This might also be relevant:
http://web.engr.oregonstate.edu/~erwig/zurg/
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who is maintainer of containers package ...
From: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Subject: containers-0.1.0.1
Date: Wed, 12 Mar 2008 23:48:33 +
containers-0.1.0.1 will not build with ghc-6.6, the lines
#include Typeable.h
Bulat Ziganshin wrote:
plus a b = unsafePerformIO (modifyIORef counter (+1)) `seq` a+b
Erm... might it be better to use an MVar? (To avoid lost updates if
there are multiple render threads.)
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Hello Andrew,
Thursday, March 27, 2008, 12:27:47 PM, you wrote:
plus a b = unsafePerformIO (modifyIORef counter (+1)) `seq` a+b
Erm... might it be better to use an MVar? (To avoid lost updates if
there are multiple render threads.)
you are right, IORef is appropriate only for single-threaded
Thankyou all. Once I get more familiar with Parsec I might do my own
lexeme parser. For now I've changed its definition of simpleSpace to
simpleSpace =
skipMany1 (satisfy (\c - (c /= '\n') (isSpace c)))
so that it skips whitespace, but not newlines. My parser then explicitly
matches
On 27/03/2008, at 3:49, Ian Lynagh wrote:
On Wed, Mar 26, 2008 at 02:33:20PM -0700, Jim Snow wrote:
-Memory consumption is atrocious: 146 megs to render a scene that's a
33k ascii file. Where does it all go? A heap profile reports the
max
heap size at a rather more reasonable 500k or so.
When experimenting with list index sets (i.e. lists more general than
provided by Haskell), I arrived at the problem that in the example
code below for example
h(list 6)
does not (in Hugs) write out the beginning of the list lazily. It
does work for
list 6
first (list 6)
rest (list
Hans Aberg wrote:
When experimenting with list index sets (i.e. lists more general than
provided by Haskell), I arrived at the problem that in the example code
below for example
h(list 6)
does not (in Hugs) write out the beginning of the list lazily. It does
work for
list 6
first (list
Don Stewart wrote:
That said, I know that type families are provisionally available, so
maybe doing something with generalised tries might be possible.
I don't mind mentoring anyone who wants to do something with any of
this.
Great! Would you like to revise the Soc ticket, with this
On Thu, Mar 27, 2008 at 2:18 PM, Claude Heiland-Allen
The combination of (-+) and h is too strict, this modification works:
(-+) :: a - List a - List a
x -+ ~(List y) = List(f) where -- lazy pattern match
f 0 = x
f k = y(k-1)
More to the point, if List is declared as:
On 27 Mar 2008, at 15:18, Claude Heiland-Allen wrote:
The combination of (-+) and h is too strict, this modification works:
(-+) :: a - List a - List a
x -+ ~(List y) = List(f) where -- lazy pattern match
f 0 = x
f k = y(k-1)
Thank you for the fast response. Yes, that might be what I
On 27 Mar 2008, at 15:32, Luke Palmer wrote:
More to the point, if List is declared as:
newtype List a = List (Integer - a)
Instead of with data, it also works.
The problem, as was stated, was that -+ is too strict. That is,
without the ~ there, -+ evaluates its right argument to make
Hmmm, seems like your (-+) is not lazy enough.
Since pattern matching is strict by default, you have
anything -+ (_|_) = (_|_)
Therefore, the function, which is constantly (_|_), is a fixed point
for the equation defining h. In other words, if you define
h' x = undefined
then you have
h'
On 27 Mar 2008, at 15:58, Miguel Mitrofanov wrote:
Hmmm, seems like your (-+) is not lazy enough.
...
You can fix it by defining (-+) as
x -+ ~(List y) = ...
Yes, this has been pointed out...
Since pattern matching is strict by default, you have
anything -+ (_|_) = (_|_)
Therefore,
The current implementation is wrong, as it permits
type S a b = a
type family F a :: * - *
type instance F a = S a
Why do we need to forbid this type instance? Because it breaks the
confluence of equality constraint normalisation. Here are two
diverging normalisations:
(1)
Sorry, I meant
type FList a x = Either One (a,x)
type instance F [a] = FList a
On Thu, Mar 27, 2008 at 4:45 PM, Hugo Pacheco [EMAIL PROTECTED] wrote:
The current implementation is wrong, as it permits
type S a b = a
type family F a :: * - *
type instance F a = S a
Why do
I notice that you omit from the advantages of calling Haskell from
Python what I consider the most important reason of all (at least from
the Haskell community side).
