RE: [Haskell-cafe] Unable to hc-build ghc 6.6.1
From: Ian Lynagh [mailto:[EMAIL PROTECTED] You're likely to find it easier to bootstrap by installing a bindist onto the machine, unless that is impossible for some reason. Unfortunately it is due to policy. GenApply.o(.text+0x13a55): In function `s5cr_info': : undefined reference to `base_DataziList_zdsintersperse_info' Nothing comes to mind. Were the libraries rebuilt after building GenApply on the machine on which the hc files were generated? Nope. After building the hc tarball with a new copy of ghc 6.6.1 on the host machine, I pulled it along with a new copy of the source tarball from http://www.haskell.org/ghc onto the target machine. Untarred the hc files, changed mk/build.mk and fixed mk/bootstrap.mk, and ran distrib/hc-build. NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] Unable to hc-build ghc 6.6.1
-Original Message- From: Ian Lynagh [mailto:[EMAIL PROTECTED] Nothing comes to mind. Were the libraries rebuilt after building GenApply on the machine on which the hc files were generated? Nope. After building the hc tarball with a new copy of ghc 6.6.1 on the host machine, I pulled it along with a new copy of the source tarball from http://www.haskell.org/ghc onto the target machine. Untarred the hc files, changed mk/build.mk and fixed mk/bootstrap.mk, and ran distrib/hc-build. Just wanted to note that I get the same error with ghc 6.4.2 (after patching ghc/Makefile's ordering of the SUBDIRS line as noted in http://hackage.haskell.org/trac/ghc/ticket/841, adding -lncurses to mk/bootstrap.mk, and removing ghc 6.6.1 to prevent conflicts). NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Unable to hc-build ghc 6.6.1
I'm trying to do a registered hc-build on linux2.4 x86 with ghc 6.6.1. After fixing mk/bootstrap.mk to include -lncurses in HC_BOOT_LIBS to get past an undefined reference to tputs et al, I've gotten stuck with the following undefined reference error: == gmake all -wr; in /tmp/ghc-6.6.1/utils/runstdtest gmake[1]: Nothing to be done for `all'. Finished making all in runstdtest: 0 == gmake all -wr; in /tmp/ghc-6.6.1/utils/genapply gcc -o genapply -fno-defer-pop -fomit-frame-pointer -fno-builtin -DDONT_WANT_WIN32_DLL_SUPPORT -D__GLASGOW_HASKELL__=606 -O -I/tmp/ghc-6.6.1/includes -I/tmp/ghc-6.6.1/libraries/base/include -I/tmp/ghc-6.6.1/libraries/unix/include -I/tmp/ghc-6.6.1/libraries/parsec/include -I/tmp/ghc-6.6.1/libraries/readline/include-L/tmp/ghc-6.6.1/rts -L/tmp/ghc-6.6.1/libraries/base -L/tmp/ghc-6.6.1/libraries/base/cbits -L/tmp/ghc-6.6.1/libraries/haskell98 -L/tmp/ghc-6.6.1/libraries/parsec -L/tmp/ghc-6.6.1/libraries/regex-base -L/tmp/ghc-6.6.1/libraries/regex-compat -L/tmp/ghc-6.6.1/libraries/regex-posix -L/tmp/ghc-6.6.1/libraries/Cabal -L/tmp/ghc-6.6.1/libraries/template-haskell -L/tmp/ghc-6.6.1/libraries/readline -L/tmp/ghc-6.6.1/libraries/unix -L/tmp/ghc-6.6.1/libraries/unix/cbits -u base_GHCziBase_Izh_static_info -u base_GHCziBase_Czh_static_info -u base_GHCziFloat_Fzh_static_info -u base_GHCziFloat_Dzh_static_info -u base_GHCziPtr_Ptr_static_info -u base_GHCziWord_Wzh_static_info -u base_GHCziInt_I8zh_static_info -u base_GHCziInt_I16zh_static_info -u base_GHCziInt_I32zh_static_info -u base_GHCziInt_I64zh_static_info -u base_GHCziWord_W8zh_static_info -u base_GHCziWord_W16zh_static_info -u base_GHCziWord_W32zh_static_info -u base_GHCziWord_W64zh_static_info -u base_GHCziStable_StablePtr_static_info -u base_GHCziBase_Izh_con_info -u base_GHCziBase_Czh_con_info -u base_GHCziFloat_Fzh_con_info -u base_GHCziFloat_Dzh_con_info -u base_GHCziPtr_Ptr_con_info -u base_GHCziStable_StablePtr_con_info -u base_GHCziBase_False_closure -u base_GHCziBase_True_closure -u base_GHCziPack_unpackCString_closure -u base_GHCziIOBase_stackOverflow_closure -u