On Jun 7, 2011, at 7:53 PM, Isaac Potoczny-Jones wrote:
> For 2011, the winners of the award are
>
> Simon Peyton Jones and Simon Marlow of
> Microsoft Research, Cambridge, for GHC
Congratulations :)!
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On 7/06/2011, at 9:36 PM, Guy wrote:
>
> Out of interest, is there any other language where the comment delimiter is
> invalid if immediately followed by a symbol?
Not exactly what you asked, but in some implementations of Algol,
comment This is a comment;
commentThis is a synta
Didn't get to this last night but I've just now confirmed this. With a normal
build (defaulting to -O) the test code below generates only 3 failures (MacOS
Leopard w/GHC 6.12.3 and HUnit 1.2.2.3). When using -O0 or by changing
assertFailure in Test.HUnit.Lang (line 81) to use E.throwIO instea
On 07/06/11 14:03, Brandon Allbery wrote:
On Tue, Jun 7, 2011 at 07:34, Tim Docker wrote:
do others go about testing their code with many hackage dependencies against
a new ghc? I would have expected that the first thing to do would be get the
We don't, for the most part; ghc is a quickly mo
...and the other one being operational (which I find simpler).
2011/6/8 Brandon Allbery
> On Tue, Jun 7, 2011 at 16:16, Arnaud Bailly
> wrote:
> > For example, while designing some program (a game...) I defined a type
> class
> > thus:
> >
> >> class (Monad io) => CommandIO io where
> >> read
On Tue, Jun 7, 2011 at 16:16, Arnaud Bailly wrote:
> For example, while designing some program (a game...) I defined a type class
> thus:
>
>> class (Monad io) => CommandIO io where
>> readCommand :: io Command
>> writeResult :: CommandResult -> io ()
This is in fact one of the reasons to use
> Is this badly designed code that tries to mimic OO in a functional
setting? If the answer is yes, how could I achieve same result (eg. testing
the code that does command REPL) without defining type classes?
Why would that be badly designed? And why would that be more OO? IMO it is a
perfectly s
>> Here's how I do it:
>>
>> data InteractiveState = InteractiveState {
>> state_read :: IO Command
>> , state_write :: Result -> IO ()
>> }
>>
>
> How about :
>
>> data InteractiveState io = InteractiveState {
>> state_read :: io Command
>> , state_write :: Result -> io ()
>> }
I guess you cou
On Tue, 07 Jun 2011 12:58:52 +0200, Pedro Vasconcelos
wrote:
Hello,
I've implemented a Haskell program to play a modern board game. I've
put it on Hackage (http://hackage.haskell.org/package/hstzaar)
but would also like to distribute to people without the Haskell
development tools.
Are ther
On 6/7/11 1:01 PM, James Cook wrote:
On Jun 7, 2011, at 12:43 PM, MigMit wrote:
wren ng thornton wrote:
One particularly trivial example that comes to mind is:
newtype Mu f = Mu (f (Mu f))
instance Show (f (Mu f)) => Show (Mu f) where
show (Mu x) = "Mu (" ++ show x ++ ")"
-- Or however you'd
On Tue, Jun 7, 2011 at 10:32 PM, Evan Laforge wrote:
> > Is this badly designed code that tries to mimic OO in a functional
> setting?
> > If the answer is yes, how could I achieve same result (eg. testing the
> code
> > that does command REPL) without defining type classes?
>
> Here's how I do
> Is this badly designed code that tries to mimic OO in a functional setting?
> If the answer is yes, how could I achieve same result (eg. testing the code
> that does command REPL) without defining type classes?
Here's how I do it:
data InteractiveState = InteractiveState {
state_read :: IO C
Hello,
In a recent thread, it has been asserted that defining type class is
something you seldom need when programming in Haskell.
There is one thing that as non-professional Haskell programmer I found
type-classes useful for: Testing. This is probably very OO and is pretty
much influenced by what
2011/6/7 Bryan O'Sullivan :
> On Tue, Jun 7, 2011 at 1:40 AM, Simon Meier wrote:
>>
>> Why would you need 'unsafePerformIO'. You can scrutinise the 'PS'
>> constructors of the slice without dropping down to IO.
>
> True. Oops :-)
>
>>
>> Using a Builder for concatentation makes sense, if you want
I'm happy to announce the first fully functional release of time-recurrence:
http://hackage.haskell.org/package/time-recurrence
As of version 0.5.2, the library is now powerful enough to express all
recurring dates which can be specified via the iCalendar RFC.