The choice of programming language (at least at the top level) is
primarily a political or managerial choice, not a technical
Hello Everyone,GSoC Project: Parallel Profiling Tools for GHC.
Student: Donnie Jones
Mentor: Simon Marlow
Project based upon suggestion by Simon Marlow:
http://hackage.haskell.org/trac/summer-of-code/ticket/1559
Overview:
For Haskell there are currently no tools to investigate the performance of
On 27 Mar 2008, at 17:51, Luke Palmer wrote:
By your naming, am I correct in assuming that you're implementing
transfinite lists?
If so, cool!
Yes, it is an old idea I brought up now. If list length is written
also for infinite lists, then concatenated lists get indexed by the
sum of
Remember that there are two proposals here, one potentially to the
Python team, one to the Haskell team . Of course the Haskell guys are
strongly interested in the use case Dan describes -- mitigating risk by
using Haskell for small components first, as part of larger legacy
systems.
The Python
On 27 Mar 2008, at 17:51, Luke Palmer wrote:
A more standard way to do this would be:
data List a = List (Ordinal - a) Ordinal
I used
data List a = Empty | (Ordinal-a) :+ Ordinal
which might then be simplified by dropping Empty.
Hans Aberg
On 3/25/08, Luke Palmer [EMAIL PROTECTED] wrote:
Er, not Ctrl, of course... Mod-Shift-C. /me goes to punish his hand
for compusive send presses.
I believe that is to kill a window rather than a normal window close.
--
Regards,
Paul Liu
Yale Haskell Group
http://www.haskell.org/yale
pepe wrote:
On 27/03/2008, at 3:49, Ian Lynagh wrote:
On Wed, Mar 26, 2008 at 02:33:20PM -0700, Jim Snow wrote:
-Memory consumption is atrocious: 146 megs to render a scene that's a
33k ascii file. Where does it all go? A heap profile reports the max
heap size at a rather more reasonable
FWIW, my MissingPy project accomplishes part of this (calling Python
from Haskell) already.
-- John
On 2008-03-27, Dan Weston [EMAIL PROTECTED] wrote:
I notice that you omit from the advantages of calling Haskell from
Python what I consider the most important reason of all (at least from
Hi again,
I'm currently working on a project that has a Web interface to data
stored in a SQL database. I wrote this thing in WASH a few years
back. Overall, this has been acceptable, but the non-Haskell-adepts
around here run away screaming from the code. Not only that, but we
don't get
Hi folks,
I was recently looking for HTTP client libraries for Haskell. I
investigated several, and it seems that there aren't any really ready
for primetime. Am I missing anything? Here's what I found:
* Bjorn's String-based HTTP
It eats RAM. Does not appear to read data lazily, returns
Hello,
I added some additional goals below.
On Thu, Mar 27, 2008 at 2:23 PM, Donnie Jones [EMAIL PROTECTED] wrote:
Hello Everyone,GSoC Project: Parallel Profiling Tools for GHC.
Student: Donnie Jones
Mentor: Simon Marlow
Project based upon suggestion by Simon Marlow:
Hi
* tagsoup
Broken in many ways. Does not support chunked encoding that is
mandated by HTTP RFC. Will be incompatible with numerous HTTP
servers, and the manual states as much. Port 80 hardcoded.
I'd just like to stress that the one in tagsoup shouldn't be used for
anything! It
On 27 mar 2008, at 20.08, John Goerzen wrote:
Hi folks,
I was recently looking for HTTP client libraries for Haskell. I
investigated several, and it seems that there aren't any really ready
for primetime. Am I missing anything? Here's what I found:
* Bjorn's String-based HTTP
It eats
I did not see MissingPy on Hackage (presumably it would be next to
MissingH?)
I found it (listed on http://www.complete.org/jgoerzen/softindex.html)
at http://darcs.complete.org/missingpy
Is this the right place to get it?
Dan
John Goerzen wrote:
FWIW, my MissingPy project accomplishes
HSP: big on dynamic pages. I don't want to make my webserver able
to compile Haskell code. Develop code, compile, test, make sure it's
right, then push to production every 6 months around here.
Being one of the main developers of HSP, I guess I should reply to this. :-)
HSP is indeed big
Oh, I thought I added that as related work to the ticket page.
