On May 8, 2010, at 02:16 , Ivan Lazar Miljenovic wrote:
David Menendez writes:
That does not invoke fail.
Let's take a simpler example: do { x <- Nothing; stmt }. This
translates to
let
ok x = do { stmt }
ok _ = fail "..."
in Nothing >>= ok
By the definition of (>>=) for Maybe, 'ok'
David Menendez writes:
> That does not invoke fail.
>
> Let's take a simpler example: do { x <- Nothing; stmt }. This translates to
>
> let
> ok x = do { stmt }
> ok _ = fail "..."
> in Nothing >>= ok
>
> By the definition of (>>=) for Maybe, 'ok' is never called.
As I said in another ema
On Sat, May 8, 2010 at 1:16 AM, Ivan Lazar Miljenovic
wrote:
> David Menendez writes:
>
>> On Sat, May 8, 2010 at 12:15 AM, Ivan Lazar Miljenovic
>>> Well, any time you have a do-block like this you're using failable
>>> patterns:
>>>
>>> maybeAdd :: Maybe Int -> Maybe Int -> Maybe Int
>>>
> On the one hand, this is doable with the GHC API. On the other, that more
> or less means your program contains what amounts to a full copy of GHC.
And the result is that your binary will grow by 35mb, add a few
seconds to launch time, the first expression will take 3 or 4 seconds
to evaluate,
"Brandon S. Allbery KF8NH" writes:
> On May 8, 2010, at 01:16 , Ivan Lazar Miljenovic wrote:
>> Huh? What about "maybeAdd (Just 2) Nothing" ?
>
> Isn't that handled by the definition of (>>=) in Maybe, as opposed to
> by invoking fail?
>
>> instance Monad Maybe where
>> -- ...
>> Nothing >>=
On Fri, 2010-05-07 at 19:26 -0700, John Meacham wrote:
> On Fri, May 07, 2010 at 08:27:04PM -0400, Dan Doel wrote:
> > Personally, I don't really understand why unfailable patterns were canned
> > (they don't seem that complicated to me), so I'd vote to bring them back,
> > and
> > get rid of fail
On May 8, 2010, at 01:16 , Ivan Lazar Miljenovic wrote:
David Menendez writes:
On Sat, May 8, 2010 at 12:15 AM, Ivan Lazar Miljenovic
Well, any time you have a do-block like this you're using failable
patterns:
maybeAdd :: Maybe Int -> Maybe Int -> Maybe Int
maybeAdd mx my = do x <- mx
David Menendez writes:
> On Sat, May 8, 2010 at 12:15 AM, Ivan Lazar Miljenovic
>> Well, any time you have a do-block like this you're using failable
>> patterns:
>>
>> maybeAdd :: Maybe Int -> Maybe Int -> Maybe Int
>> maybeAdd mx my = do x <- mx
>>y <- my
>>
On Sat, May 8, 2010 at 12:15 AM, Ivan Lazar Miljenovic
wrote:
> David Menendez writes:
>>
>> I wonder how often people rely on the use of fail in pattern matching.
>> Could we get by without fail or unfailable patterns?
>>
>> ensureCons :: MonadPlus m => [a] -> m [a]
>> ensureCons x@(_:_) = retur
David Menendez writes:
>
> I wonder how often people rely on the use of fail in pattern matching.
> Could we get by without fail or unfailable patterns?
>
> ensureCons :: MonadPlus m => [a] -> m [a]
> ensureCons x@(_:_) = return x
> ensureCons _ = mzero
>
> do ...
> x:xs <- ensureCons $ some_c
Limestraël writes:
>> Personally I think fail is a terrible wart, and should be shunned.
>
> So do I.
> I can't understand its purpose since monads which can fail can be
> implemented through MonadPlus.
Polyparse uses it, and I believe Parsec does as well...
--
Ivan Lazar Miljenovic
ivan.milje
On May 7, 2010, at 22:18 , Limestraël wrote:
When using hint, one wants the script to be interpreted.
It is interpreted when called " loadModules ["Script"] ", but if we
call later " interpret something (as :: Something) ", the something
can be any Haskell code, not just a function name, whic
Has anyone had problems getting Haskell Platform installed on Ubuntu
10.04?
I've got GHC 6.12.1 installed via apt-get, and I've
downloaded/untarred haskell-platform-2010.1.0.0.tar.gz. But when I
run ./configure, it fails fairly quickly, with an error 'cause it
can't build the "hello world" t
On Fri, May 7, 2010 at 10:26 PM, John Meacham wrote:
> On Fri, May 07, 2010 at 08:27:04PM -0400, Dan Doel wrote:
>> Personally, I don't really understand why unfailable patterns were canned
>> (they don't seem that complicated to me), so I'd vote to bring them back, and
>> get rid of fail. But hin
On Fri, May 07, 2010 at 08:27:04PM -0400, Dan Doel wrote:
> Personally, I don't really understand why unfailable patterns were canned
> (they don't seem that complicated to me), so I'd vote to bring them back, and
> get rid of fail. But hind sight is 20/20, I suppose (or perhaps there exist
> cogen
You might have misunderstood me.
