- Haskell-Cafe - Haskell.org

GHC optimization issue
by Joel Reymont 22 Dec '05

22 Dec '05

Folks, I have been trying to improve my byte swapping routines as part of my effort to speed up serialization. I then tried to look at the core output from GHC to see what it was converting my code into. Brandon (skew on #haskell) helped me code a TH version but then I went with a regular CPP version instead. The point of contention is that the logical approach to optimization does not produce expected results. The only difference between the following two core outputs is the presence or absence of specialize and inline pragmas. The code is the same. The version without pragmas inlines foo1 into Main.foo1 :: GHC.Word.Word16 [GlobalId] [Str: DmdType] Main.foo1 = case GHC.Word.Word16 GHC.Word.$wshift3 __word 3855 (-8) of ww1_a2eo { __DEFAULT -> case GHC.Word.Word16 GHC.Word.$wshift3 __word 15 8 of ww_a2f4 { __DEFAULT -> GHC.Word.W16# (GHC.Prim.narrow16Word# (GHC.Prim.plusWord# ww1_a2eo ww_a2f4)) } } Whereas the version _with_ pragmas produces a function call: Main.foo1 :: GHC.Word.Word16 [GlobalId] [Str: DmdType] Main.foo1 = case GHC.Word.Word16 Swap1.$w$sswap16 __word 3855 of ww1_s1Ia { __DEFAULT -> GHC.Word.W16# ww1_s1Ia } Is there a reasonable explanation? Both versions compiled thusly: ghc --make Foo.hs -O -ddump-simpl > foo Swap: {-# OPTIONS_GHC -fglasgow-exts -cpp #-} module Swap1 ( swap16 ) where import Data.Word import Data.Int import Data.Bits #define BIG_ENDIAN 1 {-# SPECIALIZE swap16 :: Word16 -> Word16 #-} {-# SPECIALIZE swap16 :: Int16 -> Int16 #-} {-# INLINE swap16 #-} swap16 :: Bits a => a -> a #ifdef BIG_ENDIAN swap16 v = (v `shiftR` 8) + ((v .&. 0xFF) `shiftL` 8) #else swap16 v = v #endif Foo: module Main where import Data.Word import Swap1 foo1 :: Word16 foo1 = swap16 0x0f0f main = putStrLn $ show foo1 Core output for the version WITH pragmas, see the version w/o pragmas way below ==================== Tidy Core Rules ==================== "SPEC Swap1.swap16" __forall {$dBits_X1Co :: {Data.Bits.Bits GHC.Int.Int16}} Swap1.swap16 @ GHC.Int.Int16 $dBits_X1Co = Swap1.$sswap16 ; "SPEC Swap1.swap16" __forall {$dBits_X1Cv :: {Data.Bits.Bits GHC.Word.Word16}} Swap1.swap16 @ GHC.Word.Word16 $dBits_X1Cv = Swap1.$sswap161 ; ==================== Tidy Core ==================== Main.foo1 :: GHC.Word.Word16 [GlobalId] [Str: DmdType] Main.foo1 = case GHC.Word.Word16 Swap1.$w$sswap16 __word 3855 of ww1_s1Ia { __DEFAULT -> GHC.Word.W16# ww1_s1Ia } ==================== Tidy Core ==================== Swap1.$w$sswap16 :: GHC.Prim.Word# -> GHC.Prim.Word# [GlobalId] [Arity 1 NoCafRefs Str: DmdType L] Swap1.$w$sswap16 = \ (ww_s1I5 :: GHC.Prim.Word#) -> case GHC.Prim.Word# GHC.Word.$wshift3 ww_s1I5 (-8) of ww1_a1Gx { __DEFAULT -> case GHC.Prim.Word# GHC.Word.$wshift3 (GHC.Prim.and# ww_s1I5 __word 255) 8 of ww11_a1Hd { __DEFAULT -> GHC.Prim.narrow16Word# (GHC.Prim.plusWord# ww1_a1Gx ww11_a1Hd) } } Swap1.$w$sswap161 :: GHC.Prim.Int# -> GHC.Prim.Int# [GlobalId] [Arity 1 NoCafRefs Str: DmdType L] Swap1.$w$sswap161 = \ (ww_s1HV :: GHC.Prim.Int#) -> case GHC.Prim.Int# GHC.Int.$wshift2 ww_s1HV (-8) of ww1_a1Fk { __DEFAULT -> case GHC.Prim.Int# GHC.Int.$wshift2 (GHC.Prim.word2Int# (GHC.Prim.and# (GHC.Prim.int2Word# ww_s1HV) __word 255)) 8 of ww11_a1G5 { __DEFAULT -> GHC.Prim.narrow16Int# (GHC.Prim.+# ww1_a1Fk ww11_a1G5) } } Swap1.$sswap16 :: GHC.Int.Int16 -> GHC.Int.Int16 [GlobalId] [Arity 1 Worker Swap1.$w$sswap161 NoCafRefs Str: DmdType U(L)m] Swap1.$sswap16 = __inline_me (\ (w_s1HT :: GHC.Int.Int16) -> case GHC.Int.Int16 w_s1HT of w1_X1I5 { GHC.Int.I16# ww_s1HV -> case GHC.Int.Int16 Swap1.$w$sswap161 ww_s1HV of ww1_s1I0 { __DEFAULT -> GHC.Int.I16# ww1_s1I0 } }) Swap1.$sswap161 :: GHC.Word.Word16 -> GHC.Word.Word16 [GlobalId] [Arity 1 Worker Swap1.$w$sswap16 NoCafRefs Str: DmdType U(L)m] Swap1.$sswap161 = __inline_me (\ (w_s1I3 :: GHC.Word.Word16) -> case GHC.Word.Word16 w_s1I3 of w1_X1Ih { GHC.Word.W16# ww_s1I5 -> case GHC.Word.Word16 Swap1.$w $sswap16 ww_s1I5 of ww1_s1Ia { __DEFAULT -> GHC.Word.W16# ww1_s1Ia } }) Swap1.swap16 :: forall a_a1aQ. (Data.Bits.Bits a_a1aQ) => a_a1aQ -> a_a1aQ [GlobalId] [Arity 1 NoCafRefs Str: DmdType L] Swap1.swap16 = __inline_me (\ (@ a_a1dB) ($dBits_a1ip :: {Data.Bits.Bits a_a1dB}) -> let { $dNum_s1BO :: {GHC.Num.Num a_a1dB} [Str: DmdType {a1ip->U (SAAAAAAAAAAAAAAAAA)}] $dNum_s1BO = Data.Bits.$p1Bits @ a_a1dB $dBits_a1ip } in let { lit_s1BN :: a_a1dB [Str: DmdType {a1ip->U (SAAAAAAAAAAAAAAAAA) s1BO->U(AAAAAAAAS)}] lit_s1BN = GHC.Num.fromInteger @ a_a1dB $dNum_s1BO (GHC.Num.S# 255) } in \ (v_a1aW :: a_a1dB) -> GHC.Num.+ @ a_a1dB $dNum_s1BO (Data.Bits.shiftR @ a_a1dB $dBits_a1ip v_a1aW (GHC.Base.I# 8)) (Data.Bits.shiftL @ a_a1dB $dBits_a1ip (Data.Bits..&. @ a_a1dB $dBits_a1ip v_a1aW lit_s1BN) (GHC.Base.I# 8))) Core output without pragmas: Main.foo1 :: GHC.Word.Word16 [GlobalId] [Str: DmdType] Main.foo1 = case GHC.Word.Word16 GHC.Word.$wshift3 __word 3855 (-8) of ww1_a2eo { __DEFAULT -> case GHC.Word.Word16 GHC.Word.$wshift3 __word 15 8 of ww_a2f4 { __DEFAULT -> GHC.Word.W16# (GHC.Prim.narrow16Word# (GHC.Prim.plusWord# ww1_a2eo ww_a2f4)) } } --- Swap1.swap16 :: forall a_a1aQ. (Data.Bits.Bits a_a1aQ) => a_a1aQ -> a_a1aQ [GlobalId] [Arity 1 NoCafRefs Str: DmdType L] Swap1.swap16 = \ (@ a_a1dB) ($dBits_a1ip :: {Data.Bits.Bits a_a1dB}) -> let { $dNum_s1BK :: {GHC.Num.Num a_a1dB} [Str: DmdType] $dNum_s1BK = case {GHC.Num.Num a_a1dB} $dBits_a1ip of tpl_B1 { Data.Bits.:DBits tpl1_B2 tpl2_B3 tpl3_B4 tpl4_B5 tpl5_B6 tpl6_B7 tpl7_B8 tpl8_B9 tpl9_Ba tpl10_Bb tpl11_Bc tpl12_Bd tpl13_Be tpl14_Bf tpl15_Bg tpl16_Bh tpl17_Bi tpl18_Bj -> tpl1_B2 } } in let { lit_s1BM :: a_a1dB [Str: DmdType] lit_s1BM = case a_a1dB $dNum_s1BK of tpl_B1 { GHC.Num.:DNum tpl1_B2 tpl2_B3 tpl3_B4 tpl4_B5 tpl5_B6 tpl6_B7 tpl7_B8 tpl8_B9 tpl9_Ba -> tpl9_Ba Swap1.lvl1 } } in \ (v_a1aW :: a_a1dB) -> tpl3_B4 (case a_a1dB $dBits_a1ip of tpl10_Xy { Data.Bits.:DBits tpl11_XB tpl12_XD tpl13_XF tpl14_XH tpl15_XJ tpl16_XL tpl17_XN tpl18_XP tpl19_XR tpl20_Bb tpl21_Bc tpl22_Bd tpl23_Be tpl24_Bf tpl25_Bg tpl26_Bh tpl27_Bi tpl28_Bj -> tpl26_Bh v_a1aW Swap1.lvl }) (case a_a1dB $dBits_a1ip of tpl10_Xy { Data.Bits.:DBits tpl11_XB tpl12_XD tpl13_XF tpl14_XH tpl15_XJ tpl16_XL tpl17_XN tpl18_XP tpl19_XR tpl20_Bb tpl21_Bc tpl22_Bd tpl23_Be tpl24_Bf tpl25_Bg tpl26_Bh tpl27_Bi tpl28_Bj -> tpl25_Bg (tpl12_XD v_a1aW lit_s1BM) Swap1.lvl }) -- http://wagerlabs.com/