base_GHCziIOBase_heapOverflow_closure -u base_GHCziIOBase_NonTermination_closure -u base_GHCziIOBase_BlockedOnDeadMVar_closure -u base_GHCziIOBase_Deadlock_closure -u base_GHCziWeak_runFinalizzerBatch_closure -u __stginit_Prelude GenApply.o -lHSreadline -lreadline -lHStemplate-haskell -lHSunix -lHSunix_cbits -lHSCabal -lHShaskell98 -lHSregex-compat -lHSregex-posix -lHSregex-base -lHSbase -lHSbase_cbits -lHSparsec -lHSrts -lgmp -lm -lncurses -ldl -lrt GenApply.o(.text+0x13a55): In function `s5cr_info': : undefined reference to `base_DataziList_zdsintersperse_info' GenApply.o(.text+0x14c11): In function `s58p_info': : undefined reference to `base_DataziList_zdsintersperse_info' GenApply.o(.text+0x17d79): In function `s54x_info': : undefined reference to `base_DataziList_zdsintersperse_info' collect2: ld returned 1 exit status gmake[1]: *** [genapply] Error 1 Failed making all in genapply: 1 gmake: *** [all] Error 1 gmake: Leaving directory `/tmp/ghc-6.6.1/utils' Does anyone know why this might be occuring? The only reference to base_DataziList_zdsintersperse_info on google didn't seem to have an answer. For reference my mk/build.mk is: SRC_HC_OPTS = -H32m -O -fvia-C -Rghc-timing -keep-hc-files GhcLibHcOpts= -O GhcLibWays = SplitObjs = NO just as the example one given on http://hackage.haskell.org/trac/ghc/wiki/Building/Porting. Also- in case this is related- I moved AutoApply_thr.thr_hc to AutoApply_thr.hc (and likewise for debug, thr_debug, and thr_p). Thanks, Joseph Re NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] Re: Ubuntu and ghc
Not sure about it's current state, but a friend was working on this until he graduated recently: http://www.acm.uiuc.edu/projects/Wipt -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ketil Malde Aren't there any usable third-party package managers for windoze? The most usable one I've seen is Steam from Valve, IIRC. It'd be cool if Haskell packages were provided this way. -k NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] Looking for final year project - using Haskell, or another functional language
If you meant just non-graphic uses of a gpu, I don't know much in that area, but I do know of a very neat graphics related (but irregular on standard gpus) topic; ray tracing. First off, a basic idea of what ray tracing is: http://en.wikipedia.org/wiki/Ray_tracing Second, for great reasons why ray tracing is useful and probably neccessary for the future, Dr. Kavita Bala gave a talk in 2005 (abstract: http://www.acm.uiuc.edu/conference/2005/speakers.php#KavitaBalaAbstract video: http://www.acm.uiuc.edu/conference/2005/video/UIUC-ACM-RP05-Kavita-Bala. wmv). I don't recall if she explicitly says it, but applying her feature emphasis approach to procedurally generated textures (which should scale in resolution perfectly) would be a way for a modern engine to really shine. During the same conference Dr. Peter Shirley gave the talk Real Time Ray Tracing on the Desktop: When and How? (abtract: http://www.acm.uiuc.edu/conference/2005/speakers.php#PeteShirleyAbstract video: http://www.acm.uiuc.edu/conference/2005/video/UIUC-ACM-RP05-Peter-Shirle y.wmv) Shirley decides in that video that a hardware based solution is what he should shoot for, and his group joins the Saarland University Graphics Group. [Note: if you are willing to watch both of these I recommend watching Dr. Shirley's first. Also, note that some videos have delayed starts.] Shortly thereafter, their groups make a number of advancements in ray tracing, and they created a working RPU (http://graphics.cs.uni-sb.de/SaarCOR/) on a FPGA board that is capable of rendering basic scenes in realtime as well as come out with a software solution that does roughly the same called OpenRT (http://www.openrt.de/). Both implementations scale accross multiple