What about (Compose Form IO) Blog type? Form is Applicative, IO — the same,
their composition should be Applicative as well (one good thing about
Applicatives — they really compose). Take a look at Control.Compose module.
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> 01 окт. 2013 г., в 10:58, Michael Snoyman написал(а)
The classical reference is, I think, the paper “Haskell vs. Ada vs. C++ vs. Awk
vs. ... An Experiment in Software Prototyping Productivity”
On Sep 23, 2013, at 9:20 PM, Mike Meyer wrote:
> Hi all,
>
> I'm looking for articles that provide some technical support for why Haskell
> rocks. Not ju
OK, now video on
http://www.i-newswire.com/fp-complete-launches-fp-haskell/237230 works. Seems
like a youtube glitch
On Sep 3, 2013, at 11:37 PM, MigMit wrote:
> Confirm the issue. I have Firefox on Mac as well, and it does show for me,
> but says the same thing as Tommy's Safari
Confirm the issue. I have Firefox on Mac as well, and it does show for me, but
says the same thing as Tommy's Safari
On Sep 3, 2013, at 11:25 PM, Tommy Thorn wrote:
> This is interesting and I wish them luck, but it seems surprising
> that the below link doesn't have as much as a screenshot (fo
On Jul 31, 2013, at 2:41 PM, Никитин Лев wrote:
>
>
> 31.07.2013, 05:03, "Michael Xavier" :
>> angel is a daemon
>
> "angel is a background process" sounds better.
You're killing the joke.
>
> Sorry for offtopic
>
> ___
> Haskell-Cafe maili
On Jul 22, 2013, at 12:27 PM, Andreas Abel wrote:
> On 20.07.13 9:36 PM, Evan Laforge wrote:
>> However, I'm also not agitating for a non-recursive let, I think that
>> ship has sailed. Besides, if it were added people would start
>> wondering about non-recursive where, and it would introduce a
It really sounds rude, to demand promises from somebody who just gave you a big
present.
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10.06.2013, в 16:11, Zed Becker написал(а):
> Hi all,
>
> Haskell, is arguably the best example of a design-by-committee language. The
> syntax is clean and most importantly, consiste
Doing HTML UI with Happstack was a pleasant experience.
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21.05.2013, в 12:47, Vlatko Basic написал(а):
> Hi,
>
> I'd like to start using web pages as the UI for apps. I found out for yesod,
> snapp and happstack as the candidates.
> Would you recommend any of them as better
My result: 2000 lines of "Right ()"
ghc-pkg list aeson says "aeson-0.6.1.0"
On May 18, 2013, at 8:25 PM, Roman Cheplyaka wrote:
> I am observing a non-deterministic behaviour of aeson's parser.
>
> I'm writing here in addition to filing a bug report [1] to draw
> attention to this (pretty sca
You can stop suspecting: in Haskell, equations ARE definitions.
On May 15, 2013, at 9:15 PM, Patrick Browne wrote:
> The relation to theorem proving is the main motivation for my question.
>
> In am trying to understand why some equations are ok and others not.
>
> I suspect that in Haskell eq
Maybe I understand the problem incorrectly, but it seems to me that you're
overcomplicating things.
With that kind of interface you don't actually need existential types. Or
phantom types. You can just keep Inotify inside the Watch, like this:
import Prelude hiding (init, map)
import Data.IORef
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08.04.2013, в 21:44, Evan Laforge написал(а):
> Can't we just add some features to haddock?
No, we can't. At the very least we should FIX haddock before adding features.
> There are a lot of ways
> to improve haddock a lot, and no one is doing them, so my impression
> is
Sorry, I think that's not the right list for this question.
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23.03.2013, в 2:04, MigMit написал(а):
> Suppose I compiled some module and kept it's .hi and .o files. Is it possible
> to use this module in my program if the source code was deleted fo
Suppose I compiled some module and kept it's .hi and .o files. Is it possible
to use this module in my program if the source code was deleted for some reason?