1 0

RE: [Haskell-cafe] When to teach IO
by Bayley, Alistair 22 Dec '05

22 Dec '05

> [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of > jerzy.karczmarczuk(a)info.unicaen.fr > > PS. About the subject (when to teach IO): don't be sectarians. If > a programming course insists on algorithmics, the IO issues can be > postponed a bit. If it insists on practical data processing, IO > should come in immediately. A programming course should be > harmonious, homogeneous, well assembled, interesting, and easy to > put into practice (...sorry for triviality, you ALL know that...), > and the details depend on the language and on the teacher. > In Scheme it is easier than in Haskell. _What_ is easier in Scheme than in Haskell? IO, or teaching (IO)? ***************************************************************** Confidentiality Note: The information contained in this message, and any attachments, may contain confidential and/or privileged material. It is intended solely for the person(s) or entity to which it is addressed. Any review, retransmission, dissemination, or taking of any action in reliance upon this information by persons or entities other than the intended recipient(s) is prohibited. If you received this in error, please contact the sender and delete the material from any computer. *****************************************************************

2 1

Re: When to teach IO (was Tutorial uploaded)
by Bayley, Alistair 22 Dec '05

22 Dec '05

> From: haskell-cafe-bounces(a)haskell.org > [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of Robin Green > > No, that's not what I meant at all. I meant that for *many* > but not all > practical programming tasks, IO is important. Games, GUI office > applications, database applications, web applications, etc. > > Compilers are atypical in this regard. Something that is perceived as > being only useful for a compilers and a few other academic-ish things > isn't going to be perceived as very practically useful. > -- > Robin Hear, hear. Compilers, and computationally complex programs in general, are atypical. IMO, a lot of programming these days is integration work i.e. shuffling and transforming data from one system to another, or transforming data for reports, etc. Not many programmers write compilers these days :-( (apologies to the Simons, and John Meacham, and anyone else who *has* written a compiler, Haskell or otherwise...) http://www.mcs.vuw.ac.nz/~kjx/papers/nopp.pdf It's good to start with IO. Reading and writing files, parsing and printing (show and read), talking to databases, GUIs, and networking are more-or-less essential activities, and people want to know early on how to do these things. You don't have to introduce the IO monad; just tell people that we separate IO functions from "pure" functions with this special IO type, and, with the "imperative" do-notation, IO code in Haskell looks a lot like IO code in C/Java/.Net. The Really Good Stuff (real monadic programming) can come later. Perhaps there are two different worlds to consider. Teaching Haskell to tertiary students might well be better suited to a style where purely functional programming is explored in some detail before IO and monads are introduced. However, a jobbing programmer evaluating Haskell wants to know how they do the things they're used to doing in other langauges, and if they see the volume of stuff that must be covered before topics like IO, GUIs, and networking, they'll start to look elsewhere... How hard should it be to shove a window on the screen, or select some data from a database? Part of the problem is that we're not just introducing a new language, we're introducing a new paradigm. I can see that a noob would choke if you tried to ram it down their throat all at once. As a comparison, I have some .Net books in front of me, and although they also introduce the language first (declarations, choice, iteration, classes and interfaces), it's pretty trivial stuff and can be skimmed over fairly quickly, and then you quickly get into introspection (reflection), GUIs, IO, databases, and networking. Indeed, the bulk of the book covers these topics. Alistair ***************************************************************** Confidentiality Note: The information contained in this message, and any attachments, may contain confidential and/or privileged material. It is intended solely for the person(s) or entity to which it is addressed. Any review, retransmission, dissemination, or taking of any action in reliance upon this information by persons or entities other than the intended recipient(s) is prohibited. If you received this in error, please contact the sender and delete the material from any computer. *****************************************************************

4 3

Problems with square root...
by Daniel Carrera 22 Dec '05

22 Dec '05

Hey, The sqrt function is not doing what I want. This is what I want: round sqrt(2) The problem is that sqrt() returns a "Floating" value and round wants a "ReacFrac": --//-- *Main> round sqrt(2) <interactive>:1:0: No instances for (RealFrac (a -> a), Integral (t -> a1)) arising from use of `round' at <interactive>:1:0-4 Probable fix: add an instance declaration for (RealFrac (a -> a), Integral (t -> a1)) In the definition of `it': it = round sqrt (2) *Main> --//-- I'm trying to figure out how to turn a Float into a RealFrac so I can pass it to 'round'. Any ideas? Daniel. -- /\/`) http://oooauthors.org /\/_/ http://opendocumentfellowship.org /\/_/ \/_/ I am not over-weight, I am under-tall. /

7 9

Killer pickler combinators (was Time leak)
by Joel Reymont 21 Dec '05

21 Dec '05

The original paper is at http://research.microsoft.com/ ~akenn/fun/ picklercombinators.pdf My adaptation is at http://wagerlabs.com/timeleak.tgz. This is a full repro case, data included. The issue is that with 1000 threads my serialization is taking a few seconds. Inserting a delay or passing in trace (see README and code) gets serialization time down to 0-1s, the way it should be. What gives? Try it for yourself and please let me know! Thanks, Joel -- http://wagerlabs.com/

7 17

Re: problems with square roots...
by Scherrer, Chad 21 Dec '05

21 Dec '05

------------ From: Daniel Carrera <daniel.carrera(a)zmsl.com> Hey, The sqrt function is not doing what I want. This is what I want: round sqrt(2) --------------------------------------------------- Daniel, A lot of Haskell folks like to avoid parentheses as much as possible, and there's a really convenient way to do this. There is a Prelude function ($) f x = f x which is right-associative, so you can write round $ sqrt x == round (sqrt x) This becomes really convenient when multiple application is involved: print $ round $ sqrt x == print (round (sqrt x)) -Chad

2 1

Fwd: Monads and pedagogy (Functions with side-effects?)
by Greg Woodhouse 21 Dec '05

21 Dec '05

Oops...meant to send this to the list, too. --- Greg Woodhouse <gregory.woodhouse(a)sbcglobal.net> wrote: > Date: Wed, 21 Dec 2005 09:42:44 -0800 (PST) > From: Greg Woodhouse <gregory.woodhouse(a)sbcglobal.net> > Subject: Monads and pedagogy (Functions with side-effects?) > To: David Barton <dlb(a)patriot.net> > > --- David Barton <dlb(a)patriot.net> wrote: > > > Wolfgang Jeltsch writes: > > ----- Original Message ----- > > > > > Am Mittwoch, 21. Dezember 2005 13:15 schrieb Creighton Hogg: > > >> [...] > > > > > >> Monads, I believe, can be just thought of as containers for > state. > > > > > > I would say that you are talking especially about the I/O monad > > here. A > > > monad > > > as such is a rather general concept like a group is in algebra. > > > > While this is correct, I'm afraid that for most of us it is a > > flavorless > > answer. I wish I had the mathematical mind that made the word > > "group" in > > this context instantly intuitively recognizable, but I don't. > > Groups are actually relatively intuitive structures, representing (no > pun intended) the symmetries of some type of object. So, in teaching > group theory it is easy to immediately provide a number of easy to > grasp examples: the symmetric group (any kind of rearrangement), the > cyclic group (cyclic permutation), dihedral group (geometric > symmetries > of a "square"), SL(n, R) ("area preserving" linear transformations), > SO(n, R) (transformation preserving angles), Isom(M) (all geomteric > motions of an object so that in the end it occupies the same "space" > without any stretching or other deformation), etc., etc. > > Rings are a little more tricky, but R[x] (polynomials over R) is the > universal example, with homomorphic images like Z[i] just being > "polynomials in i" where you "reduce" according to i^2 = -1, and so > on. > Matrices over a ring give you the prototypical example of a module. I > could go on, but the point is that in abstract algebra it is usually > easy to provide simple intuitive examples of the structures > illustrating most of the basic properties of the category. (Okay, > okay, > topoi and coherent sheaves may be an exception! But even then, > analytic > functions go a long way.) > > With monads, it is not hard to give a formal definition, just as is > the > case with groups, but much harder (for me, anyway) to find a simple > intuitive set of examples that capture the essence of monads in such > a > way that the definition is obvious. Think about it: If groups are > just > symmetries, then "doing nothing" is clearly a symmetry (1), "doing > nothing" before or after a symmetry doesn't change anything. > "Undoing" > a symmetry gives you an inverse. Associativity is less obvious, > unless > you think of groups realized as permutations of a set, so that the > group product just becomes function composition. > > > > === > Gregory Woodhouse <gregory.woodhouse(a)sbcglobal.net> > "Interaction is the mind-body problem of computing." > --Philip L. Wadler >

1 0

Learning about haskell compilers
by Creighton Hogg 21 Dec '05

21 Dec '05

Hi guys, I was wondering where I should get started in learing about how to implement a haskell compiler? Are there papers, wiki entries, or other things people think would be helpful or should I just start looking at the source of one of the compilers?