processors very well due to inherent parallelism in ray tracing. My guess is that a realtime engine (and a good game) using software ray tracing will help it gain popularity, but then dedicated boards made from the FPGA designs will take over shortly thereafter (High end graphics cards from NVIDIA provide 23 times more programmable floating point performance and 100 times more memory bandwidth as our prototype). Concurrently there has also been work of doing ray tracing on existing GPUs. Here's a neat paper from someone at my university, on structures for using a gpu for ray tracing, Fast GPU Ray Tracing of Dynamic Meshes using Geometry Images (http://graphics.cs.uiuc.edu/geomrt/geomrt2006.pdf). I'm unaware if he applies any of the breakthrough techniques learned from OpenRT's research (since it's very recent), but if not, that would certainly be a viable topic to explore within the realm of GPGPU-ish work. Getting a really performance optimized haskell implementation of OpenRT or bindings to an existing library (http://liris.cnrs.fr/~bsegovia/yacort/ or http://xfrt.sourceforge.net/) would be very cool, especially when combined with a shader dsl, a procedural generation library+dsl, overall graphics engine, and *dreams on*. At that point, someone could easily write the world's most beautiful nethack with little artistic skill. - Non-graphics related GPGPU uses: ATI's Stream Computing: http://ati.amd.com/technology/streamcomputing/index.html NVIDIA's CUDA: http://developer.nvidia.com/object/cuda.html Both of these allow you to code in the standard C language and low level assembly language layer and driver interface. A number of open source GPGPU libraries (BrookGPU http://graphics.stanford.edu/projects/brookgpu/index.html and Sh http://libsh.org/) shoot for C++. One would think that given how well programming GPUs lends itself to a functional language, clearly, they must be appealing to the lowest common denominator, but their language for the hardcore is some god awful assembly language... [defense] I get that they're performance nuts, but when's the last time you wrote a large and meaningful application in assembly (not a single inlined assembly function) by hand, that beat using your compiler (it terms of developer+system execute time)? If you can answer, my guess is either you're working on a compiler, or yours is broken. [/defense] Writing a real language for general progamming on GPUs would be pretty cool, although you'd have to then think of something to do with it as otherwise it might be a short project (rough guess considering the existing work in the area). Did either of these help? -- Joseph Re From: wp [mailto:[EMAIL PROTECTED] Sent: Thursday, July 12, 2007 6:41 PM To: Re, Joseph (IT) Subject: Re: [Haskell-cafe] Looking for final year project - using Haskell,or another functional language Hi Joseph, no, I don't mind if you cc the list. I just skimmed the two papers on Vertigo and Renaissance. Very interesting ... and not just that. I have been following in the last months/years the advances of GPGPU. Surely a lot of people think this is nothing of practical usage, especially if it comes to serious
RE: [Haskell-cafe] Speedy parsing
Ah, I thought I might have to resort to one of the ByteStrings modules. I've heard of them but was more or less avoiding them due to some complexities with installing extra libraries in my current dev environment. I'll try to work that out with the sysadmins and try it out. Thanks for the advice -Original Message- From: Tillmann Rendel [mailto:[EMAIL PROTECTED] Sent: Thursday, July 19, 2007 8:48 PM To: Re, Joseph (IT) Cc: haskell-cafe@haskell.org Subject: Re: [Haskell-cafe] Speedy parsing Re, Joseph (IT) wrote: At this point I'm out of ideas, so I was hoping someone could identify something