Seems like the answer is "yes" — by creating a fake .hs file (with no real
content) and touch-in .hi and .o files I tricked ghc so that i
On Mar 13, 2013, at 12:54 AM, "Richard A. O'Keefe" wrote:
> The interesting challenge here is that we should have
>
>Date + Period -> Date Date - Period -> Date
>Period + Date -> Date Period - Date -> ILLEGAL
>Period + Period -> DeriodPeriod - Period -> Period
>
On Mar 12, 2013, at 12:44 AM, "Richard A. O'Keefe" wrote:
>
> Prelude> :type (+)
> (+) :: Num a => a -> a -> a
>
> The predefined (+) in Haskell requires its arguments and its result
> to be precisely the same type.
>
> I think you had better justify the claim that Date+Period -> Date and
> Da
On Mar 10, 2013, at 11:47 AM, Peter Caspers wrote:
> Thank you all for your answers, this helps a lot. To clarify my last point ...
>
>>> Also again, taking this way I can not provide several constructors taking
>>> inputs of different types, can I ?
>> Sorry, didn't get what you mean here.
>
On Mar 10, 2013, at 12:33 AM, Peter Caspers wrote:
> Hi,
>
> I just started playing around a bit with Haskell, so sorry in advance for
> very basic (and maybe stupid) questions. Coming from the C++ world one thing
> I would like to do is overloading operators. For example I want to write
> (
Have you tried running ghci inside Emacs?
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21.02.2013, в 13:58, Semyon Kholodnov написал(а):
> Imagine we have this simple program:
>
> module Main(main) where
>
> main = do
>x <- getLine
>putStrLn x
>
> Now I want to run it somehow, enter "résumé 履歴書 резюме" and s
Well, this runtime errors are actually type errors. Regexps are actually a DSL,
which is not embedded in Haskell. But it could be. Strings won't work for that,
but something like that would:
filter (match $ "a" <> many anyChar <> ".txt") filenames
and this certainly can be produced by TH like t
On Jan 3, 2013, at 2:09 AM, Gershom Bazerman wrote:
> On 1/2/13 4:29 PM, MigMit wrote:
>>
>>> BTW. Why you think that Eiffel type system is unsafe?
>> Well, if I remember correctly, if you call some method of a certain object,
>> and this call compiles, you can
> 2) pre&post conditions and class invariants have defined behaviour in cases
> of inheritance, even/especially multiple inheritance. They are combined
> non-trivially in subclasses. Without this I don't think you have DbC.
Yes, I forgot about that. Thanks.
> Feel free to enlighten me about the
On Jan 2, 2013, at 4:24 PM, Никитин Лев wrote:
>
> Well, we can say "concepts" in place of "theory". And I'm comparing Eiffel
> with other OOP lang, not with some langs based on a solid math theory (lambda
> calcules for FP langs, for example). ok?
I agree that there are certain concepts,
On Jan 2, 2013, at 10:52 AM, Mike Meyer wrote:
>
>
> [Context destroyed by top posting.]
> MigMit wrote:
>> But really, "Design by Contract" — a theory? It certainly is a useful
>> approach, but it doesn't seem to be a theory, not until we can actually
ore than Smalltalk, for example?
> BTW, when I started study haskell i had similar question: is it possible to
> add DbC to haskell? Does haskell need DbC?
> For example, class invariants may be expressed in DbC construction (fmap id =
> id for Functior, for example).
>
> 02.01.2
On Jan 2, 2013, at 2:26 AM, Bob Hutchison wrote:
>
> On 2013-01-01, at 3:47 PM, MigMit wrote:
>
>> Well, probably one of the reasons is that I've learned Eiffel later than
>> Haskell.
>>
>> But really, "Design by Contract" — a theory? It ce
supposed to be removed in the final version of the program). Compare this to
Haskell types, for example: an untyped version of Haskell won't be able to
choose between two class instances, so, that would be an entirely different
language.
On Jan 1, 2013, at 11:41 PM, Mike Meyer wrote:
>
On Jan 1, 2013, at 10:23 PM, Никитин Лев wrote:
> Eiffel, for my opinion, is a best OOP language. Meyer use a theoretical
> approach as it is possible in OOP.
