On Mon, Jan 12, 2009 at 07:14:36PM -0800, Tim Bauer wrote:
> Hi all. Under I have some old code that broke under ghc 6.10.1.
> Under (6.6.1), 6.8.1 (and I think 6.8.2), this compiles.
>
> import Prelude hiding(catch)
> import Control.Concurrent
> import Control.Exception(catch,throw,evaluate)
>
> a
Don Stewart wrote:
Do you have any benchmarks comparing dictionaries against Map ByteString
Int, or Map String Int?
I haven't personally run them, but Mark Wotton has compared
[(ByteString,Int)] vs (Map ByteString Int) vs (Trie Int) version 0.1.1
or 0.1.2 and using data from /usr/share/dict/w
Hi,
a new release of the 'json' package is now available via hackage,
version 0.4.1
http://hackage.haskell.org/cgi-bin/hackage-scripts/package/json
[no claims that it represents rocket science, but a number of downstream
codebases depend on this package for their operation, hence the
announce
Hi all. Under I have some old code that broke under ghc 6.10.1.
Under (6.6.1), 6.8.1 (and I think 6.8.2), this compiles.
import Prelude hiding(catch)
import Control.Concurrent
import Control.Exception(catch,throw,evaluate)
async :: IO a -> IO (MVar a)
async ioa = do
mVar <- newEmptyMVar
On Mon, Jan 12, 2009 at 8:34 PM, Phil wrote:
> Thanks Minh - I've updated my code as you suggested. This looks better than
> my first attempt!
>
> Is it possible to clean this up any more? I find:
>
> ( (), (Double, Word64) )
>
> a bit odd syntactically, although I understand this is just to fit
On Mon, Jan 12, 2009 at 6:34 PM, Phil wrote:
> -- Monad Implementation
>
> evolveUnderlying :: (Double, Word64) -> ( (), (Double, Word64) )
> evolveUnderlying (stock, state) = ( (), ( newStock, newState ) )
> where
>newState = ranq1Increment state
>newStock = stock * exp ( ( ir - (0.5*(
On Mon, Jan 12, 2009 at 5:56 PM, Stephen Hicks wrote:
> -- This instance definition is broken...
> instance (Monad m,Pick (a,b) c) => Pick (m a,m b) (m c) where
>pick (ma,mb) = do { a <- ma; b <- mb; return $ pick (a,b) }
First, and I know these types of comments are generally unwanted, but
Thanks Minh - I've updated my code as you suggested. This looks better than
my first attempt!
Is it possible to clean this up any more? I find:
( (), (Double, Word64) )
a bit odd syntactically, although I understand this is just to fit the type
to the State c'tor so that we don't have to write
Hi,
I'm trying to write a small module for conveniently writing functions
that can return any of a finite number of types. That is, I'd like to
be able to write something like
foo :: StringOrInt t => String -> IO t
This is pretty easy to do if I hard-code the classes as above, but I
run into di
Andrew Coppin wrote:
> Günther Schmidt wrote:
>> Hi Bulat,
>>
>> I do :), but I was amazed that there was no response to a post with,
>> what I thought, would be a rather common problem for an application
>> developer. That post was about writing to an MS-Access database via
>> HDBC-ODBC, which
I just tried getCPUTime on Windows and it seems to tick really slow, about
10 times per second or so. Actually it changes every 1560010
picoseconds, so about 15600 microseconds, which is indeed the interval at
which Windows updates its "tick" count.
So anyway a lot of room to go to the picoseco
On Mon, 12 Jan 2009 21:04:35 +0100 (CET)
Henning Thielemann wrote:
>
> On Mon, 12 Jan 2009, Andrew Coppin wrote:
>
> > Off the top of my head, try this:
> >
> > convert b 0 = []
> > convert b n = n `mod` b : convert b (n `div` b)
> >
> > (Takes a number and yields the radix-B representation of
On Tue, 2009-01-13 at 00:09 +0100, Peter Verswyvelen wrote:
> Gtk2Hs 0.9.13 has an annoying bug on Windows that makes it impossible
> to run via GHCi.