When using hint, one wants the script to be interpreted.
It is interpreted when called " loadModules ["Script"] ", but if we call
later " interpret *something* (as :: Something) ", the *something *can be
any Haskell code, not just a function name, which means hint
Hi Günther,
tehre is a fast darcs to git tool.
Maybe you can convert to mercurial easily then.
Ping me on irc (MarcWeber) or write back if you're interested.
I'll digg the link up then.
Marc Weber
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
Max Bolingbroke writes:
> I'm pleased to announce the release of version 0.3 of test-framework
> (http://hackage.haskell.org/package/test-framework-0.3.0).
> ...
> * There is a new command line option (--plain), which tells the test
> runner to avoid using any ANSI features - this can be handy
On May 4, 2010, at 12:31 , Gregory Crosswhite wrote:
On May 4, 2010, at 5:22 AM, John Lato wrote:
"Crashing at the point of the error" isn't necessarily useful in
Haskell due to lazy evaluation. The code will crash when the result
of the partial function is evaluated, which may be quite far awa
Daniel Fischer writes:
> On Wednesday 05 May 2010 23:36:26, Limestraël wrote:
>> but you will not object if I say that scheme is quicker to learn
>> than Haskell.
>
> Well, I do object. Learning Haskell went like a breeze (not to perfection,
> but well enough). Only Python was nearly as easy and
On May 3, 2010, at 12:14 , Henning Thielemann wrote:
Ketil Malde schrieb:
Henning Thielemann writes:
http://www.haskell.org/ghc/docs/6.12.2/html/libraries/base-4.2.0.1/Control-Exception.html#v%3Athrow
I see. This should be forbidden, at all! :-)
Why is this worse than or different from 'e
I just started using Frama-C [1] for analyzing some of our embedded C
programs. Pretty awesome suite of tools. Especially its ability to
describe and verify function contracts with ACSL [2]. The tool suite
is primarily build with OCaml.
Has anyone considered building a Haskell interface to Fram
There is a also a problem with polymorphic actions of functions. The GHC API is
typesafe only when returning elements of the Typeable class. Else you can do an
unsafeCoerce, but I assume that hint uses Typeable, with a wrapper class to
ensure monomorphism.
But if your "script" action returns a
By the way, I do not know the GHC API well enough to say if it is possible to
embed a super small bytecode interpreter, but :
- If it is the case, then users who do not want to write scripts can use it.
Others would want to compile haskell code, therefore they need GHC anyway.
- If it is not, th
Shit ! I'll have to explain him how to add monads in python 3 ;-)
El 07/05/2010, a las 19:31, Brandon S. Allbery KF8NH escribió:
> On May 5, 2010, at 21:49 , Pierre-Etienne Meunier wrote:
>> - all these >>=, significative indentation, You're from the past dude.
>
>
> Careful, or Guido (van Ros
On Friday 07 May 2010 7:54:21 pm Limestraël wrote:
> > Personally I think fail is a terrible wart, and should be shunned.
>
> So do I.
> I can't understand its purpose since monads which can fail can be
> implemented through MonadPlus.
Understanding why fail exists requires going back to before H
On May 7, 2010, at 19:54 , Limestraël wrote:
> Personally I think fail is a terrible wart, and should be shunned.
So do I.
I can't understand its purpose since monads which can fail can be
implemented through MonadPlus.
The translation of "do" syntax involves pattern matching ("do
{ [x,y,
On Sat, May 08, 2010 at 01:54:21AM +0200, Limestraël wrote:
> > Personally I think fail is a terrible wart, and should be shunned.
>
> So do I.
> I can't understand its purpose since monads which can fail can be implemented
> through MonadPlus.
It was introduced to implement pattern match failure
On May 7, 2010, at 19:51 , Limestraël wrote:
then interpret "script" (as :: ScriptFun)
There is just the line I put in bold that bothers me. Can't we get
the action "script" more easily than by re-interpreting some code?
Make up your mind: you don't want to have to compile the script
On May 7, 2010, at 4:54 PM, Limestraël wrote:
> > Personally I think fail is a terrible wart, and should be shunned.
>
> So do I.
> I can't understand its purpose since monads which can fail can be implemented
> through MonadPlus.
As far as I can tell, its purpose is to essentially allow you t
> Personally I think fail is a terrible wart, and should be shunned.
So do I.
I can't understand its purpose since monads which can fail can be
implemented through MonadPlus.