7 7

Re: [Haskell-cafe] Killer pickler combinators (was Time leak)
by Joel Reymont 21 Dec '05

21 Dec '05

On Dec 21, 2005, at 2:56 PM, Cale Gibbard wrote: > By the way, when I was doing threadDelays, I meant: > trace s = withMVar lock $ const $ threadDelay 20 > In case you didn't try that. I'm trying 5k threads and I still get delays at times. Using thread delay of 1, though. ./unstuff trace.dat unstuff: user error (ORANGE ALERT: 0s, 7s, SrvServerInfo, ix1: 6, size: 49722) unstuff: user error (ORANGE ALERT: 0s, 8s, SrvServerInfo, ix1: 6, size: 49722) unstuff: user error (ORANGE ALERT: 0s, 7s, SrvServerInfo, ix1: 6, size: 49722) unstuff: user error (ORANGE ALERT: 0s, 5s, SrvServerInfo, ix1: 6, size: 49722) unstuff: user error (ORANGE ALERT: 0s, 5s, SrvServerInfo, ix1: 6, size: 49722) unstuff: user error (ORANGE ALERT: 0s, 4s, SrvServerInfo, ix1: 6, size: 49722) unstuff: user error (ORANGE ALERT: 0s, 6s, SrvServerInfo, ix1: 6, size: 49722) -- http://wagerlabs.com/

1 0

Re: [Haskell-cafe] Killer pickler combinators (was Time leak)
by Joel Reymont 21 Dec '05

21 Dec '05

Cale is a genius! This totally solves the timeouts. Why, though? The lock is only used at the end of the unpickling. Why does it help? On Dec 21, 2005, at 2:56 PM, Cale Gibbard wrote: > By the way, when I was doing threadDelays, I meant: > trace s = withMVar lock $ const $ threadDelay 20 > In case you didn't try that. > > - Cale > > On 21/12/05, Joel Reymont <joelr1(a)gmail.com> wrote: >> I'm not sure I buy this. Again, this helps: >> >> {-# NOINLINE lock #-} >> lock :: MVar () >> lock = unsafePerformIO $ newMVar () >> >> trace s = withMVar lock $ const $ putStrLn s >> >> and then in read_ >> >> cmd <- read h trace >> >> trace is called _after_ all the timings in read so it should not >> affect the timings. >> >> You could basically say that the lock is at the end of read, after >> all the unpickling has been done. The other interesting thing is that >> replacing trace with >> >> delay _ = threadDelay 1 >> >> does not solve the issue. -- http://wagerlabs.com/

1 0

Re: [Haskell-cafe] Re: Tutorial uploaded
by John Hughes 21 Dec '05

21 Dec '05

> >---------------------------------------------------------------------- > >Message: 1 >Date: Wed, 21 Dec 2005 10:48:08 +0000 >From: Robin Green <greenrd(a)greenrd.org> >Subject: Re: [Haskell-cafe] Re: Tutorial uploaded > > > > > > >>Beginners should start with non-monadic functions in order to later avoid >>IO in their functions whereever possible. >> >> > >Whilst localising IO to a small part of the program is generally a good >idea, beginners should not be scared off by the thought that IO in >Haskell is so hard it has to be covered on page 94. This is not the >case. It should be introduced on page 1. > >If people want Haskell to be treated as a practical language, not just >something for doing academic teaching and research with, it should be >taught as a practical language - which means that things like IO and >space/time usage come to the forefront. > > > Couldn't agree more. I show my students IO in the first lecture of their first programming course in the first term of their first year. A few lectures later I discuss it in more detail, and tell to think of an IO a as instructions on a piece of paper to produce an a. My students have no difficulty understanding the difference between being given 500 crowns (a value), and being given my ATM card and code with instructions how to work an ATM! Haskell IO is mystifed far too often in my opinion--it needn't be hard at all. John

2 1

YAHT Tutorial
by Christian Maeder 21 Dec '05

21 Dec '05

Folks, I'm surprised Hal's tutorial is so less known. I recommend (and send) it to everybody who asks me. I like that it starts early with some IO and mainly promotes ghc/ghci. Hugs is a good tool as well (and I sometimes use it, too), but ghc is definitively the flagship with better error reporting, active maintainance and for producing fast code (if that is important). It's good that this tutorial is freely available, but some people prefer to have a proper textbook. I just wonder what happened to "An Introduction to Computing (with Haskell). Manuel M. T. Chakravarty and Gabriele C. Keller. Pearson Education Australia, 2002." which is also available in german as "Einführung in die Programmierung mit Haskell" http://www.pearson-studium.de/main/main.asp?page=bookdetails&ProductID=81781 It's not listed under http://www.haskell.org/bookshelf/ nor http://www.haskell.org/learning.html. Maybe it is hard to recommend a single tutorial without spoiling selling chances of others. In our teaching courses "Simon Thompson: Haskell: The Craft of Functional Programming," is mostly used. Others find "Paul Hudak: The Haskell School of Expression" the best. I just see that the recent tutorial version contains Parsec (good) and FiniteMap (deprecated) examples. I would appreciate the chapter "Advanced Techniques" being filled (but know how much time that would cost). Thanks for your tutorial so far, Hal! Cheers Christian

1 0

Re: [Haskell] A simple server (or how to do io).
by Pupeno 21 Dec '05

21 Dec '05

On Tuesday 20 December 2005 23:43, Einar Karttunen wrote: > Your problem is that the ghci prompt *is* blocking everything. ghci is > builded non-threaded. Ghci uses a blocking call to read the lines > which means that all other computations are stopped. Ok, then pressing enter each time I want one of my servers to reply. I can live with that. > > I compile it and run it. It returns immediately and the server of course, > > is not running. > > It spawns the server threads and returns immediately. Indeed. > > I think what I am missing is that server, after running runStreamServer > > should block and be able to reply to all the queries (in the final > > version I'll also have runDgramServer as well) and be able to receive a > > signal, upon which it should close the socket and finish. How can do that > > ? Any help will be appreciated. > > Catch the signal and kill the listening threads. If you > are using the new 0.3.1 release then you can use the > killServer call. Oh, new release, I am downloading it right now! So, I install a signal handler with installHandler... and then ? how do I prevent the program for quiting ? am I missing some kind of event loop here ? > ps. I think it may be best to continue on haskell-cafe@ rather > than the main list. I am posting to there as well (to continue there). -- Pupeno <pupeno(a)pupeno.com> (http://pupeno.com)

2 1

Proposal for a first tutorial.
by Daniel Carrera 20 Dec '05

20 Dec '05

Hello, I've almost finished my proposal for a very first Haskell tutorial. I notice that the Wiki is restricted. How can I upload it to show it to you? Can I send it to the list as an attachment? (it's only 4k). Cheers, Daniel. -- /\/`) http://oooauthors.org /\/_/ http://opendocumentfellowship.org /\/_/ \/_/ I am not over-weight, I am under-tall. /

5 10

RE: Haskell-Cafe Digest, Vol 28, Issue 66
by Scherrer, Chad 20 Dec '05

20 Dec '05

> From: Daniel Carrera <daniel.carrera(a)zmsl.com> > Robert Dockins wrote: > > -divides a b = (mod a b == 0) > > +divides a b = (mod b a == 0) > > Oh, thanks. My program assumed one way to define 'divides' > and the example assumed the other. > > When I wrote it I was thinking of (divides a) being a > function that tells me if the input divides 'a'. > > Thanks! > > Cheers, > Daniel. Daniel, Have you used Haskell's infix notation? It can help keep the order straight for operators like these. You can write a `mod` b -- instead of mod a b a `divides` b -- instead of divides a b. This can help with readability, too. Chad Scherrer

3 2

RE: [Haskell-cafe] First steps in Haskell
by Simon Peyton-Jones 20 Dec '05

20 Dec '05

| Actually, I have sometimes wished that the various interactive Haskell | interfaces had the possibility to enter also declarations interactively GHCi does. ghci> let f x = "hello" ghci> f True True But there's no editor -- it's strictly a one-line definition Simon | -----Original Message----- | From: Bjorn Lisper [mailto:lisper@it.kth.se] | Sent: 19 December 2005 13:06 | To: Simon Peyton-Jones | Cc: wolfgang(a)jeltsch.net; haskell-cafe(a)haskell.org | Subject: Re: [Haskell-cafe] First steps in Haskell | | Simon P-J: | >Daniel is right, by definition. He is a new user. He had difficulty. | >That much is incontrovertible. | > | >While he may seem unusual, perhaps he is only unusual in that he's told | >us about his experience rather than trying Perl instead. For which, | >much thanks, Daniel! | | Actually, I have sometimes wished that the various interactive Haskell | interfaces had the possibility to enter also declarations interactively, as | Daniel originally asked for. Lisp interpreters often support this to some | extent, so it is not out of line for a newcomer to expect it also for | Haskell. I often use hugs as a calculator, and sometimes it would be very | convenient to be able to make one or a few short declarations while making | some interactive calculations. It can be quite tedious to create and edit a | source code file on the side and then load it, when all you want is a short | declaration or two. Would it be that complex to have an interactive | interface enter a "declarations mode" when it sees a declaration coming, and | then let it create, compile and load a temporary module when the declaration | is finished? | | Björn Lisper