Really? Because when I studied it I had a very different impression: that
behind this language there was no theory at all. And it's on
Syntax extensibility is usually too powerful, it surely would be abused
extensively, which would make developer's life a nightmare, unless there is
only one developer and whole development takes no more than a couple of months.
On Dec 31, 2012, at 1:09 AM, Dan Burton wrote:
> My 2 cents on the
Sorry for the stupid mistake — when I said "Daniel" in the previous message,
I've meant "Jay".
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30.12.2012, в 23:58, Daniel Díaz Casanueva написал(а):
> Hello, Haskell Cafe folks.
>
> My programming life (which has started about 3-4 years ago) has always been
> in the functi
Well, "functional programmer" is a relatively broad term. If you're coming from
academia, so that for you Haskell is some sort of lambda-calculus, spoiled by
practical aspects, then I'd suggest Luca Cardelli's book "Theory of Objects".
Also, as Daniel told you already, don't start from C++, it r
Yes, monomorphism. "do" binding requires your fold'' to be of some monomorphic
type, but runST requires some polymorphism.
If you want, you can use special type like that:
data FoldSTVoid = FoldSTVoid {runFold :: forall a. (Int -> ST a ()) -> ST a ()}
fold :: Monad m => (Int -> m ()) -> m ()
fo
Tits?
On Nov 21, 2012, at 9:43 PM, Daniel Trstenjak
wrote:
>
> Greetings,
> Daniel
>
> ___
> Haskell-Cafe mailing list
> Haskell-Cafe@haskell.org
> http://www.haskell.org/mailman/listinfo/haskell-cafe
__
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17.11.2012, в 11:19, damodar kulkarni написал(а):
> In the second case, why the GHC doesn't give something like?
> ([Char] (a -> t), Num a) => t
Because "Num" is a class of types, while "String" is a type.
In other words, in the expression 3 "a" ghc doesn't know, what typ
{-# LANGUAGE ScopedTypeVariables #-}
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14.11.2012, в 16:03, "Serge D. Mechveliani" написал(а):
> Please,
> how to correctly set an explicit type for a local value in the body of
> a polymorphic function?
>
> Example (tested under ghc-7.6.1):
>
> data D a = D1 a | D2 a (a
=> Event a -> IO ()
> deserialize :: (Read a) => IO () -> Event a
>
> The functions would write and read the data in a file, storing/retrieving
> also the type "a" I suppose...
> BR,
> C
>
>
>
> On Sun, Oct 21, 2012 at 7:03 PM, MigMit wrote:
Seems like nobody really understands what is it that you want to accomplish or
what your problem is.
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21.10.2012, в 20:39, Corentin Dupont написал(а):
> Nobody on this one?
> Here is a simplified version:
>
> data Event a where
> InputChoice :: a -> Event a
>
> How to
Why do you need "ALike x", "BLike x" etc.? Why not just "Like u x"?
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Oct 18, 2012, в 14:36, Dmitry Vyal написал(а):
> Hello list!
>
> I've been experimenting with emulating subtyping and heterogeneous
> collections in Haskell. I need this to parse a binary representation of
t; On Thu, Oct 11, 2012 at 4:33 PM, MigMit wrote:
>>
>> On Oct 11, 2012, at 6:23 PM, Mikhail Glushenkov
>> wrote:
>>>
>>> On Thu, Oct 11, 2012 at 3:54 PM, MigMit wrote:
>>>> You have a bigger problem coming. Some extensions make
On Oct 11, 2012, at 6:23 PM, Mikhail Glushenkov
wrote:
> Hello,
>
> On Thu, Oct 11, 2012 at 3:54 PM, MigMit wrote:
>> You have a bigger problem coming. Some extensions make multiple instances
>> OK, even in Safe Haskell. For example:
>>
>&g
On Oct 11, 2012, at 5:30 PM, Mikhail Glushenkov
wrote:
> Hello Simon,
>
> On Thu, Oct 11, 2012 at 11:24 AM, Simon Marlow wrote:
>> On 08/10/2012 20:11, Mikhail Glushenkov wrote:
>>> I couldn't find anything on the interplay between orphan instances and
>>> Safe Haskell both in the Haskell'12
On Sep 29, 2012, at 9:49 PM, Gábor Lehel wrote:
> On Fri, Sep 28, 2012 at 6:36 PM, Francesco Mazzoli wrote:
>> I would expect this to work, maybe with some additional notation (a la
>> ScopedTypeVariables)
>>
>>{-# LANGUAGE FunctionalDependencies #-}
>>{-# LANGUAGE MultiParamTypeClasse
Well, it seems that you can't do exactly what you want. So, the simplest way to
do this would be not to make Foo a superclass for Bar:
class Bar a where
foo :: Foo a b => a -> b -> c
Then you would have to mention Foo everywhere.