An example:
Generate the 15th
On Tue, Jun 7, 2011 at 06:57, Keith Edmunds wrote:
> my expectation is that all followers of $USERNAME will be listed. However,
> what appears to happen is that the first 100 followers' names are
> displayed, then there is a pause, then the same 100 names are displayed
> again; this cycle repeats
On Tue, Jun 7, 2011 at 07:34, Tim Docker wrote:
> On 07/06/2011, at 8:48 PM, Don Stewart wrote:
>
>> Oh, sorry, missed the first line. Building against GHC snapshots isn't
>> supported.
>
> Surely wanting to test against a ghc snapshot isn't that odd? How
The point of the Haskell Platform is to p
Am 07.06.2011 19:37, schrieb Andrew Coppin:
On 06/06/2011 09:34 PM, Nicu Ionita wrote:
Hi,
Just to double check: that means, today it's not possible to generate 64
bit operations under Windows, including bit level .&., .|. a.s.o. (from
Data.Bits), and this situation will stay like this for a w
I'm pleased to be able to relay the following announcement from ACM SIGPLAN:
The SIGPLAN Programming Languages Software Award is awarded to an
institution or individual(s) to recognize the development a software
system that has had a significant impact on programming language
research, impleme
On 06/06/2011 09:34 PM, Nicu Ionita wrote:
Hi,
Just to double check: that means, today it's not possible to generate 64
bit operations under Windows, including bit level .&., .|. a.s.o. (from
Data.Bits), and this situation will stay like this for a while.
I'm asking this because I'm currently
> I came up with this using immutable unboxed arrays [...]
> sss :: Int -> Int -> UArray Int Int -> O
Nice. - Although what you do here is actually "C programming":
you have a "global" array, and work on its indices.
Actually you always have a pair of indices, denoting a subsequence.
It would be
I like the goal of the stability field, but I don't know how to use it.
Is it intended to track a package's overall maturity ? Eg:
experimental - alpha - beta - almost ready - stable - mature - obsolete
Or, since many packages have multiple major and minor releases, to track the
current release
On Jun 7, 2011, at 12:43 PM, MigMit wrote:
One particularly trivial example that comes to mind is:
newtype Mu f = Mu (f (Mu f))
instance Show (f (Mu f)) => Show (Mu f) where
show (Mu x) = "Mu (" ++ show x ++ ")"
-- Or however you'd like to show it
Ehm, that does look like p
>
> Did you tell cabal that Paths_my_package is a part of your library? If it
> is referenced by your code, then it should be listed in either
> "exposed-modules" or "other-modules", otherwise it won't be installed. I've
> never used dyre so I don't know whether it would cause any issues, but I
>
On Tue, Jun 7, 2011 at 6:14 AM, Casey McCann wrote:
> On Mon, Jun 6, 2011 at 7:55 PM, David Barbour wrote:
> > Earlier forms of my reactive demand programming model [1] - before I
> > switched to arrows - would qualify. The model has limited side-effects
> (e.g.
> > power a camera on only when s
On Jun 7, 2011, at 12:28 PM, Luis Cabellos wrote:
You can export things from one module that are defined in other
modules. For example:
> module MyPackage ( version, ... )
> import Paths_my_package( version )
> ...
Yes indeed, but I getting ugly errors (undefined references to
version I
> One particularly trivial example that comes to mind is:
>
>newtype Mu f = Mu (f (Mu f))
>
>instance Show (f (Mu f)) => Show (Mu f) where
>show (Mu x) = "Mu (" ++ show x ++ ")"
>-- Or however you'd like to show it
Ehm, that does look like poor design.
Sure you don't me
I wrote:
> type Model a = (Ord a) => Set a -- the set of lexemes
> -> [a] -- the original text to model
> -> [a] -- list of previous lexemes
> -> ProbDist a -- the next lexeme
>
> and then
>
> entropy :: Model a -> Set a -> [
You can export things from one module that are defined in other modules.
> For example:
>
> > module MyPackage ( version, ... )
>
> > import Paths_my_package( version )
> > ...
>
> Yes indeed, but I getting ugly errors (undefined references to version I
think) when use Paths_my_package from librar
On Mon, Jun 6, 2011 at 4:05 PM, Casey McCann wrote:
> ArrowChoice and ArrowApply are conceptually distinct and I expect
> there are instances of the former that have no possible instance for
> the latter. Branching vs. Monad I am much less certain of.