3 2

Re: [Haskell-cafe] Prime numbers
by Daniel Carrera 20 Dec '05

20 Dec '05

Henning Thielemann wrote: >>factors :: Integer -> Integer -> Bool >>factors m n | m == n = False >> | m < n = divides m n || factors (m+1) n > > > Btw. I find the recursion harder to understand than the explicit > definition: > > factors n = any (divides n) [2..(n-1)] For what it's worth, I also found this function un-intuitive. What I'd expect a function called "factors" to do is exactly what yours does, and not what the one in the example does. Cheers, Daniel. -- /\/`) http://oooauthors.org /\/_/ http://opendocumentfellowship.org /\/_/ \/_/ I am not over-weight, I am under-tall. /

2 1

RE: [Haskell-cafe] +RTS -M800M
by Simon Marlow 20 Dec '05

20 Dec '05

On 17 December 2005 21:57, Ketil Malde wrote: > "Simon Marlow" <simonmar(a)microsoft.com> writes: > >> On 16 December 2005 10:05, Joel Reymont wrote: >> >>> I'm trying to restrict GHC to 800Mb of heap at runtime by passing in >>> +RTS -M800M, the machine has 1Gb of memory and top shows free >>> physical memory dropping below 175Mb. > >> -M800m should do more or less the right thing, but it is possible for >> GHC to exceed this figure by a small percentage. > > Is there any chance there is a bug in recent GHCs (or perhaps Linux?) > affecting this? I'm fairly sure I've lately seen Haskell programs > consuming significantly larger amounts of memory than they should be > allowed to, and I can try to isolate a test case if it is of > interest. Please do isolate it if you can. I'd be interested in investigating. Cheers, Simon

1 0

Re: [Haskell-cafe] Prime numbers
by Daniel Carrera 20 Dec '05

20 Dec '05

John Peterson wrote: > Add a type signature: > > prime :: Integer -> Bool > > It's defaulting to Int and you're getting overflows Thanks. Hmm... it's still not working. Btw, I mis-reported the problem. The offending number is 38466629, which is /not/ prime but the sample program reports as prime. 38466629 = 31 * 1240859 The offending program is: --//-- prime :: Integer -> Bool prime n = not (factors 2 n) factors :: Integer -> Integer -> Bool factors m n | m == n = False | m < n = divides m n || factors (m+1) n divides :: Integer -> Integer -> Bool divides a b = (mod a b == 0) --//-- The math behind the program seems correct... :( Cheers, Daniel. -- /\/`) http://oooauthors.org /\/_/ http://opendocumentfellowship.org /\/_/ \/_/ I am not over-weight, I am under-tall. /

4 4

Prime numbers
by Daniel Carrera 20 Dec '05

20 Dec '05

Hello all, Trying to learn Haskell here... In a Haskell tutorial I found a function deciding if a number is prime: --//-- prime n = not (factors 2 n) factors m n | m == n = False | m < n = divides m n || factors (m+1) n divides a b = (mod a b == 0) --//-- Reference: http://www.cs.chalmers.se/Cs/Grundutb/Kurser/d1pt/d1pta/Function%20Definiti… This function seems to produce a wrong result on the number 38466629 (warning, slow computation). This number is prime but the function says that it's not. How do I know that 38466629 is prime? Beause: * http://www.rsok.com/~jrm/printprimes.html says that it is. * I wrote another prime function that says that it is. This is my function: --//-- prime 1 = False prime 2 = True prime n = filter (divides n) primes == [] where numbers = [x | x <- [2..n-1], x*x <= n] primes = filter prime numbers divides a b = (mod a b == 0) --//-- I can't figure out what's wrong with the first one. Can anyone spot the problem? (I'm just curious - trying to learn Haskell). Cheers, Daniel. -- /\/`) http://oooauthors.org /\/_/ http://opendocumentfellowship.org /\/_/ \/_/ I am not over-weight, I am under-tall. /

3 3

RE: [Haskell-cafe] Tutorial uploaded
by Bayley, Alistair 20 Dec '05

20 Dec '05

> From: haskell-cafe-bounces(a)haskell.org > [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of Daniel Carrera > > Hi all, > > I've finished a first draft of what I call "First steps in Haskell". > It's intended to be the very first thing a new user sees when they > decide to try out Haskell. > > http://www.haskell.org/hawiki/FirstSteps?action=show > > Thoughts and comments? There's not much wrong with doing a Hello World: main = putStrLn "Hello World" Or: fac n = if n <= 0 then 1 else n * fac (n-1) main = print (fac 12) Compiling, or at least running a haskell script (via runhaskell) should also get a mention, so you show how to achieve things outside of the interactive prompt. Alistair ***************************************************************** Confidentiality Note: The information contained in this message, and any attachments, may contain confidential and/or privileged material. It is intended solely for the person(s) or entity to which it is addressed. Any review, retransmission, dissemination, or taking of any action in reliance upon this information by persons or entities other than the intended recipient(s) is prohibited. If you received this in error, please contact the sender and delete the material from any computer. *****************************************************************

1 0

RE: [Haskell-cafe] Proposal for a first tutorial.
by Bayley, Alistair 20 Dec '05

20 Dec '05

> From: haskell-cafe-bounces(a)haskell.org > [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of Daniel Carrera > > Hal Daume III wrote: > > Daniel -- can you tell me what was missing from YAHT that wasn't > > sufficient for starting to use Haskell? It was really > intended to solve > > these problems, at least partially, so if it's missing out, > I'd like to > > fix it! > > I haven't read it. I refuse to give out personal information > to read a > tutorial. >From this page http://haskell.org/hawiki/LearningHaskell there's a link to the tutorial http://www.isi.edu/~hdaume/htut/tutorial.pdf which seems to make no informational demands. Alistair ***************************************************************** Confidentiality Note: The information contained in this message, and any attachments, may contain confidential and/or privileged material. It is intended solely for the person(s) or entity to which it is addressed. Any review, retransmission, dissemination, or taking of any action in reliance upon this information by persons or entities other than the intended recipient(s) is prohibited. If you received this in error, please contact the sender and delete the material from any computer. *****************************************************************

2 1

Re: First steps in Haskell
by Bayley, Alistair 20 Dec '05

20 Dec '05

> From: haskell-cafe-bounces(a)haskell.org > [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of Paul Moore > > I suspect that the reference documentation is fine, and the tutorials > are great, given what they are trying to do. But there is scope for a > very prominent "Getting going" document. Daniel's "40-second intro to > Haskell" looks good. Expand it a little with a few lines showing tow > to build and compile a "Hello, world" program in GHC and Hugs (with a > disclaimer that the code itself is magic for now, you'll understand > when you read about monads and the IO monad) to help people who need > to get over the "but how do I write a *program*" hump, and you're > pretty much there. For someone getting started, in IMO the Learning Haskell page has too much stuff on it. The total beginner doesn't have the knowledge they need to decide which implementation to install, which tutorial to read, or which textbook to buy. At the risk of alienating some tutorials and implementations, we ought to pick one of each and say "here, start with these". There's a balance to be struck between being fair to all resource producers (be it implementation, textbook, tutorial, or reference), and being as easy as possible for someone to get started, and I think the needle is currently too far over to the "fair" side of the scale. There should be a "getting started" page which says: - download and install this interpreter (Hugs or GHCi) - run it, type these expressions, and see the results - create a HelloWorld program, compile and execute. - now start the following tutorial... (BTW, the link to Hal Daume's tutorial from the Learning page needs fixing) As an example (checking out the competition), the Ruby community have a good free book. The book is fairly easy to find from the ruby-lang.org homepage, although it could be more prominent. The preface contains a brief tutorial for working with the interpreter (how to build & install, the REPL, and a Hello World program): http://www.rubycentral.com/book/preface.html And there's this interesting site, which demos a interpreter running in your browser (although it really seems to be showcasing some AJAX-ish javascript libraries): http://tryruby.hobix.com/ The Ruby community have put quite a bit of effort into easing beginners into the langauge and tools. Alistair ***************************************************************** Confidentiality Note: The information contained in this message, and any attachments, may contain confidential and/or privileged material. It is intended solely for the person(s) or entity to which it is addressed. Any review, retransmission, dissemination, or taking of any action in reliance upon this information by persons or entities other than the intended recipient(s) is prohibited. If you received this in error, please contact the sender and delete the material from any computer. *****************************************************************

4 4

RE: [Haskell-cafe] First steps in Haskell
by Simon Peyton-Jones 20 Dec '05

20 Dec '05

| (mild) culture shock here. It is typical for people in the Haskell | community to view things in a rather principled way. A language | tutorial is supposed to introduce /the language/. If you want to know | how to compile or execute a Haskell program, well then, look at the | appropriate tutorial on the /implementation/. At first this may appear | like deliberately creating hurdles, but it isn't, it's merely the way | many (though not all) Haskell people tend to think. They take it for | granted that a new user is at least educated enough to be aware of the | difference between the language itself, and its concrete implementation | in the form of an interpretation or a compilation system. I, for one, don't take it for granted! Furthermore, I think the Haskell community is pretty friendly; for example, a great deal of entirely non-condescending advice is given to newcomers on Haskell Café. I'm certain there are hurdles, but I think on the whole they are there by accident rather than design. (Apart from functional programming itself, which often is a bit of a hurdle, but that's the reason we are here!) It turns out that there are a couple of introductory Wiki pages already: http://www.haskell.org/hawiki/HaskellNewbie http://www.haskell.org/hawiki/HaskellDemo It'd be great if someone would like to improve them in the light of this thread. (Anyone can do this.) Ideally there should be a single Wiki page that the Haskell.org web site can point to; perhaps the editing could bear that in mind? Simon