If its not, couldyou add it?
jgoerzen:
FWIW, my MissingPy project accomplishes part of this (calling Python
from Haskell) already.
-- John
On 2008-03-27, Dan Weston [EMAIL PROTECTED] wrote:
I notice that you omit from the
On Thu, Mar 27, 2008 at 12:26 PM, John Goerzen [EMAIL PROTECTED] wrote:
What I really want is some sort of simple tool that supports FastCGI
or some such, has basic support for form data input validation and
marshalling to/from Haskell types, and basic control flow.
So I've looked around a
On Thu, Mar 27, 2008 at 12:08 PM, John Goerzen [EMAIL PROTECTED] wrote:
* Bjorn's String-based HTTP
It eats RAM. Does not appear to read data lazily, returns a String,
and may have a memory leak as well. Does not appear to be suited
for anything except very small file downloads.
Do
Am Mittwoch, 26. März 2008 03:07 schrieb Hugo Pacheco:
The extra syntax has its advantages (more local information) and
disadvantages (more clutter). We weren't convinced that we need the
extra syntax, so left it out for the moment. However, this is
something that can always be changed if
Am Donnerstag, 27. März 2008 22:43 schrieb Wolfgang Jeltsch:
Am Mittwoch, 26. März 2008 03:07 schrieb Hugo Pacheco:
The extra syntax has its advantages (more local information) and
disadvantages (more clutter). We weren't convinced that we need the
extra syntax, so left it out for the
Two questions came to mind while thinking of memory references in Haskell:
1. Is there a standard equivalent of the following:
class (Monad m) = MonadMemory m r | m - r where
new :: a - m (r a)
read :: r a - m a
write :: r a - a - m ()
What kind of axioms should an instance of this
The reason for the braces in type families is because type indices are
treated differently than normal parameters. I don't think this should be
adopted for type synonyms either.
Cheers,
hugo
On Thu, Mar 27, 2008 at 9:48 PM, Wolfgang Jeltsch
[EMAIL PROTECTED] wrote:
Am Donnerstag, 27. März
Hello Ariel,
Friday, March 28, 2008, 1:02:39 AM, you wrote:
class (Monad m) = MonadMemory m r | m - r where
there are more than one way to define such class. look at
http://haskell.org/haskellwiki/Library/ArrayRef for examples
--
Best regards,
Bulatmailto:[EMAIL
On Fri, 2008-03-28 at 00:02 +0200, Ariel J. Birnbaum wrote:
Two questions came to mind while thinking of memory references in Haskell:
1. Is there a standard equivalent of the following:
class (Monad m) = MonadMemory m r | m - r where
new :: a - m (r a)
read :: r a - m a
On 3/27/08, Ariel J. Birnbaum [EMAIL PROTECTED] wrote:
class (Monad m) = MonadMemory m r | m - r where
new :: a - m (r a)
read :: r a - m a
write :: r a - a - m ()
What kind of axioms should an instance of this class satisfy?
Here's some thoughts:
(~=) means equivalent excluding
On Thu, Mar 27, 2008 at 12:08 PM, John Goerzen [EMAIL PROTECTED] wrote:
* network-minihttp
Doesn't appear to actually be very useful as a client.
Also, as far as I have been able to deduce, none of these have
built-in support for https (SSL) URLs.
The client doesn't do a lot, but I
look at http://haskell.org/haskellwiki/Library/ArrayRef for examples
Thanks, Data.Ref.Universal looks just like it!
One question though. In:
class (Monad m) = Ref m r | m-r, r-m where
Why is the second fundep necessary?
--
Ariel J. Birnbaum
___
This has come up a few times and been written by many Haskellers
I was quite certain of that, hence my puzzlement at being unable to find it =)
What kind of axioms should an instance of this class satisfy?
There are quite a few obvious ones, but I'm not sure it's particularly
necessary.
I'm
Hi,
Does anyone know why this reduced Parsec production stops compilation, and how
I can fix it?
tester = reserved parameter
| do { reserved dimension; symbol : }
Thanks,
Paul
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(write r x = read) == (write r x return x)
You probably mean (write r x read r) == (write r x return x)?
3) References are independent:
If m does not refer to r, then:
(read r = (\x - m return x)) == m read r
(write r x m) == m = (\v - write r x return v)
What if m writes to r' which
Hugo Pacheco:
Sorry, I meant
type FList a x = Either One (a,x)
type instance F [a] = FList a
We should not allow such programs.