>
>
> So to see if the latest development version works better, I tried to
> build it on Windows using GHC 6.10.1, but I failed to do so with both
On Mon, Jan 12, 2009 at 2:16 PM, Daniel Kraft wrote:
> This was probably my fault at that time, because I surely did something
> completely wrong for the Haskell style. However, I fear I could run into
> problems like that in the new project, too. So I want to ask for your
> opinions, do you th
On Sun, 2009-01-11 at 10:44 +0100, Apfelmus, Heinrich wrote:
> Ertugrul Soeylemez wrote:
> > Let me tell you that usually 90% of my code is
> > monadic and there is really nothing wrong with that. I use especially
> > State monads and StateT transformers very often, because they are
> > convenient
Gtk2Hs 0.9.13 has an annoying bug on Windows that makes it impossible to run
via GHCi.
So to see if the latest development version works better, I tried to build
it on Windows using GHC 6.10.1, but I failed to do so with both MSYS and
Cygwin.
Does anybody know how to build it on Windows?
Thanks,
On Mon, 2009-01-12 at 20:23 +0100, Bas van Dijk wrote:
> On Mon, Jan 12, 2009 at 6:06 PM, Robin Green wrote:
> > The fix-style equivalent to your repeat above, would be something like
> > this:
> >
> > repeat x = fix $ \me -> x ::: me
>
> Interesting.
The definition of fix is small and non-recur
Tony Finch wrote:
The FreeBSD kernel uses a 64+64 bit fixed point type to represent time,
where the integer part is a normal Unix time_t. The fractional part is
64 bits wide in order to be able to represent multi-GHz frequencies
precisely.
"multi-GHz" being a euphemism for 18.45*10^9 GHz, over
On Mon, 2009-01-12 at 19:43 +0100, Bas van Dijk wrote:
> On Mon, Jan 12, 2009 at 6:47 PM, Max Bolingbroke
> wrote:
> > GHC should indeed be doing so. I'm working (on and off) to work out
> > some suitable heuristics and put the transformation into ghc -O2.
> > There are a few wrinkles that still n
On Mon, Jan 12, 2009 at 10:11:19PM +, ChrisK wrote:
> Haskeline is designed to remove the readline dependency, because Windows
> does not have readline. So rlwrap is useless there.
>
Ah, I hadn't considered Windows support--that makes sense. Thanks,
that answers my questions.
AHH
Hi all,
I'm trying to build a library that has the following code:
hasTypeOf (TermRep (dx,_,_)) (x::t) = ((fromDynamic dx)::Maybe t)
When I try to compile with ghc-6.8.3 I got the following error:
../../StrategyLib/models/drift-default//TermRep.hs:63:30: A pattern type signature cannot bind scope
* Andrew Hunter [2009-01-12 13:41:03-0800]
> On Mon, Jan 12, 2009 at 12:57:57PM -0800, Judah Jacobson wrote:
> > I'm pleased to announce the first release of ghci-haskeline. This
> > package uses the GHC API to reimplement ghci with the Haskeline
> > library as a backend. Haskeline is a library
Haskeline is designed to remove the readline dependency, because Windows does
not have readline. So rlwrap is useless there.
