Hello haskell-cafe!
After making data Number = Zero | Succ Number an instance of
Integral, I wondered how I could do the same with galois fields. So
starting with Z mod p, I figured I'd need something like this
data GF = GF Integer Integer
so that each element of the finite field would
On Dec 20, 2007 9:34 AM, Adrian Neumann [EMAIL PROTECTED] wrote:
Hello haskell-cafe!
After making data Number = Zero | Succ Number an instance of
Integral, I wondered how I could do the same with galois fields. So
starting with Z mod p, I figured I'd need something like this
data GF = GF
Joost Behrends wrote:
since about three weeks i am learning Haskell now. One of my first exercises is
to decompose an Integer into its primefactors.
How about separating the candidate prime numbers from the recursion
factorize :: Integer - [Integer]
factorize = f primes'
where
Hello all!
How come in GHC 6.6 I could to write
{-# OPTIONS_GHC -fglasgow-exts -fallow-undecidable-instances #-}
data Foo = Foo deriving Show
data Bar c = Bar (c Foo) deriving Show
but in GHC 6.8.2 I get the error
No instance for (Show (c Foo))
arising from the
Don, and others,
This thread triggered something I've had at the back of my mind for some time.
The traffic on Haskell Cafe suggests that there is a lot of interest in the
performance of Haskell programs. However, at the moment we don't have any good
*performance* regression tests for GHC. We
Alfonso Acosta wrote:
mapSY :: (Typeable a, Typeable b) = (a - b) - Signal a - Signal b
mapSY f (Signal primSig) = Signal (PrimSignal (MapSY (toDyn f) primSig))
The following process would be really useful but its compilation
obviously fails:
mapSnd :: Signal (a, a) - Signal a
mapSnd =
After looking more closely at user's manual, I just found that the following
works:
{-# OPTIONS_GHC -fglasgow-exts -fallow-undecidable-instances #-}
data Foo = Foo deriving Show
data Bar c = Bar (c Foo)
deriving instance Show (c Foo) = Show (Bar c)
/ Emil
On 2007-12-20
* Simon Peyton-Jones wrote:
Does anyone feel like doing this? It'd be a great service. No need to
know anything much about GHC.
I'd like to do that. For a lecture I'm already generated performance tests
for various sorting algorithms.
It's designed about a function performance :: Size - IO
Adrian Neumann wrote:
I figured I'd need something like this
data GF = GF Integer Integer
so that each element of the finite field would remember p. However I
can't think of a way to use the typesystem to ensure that p is always
the same.
You might like:
Vectro: Haskell library
I added Don's three benchmarks and redid all my benchmarks with:
ghc 6.6.1
ghc 6.8.2
ghc 6.8.2 + bytestring 0.9.0.2
ghc 6.9.20071119
ghc 6.9.20071119 + bytestring 0.9.0.2
ghc head-as-of-yesterday-around-noon
ghc head-as-of-yesterday-around-noon + bytestring 0.9.0.2
I tried to get
Simon Peyton-Jones [EMAIL PROTECTED] wrote:
What would be v helpful would be a regression suite aimed at
performance, that benchmarked GHC (and perhaps other Haskell
compilers) against a set of programs, regularly, and published the
results on a web page, highlighting regressions.
Something
On Thu, 2007-12-20 at 10:37 +, Simon Peyton-Jones wrote:
Don, and others,
This thread triggered something I've had at the back of my mind for some time.
The traffic on Haskell Cafe suggests that there is a lot of interest
in the performance of Haskell programs. However, at the moment
Hi Fernand,
Everything works fine except for the fact that all the nodes « this
/this »
(that is, a space (an XML text node whose contents are a single space
character)
within a this element node) get transformed to a « this/ » element
I can't really reproduce this:
A simple ghci session
I can't really reproduce this:
A simple ghci session gives the following:
---
[EMAIL PROTECTED]:~/haskell/hxt/curr/examples/arrows/HelloWorld ghci
HelloWorld.hs
GHCi, version 6.8.1: http://www.haskell.org/ghc/ :? for help
Loading package base ... linking
Hi Miguel,
Hmmm, with 'readString ... this /this' everything works fine,
but with 'readString ... itemsthis /this/items' it doesn't.
Seems to be a bug in HXT.
I don't see the bug:
--
*Main runX $ ( readString [(a_validate,v_0)] itemsthis /this/items
* Malcolm Wallace wrote:
Something along these lines already exists - the nobench suite.