2010/5/8 Ross Paterson
> On Sat, May 08, 2010 at 07:49:57AM +1000, Ivan Lazar Miljenovic wrote:
> > Limestraėl writes:
There is the package hint, which embeds the calls to GHC API.
Quite easy to use:
Let's say your configuration file (cfg/Script.hs) contains a function
"script" that you want to get:
type ScriptFun = IO ()
loadScript :: IO ScriptFun
loadScript = do
liftM (either (error . show) id) $ runInterpre
On May 6, 2010, at 11:08 , Donn Cave wrote:
different ambitions. Who would pick Tcl for a programming language?
but it has been popular for scripting (still? don't know.) It would
I think Lua has superseded it, because it has the compactness
advantage and easy embeddability of of the Tcl c
On May 5, 2010, at 21:49 , Pierre-Etienne Meunier wrote:
- all these >>=, significative indentation, You're from the past dude.
Careful, or Guido (van Rossum) is going to show up on your doorstep
--
brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allb...@kf8nh.com
system administra
On Sat, May 08, 2010 at 07:49:57AM +1000, Ivan Lazar Miljenovic wrote:
> Limestraël writes:
> > 2010/5/1 John Millikin
> >
> >> You might want to make a local version of ErrorT in your library, to
> >> avoid the silly 'Error' class restriction. This is pretty easy; just
> >> copy it from the 'tra
On May 4, 2010, at 01:52 , Maciej Piechotka wrote:
After change of file you have to wait a long time as it compiles and
links with yi. On my system (1 GB of RAM taken by system + 1 GB
'free' +
2 GB swaps, x86-64) it could in some situations it caused OOM. I'd
prefer if the code was interpreted
begin Ivan Lazar Miljenovic quotation:
> Neil Mitchell writes:
> > You might want to try Derive
> > (http://community.haskell.org/~ndm/derive) if DrIFT doesn't work for
> > you. They do roughly the same jobs, but Derive has more output formats
> > (it can be spliced in as Template Haskell, generat
>From the Haskell 98 report (section 6.3.4):
> For Float and Double, the semantics of the enumFrom family is given by the
> rules for Int above, except that the list terminates when the elements become
> greater than e3+i/2 for positive increment i, or > when they become less
> than e3+i/2 f
Gene A writes:
> The problem I see is that in both:
> Version: September 2006 of hugs, which is the one that is current for
> Ubuntu 9.10 release, and
> ghci 6.10.4, they both exhibit a {I think} strange behaviour, in regards
> to the shorthand way of calling out a list of enumerable values. I
The problem I see is that in both:
Version: September 2006 of hugs, which is the one that is current for
Ubuntu 9.10 release, and
ghci 6.10.4, they both exhibit a {I think} strange behaviour, in regards
to the shorthand way of calling out a list of enumerable values. I will
explain the problem th
Limestraël writes:
> 2010/5/1 John Millikin
>
>> You might want to make a local version of ErrorT in your library, to
>> avoid the silly 'Error' class restriction. This is pretty easy; just
>> copy it from the 'transformers' or 'mtl' package.
>>
> Yes, I wonder why mtl is not updated so as to rem
On Mon, Dec 28, 2009 at 9:03 AM, Aaron Tomb wrote:
>
> On Dec 22, 2009, at 9:36 PM, wren ng thornton wrote:
>
> Aaron Tomb wrote:
>>
>>> I've come across the issue with iconv, as well.
>>> The problem seems to be that some versions of iconv define iconv_open and
>>> some related functions as mac
Yes, I wonder why mtl is not updated so as to remove this restriction.
2010/5/1 John Millikin
> You might want to make a local version of ErrorT in your library, to
> avoid the silly 'Error' class restriction. This is pretty easy; just
> copy it from the 'transformers' or 'mtl' package.
>
_
Neil Mitchell writes:
> You might want to try Derive
> (http://community.haskell.org/~ndm/derive) if DrIFT doesn't work for
> you. They do roughly the same jobs, but Derive has more output formats
> (it can be spliced in as Template Haskell, generate #include files,
> output text etc) more derivat
On 5/7/10 10:49 AM, Max Bolingbroke wrote:
* There is a new command line option (--plain), which tells the test
runner to avoid using any ANSI features - this can be handy if you are
(for example) viewing test output in Emacs
Thanks! I'll use that in the next release of shelltestrunner.
___
On Fri, May 7, 2010 at 10:09, Sergei Trofimovich wrote:
> 1. gsasl hackage package did not build for me against libgsasl-0.2.28.
> It did not define _MAJOR _MINOR macros, So I had to update
> up to libgsasl-1.4 which worked fine. Is there way to put constraints
> to pkgconfig-depends to .