Andrew Hunter wrote:
On Mon, Jan 12, 2009 at 12:57:57PM -0800, Judah Jacobson wrote:
I'm pleased to announce the first release of ghci-haskeline. This
package uses th
On Mon, Jan 12, 2009 at 12:57:57PM -0800, Judah Jacobson wrote:
> I'm pleased to announce the first release of ghci-haskeline. This
> package uses the GHC API to reimplement ghci with the Haskeline
> library as a backend. Haskeline is a library for line input in
> command-line programs, similar t
d:
> Hi all,
>
> I'm going to start a project where I'll have to do some data analysis
> (statistics about product orders) based on database entries; it will
> mostly be some very basic stuff like grouping by certain rules and
> finding averages as well as summing up and such. It will however
Hi all,
I'm going to start a project where I'll have to do some data analysis
(statistics about product orders) based on database entries; it will
mostly be some very basic stuff like grouping by certain rules and
finding averages as well as summing up and such. It will however be
more than
Here's a minimal bit of code that gives you the error:
> data FL p x z where
> ConsFL :: p x y -> FL p y z -> FL p x z
> NilFL :: FL p x x
> data GTE a1 a2 x z where
> GTE :: a1 x y -> a2 y z -> GTE a1 a2 x z
> ccwo (ConsFL x xs) (ConsFL y ys) =
>case ccwo xs ys of
>GTE nx
2009/1/12 Phil :
> Hi,
>
> I've been reading the Monads aren't evil posts with interest – I'm a 2nd
> week Haskell newbie and I'm doing my best to use them where (I hope) it is
> appropriate. Typically I'm writing my code out without using Monads
> (normally using list recursion), and then when I
Hi all,
If you are interested in helping out with the haskell platform project
then we invite you to subscribe to the haskell-platform mailing list.
http://projects.haskell.org/cgi-bin/mailman/listinfo/haskell-platform
This mailing list is for discussing practical stuff. We expect to
discuss pol
Ertugrul Soeylemez schrieb:
> "Apfelmus, Heinrich" wrote:
>
>> The insistence on avoiding monads by experienced Haskellers, in
>> particular on avoiding the IO monad, is motivated by the quest for
>> elegance.
>>
>> The IO and other monads make it easy to fall back to imperative
>> programming pa
Hi,
I¹ve been reading the Monads aren¹t evil posts with interest I¹m a 2nd
week Haskell newbie and I¹m doing my best to use them where (I hope) it is
appropriate. Typically I¹m writing my code out without using Monads
(normally using list recursion), and then when I get them working, I delve
in
Apfelmus, Heinrich schrieb:
> Ertugrul Soeylemez wrote:
>> Let me tell you that usually 90% of my code is
>> monadic and there is really nothing wrong with that. I use especially
>> State monads and StateT transformers very often, because they are
>> convenient and are just a clean combinator fron
On Mon, 12 Jan 2009, Andrew Coppin wrote:
Off the top of my head, try this:
convert b 0 = []
convert b n = n `mod` b : convert b (n `div` b)
(Takes a number and yields the radix-B representation of it. Backwards.)
convert b = unfoldr (\n -> if n > 0 then Just (n `mod` b, n `div` b) else
Not
On Sun, 11 Jan 2009, Duncan Coutts wrote:
We really need to upgrade the whole thing. Not an easy job given the
range of stuff being run on there by lots of different people.
Btw. is there a simple way to download all the Wiki content?
___
Haskell-Ca
Neil Mitchell wrote:
Hi Andrew,
HLint will automatically detect if you should have used a map, a foldr
or a foldl and suggest how to change your code. In the GHC, darcs and
Hoogle code bases there are no obvious map-like functions, which is a
good sign :-)
...What an intriguing idea
On Mon, Jan 12, 2009 at 8:33 PM, Felipe Lessa wrote:
>
> z1' = let f = (let y1 = e1 1; y2 = e2 2 in (\x -> op2 y2 y1 x)) in (f 3, f
> 4)
oooh! sweet! I didn't think of that. many thanks
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How about using "let"s?
2009/1/12 Peter Verswyvelen :
> e = trace "e"
> op = (+)
> a1 = let f = (op (e 1)) in (f 10, f 100)
> a2 = let f = (\x -> op (e 1) x) in (f 10, f 100)
> a1 and a2 are operationally not the same: a1 will evaluate (e 1) once, a2
a3 = let f = (let y = e 1 in (\x -> op y x)) i
Do you have any benchmarks comparing dictionaries against Map ByteString
Int, or Map String Int?