>
For a real-time or embedded DSL, or hardwa
On Sun, Jun 5, 2011 at 12:51 PM, KC wrote:
> If new intermediate classes crop up then there would be no point in fixing
>
> class (Applicative m) => Monad m where
>
> since it would have to be changed if new intermediate classes are found.
>
You might check out a few articles regarding Kleisli a
GHC starts threads with a small stack size to efficiently support lightweight
concurrency. As a thread uses more stack space, it will be expanded as needed
up to some maximum fixed size. I think these stack overflow events you see are
the runtime expanding the thread stacks.
You can adjust the
On 07/06/2011 10:55, Ivan Lazar Miljenovic wrote:
Another argument against special-casing "--|": what happens if you
want to use a _different_ documentation generator (I don't know why
you would, but someone might) than Haddock, which uses a different
markup identifier?
We can declare new opera
Hi,
On 07/06/11 14:22, Johannes Waldmann wrote:
Would this work better with Data.Sequence instead of List?
(Is there a really cheap way (O(1)) to split some Data.Sequence roughly in
half?)
I came up with this using immutable unboxed arrays, which gives a nice
parallel speedup (and somehow av
Personally, I came much less against UndecidableInstances when I was trying
to do OOP in Haskell than when I was trying do Prolog-like things at the
type level.
Things like transitive relations: (If a type B contains an A, and if C
contains B, then C contains A, and so on).
I kind of abandonned qui
Hi cafe!
I'm hitting a very strange problem when using haskell-src-exts and
haskell-src-exts-qq. Consider the following module:
\begin{code}
{-# Language QuasiQuotes #-}
module TestBug where
import Language.Haskell.Exts
import Language.Haskell.Exts.QQ
unit = TyTuple Boxed []
ty = [dec| quux ::
I wrote:
>>> You almost never want to use UndecidableInstances
>>> when writing practical programs in Haskell.
>>> When GHC tells you that you need them, it almost
>>> always means that your types are poorly designed,
>>> usually due to influence from previous experience
>>> with OOP.
wren ng thor
On Jun 7, 2011, at 11:10 AM, Luis Cabellos wrote:
Hello,
I have a question about cabal versioning. It's possible to export
in a cabal library a version, so instead of getting version from:
import Paths_my_package( version )
I want to get version from my library using:
import MyPack
Hello,
I have a question about cabal versioning. It's possible to export in a
cabal library a version, so instead of getting version from:
import Paths_my_package( version )
I want to get version from my library using:
import MyPackage( version )
And then using this from programs.
Than
On Tue, Jun 7, 2011 at 1:40 AM, Simon Meier wrote:
> Why would you need 'unsafePerformIO'. You can scrutinise the 'PS'
> constructors of the slice without dropping down to IO.
True. Oops :-)
> Using a Builder for concatentation makes sense, if you want to exploit
> that copying a slice of the
On Jun 7, 2011, at 10:17 AM, Christopher Done wrote:
On 7 June 2011 15:05, James Cook wrote:
It's good, in my opinion, to be able to state succinctly in a
standardized way that, although it does something now, what the code
does and how it does it are probably going to change in the future.
- Original Message -
> From: Johannes Waldmann
> Sent: Tuesday, June 7, 2011 8:22 AM
>
> Here's source and logs:
>
> http://www.imn.htwk-leipzig.de/~waldmann/draft/skpp11/subseqsum/Subseqsum.hs
>
> The program is meant to show an application of the "third homomorphism
> theorem"
> app
On 7 June 2011 15:05, James Cook wrote:
> It's good, in my opinion, to be able to state succinctly in a standardized
> way that, although it does something now, what the code does and how it does
> it are probably going to change in the future.
>
I think no one really updates this field and it's
On Tue, Jun 7, 2011 at 3:05 PM, James Cook wrote:
> On Jun 6, 2011, at 10:57 PM, Chris Smith wrote:
>
>> I got asked a question today about why Control.Applicative is labeled as
>> "experimental" on Hackage. Perhaps that field is something of a failed
>> experiment, and it remaining there is like
On Tue, Jun 7, 2011 at 9:22 AM, Tillmann Rendel
wrote:
> On
> http://hackage.haskell.org/packages/archive/base/latest/doc/html/Control-Applicative.html,
> in the upper right corner, the module is marked as "experimental". I think
> this is a Haddock feature, not a Hackage feature.