If you really need, for some reason, to ensure that every Bar
Mind if I join you in praising this?
On Sep 17, 2012, at 12:06 AM, Kristopher Micinski
wrote:
> Agreed. Great. I still contend that it would be cool to get this to
> be a real thing at something like the Haskell workshop, I think
> hearing the different perspectives would be an interesting in
It shoudn't typecheck.
Suppose you have instances like
instance ReplaceOneOf Foo where
type Item Foo = Baz
element = elementFoo
instance ReplaceOneOf Bar where
type Item Bar = Baz
element = elementBar
Now if you call replaceOneOf manyBazs foo1 foo2, Haskell should consult
"element ::
Why modify it instead of creating the new one and let the previous tree get
garbage collected?
On Sep 9, 2012, at 12:46 PM, Milan Straka wrote:
> Hi all,
>
> is there any way to perform a destructive update on a plain ADT?
> Imagine I have a simple
> data Tree a = Nil | Node a (Tree a) (Tree
On Aug 18, 2012, at 12:35 AM, "Bryan O'Sullivan" wrote:
> We already have a simple versioning scheme for which, despite it being easy
> to grasp, we have amply demonstrated that we cannot make it work well,
> because it has emergent properties that cause it to not scale well across a
> large
What if instead of upper (and lower) bounds we just specify our interface
requirements? Like "package bull-shit should provide value Foo.Bar.baz ::
forall a. [a] -> [a] -> [a] or more general". Sure, it won't help dealing with
strictness/lazyness, but it would capture most interface differences.
It really seems to me that the error message you've got explains everything
quite clear.
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31.07.2012, в 22:59, Shayan Najd Javadipour написал(а):
> Hi,
>
> I wonder why the following code doesn't typecheck in GHC 7.4.1:
>
> {-# LANGUAGE GADTs,RankNTypes #-}
> data T a where
Works here.
GHC 7.4.2
On Jul 30, 2012, at 11:32 PM, Artyom Kazak wrote:
> Hello,
>
> I have accidentally written my version of polyvariadic composition
> combinator, `mcomp`. It differs from Oleg’s version (
> http://okmij.org/ftp/Haskell/polyvariadic.html#polyvar-comp ) in three
> aspects:
Actually, both examples show that the problem isn't type inference, it's
defaulting mechanism.
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Jul 17, 2012, в 12:46, o...@okmij.org написал(а):
>
>> 1. Haskell's type inference is NON-COMPOSITIONAL!
>
> Yes, it is -- and there are many examples of it. Here is an example
Actually, using cast seems to be a perfect solution here. I can't see anything
wrong with it.
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03.07.2012, в 20:33, Corentin Dupont написал(а):
> Hi all,
> I read somewhere (here:
> http://stackoverflow.com/questions/2300275/how-to-unpack-a-haskell-existential-type)
> that i
On 23 Jun 2012, at 21:27, Anton Kholomiov wrote:
> At last..
>
> No, it wants me to define an instance for
> (StateT s) which is supposed to be defined
> be the authors of the library.
>
> Actually I discovered that I have two libraries
> called transformers.
>
>transformers-0.2.2.0
>
Well, it's not "do" notation, since replacing "standard g" with "standard g >>=
return" gives the same poor performance. I wonder if it has something to do
with error checking.