-- Don
wren:
>
> -- bytestring-trie 0.1.4
>
>
> Another release for efficient finite maps from (byte)strings
Please correct me if I'm wrong in any of the reasoning below.
Haskell provides the ability the perform partial application on the
rightmost arguments.
I learned from some pretty smart guys that partial application cannot be
emulated with lambas, because they behave differently operationally, e.g.
On Mon, Jan 12, 2009 at 6:06 PM, Robin Green wrote:
> The fix-style equivalent to your repeat above, would be something like
> this:
>
> repeat x = fix $ \me -> x ::: me
Interesting.
Your repeat and mine are compiled to the same code:
Data.Stream.repeat :: forall a_aVi.
a_
On Mon, 12 Jan 2009, Robin Green wrote:
I tend to use Control.Monad.Fix.fix (which actually has nothing to do
with monads, despite the package name)
That's why it is also available from Data.Function now:
http://www.haskell.org/ghc/docs/latest/html/libraries/base/Data-Function.html
___
Thanks for your help, Duncan.
On Jan 12, 2009, at 6:10 AM, Duncan Coutts wrote:
Do the (ForeignPtr e) and the (Ptr e) point to the same thing? They
appear to be related because you dereference p but touch f.
It used to be the ForeignPtr was slower to dereference than a Ptr
and so
caching
On Mon, 12 Jan 2009 19:43:00 +0100
"Bas van Dijk" wrote:
> On Mon, Jan 12, 2009 at 6:47 PM, Max Bolingbroke
> wrote:
> > GHC should indeed be doing so. I'm working (on and off) to work out
> > some suitable heuristics and put the transformation into ghc -O2.
> > There are a few wrinkles that sti
rodrigo.bonifacio:
>Hi all, I'm trying to build a library whose configuration process requires
>the data, util, and lang packages. I guess that these are *deprecated*
>packages, since the library is said to be ghc 6.4.1 compliant.
>
>Which packages should I use instead?
>
>Whe
On Jan 12, 2009, at 12:47 PM, Max Bolingbroke wrote:
2009/1/12 Jan-Willem Maessen :
On Jan 12, 2009, at 9:01 AM, Duncan Coutts wrote:
No because the current definition are recursive and ghc cannot
inline
recursive functions.
Then the map can be inlined at the call site and the 'f' i
Hi all, I'm trying to build a library whose configuration process requires the data, util, and lang packages. I guess that these are *deprecated* packages, since the library is said to be ghc 6.4.1 compliant.
Which packages should I use instead?
Where can I find such packages (if they are not depre
On Mon, Jan 12, 2009 at 6:47 PM, Max Bolingbroke
wrote:
> GHC should indeed be doing so. I'm working (on and off) to work out
> some suitable heuristics and put the transformation into ghc -O2.
> There are a few wrinkles that still need sorting out, but preliminary
> indications are that it decrea
dons:
> ndmitchell:
> > Hi
> >
> > > Does GHC specialize map? If it doesn't, then hand crafted version
> > > could be faster.
> >
> > GHC doesn't specialize map, and a hand-crafted one could be faster -
> > but you then wouldn't get foldr/build fusion. In general HLint tries
> > to make the code
ndmitchell:
> Hi
>
> > Does GHC specialize map? If it doesn't, then hand crafted version
> > could be faster.
>
> GHC doesn't specialize map, and a hand-crafted one could be faster -
> but you then wouldn't get foldr/build fusion. In general HLint tries
> to make the code prettier, but sometimes
I should've included these when I forwarded it, but that was pre-coffee
today. =P
class MyEq p where
unsafeCompare :: p C(a b) -> p C(c d) -> Bool
-- more stuff
data FL a C(x z) where
(:>:) :: a C(x y) -> FL a C(y z) -> FL a C(x z)
NilFL :: FL a C(x x)
data (a1 :> a2) C(x y) = FORALL(z)
Some questions first:
What's the type of this function supposed to be?
What's the type of unsafeCompare?
How is the data type with NilFL and :>: defined?