Ok, your turn.
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jlw501 wrote:
I'm new to functional programming and Haskell and I love its expressive
ability! I've been trying to formalize the following function for time.
Given people and a piece of information, can all people know the same thing?
Anyway, this is just a bit of fun... but can anyone help me
Prelude Text.XML.HXT.Arrow runX $ ( readString [(a_validate,v_0)]
xy /y/x setTraceLevel 4 traceDoc doc after reading
s
etTraceLevel 0 writeDocumentToString [(a_indent, v_1)])
-- (1) doc after reading
x
y/
/x
content of: xy /y/x
=
---XTag /
| source=\xy
Tim Chevalier wrote:
On 12/14/07, Dan Piponi [EMAIL PROTECTED] wrote:
There have been some great improvements in array handling recently. I
decided to have a look at the assembly language generated by some
simple array manipulation code and understand why C is at least twice
as fast as ghc
Malcolm Wallace wrote:
Simon Peyton-Jones [EMAIL PROTECTED] wrote:
What would be v helpful would be a regression suite aimed at
performance, that benchmarked GHC (and perhaps other Haskell
compilers) against a set of programs, regularly, and published the
results on a web page, highlighting
Simon Marlow wrote:
Nobench does already collect code size, but does not yet display it in
the results table. I specifically want to collect compile time as well.
Not sure what the best way to measure allocation and peak memory use
are?
With GHC you need to use +RTS -s and then slurp in the
Hi,
I'm newbie in Haskell, and I have some doubts... In this programming
language, do we have storable values? Case affirmative, what are the
storable types in Haskell, and how can I implement then...
thanks!
--
Clerton Ribeiro de Araujo Filho
Graduando em Ciência da Computação
Integrante do
Hallo fellow Brazilian,
Clerton Filho escreveu:
Hi,
I'm newbie in Haskell, and I have some doubts... In this programming
language, do we have storable values? Case affirmative, what are the
storable types in Haskell, and how can I implement then...
What exactly is a storable type?
On Thu, 20 Dec 2007, Alex Sandro Queiroz e Silva wrote:
Hallo fellow Brazilian,
Clerton Filho escreveu:
Hi,
I'm newbie in Haskell, and I have some doubts... In this programming
language, do we have storable values? Case affirmative, what are the
storable types in Haskell, and how
Clerton Filho wrote:
Hi,
I'm newbie in Haskell, and I have some doubts... In this programming
language, do we have storable values? Case affirmative, what are the
storable types in Haskell, and how can I implement then...
Not entirely sure what you mean.
There is a haskell typeclass called
On 12/20/07, Simon Marlow [EMAIL PROTECTED] wrote:
That's not entirely true - there is a fairly decent linear-scan register
allocator in GHC
http://darcs.haskell.org/ghc/compiler/nativeGen/RegAllocLinear.hs
the main bottleneck is not the quality of the register allocation (at
least, not
Hi Miguel,
Try xy /y/x and a_indent writing option.
yes, with the indent option set, whitespace
becomes insignificant and will change during
formating, and so the contents
of the inner element reduces to empty
Turn of the indentation and you get the
result you want.
Cheers,
Uwe
--
Web:
I'm really inexperienced at this :
---
{-# OPTIONS_GHC -fglasgow-exts -funbox-strict-fields
-fallow-undecidable-instances -O2 #-}
class Gadget g where
fInit :: g - a - g
data FString = FString !Int !String deriving Show
instance Gadget FString where
fInit (FString n _) s = FString
On Wed, 19 Dec 2007 02:00:53 -0500, Jules Bean [EMAIL PROTECTED]
wrote:
Brad Larsen wrote:
Hi there list,
How would one go about creating a new type for a subset of the
integers, for (contrived) example just the even integers? I was
thinking of making a new type
newtype EvenInt =
david48 wrote:
| I'm really inexperienced at this :
class Gadget g where
fInit :: g - a - g
data FString = FString !Int !String deriving Show
instance Gadget FString where
fInit (FString n _) s = FString n (take n s)
The types of:
fInit :: g - a - g
and:
take :: Int - [a] - [a]
Brad Larsen wrote:
On Wed, 19 Dec 2007 02:00:53 -0500, Jules Bean [EMAIL PROTECTED]
wrote:
Brad Larsen wrote:
Hi there list,
How would one go about creating a new type for a subset of the
integers, for (contrived) example just the even integers? I was
thinking of making a new type
On Dec 20, 2007 5:03 PM, Claude Heiland-Allen
[EMAIL PROTECTED] wrote:
You're trying to apply 'take n' to a value of type 'a' ('take n'
requires [a]), moreover putting the value of 'take n s' into the FString
further constrains its type to be [Char] == String.