stupid I've done (I'm still novice of FP in general, let alone for high performance) or direct me to a guide,website,paper,library, or some other form of help. Two ideas about your aproaches: (1) try to avoid explicit recursion by using some standard library functions instead. it's easier (once you learned the library) and may be faster (since the library may be written in a easy to optimize style). (2) try lazy ByteStrings, they should be faster. http://www.cse.unsw.edu.au/~dons/fps.html As an example, sorting of the individual lines of a csv files by key. csv parses the csv format, uncsv produces it. these functions can't handle '=' in the key or ',' in the key or value. treesort sorts by inserting stuff into a map and removing it in ascending order: import System.Environment import qualified Data.ByteString.Lazy.Char8 as B import qualified Data.Map as Map import Control.Arrow (second) csv = (map $ map $ second B.tail . B.break (== '=')) . (map $ B.split ',') . (B.split '\n') uncsv = (B.join $ B.pack \n) . (map $ B.join $ B.pack ,) . (map $ map $ \(key, val) - B.concat [key, B.pack =, val]) treesort = Map.toAscList . Map.fromList main = B.interact $ uncsv . map treesort . csv Tillmann NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] Speedy parsing
Oh, I didn't realize how much of a difference it would make. Thanks a lot! -- Joseph Re -Original Message- From: Salvatore Insalaco [mailto:[EMAIL PROTECTED] Sent: Friday, July 20, 2007 12:21 PM To: Tillmann Rendel Cc: Re, Joseph (IT); haskell-cafe@haskell.org Subject: Re: [Haskell-cafe] Speedy parsing 2007/7/20, Tillmann Rendel [EMAIL PROTECTED]: Re, Joseph (IT) wrote: At this point I'm out of ideas, so I was hoping someone could identify something stupid I've done (I'm still novice of FP in general, let alone for high performance) or direct me to a guide,website,paper,library, or some other form of help. I think that your problem is simply an excess of lazyness :). foldr is too lazy: you pass huge structures to fold, that you evaluate anyway. Try to import Data.List and use foldl' (not foldl), that is strict. Being left fold, you probably need to rework a bit your functions (I tried to simply flip them, but the result of the program wereflipped too), but the time (and memory) difference is unbelievabl (foldl' is constant in memory allocation). Salvatore NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Speedy parsing
I was hoping someone could direct me to material on how I might go about
optimizing a small parsing program I wrote. Used for calculating
differences between two files that store a hash of hashes (each line is
a hash, each line has key=value pairs seperated by commas), the
bottleneck seems to be in getting the data into memory (in a usable
structure) quickly, as I'm working with extremely large files (250,000
line, 100MB+ files are normal in size, some are quite larger, and I have
to process a large number of them often).
Extracting just the parsing elements of my current python
implementation:
FILE: compare.py
import sys
def parse(lines):
print Parsing,len(lines),lines...
failed = 0
hashes = {}
for line in lines:
try:
hash = {}
parts = line.split(,)
for part in parts:
k,v = part.split(=)
hash[k] = v
hashes[ hash[LogOffset] ] = hash
except:
if line != :
failed += 1
if failed 0:
print [ERROR] Failed to parse:,failed,lines
print ...Parsing resulted in,len(hashes),unique hashes
return hashes
def normalize(lines):
lineset = set()
for line in lines:
if Type=Heartbeat == line[0:14]: pass
elif line == : pass
else: lineset.add( line ) #use set to get only uniques
return lineset
def main():
hashes = parse( normalize ( open(sys.argv[1]).readlines() ))
if __name__ == '__main__': main()
$ time python compare.py 38807lineFile
Removed 52 bad lines
Parsing 38807 lines...