-- ryan
On Mon, Jan 12, 2009 at 5:43 AM, Rob Hoelz wrote:
> Forwarding to Haskell Cafe per Eric's suggestion.
>
> Begin forwarded message:
>
2009/1/12 Jan-Willem Maessen :
> On Jan 12, 2009, at 9:01 AM, Duncan Coutts wrote:
>
>> No because the current definition are recursive and ghc cannot inline
>> recursive functions.
>>
>>
>>
>> Then the map can be inlined at the call site and the 'f' inlined into
>> the body of 'go'.
>
> This
Patrick Perry wrote:
I have the following code:
IOVector n e = IOVector !ConjEnum !Int (ForeignPtr e)! (Ptr e)! Int!
newtype Vector n e = IOVector n e
unsafeAtVector :: Vector n e -> Int -> e
unsafeAtVector (Vector (IOVector c _ f p inc)) i =
let g = if c == Conj then conjugate else id
On Jan 12, 2009, at 9:01 AM, Duncan Coutts wrote:
No because the current definition are recursive and ghc cannot inline
recursive functions.
map :: (a -> b) -> [a] -> [b]
map _ [] = []
map f (x:xs) = f x : map f xs
It has to be manually transformed into a version that is not recursive
at
On Mon, 12 Jan 2009, Neil Mitchell wrote:
Hi
No because the current definition are recursive and ghc cannot inline
recursive functions.
map :: (a -> b) -> [a] -> [b]
map f = go
where
go [] = []
go (x:xs) = f x : go xs
Then the map can be inlined at the call site and the 'f' inlin
On Mon, 2009-01-12 at 15:06 +0100, Henning Thielemann wrote:
> > It has to be manually transformed into a version that is not recursive
> > at the top level:
> >
> > map :: (a -> b) -> [a] -> [b]
> > map f = go
> > where
> >go [] = []
> >go (x:xs) = f x : go xs
> >
> > Then the map c
Hi
>> No because the current definition are recursive and ghc cannot inline
>> recursive functions.
>
>> map :: (a -> b) -> [a] -> [b]
>> map f = go
>> where
>> go [] = []
>> go (x:xs) = f x : go xs
>>
>> Then the map can be inlined at the call site and the 'f' inlined into
>> the body of
On Sun, 2009-01-11 at 17:43 -0800, Patrick Perry wrote:
> The "touchForeignPtr" is there to keep the garbage collector from
> deallocating the memory before we have a chance to read 'e'. My
> question is the following:
> Is the `seq` on `io` necessary (from a safety standpoint)? Or am I
> ju
On Mon, 12 Jan 2009, Duncan Coutts wrote:
On Mon, 2009-01-12 at 01:02 +0100, Lennart Augustsson wrote:
Does GHC specialize map? If it doesn't, then hand crafted version
could be faster.
No because the current definition are recursive and ghc cannot inline
recursive functions.
map :: (a ->
On Mon, 2009-01-12 at 01:02 +0100, Lennart Augustsson wrote:
> Does GHC specialize map? If it doesn't, then hand crafted version
> could be faster.
No because the current definition are recursive and ghc cannot inline
recursive functions.
map :: (a -> b) -> [a] -> [b]
map _ [] = []
map f (x:
Neil Mitchell escribió:
> Hi
>
>> Does GHC specialize map? If it doesn't, then hand crafted version
>> could be faster.
>
> GHC doesn't specialize map, and a hand-crafted one could be faster -
> but you then wouldn't get foldr/build fusion. In general HLint tries
> to make the code prettier, but
On Mon, 2009-01-12 at 13:21 +0100, Henning Thielemann wrote:
> I repeatedly encounter the following versioning problem on Hackage:
> There is a package A with version 1.0.
> I upload a package B which imports A.
> Thus B is bound to A-1.0
> Now a new version of A is uploaded, say 1.0.1.
> then I up
Forwarding to Haskell Cafe per Eric's suggestion.