First of all, thanks a lot for
david48 wrote:
class Gadget g where
fInit :: g - a - g
data FString = FString !Int !String deriving Show
instance Gadget FString where
at this point fInit has this type:
FString - a - FString
fInit (FString n _) s = FString n (take n s)
but your implementation has this type
Tillmann Rendel wrote:
david48 wrote:
class Gadget g where
fInit :: g - a - g
Tillman's two suggestions (below) are probably your answer.
Just to say what everyone else has said in a bunch of different ways:
your class says that for ANY Gadget, fInit will work with ANY OTHER type a.
On Dec 20, 2007 5:26 PM, Tillmann Rendel
[EMAIL PROTECTED] wrote:
at this point fInit has this type:
FString - a - FString
fInit (FString n _) s = FString n (take n s)
but your implementation has this type
FString - String - FString
These types are incompatible, your fInit
On Dec 20, 2007 5:44 PM, david48 [EMAIL PROTECTED] wrote:
fString :: Int - FString
fString n = FString n
Oo do I feel dumb for writing this !
Problem solved :)
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On Dec 20, 2007 5:36 PM, Jules Bean [EMAIL PROTECTED] wrote:
2. Maybe you want lots of possible different as for each g. Then you
make a a parameter of the class too.
3. Maybe you want just one particular a for each g. I.e. g
determines a. Then you can proceed as for (2), but add the
firefly:
I added Don's three benchmarks and redid all my benchmarks with:
ghc 6.6.1
ghc 6.8.2
ghc 6.8.2 + bytestring 0.9.0.2
ghc 6.9.20071119
ghc 6.9.20071119 + bytestring 0.9.0.2
ghc head-as-of-yesterday-around-noon
ghc head-as-of-yesterday-around-noon + bytestring 0.9.0.2
simonpj:
Don, and others,
This thread triggered something I've had at the back of my mind for some time.
The traffic on Haskell Cafe suggests that there is a lot of interest in the
performance of Haskell programs. However, at the moment we don't have any
good *performance* regression
Malcolm.Wallace:
Simon Peyton-Jones [EMAIL PROTECTED] wrote:
What would be v helpful would be a regression suite aimed at
performance, that benchmarked GHC (and perhaps other Haskell
compilers) against a set of programs, regularly, and published the
results on a web page, highlighting
simonmarhaskell:
Malcolm Wallace wrote:
Simon Peyton-Jones [EMAIL PROTECTED] wrote:
What would be v helpful would be a regression suite aimed at
performance, that benchmarked GHC (and perhaps other Haskell
compilers) against a set of programs, regularly, and published the
results on a web
On Thursday 20 December 2007 19:02, Don Stewart wrote:
Ok, so I should revive nobench then, I suspect.
http://www.cse.unsw.edu.au/~dons/nobench/x86_64/results.html
that kind of thing?
Many of those benchmarks look good.
However, I suggest avoiding trivially reducible problems like
jon:
On Thursday 20 December 2007 19:02, Don Stewart wrote:
Ok, so I should revive nobench then, I suspect.
http://www.cse.unsw.edu.au/~dons/nobench/x86_64/results.html
that kind of thing?
Many of those benchmarks look good.
However, I suggest avoiding trivially reducible
However, I suggest avoiding trivially reducible problems like computing
constants (e, pi, primes, fib) and redundant operations (binary trees). Make
sure programs accept a non-trivial input (even if it is just an int over a
wide range). Avoid unnecessary repeats (e.g. atom.hs). This will
According to this
http://www.randomhacks.net/articles/2007/03/10/haskell-8-ways-to-report-errors
Either is an instance of class Monad, but when I try to use the do
notation I get a compiler error. What's going on?
E.
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On 12/20/07, Eric [EMAIL PROTECTED] wrote:
According to this
http://www.randomhacks.net/articles/2007/03/10/haskell-8-ways-to-report-errors
Either is an instance of class Monad, but when I try to use the do
notation I get a compiler error. What's going on?