On 11 Jun 2012, at 13:38, Dmitry Dzhus wrote:
> Hello everyone.
>
> I wonder why using do notation with `<-` can ruin
On 7 Jun 2012, at 20:55, Gábor Lehel wrote:
>
> If I'm understanding you correctly, this is similar to something I
> recently filed as a feature request:
>
> http://hackage.haskell.org/trac/ghc/ticket/5927
Yes, that seems to be it. Now I know I'm not alone.
> In the meantime it's possible to e
I'd call your pair method
> (or the class it lives in) something like congruent or
> ProductsRespectThisRelation :)
>
> Dan
>
> On Tue, May 8, 2012 at 3:15 PM, Daniel Peebles wrote:
> FullBinaryTreeRelation? :P
>
> On Tue, May 8, 2012 at 1:36 PM, MigMit
On 8 May 2012, at 21:42, Felipe Almeida Lessa wrote:
> On Tue, May 8, 2012 at 2:36 PM, MigMit wrote:
>> Hi café, a quick question.
>>
>> Is there a somewhat standard class like this:
>>
>> class Something c where
>>unit :: c () ()
>>
Hi café, a quick question.
Is there a somewhat standard class like this:
class Something c where
unit :: c () ()
pair :: c x y -> c u v -> c (x, u) (y, v)
?
I'm using it heavily in my current project, but I don't want to repeat somebody
else's work, and it seems general enough to be de
I would argue that there is just one ST monad, which makes the question even
more strange.
On 23 Apr 2012, at 22:32, KC wrote:
> Is it only one data structure per ST monad?
>
> --
> --
> Regards,
> KC
> ___
> Haskell-Cafe mailing list
> Haskell-Cafe@
Ehm... why exactly don't domain products form domains?
On 21 Feb 2012, at 19:44, wren ng thornton wrote:
> On 2/21/12 2:17 AM, Roman Cheplyaka wrote:
>> * Sebastian Fischer [2012-02-21 00:28:13+0100]
>>> On Mon, Feb 20, 2012 at 7:42 PM, Roman Cheplyaka wrote:
>>>
Is there any other interp
Isn't that just something like liftA2 mplus?
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Feb 19, 2012, в 15:50, Jon Fairbairn написал(а):
>
> This is probably a failure of my search fu or some other mental
> lacuna, but is there already a definition of this function
> somewhere:
>
> \a b -> runKleisli $ (Kleisli a)
is optimization
> triggers?
>
> Heinrich
>
> On 18.02.2012 11:10, MigMit wrote:
>> Different kinds of optimization. I expect you'd have different results even
>> if you use one type, but different -O flags.
>>
>> On 18 Feb 2012, at 13:28, Heinrich Hördegen wr
Different kinds of optimization. I expect you'd have different results even if
you use one type, but different -O flags.
On 18 Feb 2012, at 13:28, Heinrich Hördegen wrote:
>
> Dear all,
>
> I have a question about evaluation with respect to types and currying.
> Consider this programm:
>
> i
Well, if you want that in production, not for debugging purposes, you should
change the type signature of mergesort so that it uses some monad. Printing
requires IO monad; however, I would advise to collect all intermediate results
using Writer monad, and print them afterwards:
mergesort [] = r
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22.01.2012, в 20:25, David Barbour написал(а):
> Attempting to shoehorn `undefined` into your reasoning about domain algebras
> and models and monads is simply a mistake.