Hi Leonel,
You might want to try Derive
(http://community.haskell.org/~ndm/derive) if DrIFT doesn't work for
you. They do roughly the same jobs, but Derive has more output formats
(it can be spliced in as Template Haskell, generate #include files,
output text etc) more derivations (but not quite o
Hi,
If you think you can write an algorithm for deriving Applicative, I'd
welcome you to try adding it to Derive:
http://community.haskell.org/~ndm/derive
The Functor/Foldable/Traversable derivations all started out in
Derive, got tested/implemented/refined there, then moved to GHC later.
I think
I'm pleased to announce the release of version 0.3 of test-framework
(http://hackage.haskell.org/package/test-framework-0.3.0).
This package provides a nice test runner for HUnit, QuickCheck 1 and
QuickCheck 2 tests. To see a detailed example of the runner in action,
please check out our website a
On Mon, 3 May 2010 07:43:25 -0700
John Millikin wrote:
> My library, network-protocol-xmpp[2], is an implementation of most of
> RFC 3920 and a bit of RFC 3921. It supports opening client-to-server
> and component-to-server sessions, which is useful for implementing
> XMPP-based clients. This lib
On Fri, May 7, 2010 at 2:29 AM, Nicolas Pouillard <
nicolas.pouill...@gmail.com> wrote:
> On Thu, 06 May 2010 01:08:08 +0200, Günther Schmidt
> wrote:
> > Hello,
> >
> > I'm switching from darcs to mercurial with some of my projects.
> >
> > I'd like to retain as much of the history as possible,
On Friday 07 May 2010 17:05:08, Dupont Corentin wrote:
> Hello,
> i'm still struggling with ghci and accents.
>
> Prelude> "é"
> "\233"
That uses the Show instance of Char, which escapes all characters greater
than '\127' ('\DEL'), so that's no problem, jut inconvenient.
>
> I've installed GHC 6
Hello,
I think your type should be:
type Board a b c d e f g h i =
Either (Three a b c)
(Either (Three d e f)
(Either (Three g h i)
(Either (Three a d g)
(Either (Three b e h)
(Either (Three c f i)
(Either (Three a e i)
(Three c e g)))
as far as i can understand, it
Hello,
i'm still struggling with ghci and accents.
Prelude> "é"
"\233"
I've installed GHC 6.12.1, which gave me a better result:
Prelude> putStrLn "é"
é
but still:
Prelude> "é"
"\233"
I'm trying to search a file with french words with Regex, but i
stumble on accents:
*Main> findRegexFile "ab
On Friday 07 May 2010 16:15:41, Daniel Fischer wrote:
> b) using Don Stewart's ghc-core (http://hackage.haskell.org/package/ghc-
> core), e.g. ghc.core -f html -- -O2 Source.hs > Source.html
And of course, the html backend of ghc-core was removed with version 0.5 :(
If you want html output,
$ caba
On Friday 07 May 2010 03:15:19, Maciej Piechotka wrote:
> On Thu, 2010-05-06 at 23:46 +0200, Daniel Fischer wrote:
> > Share.share :: GHC.Types.Int
> > GblId
> > [Str: DmdType]
> > Share.share =
> > case GHC.List.$wlen @ GHC.Integer.Type.Integer Share.share_a 0
> > of ww_amc { __DEFAULT ->
> >
On Fri, May 7, 2010 at 4:12 AM, Felipe Lessa wrote:
> On Thu, May 06, 2010 at 09:30:50PM +0300, Sergei Trofimovich wrote:
>> /me wonders if Miss lambdabot might like to have such functionality.
>> What do you think?
>
> Do the terms of use of Google Translate allow it?
I can't remember, but they
On Fri, May 7, 2010 at 1:02 AM, Bas van Dijk wrote:
> On Thu, May 6, 2010 at 11:54 PM, Bas van Dijk
> wrote:
> > On Thu, May 6, 2010 at 7:48 PM, Bas van Dijk
> wrote:
> >> On Thu, May 6, 2010 at 3:24 PM, Michael Snoyman
> wrote:
> >>>
> >>>
> >>> On Thu, May 6, 2010 at 9:13 AM, Bryan O'Sulliva
Hi all,
Because code.haskell.org is unstable recently,
and many gtk2hs users can't get code from http://code.haskell.org/gtk2hs
So i build a mirror repository at
http://patch-tag.com/r/AndyStewart/gtk2hs-sync-mirror/home
You can access this mirror repository when code.haskell.org down.
This mir
On Thu, 06 May 2010 01:08:08 +0200, Günther Schmidt wrote:
> Hello,
>
> I'm switching from darcs to mercurial with some of my projects.
>
> I'd like to retain as much of the history as possible, what tools are
> there available for this?
I recommend you darcs-fast-export and then use the/a mer
60 matches
Mail list logo