Begin forwarded message:
Date: Sun, 11 Jan 2009 23:01:31 -0600
From: Rob Hoelz
To: darcs-de...@darcs.net
Subject: [darcs-devel] "Inferred type is less polymorphic than
expected" and type witnesses
Hello again, Darcs users and developers,
As I
On Mon, 12 Jan 2009, Jan Christiansen wrote:
Hi,
Although it seems to be overkill for a single module - How about a
cabalized version on Hackage and a darcs repository? It would simplify
using and updating it.
I am not sure whether this would be a good idea. The original version makes a
l
On Mon, 12 Jan 2009, ChrisK wrote:
>
> Lennart is right that 1 picosecond accuracy is absurd compared to all
> the jitters and drifts in anything but an actual atomic clock in your
> room. But since CPUs tick faster than nanosecond the CPUTime needs
> better than 1 nanosecond granularity. I agree
Hi,
Although it seems to be overkill for a single module - How about a
cabalized version on Hackage and a darcs repository? It would
simplify using and updating it.
I am not sure whether this would be a good idea. The original version
makes a lot of suggestions which are not satisfiable b
I repeatedly encounter the following versioning problem on Hackage:
There is a package A with version 1.0.
I upload a package B which imports A.
Thus B is bound to A-1.0
Now a new version of A is uploaded, say 1.0.1.
then I upload package C which depends both on A and B.
However C is bound to the
Hi all,
I'm trying to build the Sdf2Haskell library. However, I've got the following problem:
Making all in generatorlocate: illegal option -- nusage: locate [-0Scims] [-l limit] [-d database] pattern ...default database: `/var/db/locate.database' or $LOCATE_PATHmake Sdf.tbllocate: illegal option -
patients, I wanted to be sure not to save wrong
information. It wouldn't matter if the clock is
saying we are on XVII century, as long as 10 seconds
would never be 10.1.
What are the interval durations you need to measure?
Since they are from equipment, what is the spec?
I read from serial p
Neil Davies wrote:
I've found the pico second accuracy useful in working with 'rate
equivalent' real time systems. Systems where the individual timings
(their jitter) is not critical but the long term rate should be accurate
- the extra precision helps with keeping the error accumulation under
Aren't Doubles evil? Integer is a nice type, Haskell
filosofy compliant. Doubles are not CDoubles, IEEE, infinite
precision or anything long term meaninfull. (Warning:
non-expert opinion.)
I've found the pico second accuracy useful in working with 'rate
equivalent' real time systems. Systems whe
I've found the pico second accuracy useful in working with 'rate
equivalent' real time systems. Systems where the individual timings
(their jitter) is not critical but the long term rate should be
accurate - the extra precision helps with keeping the error
accumulation under control.
When
Dear Haskellers,
I would like to forward this announcement on behalf of Petr Ročkai
(the current darcs Release Manager).
Darcs 2.2 is scheduled for release in 2009-01-15, only three days from
now! This is the first of our biannual time-based releases. We hope
you'll like it, and to help us ensu
Neal Alexander wrote:
Simon Marlow wrote:
Neal Alexander wrote:
Thomas DuBuisson wrote:
It seems like we could get some priority based scheduling (and
still
be slackers) if we allow marked green threads to be strictly
associated with a specific OS thread (forkChildIO?).
I think
Don Stewart wrote:
marlowsd:
Neal Alexander wrote:
Thomas DuBuisson wrote:
It seems like we could get some priority based scheduling (and still
be slackers) if we allow marked green threads to be strictly
associated with a specific OS thread (forkChildIO?).
I think you want the GHC-
Hi
> Does GHC specialize map? If it doesn't, then hand crafted version
> could be faster.
GHC doesn't specialize map, and a hand-crafted one could be faster -
but you then wouldn't get foldr/build fusion. In general HLint tries
to make the code prettier, but sometimes you will need to deviate fr
minh thu gmail.com> writes:
http://www.haskell.org/haskellwiki/Haddock/FAQ
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