] Now, I want to use this module as an alternative prelude: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ module BUG2B where import qualified Prelude import BUG2A ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Unfortunately, this does not behave as (I think) it should: Reading file "BUG2B.hs": Parsing........................................................................ ERROR "BUG2B.hs": Entity "head" imported from module "BUG2A" already defined in module "Prelude" However, this should be legal from my reading of the report. Any help appreciated. -Peter

1 0

ANNOUNCE: HasChorus - some modules for Haskore
by Martin Schwenke 20 Mar '01

20 Mar '01

HasChorus: A set of Haskell (http://haskell.org/) modules written on top of Haskore (http://haskell.org/haskore/) to make it easier to sequence simple, repetitive music. HasChorus is available via: http://meltin.net/hacks/haskell/ ---------------------------------------------------------------------- HasChorus *has* a bunch of useful modules: HasChords.lhs: Build (diatonic) chords from scales and scale degrees. HasDrums.lhs: Sequence drums in a similar manner to a drum machine. HasEasyMusic.lhs: Allow simple specification of simple music sequences. HasGroove.lhs: Modify Haskore performances via normal distributions. HasPatterns.lhs: Sequence patterns by playing chords in different ways. HasScales.lhs: Build scales and pick notes by scale degree. HasSounds.lhs: Some boring ways of playing some instruments. HaskoreExtras.lhs: Some useful functions that aren't in Haskore. BubbleSort.lhs: An implementation of bubble sort. Used by HasGroove.lhs. Normal.lhs: Generate normal distributions. Used by HasGroove.lhs. TwelveBar.lhs: An example song. Many of the modules can be used without requiring all of the others. The dependencies look something like: HasEasyMusic -> HasChords -> HasScales HasDrums -> HaskoreExtras HasSounds -> HasPatterns HasGroove -> BubbleSort, Normal TwelveBar -> HasChorus -> *EVERTHING ELSE* ---------------------------------------------------------------------- HasChorus has been tested under: * Hugs: Currently I use Hugs 98, February 2000. I use -h1000000 so that HasGroove doesn't melt down... :-) * GHC: 4.08 (previously under 4.07) under x86 Linux. ---------------------------------------------------------------------- I use HasChorus to sequence up simple backing tracks for my own compositions. Enjoy... peace & happiness, martin Martin Schwenke <martin(a)meltin.net> p.s. Several people who have expressed interest in this project during the last few years have received this announcement via a BCC. They haven't been secretly subscribed to the Haskell mailing list. :-)

1 0

knight's tour - please help
by The Ghost 19 Mar '01

19 Mar '01

Hello everyone, I have a little problem with implementing the knight's tour in haskell. My goal is to print out all possible solutions for the knight's tour. Allthough finding one path (with given startinposition (x,y) of the horse and dimension of the bord M*N) is not enough. I have to find all of them. (the printing out may be very simpel) I've wrote this problem is several other languages and there they work perfect. But I'm searching for an implementation in Haskell. The implementation may also be simpel (I think it can be solved only by using lists and backtracking). If I have the implementation I can go one with my project, I should use it to explain the differences between a functional language and the others (effiency, speed,..) Is ther someone who has such an implementation (that is not too complicated and not too lang). Would you be so kind to send it to me? I should be very thankfull. Greetings, The White Ghost. _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.

1 0

question does haskell have a something like a wild character
by john xxx 19 Mar '01

19 Mar '01

i want to know if HAskell has an inbuilt function in the prelude a function that allows me to use wild character like so: ie. if a list of strings contains a word or a combination of words that do not necessarily have to be side by side. someting that works like so [.. "hello" ..] == ["my", "tie" , "egg", "hello", "good"] would return True. where .. represents other elements of the list it counld be 1element or a hundred elements. please reply urgently to johnjohnjohn64(a)hotmail.com if haskell does not provide such a function can you please give me information on how to create one that would do such a thing that i need. THANKYOU FOR YOUR TIME. please reply! i need this function for an assignment for university. p.s if you're interested in the question visit. http://www.cse.unsw.edu.au/~cs1711/ass1/spec-ass1.html _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com.

2 1

Re: Greencard, GHC and FFI.
by Sigbjorn Finne 17 Mar '01

17 Mar '01

Mike Thomas mthomas(a)gil.com.au writes: > > I'm having trouble with using green-card 2 on Windows > with GHC-4.08.2. As the default output for -target ghc seems > to be for the C back-end rather than native code, I thought I would > try the FFI target. > .... example code deleted > > I get > > $ ghc main.hs -o main.exe GCTest.o StdDIS.o -package lang -package greencard > --------------------------------------------- > Compilation IS NOT required > GCTest.o(.text+0x7f):fake: undefined reference to `prim_my_sin' > .... Hi, Greencard lets you write C and Haskell in one source file. When using GHC's C back end, it is possible to combine the two in one source file (via GHC's _casm_s.) The FFI doesn't let you do this, but requires you to provide the C bits separately, and link the Haskell code to it via 'foreign' declarations. So, when using GC's FFI backend, it generates two source files for you (and some header files) - in your case, GCTest.hs and GCTest_stub.c. To achieve linker happiness, you need to compile up the latter and include it on the link line *and* drop StdDIS.o from that link line. hth --sigbjorn

2 1

Greencard, GHC and FFI.
by Mike Thomas 17 Mar '01

17 Mar '01

Hi all. I'm having trouble with using green-card 2 on Windows with GHC-4.08.2. As the default output for -target ghc seems to be for the C back-end rather than native code, I thought I would try the FFI target. Using the example from the green-card doc: --------------------------------------------- module GCTest where import StdDIS %fun my_sin :: Double -> Double %code res1=sin(arg1); --------------------------------------------- Compiling for target FFI: --------------------------------------------- green-card -c GCTest.gc -o GCTest.hs --target ffi ghc -c GCTest.hs -fglasgow-exts --------------------------------------------- Linking with this main module: --------------------------------------------- module Main(main) where import GCTest main :: IO() main = putStrLn (show (my_sin (20.0))) --------------------------------------------- I get: --------------------------------------------- $ ghc main.hs -o main.exe GCTest.o StdDIS.o -package lang -package greencard Compilation IS NOT required GCTest.o(.text+0x7f):fake: undefined reference to `prim_my_sin' StdDIS.o(.text+0x549):fake: undefined reference to `prim_free' StdDIS.o(.text+0x600):fake: undefined reference to `prim_allocCharStar' StdDIS.o(.text+0x731):fake: undefined reference to `prim_readCharAddr' StdDIS.o(.text+0xc84):fake: undefined reference to `prim_malloc' StdDIS.o(.text+0xd38):fake: undefined reference to `access_prim_malloc_res1' StdDIS.o(.text+0xdec):fake: undefined reference to `access_prim_malloc_gc_failed ' StdDIS.o(.text+0xea0):fake: undefined reference to `access_prim_malloc_gc_failst ring' StdDIS.o(.text+0x1206):fake: undefined reference to `prim_writeCharAddr' collect2: ld returned 1 exit status --------------------------------------------- Where have I gone wrong? Cheers Mike Thomas.

1 0