3 3

Haskell trickery
by Joel Reymont 20 Dec '05

20 Dec '05

Folks, How is one to interpret the following? I'm particularly interested in the "IO $ \ s -> " notatoin as I have never seen that before. allocaBytes :: Int -> (Ptr a -> IO b) -> IO b allocaBytes (I# size) action = IO $ \ s -> case newPinnedByteArray# size s of { (# s, mbarr# #) -> case unsafeFreezeByteArray# mbarr# s of { (# s, barr# #) -> let addr = Ptr (byteArrayContents# barr#) in case action addr of { IO action -> case action s of { (# s, r #) -> case touch# barr# s of { s -> (# s, r #) }}}}} Lemmih suggested that this is unrolling the code (manual inlining?) but how much speedup is that buying you? Last but not least, what is case action addr of { IO action -> case action s of { (# s, r #) -> Thanks, Joel -- http://wagerlabs.com/

2 1

Array performance is killing me
by Joel Reymont 20 Dec '05

20 Dec '05

Folks, I managed to reduce my memory consumption but I have a performance problem now. This is a profiling report from my app. -O was not supplied when compiling the library and the relevant modules are at http://wagerlabs.com/array.tgz. COST CENTRE MODULE %time %alloc byteArrayFromPtr Script.Array 39.1 43.9 readBits Script.Array 23.6 25.5 emptyByteArray Script.Array 7.6 6.0 endian#2 Script.Endian 4.4 4.2 bytearray Script.Pickle 3.9 3.4 copyMArray Script.Array 2.8 3.4 sequ Script.Pickle 2.7 2.0 withByteArray Script.Array 2.3 2.1 num#2 Script.Pickle 1.3 1.7 wstr#5 Script.Endian 1.1 0.6 byteSize Script.Pickle 1.1 0.5 I run into trouble with packets of ~50K that consist of a header (a few bytes) and compressed data. The compressed data has to be uncompressed and then parsed again. Overall, this takes a copy from array (I use hGetArray) into Ptr Word8 to be supplied to ZLib's compress and then another copy from Ptr Word8 into a byte array for parsing. readBits is supposed to extract numbers from a byte array and can be found in Array.hs. uncompress is in ZLib.hs and the endian bits in Endian.hs. The code should compile without problems. Please help me optimize this! Thanks, Joel -- http://wagerlabs.com/

1 1

comprehension generators from IO [a]'s ?
by Steve Harris 20 Dec '05

20 Dec '05

[reposted from haskell mailing list where I got no bites :) ] Folks, I'm new to using monads, and I'd like some help improving a function definition that I wrote and which works, but for which I think there should be a clearer way to write it. What I'm after is something like: -- (psuedo-code) [(b,c,d) | b <- getDirectoryContents a_dir, c <- getDirectoryContents (a_dir ++ "/" ++ b), d <- getDirectoryContents (a_dir ++ "/" ++ b ++ "/" ++ c) ], ie. where the generators feed from IO actions instead of lists, but I gather this comprehension style isn't supported, which is too bad because it's really easy to read. (Is this what was meant by "monad comprehensions" that I've heard reference to?) Here's how I actually wrote it, using nested folds: import System.IO -- Load directory entries 3 levels deep under a_dir, as list of tuples (b,c,d) load3DirLevels :: FilePath -> IO [(String,String,String)] load3DirLevels a_dir = do bs <- getDirectoryContents a_dir foldM (\tups b -> do cs <- getDirectoryContents (a_dir ++ "/" ++ b) foldM (\tups' c -> do ds <- getDirectoryContents (a_dir ++ "/" ++ b ++ "/" ++ c) foldM (\tups'' d -> do return $ (b, c, d) : tups'' ) tups' ds ) tups cs ) [] bs This function isn't so clear at a glance, and yet what it's doing seems like a pretty common thing to want to do: are there any library functions for monads (or IO in particular) that make this sort of thing easier, or should I to try and write my own function? Looks not too difficult to write but I think I might miss something important if I didn't ask first... How would you do it? Thanks Steve

4 5

Help with division
by Daniel Carrera 19 Dec '05

19 Dec '05

Hello all, Playing around with Haskell... I'm writing a 'choose' function: --//-- fac :: Int -> Int fac 0 = 1 fac n = n*fac(n-1) choose :: Int -> Int -> Int choose n k = fac(n) / (fac(k) * fac(n-k)) --//-- I'm having problems with the last line. --//-- Prelude> :l test.hs Compiling Main ( test.hs, interpreted ) test.hs:13:20: No instance for (Fractional Int) arising from use of `/' at test.hs:13:20 Probable fix: add an instance declaration for (Fractional Int) In the definition of `choose': choose n k = (fac (n)) / ((fac (k)) * (fac (n - k))) Failed, modules loaded: none. --//-- The problem is that it doesn't like the / sign. For example, if I replace the / by * the function is compiled just fine. Does anyone know what I'm missing? Cheers, Daniel. -- /\/`) http://oooauthors.org /\/_/ http://opendocumentfellowship.org /\/_/ \/_/ I am not over-weight, I am under-tall. /

2 2

Int vs Integer
by Daniel Carrera 19 Dec '05

19 Dec '05

Hello all, I found a good Haskell tutorial (second link on the Tutorials column) (now that I know how to run the programs in it). I have a question. What's the difference between the types Int and Integer? Likewise, what's the difference between the types Float and Double? Are those just synonims? Thanks for the help. Cheers, Daniel. -- /\/`) http://oooauthors.org /\/_/ http://opendocumentfellowship.org /\/_/ \/_/ I am not over-weight, I am under-tall. /

5 5

Using MonadError within other Monads
by Karl Grapone 19 Dec '05

19 Dec '05

Hi, I'm having trouble making use of MonadError within another Monad, in this case IO. I've blundered around for a while, trying various combinations of things, but I don't think I've fully cottoned-on to nesting of monads. Following is some code which does not compile, but hopefully shows you what my intentions are. I'd appreciate it if someone could show me how to use the nested monads in this situation. Thanks. module Test where import Control.Monad.Error import Data.Char import System.IO instance Error Int where noMsg = 1 strMsg = length f :: IO (Either String String) f = do n <- readLn if n == 2 then return $ throwError "I don't like strings with 2 characters." else do s <- mapErrs2 (g n) putStrLn s g :: Int -> IO (Either String String) g 0 = throwError "I won't do zero length strings." g 1 = do c <- getChar c' <- mapErrs (h c) return [c'] g n = do c <- getChar cs <- g (n-1) c' <- mapErrs (h c) return (c':cs) h :: Char -> Either Int Char h c | isUpper c = throwError 200 | otherwise = return $ toUpper c mapErrs :: Either Int Char -> Either String Char mapErrs (Right c) = Right c mapErrs (Left 200) = Left "The String contained uppercase characters." mapErrs (Left i) = Left ("Unrecognised failure in h, code = " ++ (show i)) mapErrs2 :: Either String String -> Either String String mapErrs2 (Right s) = Right s mapErrs2 (Left e) = Left ("g Error: " ++ e)

2 3

RE: [Haskell-cafe] First steps in Haskell
by Simon Peyton-Jones 19 Dec '05

19 Dec '05

Daniel is right, by definition. He is a new user. He had difficulty. That much is incontrovertible. While he may seem unusual, perhaps he is only unusual in that he's told us about his experience rather than trying Perl instead. For which, much thanks, Daniel! In any case, I think it'd be great if he, or anyone else, started a Wiki page on "very first steps in Haskell", along the lines he suggests. Maybe one exists already? Once it does, it'd be good to point to it from haskell.org. Simon | -----Original Message----- | From: haskell-cafe-bounces(a)haskell.org [mailto:haskell-cafe-bounces@haskell.org] On Behalf Of | Wolfgang Jeltsch | Sent: 19 December 2005 09:50 | To: haskell-cafe(a)haskell.org | Subject: Re: [Haskell-cafe] First steps in Haskell | | Am Sonntag, 18. Dezember 2005 17:25 schrieb Daniel Carrera: | > [...] | | > This is a real problem for Haskell. I expect that a lot of people try | > Haskell and give up because they can't even write the simplest function. | | Hello Daniel, | | honestly, I have to say that during my years with Haskell, this seems to be | the first time that I see somebody trying to enter a Haskell program via the | command line of an interactive environment. So I suppose that it's not "a | lot of people" who experience the problems you do. | | > It's hard not to be put off by this. I love the theory behind Haskell, | > but the practice of it seems to be a real problem. | | Did you have a look at the Hugs or GHCi documentation? I'm very sure, it will | tell you that what you may enter at the command line are (merely) expressions | to evaluate and special commands like :t for displaying the type of an | expression, and that the Haskell declarations (normally) have to be read from | a file. | | > I hope someone will show me how to make this program work. Even better, | > I hope someone will fix the compilers and interpreters if they need | > fixing, or fix the documentation if that's what needs fixing. | | I suppose that neither the compilers and interpreters nor the documentation | need(s) fixing, although I might be wrong with the documentation. | | > Best, | > Daniel. | | Best wishes, | Wolfgang | _______________________________________________ | Haskell-Cafe mailing list | Haskell-Cafe(a)haskell.org | http://www.haskell.org/mailman/listinfo/haskell-cafe