Oddly, I couldn
On Jun 7, 2011, at 9:22 AM, Tillmann Rendel wrote:
Hi,
James Cook wrote:
As far as Control.Applicative, I'm not sure to what package you're
referring. That label doesn't apply to modules, it applies to
packages,
and Control.Applicative is a part of the "base" package (which is not
labeled e
Hi,
James Cook wrote:
As far as Control.Applicative, I'm not sure to what package you're
referring. That label doesn't apply to modules, it applies to packages,
and Control.Applicative is a part of the "base" package (which is not
labeled experimental).
On
http://hackage.haskell.org/packages/
Here's source and logs:
http://www.imn.htwk-leipzig.de/~waldmann/draft/skpp11/subseqsum/Subseqsum.hs
The program is meant to show an application of the "third homomorphism theorem"
approach (hom-based structural parallel programming).
My observation (for this program) is that there is little spe
On Jun 6, 2011, at 10:57 PM, Chris Smith wrote:
I got asked a question today about why Control.Applicative is
labeled as
"experimental" on Hackage. Perhaps that field is something of a
failed
experiment, and it remaining there is likely to confuse people.
Just a thought... not sure of the
Bryan O'Sullivan wrote:
>> Now that I think of it: in principle, you could
>> write a specialised concat that would check the pointer/offset/length
>> combinations of its arguments and, if they all abutted perfectly, would just
>> return a new view into that same array, sans copying.
Gregory Colli
On 7 June 2011 21:34, Tim Docker wrote:
>
> Surely wanting to test against a ghc snapshot isn't that odd? How
> do others go about testing their code with many hackage dependencies against
> a new ghc? I would have expected that the first thing to do would be get the
> platform up and running.
Si
On 07/06/2011, at 8:48 PM, Don Stewart wrote:
Oh, sorry, missed the first line. Building against GHC snapshots isn't
supported.
Surely wanting to test against a ghc snapshot isn't that odd? How
do others go about testing their code with many hackage dependencies
against
a new ghc? I would h
On Tue, Jun 07, 2011 at 11:58:52 +0100, Pedro Vasconcelos wrote:
> Are there any easy ways of making installers for Windows/MacOS
> (preferably using free or open source tools)?
On MacOS X, applications typically do not come with installers.
Instead you have some kind of disk image (a tarball will
There is bamse [1], but it's last been updated in 2009, and has
build-failures for 6.10, 6.12 and 7.0. It has some dependency weirdness,
like wanting both base >= 4 and < 4.
I don't know how difficult it would be to upgrade it to modern haskell,
but I'm sure the changes would be appreciated.
[1]
Hello,
I've implemented a Haskell program to play a modern board game. I've
put it on Hackage (http://hackage.haskell.org/package/hstzaar)
but would also like to distribute to people without the Haskell
development tools.
Are there any easy ways of making installers for Windows/MacOS
(preferably
The github Twidge page [https://github.com/jgoerzen/twidge/wiki] states
that this is the right place for questions about Twidge, so here goes.
When running
twidge lsfollowers --all $USERNAME
my expectation is that all followers of $USERNAME will be listed. However,
what appears to happen
Oh, sorry, missed the first line. Building against GHC snapshots isn't
supported.
On Tue, Jun 7, 2011 at 6:48 AM, Don Stewart wrote:
> It should build. If it doesn't, please report a bug.
>
> On Tue, Jun 7, 2011 at 8:53 AM, Tim Docker wrote:
>> I'd like to build the haskell platform against a re
It should build. If it doesn't, please report a bug.
On Tue, Jun 7, 2011 at 8:53 AM, Tim Docker wrote:
> I'd like to build the haskell platform against a recent GHC snapshot, for
> testing purposes.
>
> I see that I can download the source for the platform from:
>
>
> http://lambda.galois.com/hp-
I was considering using a matrix optimisation but things are out of
control enough already :)
Converting all Changes constructors to nested regular constructors may
be the easiest approach. It would certainly eliminate the mess of list
manipulations.
On Tue, Jun 7, 2011 at 6:21 PM, John Lato wro
If I'm interpreting your code properly, it's not currently catching that
case anyway.
