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RE: Counting occurrences question
by Andy Fugard 05 Jun '02

05 Jun '02

>===== Original Message From "xoo" <ixoo21(a)hotmail.com> ===== >hi.. i was just wondering if some body could give a simple equation for the following situation.other than recursion plz.. > >occurrences :: Eq a => a -> [a] -> [a] >--occurrences xs ys returns the number of times that xs occurs in ys You may find it easier if you make occurrences :: Eq a => a -> [a] -> Integer since it would seem it is to return a number, and not another list! Also I would guess the function will have a form something like occurrences x xs = foldr (countOp x) 0 xs where countOp :: Eq a => a -> a -> Integer -> Integer ... I'm not sure if I should go any further, in case this is a homework question... Andy -- [ Andy Fugard ] [ +44 (0)7901 603075 ]

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Bilgisayar Egitiminde Bir Numara
by Sertifikam.Com 05 Jun '02

05 Jun '02

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Bilgisayar Egitiminde Bir Numara
by Sertifikam.Com 05 Jun '02

05 Jun '02

1 0

Direct Email Blaster, Email extractor, email downloader, email verify ...........
by targetemailextractor＠btamail.net.cn 03 Jun '02

03 Jun '02

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HTTP Implementation
by Warrick Gray 02 Jun '02

02 Jun '02

I've been tinkering with a client-side HTTP/1.1 implementation for Haskell. My ambition is to write a small Haskell program for checking my Hotmail account. In the interests of finding all bugs and giving something for nothing I've made the code available: http://homepages.paradise.net.nz/warrickg/haskell/http Significantly missing is any hint of SSL and request pipelining. Suggestions on improvements are welcome. Warrick. _________________________________________________________________ Send and receive Hotmail on your mobile device: http://mobile.msn.com

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RE: Naming conventions for compiler options [Was: layout rule infelicity]
by Jay Allen 31 May '02

31 May '02

-Wmissing-prototypes, actually (http://www.esat.kuleuven.ac.be/~gcc/) But good guess. ;) -J- -----Original Message----- From: Ashley Yakeley [mailto:ashley@semantic.org] Sent: Thu 5/30/2002 5:26 PM To: Haskell Cafe List Cc: Subject: Re: Naming conventions for compiler options [Was: layout rule infelicity] At 2002-05-30 16:51, oleg(a)pobox.com wrote: >-Wmissing-protons Compiles BASIC? -- Ashley Yakeley, Seattle WA _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe(a)haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

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Re: Naming conventions for compiler options [Was: layout rule infelicity]
by Ashley Yakeley 31 May '02

31 May '02

At 2002-05-30 16:51, oleg(a)pobox.com wrote: >-Wmissing-protons Compiles BASIC? -- Ashley Yakeley, Seattle WA

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Naming conventions for compiler options [Was: layout rule infelicity]
by oleg＠pobox.com 30 May '02

30 May '02

[redirected to haskell-cafe] Jón Fairbairn wrote: > 1. Why "-f" anyway? It took me ages to work out what > "-fallow-overlapping-instances" meant -- I wondered how > "fallow" could apply to overlapping instances. I believe the authors of GHC followed the naming conventions of GCC, which can be gleaned from GCC's info page. -warning-related options typically start with -W -machine-independent flags that control optimization, code-generation or language dialects start with -f. Most flags have positive and negative forms. -many pre-processor-related options start with -i -hardware-dependent options start with -m, e.g., -mcpu=i686 -mno-fancy-math-387 -malign-int -mno-power [RS/6000-related option] -myellowknife [On embedded PowerPC systems, assume that the startup module is called `crt0.o' and the standard C libraries are `libyk.a' and `libc.a'] Of possible interest is a file gcc-2.95.2/gcc/future.options from GCC's source code. The file lists a few suggested options. The file is an e-mail message from Noah Friedman to Richard Stallman, Jim Blandy and a few other people. Some of the suggested options are: -Waggravate-return -Wcast-spell -Wcaste-align [cf. the existing GCC option -Wcast-align] -Win [I guess warn about the Windows system] -Wmissing-protons -Wredundant-repetitions -antsy -fbungee-jump -fexpensive-operations [cf. -fexpensive-optimizations] -fextra-strength [must be a negative form of -fstrength-reduce] -fkeep-programmers-inline [cf. the existing option -fkeep-inline-functions] -fjesus-saves [cf. the existing option -fcaller-saves] -fno-peeping-toms [cf. the existing option -fno-peephole] -fruit-roll-ups [cf. the existing option -funroll-loops] -fshort-enough -mno-dialogue -vomit-frame-pointer

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Re: layout rule infelicity
by Frank Atanassow 30 May '02

30 May '02

[redirected to haskell-cafe] Ashley Yakeley wrote (on 30-05-02 03:18 -0700): > At 2002-05-30 02:54, Lennart Augustsson wrote: > > >If you look at C (& offspring), it's not the {;} that makes the code > >readable, it's the indentation that does. So why not acknowledge that? > > In C, the indentation is an important visual clue, but there are many > different indentation styles. I think there are not so many different _indentation_ styles. The differences seem mostly to revolve around where to put _the braces_. And one might argue that the reason for that is precisely that it's so arbitrary, since the indentation is the main visual clue to structure anyway. Personally, I always try to factor out arbitrariness from my programs. I think layout does the same thing for syntax. > If you're used to braces, complicated Haskell expressions with layout > look confusing, since it's not immediately clear which indentation style > the layout rules are trying to enforce. If you're used to C, then layout and indentation will be the least of your difficulties when you start using Haskell... Anyway, I have the feeling that, for every person on this list who complains about layout being unintuitive, there are 10 people who would say the opposite. Shall we take a poll? -- Frank Atanassow, Information & Computing Sciences, Utrecht University Padualaan 14, PO Box 80.089, 3508 TB Utrecht, Netherlands Tel +31 (030) 253-3261 Fax +31 (030) 251-379

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Space problem: reading a list of records from a binary database
by Eray Ozkural 29 May '02

29 May '02

Hi there, While trying to read a list of records from a binary database I think I've encountered a space leak but I'm not proficient enough to detect the cause of the error. The culprit is the readSessionDB function in SessionDB module which I attach with other relevant code. What I do in Session.readSession is using FFI to read a fixed size record from an input stream. That far, okay. (I have no idea if I'm doing it right, though) The problem is, combined with my approach in Session.readSessionDB, it results in huge amounts of space allocation, about 1MB, whereas the raw data would consume about 50K. It would be a [Session] with about 3000 elements, each of which contains 3 Ints and 6 Floats. I wonder if the following code in SessionDB is the proper way to read a list of records from a file. I get the feeling that the (s:rest) in the last return statement causes my problems. readSessionList :: Handle -> IO [Session] readSessionList h = do session <- readSession h case session of Nothing -> return [] Just s -> do rest <- readSessionList h return (s:rest) Comments appreciated, -- Eray Ozkural (exa) <erayo(a)cs.bilkent.edu.tr> Comp. Sci. Dept., Bilkent University, Ankara www: http://www.cs.bilkent.edu.tr/~erayo Malfunction: http://mp3.com/ariza GPG public key fingerprint: 360C 852F 88B0 A745 F31B EA0F 7C07 AE16 874D 539C

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