3 2

XML Schema for Haskell parsing?
by Dimitry Golubovsky 19 Dec '05

19 Dec '05

GCCXML defines some XML schema for the results of a C(++) program parsing. Does there exist any agreed-upon XML schema to represent the results of Haskell program parsing? Thanks. -- Dimitry Golubovsky Anywhere on the Web

1 0

RE: [Haskell-cafe] +RTS -M800M
by Simon Peyton-Jones 19 Dec '05

19 Dec '05

| Is there any chance there is a bug in recent GHCs (or perhaps Linux?) | affecting this? I'm fairly sure I've lately seen Haskell programs | consuming significantly larger amounts of memory than they should be | allowed to, and I can try to isolate a test case if it is of | interest. New bugs are always possible! And in the last few months, Simon has been doing fairly major surgery on parts of the runtime system, as part of getting multiprocessor-GHC to play nicely. So if you can find a test case where GHC is generating code that uses a lot more memory than it used it, it would be very valuable to us. Thanks! Simon

1 0

c2hs seems to ignore the types I give it when generating foreign import declarations
by Cale Gibbard 19 Dec '05

19 Dec '05

Hello, I've just started writing bindings to the Enlightenment Foundation Libraries, using c2hs. I've run into the following problem with the types in the foreign import declarations generated. In Imlib2.h, there is a function prototype: int imlib_get_visual_depth(Display * display, Visual * visual); In Imlib.chs, I have (among other things) import qualified Graphics.X11.Xlib.Types as Xlib -- ... {# fun imlib_get_visual_depth as getVisualDepth { id `Xlib.Display', id `Xlib.Visual' } -> `Int' #} I run: c2hs -k /usr/local/include/Imlib2.h Imlib.chs and in the resulting Imlib.hs, I get: --- this part is correct: getVisualDepth :: Xlib.Display -> Xlib.Visual -> IO (Int) getVisualDepth a1 a2 = let {a1' = id a1} in let {a2' = id a2} in getVisualDepth'_ a1' a2' >>= \res -> let {res' = cIntConv res} in return (res') --- this part is not: foreign import ccall safe "Imlib.h imlib_get_visual_depth" getVisualDepth'_ :: ((Ptr ()) -> ((Ptr ()) -> (IO CInt))) Why did it choose the type Ptr (), when I gave the type Xlib.Display? I could do an additional cast, but it will get tedious, as I have a lot of functions to import, and there shouldn't be any need for it anyway. As this is, it doesn't typecheck at all. If by hand, I change it to read: foreign import ccall safe "Imlib.h imlib_get_visual_depth" getVisualDepth'_ :: Xlib.Display -> Xlib.Visual -> IO CInt (which is what I expected it to produce in the first place) then it works as expected. Am I making a grievous error, or is this a bug/lack of a feature? - Cale

3 5

About print and side-effects
by Daniel Carrera 18 Dec '05

18 Dec '05

Hi all, The recent responses to my first question (thanks guys!) included the following bit: main = print (fact 42) Now, print is a side-effect. Shouldn't it involve a do-block or a nomad or one of those scary things you hear about when learning about side effects in functional programs? How come 'print' is allowed to exist alone if it's a side-effect? Thanks for the help. Cheers, Daniel. -- /\/`) http://oooauthors.org /\/_/ http://opendocumentfellowship.org /\/_/ \/_/ I am not over-weight, I am under-tall. /

4 4

Substring replacements
by Daniel Fischer 18 Dec '05

18 Dec '05

Okay, I have looked up KMP and implemented it. Seems to work -- my first use of QuickCheck, too. It's slower than Bulat's and Tomasz' for Branimir's test :-(, but really fast for my test. Undoubtedly, one can still tune it. Here's the code: module KMP where import Data.Array searchReplace :: String -> String -> String -> String searchReplace "" _ str = str searchReplace src@(c:cs) dst str = process 0 str "" where len = length src pat = listArray (0,len-1) src bord = array (0,len) $ (0,-1):(1,0):[(i+1,boun i (bord!i)) | i <- [1 .. len-1]] boun i j | j < 0 = 0 | pat!i == pat!j = j+1 | otherwise = boun i (bord!j) getBord s n | m < 1 = m | s == pat!m = m | otherwise = getBord s m where m = bord!n process n str _ | n >= len = dst ++ process 0 str "" process _ "" mat = reverse mat process 0 (s:st) _ | s == c = process 1 st [s] | otherwise = s:process 0 st "" process n str@(s:st) mat | s == pat!n = process (n+1) st (s:mat) | otherwise = let j = getBord s n (ret,skip) = splitAt j mat in if j < 0 then reverse mat ++ process 0 str "" else reverse skip ++ process j str ret Cheers, Daniel

5 25

RE: [Haskell-cafe] +RTS -M800M
by Simon Marlow 17 Dec '05

17 Dec '05

On 16 December 2005 10:05, Joel Reymont wrote: > I'm trying to restrict GHC to 800Mb of heap at runtime by passing in > +RTS -M800M, the machine has 1Gb of memory and top shows free > physical memory dropping below 175Mb. I suppose I'm missing something > obvious or paying attention to the wrong statistics, Unix has a good > VM manager after all. Are my runtime options correct, though? -M800m should do more or less the right thing, but it is possible for GHC to exceed this figure by a small percentage. Rather than considering the "worst case" requirements for the next GC, GHC uses a more "average case" estimate, which sometimes ends up being wrong, but in most cases results in better utilisation of the available memory. Cheers, Simon

3 2

Darcs apply error while getting the complete GHC tree
by Joel Reymont 17 Dec '05

17 Dec '05

I thought I would get the _complete_ ghc tree so that I could build ghc with patches of my own. I decided to get the libraries while I'm at it. I got two errors and don't know what to do now. Do I need to get the whole tree again? Can I somehow reapply the patches that did not get applied? Should I just get the CVS trees instead? Thanks, Joel P.S. -- darcs get http://cvs.haskell.org/darcs/ghc.ghc-6.4/ Copying patch 13136 of 13136... done!es.ghc-6.4/ Applying patch 12 of 13136... Unapplicable patch: Thu Jan 11 14:26:13 GMT 1996 partain * [project @ 1996-01-11 14:06:51 by partain] darcs failed: Error applying hunk to file ./ghc/includes/rtsTypes.lh -- and then -- darcs get http://cvs.haskell.org/darcs/libraries.ghc-6.4/ ... Copying patch 3403 of 3403... done! Applying patch 2115 of 3403... Unapplicable patch: Sat Mar 27 14:07:36 GMT 2004 panne * [project @ 2004-03-27 14:07:33 by panne] Moved around the sources and the test examples to the standard places in the hierarchical libs. The NHC98 build is currently untested, but it might work, nevertheless... :-} darcs: ./HUnit/Test: createDirectory: already exists (File exists) -- http://wagerlabs.com/

4 4

Re: [Haskell-cafe] Darcs apply error while getting the complete GHC tree
by Joel Reymont 17 Dec '05

17 Dec '05

I thought I did :-). I just didn't get to 7.1. My bad and apologies! On Dec 17, 2005, at 7:07 PM, wld wrote: > Well, RTBG (Building Guide) ! > When building from CVS (I think, from darcs repo too), > you should do: > > autoreconf > ./configure -- http://wagerlabs.com/

1 0

Haskell School of Expression?
by Creighton Hogg 17 Dec '05

17 Dec '05

Hi, Has anyone recently tried to install the graphics libraries included on http://haskell.org/soe/software.htm ? I've tried to make the libraries, but I get these errors. make: Entering directory `/home/wchogg/coding/haskell/GraphicsLib/lib/x11' ffihugs +G +L"X_stub_ffi.c" X.hs Warning: unknown toggle `G'; ignoring. Warning: unknown toggle `L'; ignoring. runhugs: Unable to initialise Hugs (Unrecognised option ) I honestly can't figure out what the incompatibility is? I'm using version 20050308 of Hugs

2 1

Barrier implementation
by Peter Eriksen 17 Dec '05

17 Dec '05

Greeting, Something is not working for me, and I could use some more eyes on this. What I'm trying to accomplish is to implement a simpel barrier for ten worker threads (id = 0..9) using STM. With or without the barrier, the program produces an unordered interleaving of the output from the workers. Here's what I get with the program below: $ ghc --make Main.lhs $ a.out 0134568027913457896012579026813423904671238455702468159367839684012570279134685049137825901642375689134057892610462578903156012389473268457910267801345923924567801304689235714013679458256702465913878... And here's what I get without the line "atomically $ barrier tv id": $ a.out 1249056782934567210845619720538461975203698469175203469850123485076912348579406123894625738942106381592740631859274163841092315768491302578416930728254169302785693024917853029640217390856490... The first run should've been something like: 012345678901234567890123456789012345... since each worker thread 0..9 should write its id out once per iteration, and the workers should iterate in sync. Here's the code: > module Main where > > import Control.Concurrent > import Control.Concurrent.STM > import System.Random > > worker :: Int -> TVar Int -> IO () > worker id tv = do > sleepingTime <- randomRIO (0, 50000) > threadDelay sleepingTime > putStr $ show id > atomically $ barrier tv id > worker id tv Each worker sleeps for some time, then outputs its id and waits at the barrier for all the other workers to finish their sleep+output. > barrier :: TVar Int -> Int -> STM () > barrier tv id = do > passed <- readTVar tv > if (passed `mod` 10 == id) > then writeTVar tv (passed+1) > else retry The barrier is simply a global variable, tv, which holds the number of times any worker passed the barrier. Now, a worker may only pass the barrier iff the worker with an id one less just passed, or else it should block. > main :: IO () > main = do > tv <- atomically $ newTVar 0 > for [0..9] $ \i -> forkIO $ worker i tv > threadDelay (10*10^6) > > for = flip mapM_ The main thread just initializes the pass counter, starts 10 worker threads, and waits for ten seconds. I'd like to hear some comments on the approach, and perhaps even some insight into why it doesn't work. Regards, Peter Eriksen