Near the bottom of that page is a
Tom Phoenix wrote:
On 12/20/07, Eric [EMAIL PROTECTED] wrote:
According to this
http://www.randomhacks.net/articles/2007/03/10/haskell-8-ways-to-report-errors
Either is an instance of class Monad, but when I try to use the do
notation I get a compiler error. What's going on?
Near the
It seems I can't find it.
David.
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dav.vire+haskell:
It seems I can't find it.
hscurses, Stefan Wehr's package of the curses binding is pre-hackage
and pre-cabal, so you can only get the source:
http://www.informatik.uni-freiburg.de/~wehr/haskell/
there's another curses binding in hmp3,
Eric wrote:
According to this
http://www.randomhacks.net/articles/2007/03/10/haskell-8-ways-to-report-errors
Either is an instance of class Monad, but when I try to use the do
notation I get a compiler error. What's going on?
Try to import Control.Monad.Error to get a Monad instance for
On Dec 20, 2007 11:24 PM, Don Stewart [EMAIL PROTECTED] wrote:
there's another curses binding in hmp3,
http://www.cse.unsw.edu.au/~dons/code/hmp3/Curses.hsc
that i keep meaning to package up, but never do.
Thanks !
There's quite a lot of stuff I don't understand in Curses.hsc ( the
use
Albert Y. C. Lai trebla at vex.net writes:
Theoretically the recursions in
oddFactors k n | otherwise = oddFactors (k+2) n
and
(*) divisions y |divisor y = bound y = divisions (divstep y)
do not cost stack space. They are tail recursions too!
In general similar tail
apfelmus apfelmus at quantentunnel.de writes:
How about separating the candidate prime numbers from the recursion
factorize :: Integer - [Integer]
factorize = f primes'
where
primes' = 2:[3,5..]
f (p:ps) n
| r == 0= p : f (p:ps) q
| p*p n
On 12/20/07, Joost Behrends [EMAIL PROTECTED] wrote:
makes a DESTRUCTIVE UPDATE of the DivIters (by put) and this kind of
recursion
seems not to remember itself (as i have understood, that is achieved by
tail recursion). I just didn't like making DivIters to States.
It's kind of lying code.
Hello, I have an application that uses/used Text.Regex and have just updated
GHC from 6.6.1 to 6.8.2 and it seems that Text.Regex is gone, so I'm trying
to install the replacement from Hackage.
First of all, the procedure is quite tedious as one has to install the
hierarchy of dependencies
I'm curious how much of the unboxing helped performance and how much
didn't. In my experience playing with this stuff, GHC's strictness
analyzer has consistently been really excellent, given the right
hints. Unboxed tuples are generally a win, but GHC was often smarter
at unboxing ints
On Fri, 2007-12-21 at 13:58 +1030, Michael Mounteney wrote:
Hello, I have an application that uses/used Text.Regex and have just updated
GHC from 6.6.1 to 6.8.2 and it seems that Text.Regex is gone, so I'm trying
to install the replacement from Hackage.
First of all, the procedure is
I'm playing around with smart constructors, and I have encountered a
weird puzzle.
My goal is to do vector arithmetic. I'm using smart constructors so
that I can store a vector as a list and use the type system to
staticly enforce the length of a vector.
So my first step is to define Peano
On Dec 21, 2007 4:39 AM, Ronald Guida [EMAIL PROTECTED] wrote:
Finally, I tried to define vecLength, but I am getting an error.
vecLength :: (Peano s) = Vec s t - Int
vecLength _ = pToInt (pGetValue :: s)
The s in (pGetValue :: s) is different from the s in (Peano s). Use
the scoped type
Ronald Guida wrote:
I'm playing around with smart constructors, and I have encountered a
weird puzzle.
My goal is to do vector arithmetic. I'm using smart constructors so
that I can store a vector as a list and use the type system to
staticly enforce the length of a vector.
So my first step
On Thu, Dec 20, 2007 at 11:39:42PM -0500, Ronald Guida wrote:
data PZero = PZero deriving (Show)
data PSucc a = PSucc a deriving (Show)
type P1 = PSucc PZero
type P2 = PSucc P1
type P3 = PSucc P2
-- etc
...
Now here's the puzzle. I want to create a function vecLength that
Searchpath already does recursive module chasing accross the internet.
If your module is available at a url in an unpacked module hierarchy or
in a tgz file or if it is exposed in a darcs/svn/cvs etc repo,
searchpath can retrieve it and put it on your local import path.
The main limitations
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