...Parsing resulted in 38807 unique hashes
real0m3.807s
user0m3.330s
sys 0m0.470s
$ time python compare.py 255919lineFile
Removed 0 bad lines
Parsing 255919 lines...
...Parsing resulted in 255868 unique hashes
real0m30.889s
user0m23.970s
sys 0m2.900s
*note: profiling shows over 7.1 million calls to the split() function,
to give you a good idea of the number of pairs the file contains.
Once you factor in much increased filesizes, actually preforming the
analysis, and running it on a few dozen files, my tests started to
become quite time consuming (not to mention it takes 1GB of memory for
just the 250K line files, although execution time is still much more
important at the moment thanks to ram being cheap).
Thusly, I figured I'd rewrite it in C, but first I wanted to give
Haskell a shot, if only to see how it compared to python (hoping maybe I
could convince my boss to let me use it more often if the results were
good). The first thing I wanted to check was if parsec was a viable
option. Without even putting the data into lists/maps, I found it too
slow.
FILE: compare_parsec.hs
{-# OPTIONS_GHC -O2 #-}
module Main where
import System.Environment (getArgs)
import Text.ParserCombinators.Parsec
csv = do x - record `sepEndBy` many1 (oneOf \n)
eof
return x
record = field `sepBy` char ','
field = many (anyToken)
main = do
~[filename] - getArgs
putStrLn Parsing log...
res - parseFromFile csv filename
case res of
Left err - print err
Right xs - putStrLn ...Success
$ time ./compare_parsec 38807lineFile
Parsing log...
...Success
real0m13.809s
user0m11.560s
sys 0m2.180s
$ time ./compare_parsec 255919lineFile
Parsing log...
...Success
real1m28.983s
user1m8.480s
sys 0m9.530s
This, sadly, is significantly worse than the python code above. Perhaps
someone here can offer advice on more efficient use of parsec?
Unfortunately I don't have profiling libraries for parsec available on
this machine, nor have I had any luck finding material on the web.
After this, I tried doing my own parsing, since the format is strict and
regular. I tried pushing it to lists (fast, not very usable) and maps
(much easier for the analysis stage and what the python code does, but
much worse speedwise).
FILE: compare_lists.hs
{-# OPTIONS_GHC -O2 -fglasgow-exts #-}
module Main where
import System.Environment (getArgs)
type Field = (String,String)
type Record = [Field]
type Log = [Record]
main = do
~[filename1] - getArgs
file1 - readFile filename1
putStrLn Parsing file1...
let data1 = parseLog file1
print data1
putStrLn ...Done
-- parse file
parseLog :: String - Log
parseLog log = foldr f [] (lines log)
where f a = a
f \n a = a
f x a = (parseRecord x):a
-- parse record
parseRecord :: String - Record
parseRecord record = foldr (\x a - (parseField x):a) [] (split ','
record)
-- parse field
-- no error detection/handling now
parseField :: String - Field
parseField s = (takeWhile isntCharEq s, tail $ dropWhile isntCharEq s)
isntCharEq :: Char - Bool
isntCharEq '=' = False
isntCharEq _ = True
split :: Eq a = a - [a] - [[a]]
split delim = foldr f [[]]
where
f x rest@(r:rs)
| x == delim = [] : rest
| otherwise = (x:r) : rs
I wasn't sure the best way to force evaluation on this, so I opt'd
RE: [Haskell-cafe] Haskell shootout game
Interestingly enough, we're doing something very similar for [EMAIL PROTECTED]'s 2007 MechMania XIII contest (http://en.wikipedia.org/wiki/Mechmania), an AI competition hosted during our annual Reflections Projections conference. I can't release too many details until the day of the contest (Oct 13), but it's tactical, grid based combat game where you get one day to write an AI (while testing in a pre-arena of sorts that is rendered to a video wall in the middle of the conference building's atrium) and then the next morning we run a (usually double elimination) tournament and display all the simulations on a giant projector. You can look at screenshots / client API docs from 2006 as an example until we post the details the night of the contest. After the contest we post results, (hopefully) clean up the code, and release it for people to play with. We're not professionals, nor do we mainly write games, but it should be clean enough for someone to modify and play around with. I guess it goes without saying that you can actually enter the contest proper by coming to the conference if you happen to live in the middle of nowhere (Champaign-Urbana, IL