6 9

RE: Re[2]: [Haskell-cafe] Substring replacements
by Branimir Maksimovic 17 Dec '05

17 Dec '05

>From: Bulat Ziganshin <bulatz(a)HotPOP.com> >Reply-To: Bulat Ziganshin <bulatz(a)HotPOP.com> >To: "Branimir Maksimovic" <bmaxa(a)hotmail.com> >CC: daniel.is.fischer(a)web.de, Haskell-Cafe(a)haskell.org >Subject: Re[2]: [Haskell-cafe] Substring replacements >Date: Fri, 16 Dec 2005 16:51:32 +0300 > >Hello Branimir, > >Friday, December 16, 2005, 5:36:47 AM, you wrote: >BM> I've also performed tests on dual Xeon linux box and results are > >just to let you know - GHC don't uses pentium4 hyperthreading, >multiple cpus or multiple cores in these tests Oh yes it does. I clearly see multiple threads that take unequal percentage on each virtual CPU. I guess that other thread is garbage collector thread. In case of hyperthreading, speed is gained by reduced memory latency by 30-60 % > >only way to make ghc using multiple processors is to use 6.5 beta >version, compile with "-smp" and explicitly fork several threads This is not the case as I see. On windows search replace test programs spawn 3 threads and on linux I'm not sure, but I've checked program that calls Haskell from C++ and GHC spawns additional thread, which is not my thread, that also performs something constantly, and I didn't spawn any thread from Haskell. So hyperthreading helps as it helps to optimise when several threads accesses memory as is in this test case. I can't see any other explanation why KMP search is slower on AMD 20% , but faster on Intel 30%, then straightforward search with my test. Greetings, Bane. _________________________________________________________________ Express yourself instantly with MSN Messenger! Download today it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/

1 0

Optimizing a high-traffic network architecture
by Joel Reymont 17 Dec '05

17 Dec '05

Folks, In my current architecture I launch a two threads per socket where the socket reader places results in a TMVar and the socket writer takes input from a TChan. I also have the worker thread the does the bulk of packet processing and a timer thread. The time thread sleeps for a few minutes and exits after posting a timeout event if it hasn't been killed before. My goal is to launch poker 2,000 bots that join the server "lobby" and sit there sending small keep-alive packets every few minutes. The ultimate goal is for 4,000 bots to be playing but I'm taking it one step at a time. This is Mac OSX Tiger with a couple of header files modified to allow FD_SETSIZE of 10240. This is the maximum allowed by 'ulimit -n'. I'm also running ghc 6.4.1, compiled after FD_SETSIZE has been increased. I can get to 2k bots without any trouble if I use a keep-alive timeout of 9 minutes. Memory usage with 2k bots is 161Mb of physical memory and 262Mb VM. CPU usage 20-40%. Memory usage is constant once all bots have been launched. With a 1 minute keep-alive timeout system is starting to get stressed almost right away. There's verbose logging going on and almost every event/packet sent and received is traced. The extra logging of the timeout events probably adds to the stress and so, I assume, do the extra packets. New bots are being launched very slowly even with just 200 bots already running. Based on the above, would you have any suggestions for an improved architecture? I will try 1) disabling logging alltogether and 2) increase thread stack size to 3k (+RTS -k3k) as per Simon Marlow's suggestion. As per simon if a thread stack space is between 2k and 4k then each thread gets its own memory block (right Simon?) and threads are not GCd then. I'm a bit concerned about trippling my memory use with -k3k, though. I'm not sure if switching to a continuations-based framework will help me. Has anyone tried this? Thanks, Joel -- http://wagerlabs.com/

6 27

RE: [Haskell-cafe] Battling laziness
by Simon Marlow 16 Dec '05

16 Dec '05

On 16 December 2005 15:23, Joel Reymont wrote: > Looking at http://wagerlabs.com/randomplay.hd.ps I see closures > (constructors?) in this order > > <Script.Array.sat_s46N> > W8# > I# > <Script.Array.fromIntegral_s453> > <Script.Endian.sat_s1WxM> >> > <Script.Endian.sat_s1WF2> > W16# > <Script.PicklePlus.sat_s38YS> > stg_ap_2_upd_info Ok, so your heap is mainly full of (a) thunks generated by something in Script.Array, (b) Word8s, and (c) Ints. > This tells me it's something having to do with array code. I'm > attaching the Script.Array module at the end. This report does not > tell me who is retaining the data, though. > > Looking at http://wagerlabs.com/randomplay.hy.ps I see types ordered > like this > > * > Word8 > Int > ->* > [] > Char > Word16 > TableInfo interesting... Word8 and Int correspond to the -hd output above, but '*' indicates that the type of the <Script.Array.sat_s46N> is polymorphic. Completely polymorphic closures like this are usually (error "something"), which is a silly thing to fill up your heap with :-) I'm a bit mystified though, because looking at the code for Script.Array, all your arrays are unboxed, so I don't know where all the Word8s and Ints are coming from. It might be useful to do "+RTS -hyWord8 -hc" to see who generated the Word8s. Oh, and it looks like you aren't doing -auto-all, that would probably be helpful. Cheers, Simon

2 5

RE: [Haskell-cafe] Optimizing a high-traffic network architecture
by Simon Marlow 16 Dec '05

16 Dec '05

On 16 December 2005 15:19, Lennart Augustsson wrote: > John Meacham wrote: >> On Thu, Dec 15, 2005 at 02:02:02PM -0000, Simon Marlow wrote: >> >>> With 2k connections the overhead of select() is going to start to >>> be a problem. You would notice the system time going up. >>> -threaded may help with this, because it calls select() less often. >> >> >> we should be using /dev/poll on systems that support it. > > And kqueue for systems that support that. Much, much more efficient > than select. Yeah, yeah. We know. We just haven't got around to doing anything about it :-( It's actually quite fiddly to hook this up to Handles - see Einar's implementation in Network.Alt for instance. Cheers, Simon (who wished he hadn't mentioned select() again)

1 0

RE: [Haskell-cafe] Battling laziness
by Simon Marlow 16 Dec '05

16 Dec '05

On 16 December 2005 12:42, Joel Reymont wrote: > On Dec 16, 2005, at 12:36 PM, Simon Marlow wrote: > >> If script#9 is the cost center attached to all of your leaking heap >> data, then you're already a long way to finding the problem. It'll >> help even more to find out whether it is just unevaluated copies of >> "takeEmptySeat Holdem affid []", or something else (-hd, -hy will >> help here). Try +RTS -hy -hcscript#9, for example. >> >> One obvious thing to try is replacing the '$' before {-# SCC >> "script#9" #-} with '$!'. And similarly in takeEmptySeat. > > Let me try these and report my findings. > >> (I should say that we definitely plan to update these for STM, but >> it's not completely trivial (I checked). Volunteers definitely >> welcome). > > I volunteer! Just need some pointers on where to get started. I learn > quickly but need to be guided ;-). Plus, I need this the most, right? I was slightly mistaken: lag/drag/void profiling is pretty easy. Take a look at ghc/rts/LdvProfile.c and add relevant cases for STM objects to processHeapClosureForDead(). If you fix this up and test it we should be able to get it into 6.4.2. Retainer profiling is much harder; the code is in RetainerProfile.c/RetainerSet.c. Cheers, Simon

2 2

RE: [Haskell-cafe] Optimizing a high-traffic network architecture
by Simon Marlow 16 Dec '05

16 Dec '05

On 15 December 2005 10:21, Joel Reymont wrote: > Here are statistics that I gathered. I'm almost done modifying the > program to use 1 timer thread instead of 1 per bot as well as writing > to the socket from the writer thread. This should reduce the number > of threads from 6k (2k x 3) to 2k plus change. > > It appears that +RTS -k3k does make a difference. As per Simon, 2-4k > avoids the thread being garbage collected because each thread gets > its own block in the storage manager. Simon, did I get that right? > > BTW, how does garbage-collecting a thread works in this scenario? My > threads are very long-running. > > The total is the number of bots launched, lobby is how many bots > connected to the lobby. Failed is mostly due to connection reset by > peer errors. The Windows C++ server uses IOCP and running a firewall > was apparently interfering with that somehow. I hate Windows :-(. > > --- Test#1 +RTS -k3k as per Simon. Keep-alive timeout of 9 minutes. > > Total: 1961, Lobby: 1961, Failed: 0 > Total: 2000, Lobby: 2000, Failed: 1 > > This test went smoothly and got to 2k connections very quickly. Maybe > within 30 minutes or so. I did not gather CPU usage, etc. statistics. > > --- Test #2, No thread stack increase, 1 minute keep-alive timeout, > more network traffic > > With a 1 minute timeout things run veeery slow. 86 physical and 158Mb > of VM with 1k bots, CPU 50-60%. Data sent/received is 60-70 packets > and 6-7kb/sec. Killed after a while. > > The statistics are phys/VM, CPU usage in % and #packets/transfer speed > > Total: 1345, Lobby: 1326, Failed: 0, 102/184, 50%, 90/8kb > Total: 1395, Lobby: 1367, Failed: 2 > Total: 1421, Lobby: 1394, Failed: 4 > Total: 1490, Lobby: 1463, Failed: 4, 108/194, 50%, 110/11Kb > Total: 1574, Lobby: 1546, Failed: 4, 113/202, 50%, 116/11kb Hmm, your machine is spending 50% of its time doing nothing, and the network traffic is very low. I wouldn't expect 2k connections to pose any problem at all, so further investigation is definitely required. With 2k connections the overhead of select() is going to start to be a problem. You would notice the system time going up. -threaded may help with this, because it calls select() less often. If that's not the cause, we should find out what your app is doing while it's idle. If there are runnable threads (eg. the lauchner), then the app should not be spending any of its time idle. Cheers, Simon