The problem is that you've got two sets of modifiers that both should be
optimized, explicit Modifier constructors in the Image, and a list contained
in Changes. Since 'Changes' is just a list of Modifiers, and
Guy writes:
> Out of interest, is there any other language where the comment
> delimiter is invalid if immediately followed by a symbol?
Perl has a rather infamous example where the comment syntax may depend
on run-time properties - would that count?
whatever / 25 ; # / ; die "this dies!";
On 07/06/2011 10:55, Ivan Lazar Miljenovic wrote:
On 7 June 2011 17:50, Guy wrote:
On 07/06/2011 10:45, Ivan Lazar Miljenovic wrote:
On 7 June 2011 17:41, Guywrote:
I originally posted because I found that --| stood out much more clearly
as
a structured comment than -- |.
How does a mi
The fixpoint nature of rewrite catches some cases that transform might
not if I'm interpreting it correctly.
(Changes [Translate 1 1, Scale 1 1, Translate 1 1]) could be rewritten
as (Translate 2 2), but I'm not sure that it could be translated as
such if it matches against (Changes [Translate _ _
Is it necessary (helpful) to use 'rewrite'? Nearly every time I've tried
it, in the end 'transform' has been a better choice. Then you wouldn't need
the 'Just's at all, and it should work fine.
John
> From: Lyndon Maydwell
>
> (missed including cafe)
>
> f :: [Modification] -> Maybe [Modifica
> As a workaround, you can use the "show-ghc-events" binary that is
> provided by the ghc-events package.
Thanks, I wasn't aware of that.
Are the following lines normal for an eventlog?
...
1877298000: cap 1: waking up thread 4 on cap 1
1877299000: cap 1: thread 4 is runnable
1877305000: cap 6
2011/6/6 Bryan O'Sullivan :
> On Sun, Jun 5, 2011 at 11:00 AM, Yitzchak Gale wrote:
>>
>> If behind the scenes the concat is copying directly from slices of the
>> original
>> input, then no, in principle we're not saving much then.
>> I thought there were *two* copies going on.
>
> If you're usin
I don't think a stack overflow event indicates an RTS bug. Stack
overflow events usually result in the RTS trying to adjust the stack
size, and only if that fails, the program is halted.
> (... and why can't I copy/paste the text from threadscope's output window)
As a workaround, you can use the
I am running a Haskell program with some par/pseq annotations.
When I use threadscope to view the eventlog (not "timeline" but "events")
I see a lot of stackoverflow messages. What is this?
I don't get any RTS errors printed on the console.
The program finishes normally (albeit with less speedup
On 7 June 2011 17:50, Guy wrote:
> On 07/06/2011 10:45, Ivan Lazar Miljenovic wrote:
>>
>> On 7 June 2011 17:41, Guy wrote:
>>> I originally posted because I found that --| stood out much more clearly
>>> as
>>> a structured comment than -- |.
>>
>> How does a missing space character make that st
It seems that UndercidableInstances keep getting a bad rap. There are
legitimate and decidable applications of UndercidableInstances. These
applications have nothing to do with OOP, or HList for that matter.
This topic is discussed at length in the article
http://okmij.org/ftp/Haskell/typ
On 07/06/2011 10:45, Ivan Lazar Miljenovic wrote:
On 7 June 2011 17:41, Guy wrote:
On 06/06/2011 22:14, Evan Laforge wrote:
Back to Haskell: I agree, the choice of the comment delimiter was not the
best in light of the possibility to define operators containing it as a
substring. But changing
On 7 June 2011 17:41, Guy wrote:
> On 06/06/2011 22:14, Evan Laforge wrote:
>>>
>>> Back to Haskell: I agree, the choice of the comment delimiter was not the
>>> best in light of the possibility to define operators containing it as a
>>> substring. But changing it to have "--|" start a comment too
On 06/06/2011 22:14, Evan Laforge wrote:
Back to Haskell: I agree, the choice of the comment delimiter was not the
best in light of the possibility to define operators containing it as a
substring. But changing it to have "--|" start a comment too might break
too much code (and eliminating "--" a
On 6/6/11 7:05 PM, Casey McCann wrote:
On Mon, Jun 6, 2011 at 5:32 PM, Matthew Steele wrote:
branchApplicative = liftA3 (\b t f -> if b then t else f)
This definition doesn't satisfy the laws given for the Branching
class; it will execute the effects of both branches regardless of
which is c
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