Manuel
On Thu, Mar 27, 2008 at 4:45 PM, Hugo Pacheco [EMAIL PROTECTED]
wrote:
The current implementation is wrong, as it permits
type S a b = a
type
Am Montag, 24. März 2008 20:47 schrieb Henning Thielemann:
[…]
Here is another approach that looks tempting, but unfortunately does not
work, and I wonder whether this can be made working.
module RestrictedMonad where
import Data.Set(Set)
import qualified Data.Set as Set
class
Yes, but doesn't the confluence problem only occur for type synonyms that
ignore one or more of the parameters? If so, this could be checked...
On Fri, Mar 28, 2008 at 12:04 AM, Manuel M T Chakravarty
[EMAIL PROTECTED] wrote:
Hugo Pacheco:
Sorry, I meant
type FList a x = Either One (a,x)
Hi Paul,
2008/3/27 Paul Keir [EMAIL PROTECTED]:
Hi,
Does anyone know why this reduced Parsec production stops compilation, and
how I can fix it?
tester = reserved parameter
| do { reserved dimension; symbol : }
Look at the types of reserved and symbol (from
paulrbrown+haskell-cafe:
On Thu, Mar 27, 2008 at 12:08 PM, John Goerzen [EMAIL PROTECTED] wrote:
* Bjorn's String-based HTTP
It eats RAM. Does not appear to read data lazily, returns a String,
and may have a memory leak as well. Does not appear to be suited
for anything except
On Thursday 27 March 2008 04:38:21 pm Paul Brown wrote:
On Thu, Mar 27, 2008 at 12:08 PM, John Goerzen [EMAIL PROTECTED]
wrote:
* Bjorn's String-based HTTP
It eats RAM. Does not appear to read data lazily, returns a String,
and may have a memory leak as well. Does not appear to be
On Thursday 27 March 2008 04:07:23 pm Dan Weston wrote:
I did not see MissingPy on Hackage (presumably it would be next to
MissingH?)
I found it (listed on http://www.complete.org/jgoerzen/softindex.html)
at http://darcs.complete.org/missingpy
Is this the right place to get it?
Yes, it is.
Am Donnerstag, 27. März 2008 23:12 schrieben Sie:
The reason for the braces in type families is because type indices are
treated differently than normal parameters. I don't think this should be
adopted for type synonyms either.
Cheers,
hugo
In a way, there is also different treatment in the
On 27 Mar 2008, at 8:25 pm, Robert Wills wrote:
This might also be relevant:
http://web.engr.oregonstate.edu/~erwig/zurg/
But note that the Prolog code that they compared against was, um,
let's put this kindly, seriously naive. For example,
(a) it has 36 SLOC.You can do it naturally
Hi,
suppose there are two (identical) classes:
class Res a b | a - b where
getRes :: a - b
and
class Res2 t where
type Member t
getRes2 :: t - Member t
It is easy to automatically make every instance of Res2 an instance of
res:
instance Res2 a = Res a (Member a)
I want to unescape an encoded XML or HTML string, e.g. converting quot;
to the quote character, etc.
Since I'm using HaXml anyway, I tried using xmlUnEscapeContent with no
luck, e.g. with HaXml 1.19.1:
let (CString _ s _) =
head $ xmlUnEscapeContent stdXmlEscaper $
[CString False This
On 3/27/08, Ariel J. Birnbaum [EMAIL PROTECTED] wrote:
(write r x = read) == (write r x return x)
You probably mean (write r x read r) == (write r x return x)?
Yes. Oops!
3) References are independent:
If m does not refer to r, then:
(read r = (\x - m return x)) == m read r
Another way to defer the evaluation of the second argument of (-+) is like this:
(-+) :: a - List a - List a
x -+ y = List(f) where
f 0 = x
f k = case y of List g - g (k-1)
This is exactly what the lazy pattern will do at compile-time. Does
this give you a better understanding of how lazy
While hvac, which I announced here recently, is not yet ready for
primetime, so to speak, you may want to take a look at it -- with a
few tweaks it should match your specs. (darcs get http://
community.haskell.org/~sclv/hvac/)
It does include some templating, though you don't have to use it
Hello,
Recently, someone (I forgot who, exactly) mentioned in #haskell this article:
http://okmij.org/ftp/Haskell/types.html#unsound-typeable
where Oleg demonstrates that Typeable makes the type system unsound, and one
can get back unsafeCoerce (which is used in the implementation, I
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