9 10

RE: [Haskell-cafe] Battling laziness
by Simon Marlow 16 Dec '05

16 Dec '05

On 16 December 2005 12:08, Joel Reymont wrote: > -hc points to script#9 below. > > script (_, _, affid) (Custom (JoinedTable 0)) = > do {-# SCC "script#8" #-}push "takeEmptySeat" $ > {-# SCC "script#9" #-}takeEmptySeat Holdem affid [] > {-# SCC "script#10" #-}return $ Eat $ Just Go > > What takeEmptySeat does it call pickTable > > takeEmptySeat game_type _ filters Go = > do push "pickTable" $ pickTable game_type filters > return $ Eat $ Just Go It's hard to pick out the cause of a space leak from just a fragment of the program, but I'll try to give you some pointers. If script#9 is the cost center attached to all of your leaking heap data, then you're already a long way to finding the problem. It'll help even more to find out whether it is just unevaluated copies of "takeEmptySeat Holdem affid []", or something else (-hd, -hy will help here). Try +RTS -hy -hcscript#9, for example. One obvious thing to try is replacing the '$' before {-# SCC "script#9" #-} with '$!'. And similarly in takeEmptySeat. > Overall, -hc does not help me figure out where my data is being > retained. My understanding is that I need to do -hbdrag,void fo > rthat. I did not try -hd and -hy, they would only help me narrow down > the producers, right? Not necessarily; lag/drag/void only tells you about certain kinds of space leaks. It's another tool in the box, and quite often you can get away without it. Retainer profiling similarly. (I should say that we definitely plan to update these for STM, but it's not completely trivial (I checked). Volunteers definitely welcome). > My program seems to spend 70% of the time collecting garbage. Notice > the HUGE overall allocations. This is my trying to launch 4k bots > over 8 hours. Only 1k bots were launched and just 300 of those got to > play. Maybe because they did not have time with all the garbage > collection :-). Note that your GC time is inflated quite a bit due to profiling (it makes every object larger). The plan to reduce GC time is, in this order: squash space leaks, reduce allocation (to reduce GC load), and then tweak GC parameters. Cheers, Simon

2 2

Battling laziness
by Joel Reymont 16 Dec '05

16 Dec '05

Folks, I have a huge space leak someplace and I suspect this code. The SrvServerInfo data structure is something like 50K compressed or uncompressed byte data before unpickling. My thousands of bots issue this request at least once and I almost run out of memory with 100 bots on a 1Gb machine on FreeBSD. Do I need deepSeq somewhere below? This is the read. read :: Handle -> (SSL, BIO, BIO) -> IO Command read h _ = do sa <- emptyByteArray 4 hGetArray h sa 4 (size', _) <- unpickle endian32 sa 0 let size = fromIntegral $ size' - 4 packet <- emptyByteArray size hGetArray h packet size unstuff packet 0 I suspect that I need to deepSeq cmd'' instead of return $! cmd'' unstuff :: MutByteArray -> Index -> IO Command unstuff array ix = do (kind, ix1) <- unpickle puCmdType array ix (cmd', _) <- unpickle (puCommand kind) array ix1 case cmd' of InvalidCommand -> do fail $ "unstuff: Cannot parse " ++ show array SrvCompressedCommands sz bytes -> do bytes' <- uncompress bytes (fromIntegral sz) cmd'' <- unstuff bytes' 4 return $! cmd'' _ -> return cmd' This is where the list of active tables is converted to a table id list of [Word32]. pickTable _ filters (Cmd cmd@(SrvServerInfo {})) = do let tables = filter (tableMatches filters) $ activeTables cmd ids = map tiTableID tables case tables of [] -> fail $ "pickTable: No tables found: " ++ show filters _ -> do pop stoptimer "pickTable" return $! Eat $! Just $! Custom $! Tables $! ids This is where the table id list of [Word32] is consumed. takeEmptySeat _ aff_id _ (Custom (Tables ids@(table:rest))) = do trace 85 $ "takeEmptySeat: " ++ show (length ids) ++ " tables found" trace 100 $ "takeEmptySeat: tables: " ++ showTables ids trace 85 $ "takeEmptySeat: trying table# " ++ show table w <- get put_ $ w { tables_to_try = rest } push "goToTable" $ goToTable table aff_id -- kick off goToTable return $ Eat $ Just Go This is the SrvServerInfo structure. | SrvServerInfo { activeTables :: ![TableInfo], -- Word16/ removedTables :: ![Word32], -- Word16/ version :: !Int32 } And this is the table info itself. data TableInfo = TableInfo { tiAvgPot :: !Word64, tiNumPlayers :: !Word16, tiWaiting :: !Word16, tiPlayersFlop :: !Word8, tiTableName :: !String, tiTableID :: !Word32, tiGameType :: !GameType, tiInfoMaxPlayers :: !Word16, tiIsRealMoneyTable :: !Bool, tiLowBet :: !Word64, tiHighBet :: !Word64, tiMinStartMoney :: !Word64, tiMaxStartMoney :: !Word64, tiGamesPerHour :: !Word16, tiTourType :: !TourType, tiTourID :: !Word32, tiBetType :: !BetType, tiCantReturnLess :: !Word32, tiAffiliateID :: ![Word8], tiLangID :: !Word32 } deriving (Show, Typeable) Thanks, Joel -- http://wagerlabs.com/

2 1

RE: [Haskell-cafe] Battling laziness
by Simon Marlow 16 Dec '05

16 Dec '05

What does ordinary heap profiling (-hc, -hd, -hy) tell you about what's in the heap? These options should work fine with STM. Cheers, Simon On 16 December 2005 11:44, Joel Reymont wrote: > Folks, > > I have a huge space leak someplace and I suspect this code. The > SrvServerInfo data structure is something like 50K compressed or > uncompressed byte data before unpickling. My thousands of bots issue > this request at least once and I almost run out of memory with 100 > bots on a 1Gb machine on FreeBSD. Do I need deepSeq somewhere below? > > This is the read. > > read :: Handle -> (SSL, BIO, BIO) -> IO Command > read h _ = > do sa <- emptyByteArray 4 > hGetArray h sa 4 > (size', _) <- unpickle endian32 sa 0 > let size = fromIntegral $ size' - 4 > packet <- emptyByteArray size > hGetArray h packet size > unstuff packet 0 > > I suspect that I need to deepSeq cmd'' instead of return $! cmd'' > > unstuff :: MutByteArray -> Index -> IO Command > unstuff array ix = > do (kind, ix1) <- unpickle puCmdType array ix > (cmd', _) <- unpickle (puCommand kind) array ix1 > case cmd' of > InvalidCommand -> do fail $ "unstuff: Cannot parse " ++ > show array > SrvCompressedCommands sz bytes -> > do bytes' <- uncompress bytes (fromIntegral sz) > cmd'' <- unstuff bytes' 4 > return $! cmd'' > _ -> return cmd' > > This is where the list of active tables is converted to a table id > list of [Word32]. > > pickTable _ filters (Cmd cmd@(SrvServerInfo {})) = > do let tables = filter (tableMatches filters) $ activeTables cmd > ids = map tiTableID tables > case tables of > [] -> fail $ "pickTable: No tables found: " ++ show filters > _ -> > do pop > stoptimer "pickTable" > return $! Eat $! Just $! Custom $! Tables $! ids > > This is where the table id list of [Word32] is consumed. > > takeEmptySeat _ aff_id _ (Custom (Tables ids@(table:rest))) = > do trace 85 $ "takeEmptySeat: " ++ show (length ids) > ++ " tables found" > trace 100 $ "takeEmptySeat: tables: " ++ showTables ids > trace 85 $ "takeEmptySeat: trying table# " ++ show table > w <- get > put_ $ w { tables_to_try = rest } > push "goToTable" $ goToTable table aff_id > -- kick off goToTable > return $ Eat $ Just Go > > This is the SrvServerInfo structure. > > | SrvServerInfo > { > activeTables :: ![TableInfo], -- Word16/ > removedTables :: ![Word32], -- Word16/ > version :: !Int32 > } > > And this is the table info itself. > > data TableInfo = TableInfo > { > tiAvgPot :: !Word64, > tiNumPlayers :: !Word16, > tiWaiting :: !Word16, > tiPlayersFlop :: !Word8, > tiTableName :: !String, > tiTableID :: !Word32, > tiGameType :: !GameType, > tiInfoMaxPlayers :: !Word16, > tiIsRealMoneyTable :: !Bool, > tiLowBet :: !Word64, > tiHighBet :: !Word64, > tiMinStartMoney :: !Word64, > tiMaxStartMoney :: !Word64, > tiGamesPerHour :: !Word16, > tiTourType :: !TourType, > tiTourID :: !Word32, > tiBetType :: !BetType, > tiCantReturnLess :: !Word32, > tiAffiliateID :: ![Word8], > tiLangID :: !Word32 > } deriving (Show, Typeable) > > Thanks, Joel

2 2