USA). Registration will be up (www.acm.uiuc.edu/conference/) towards the end of summer. From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Hugh Perkins Sent: Sunday, July 15, 2007 2:47 PM To: haskell-cafe Subject: [Haskell-cafe] Haskell shootout game Had an idea: a real shootout game for Haskell. The arena itself comprises: - a 2d grid, of a certain size (or maybe variable size) - each grid cell can be a wall, or one of the opponents - the boundaries of the grid are walls - random blocks of wall are placed around the grid This can run on a hosted webserver probably, because each match is part of a webpage request, and lasts a maximum of about a second, so shouldnt be terminated prematurely by cpu-monitoring scripts. NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] Looking for final year project - using Haskell, or another functional language
I actually meant that simply as beyond opengl bindings, but added 'better' to make reference to Hugh's suggestion. The website sure could be better though ;) -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Claus Reinke Sent: Thursday, July 12, 2007 7:23 PM To: haskell-cafe@haskell.org Subject: Re: [Haskell-cafe] Looking for final year project - using Haskell,or another functional language Building on what Hugh was getting at, beyond better opengl bindings, i'm curious: just what do you think is missing in haskell's opengl binding? just be sure to ignore http://www.haskell.org/HOpenGL/ , which should be moved to the wiki or to /dev/null. instead, look at the implementation, mailing list and and api docs (which need to be read side-by-side with the specs): http://darcs.haskell.org/packages/OpenGL http://www.haskell.org/mailman/listinfo/hopengl http://www.haskell.org/ghc/docs/latest/html/libraries/OpenGL/Graphics-Re ndering-OpenGL-GL.html the mailing list has occasional progress info like this http://www.haskell.org/pipermail/hopengl/2006-November.txt Implement the entire opengl 1.3 interface specifications in Haskell. http://www.haskell.org/ghc/docs/latest/html/libraries/OpenGL/Graphics-Re ndering-OpenGL-GL-BasicTypes.html This module corresponds to section 2.3 (GL Command Sytax) of the OpenGL 2.1 specs. claus ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] Maintaining the community
Perhaps I haven't found the amazing treasure trove of open NNTP servers you appear to have, but in my experience I've yet to find a single good (read: access to most groups and quick about it) and free NNTP server (read: not from my ISP, employer, or university - which, if provided at all, have always been quite limited in which groups they serve), so I can completely understand where the others are coming from in this regard. Perhaps those of you who have found good, free NNTP servers would care to share these well kept secrets? -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Andrew Coppin Sent: Friday, July 13, 2007 5:04 PM To: haskell-cafe@haskell.org Subject: Re: [Haskell-cafe] Maintaining the community Mark T.B. Carroll wrote: Andrew Coppin [EMAIL PROTECTED] writes: ...and when you view a web page, your web browser has to connect to a web server somewhere. I don't see your point... Very many news servers will only serve news to people on the network of whoever's running the server: i.e. a rather restricted 'customer' base. Really? Most web servers will accept a connection from anybody. (Unless it's *intended* to be an Intranet.) I'm not quite sure why somebody would configure their NNTP server differently... ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe NOTICE: If received in error, please destroy and notify sender. Sender does not intend to waive confidentiality or privilege. Use of this email is prohibited when received in error. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] Looking for final year project - using Haskell, or another functional language
Building on what Hugh was getting at, beyond better opengl bindings, I'd be interested in what a modern real-time graphics engine would look like in Haskell; not a game engine, just a very flexible and well made universal graphics engine. I think there's already a lot of ground work already broken in with a practical example of Yampa via Frag, http://aegisknight.org/papers/Renaissance%202005.pdf and http://conal.net/papers/Vertigo/ for purely functional programming of shaders, etc. At the same time, however, there's still a decent amount of work to be explored outside that core with the: * Representation of objects - internal scene graph description and optimization for different types of scenes such as indoor (bsp?), landscapes (octree?) as well as issues wrt a scene or collection of scenes' actual definition. * Perhaps questions relating to collections of objects (hierarchical issues). * Procedural texture and model generation - some interesting work with Pan and derivatives, but certainly nothing incorporated into a 3d engine afaik. That being said, it's important to be able to design it separately besides just having the engine render it, but the popular demoscene (http://www.werkkzeug.com/), professional (http://www.profxengine.com/), and open source (http://www.fxgen.org/) tools all use artist oriented design methods (linking literal function boxes with arrows or stacking them upon each other) and thus are inherently crippled in functionality (and they become incomprehensible with any large size). A proper DSL incorporating some of Pan's features with the larger math libraries of the 3 examples above would allow a superior tool by simply combining [text editor of your choice] and a small app using the engine's procedural generation libraries to compile your MaterialDescriptionLanguage code and provide a preview window. * Somewhat related matters such as plugin based texture rendering (ie rendering a video to texture via external video decoding plugin). * Automatically generated LOD meshes and detecting when to apply them optimally. Haven't personally read anything on this, but a quick search on citeseer gives a large number of promising papers. Beyond the graphics aspect there are also somewhat related networking issues (simulation visualizers, multiplayer games) if you're more interested in that. * Animation - I know little about this. (I'm told) Yampa could be of great use, but I'm not sure how it ties in with standard animation techniques with key frames, IK bones, and whatnot. * Effects such as particle systems, post processing, and cloth simulation seem like a great place to exploit the easy concurrency inherent to purity (see Particle animation and rendering using data parallel computation for a start), although post processing would be very simple if you incorporated a good shader DSL similar to vertigo as noted above. * Ability to query the scene for integration with other code for object picking, that is, translating 2d-3d to figure out what the user clicked, for apps, AI if used with a simulation or game of sorts (ie accurate response to shadows cast by other actors), etc. You might be able to prevent this from forcing the rendering to pause, but nothing comes to mind. AFAIK, if STM retried your query you would get the next frame's data (or later), which may still be ok, but the delay might be visible to the user. * Resource management for large asset collections. The real trick here is you need to stay real-time and so lazy methods simply won't work. I assume you could apply a good deal of techniques from preemptive/speculative evaluation and garbage collection. If you did something with scene management above you could do a static analysis of all the scenes that need to be processed before the user is willing to wait (ie game-level, simulation-large time chunk?) to optimize when you perform the loads/clears. Dynamically generated data might pose a few extra difficulties. Games such as Halo have hard coded hallways and elevators as times for the graphics engine to load data, but I think a general heuristic for figuring out something similar is feasible with 1-2 passes over a (quasi?)4D scene graph (add [Tree] of the data required to render a collection of scenes over time). Just a few *very* rough ideas I'm thinking of at the moment; certainly more (and more depth) to consider. I apologize for the archaic formatting, I'll try to tex/wiki up a formal list of questions soon. Hope you enjoy whichever project you end up choosing, Joseph Re From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Hugh Perkins Sent: Tuesday, July 10, 2007 4:46 PM To: wp; haskell-cafe@haskell.org Subject: Re: [Haskell-cafe] Looking for final year project - using Haskell,or another functional language rpc layer, like .Net Remoting or ICE (but preferably without needing configuration/interface files) Course, if you know what you're