No. Using the complete semantics — which includes bottoms aka undefined — is a
pretty useful technique
On 21 Jan 2012, at 21:29, Victor S. Miller wrote:
> The "do" notation translates
>
> do {x <- a;f} into
>
> a>>=(\x -> f)
>
> However when we're working in the IO monad the semantics we want requires
> that the lambda expression be strict in its argument. So is this a special
> case for IO
On 18 Jan 2012, at 21:37, Henning Thielemann wrote:
>
> On Wed, 18 Jan 2012, Nathan Collins wrote:
>
>> - Portland is a very popular US city, known for beer, bikes, music,
>> and street food:
>>
>> http://en.wikipedia.org/wiki/Portland_Oregon (wikipedia is blacked out today)
>
> Maybe it is o
Type classes are inherently open. The compiler uses only the facts that there
ARE some instances of the classes it needs, but it doesn't attempt to use
information that some types AREN'T instances of certain classes. So, it can't
use information that T0 isn't an instance of C1. And that's right
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24.12.2011, в 18:50, Alexander Solla написал(а):
> In the same way, denotational semantics adds features which do not apply to a
> theory of finite computation.
And why exactly should we limit ourselves to some theory you happen to like?
>
>
> > The /defining/ feature o
On 24 Dec 2011, at 11:31, Albert Y. C. Lai wrote:
> So, on IRC in #haskell, from the same person, speaking on the same topic in
> the same context, in the same interval of 3 minutes (the first two sentences
> in the same minute):
>
> 1. a function f is strict if f ⊥ = ⊥
> 2. ⊥ represents any c
On 23 Dec 2011, at 02:11, Conor McBride wrote:
>> So... you are developing a programming language with all calculations being
>> automatically lifted to a monad? What if we want to do calculations with
>> monadic values themselves, like, for example, store a few monadic
>> calculations in a li
On 23 Dec 2011, at 02:11, Conor McBride wrote:
>> So... you are developing a programming language with all calculations being
>> automatically lifted to a monad? What if we want to do calculations with
>> monadic values themselves, like, for example, store a few monadic
>> calculations in a li
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22.12.2011, в 23:56, Conor McBride написал(а):
> I'd be glad if "pure" meant "total", but
> partiality were an effect supported by the run-time system. Then we
> could choose to restrict ourselves, but we wouldn't be restricted by the
> language.
I second that. Having a spec
On 22 Dec 2011, at 06:25, Alexander Solla wrote:
> Denotational semantics is unrealistic.
And so are imaginary numbers. But they are damn useful for electrical circuits
calculations, so who cares?
> The /defining/ feature of a bottom is that it doesn't have an interpretation.
What do you mean
On 21 Dec 2011, at 08:24, Alexander Solla wrote:
> I would rather have an incomplete semantic, and have all the incomplete parts
> collapsed into something we call "bottom".
I don't see the reason to limit ourselves to that. Of course, in total
languages like Agda there is no need for (_|_). B
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Dec 20, 2011, в 14:40, Jesse Schalken написал(а):
>
>
> On Tue, Dec 20, 2011 at 9:34 PM, Gregory Crosswhite
> wrote:
>
> On Dec 20, 2011, at 8:30 PM, Jesse Schalken wrote:
>
>>
>>
>> On Tue, Dec 20, 2011 at 8:46 PM, Ben Lippmeier wrote:
>>
>> On 20/12/2011, at 6:0
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Dec 20, 2011, в 7:10, Alexander Solla написал(а):
> * Documentation that discourages thinking about bottom as a 'value'. It's
> not a value, and that is what defines it.
It's definitely a value.
___
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Ha
No
On 23 Nov 2011, at 23:11, heathmatlock wrote:
> Question: Do you want a mascot?
>
> Answers:
> Yes
> No
>
>
> --
> This is an attempt to figure out if this idea is going anywhere.
> ___
> Haskell-Cafe mailing list
> Haskell-Cafe@haskell.org
> htt
2011, at 08:54, Magicloud Magiclouds wrote:
> I think this is where I did not understand from the very beginning.
> If the the declaration was correct, then why cannot b be H?
> Referring to Data.List.genericLength, I was confused.
>
> On Thu, Nov 17, 2011 at 12:34 PM, MigM
You've declared "from" as forall b. Test -> [b], but you're trying to implement
it as Test -> H.
On 17 Nov 2011, at 07:48, Magicloud Magiclouds wrote:
> Hi,
> Consider I have declarations like this:
> class (ClassA a) => ClassC a where
> from :: (ClassB b) => a -> [b]
> to :: (ClassB c) => a
. It also undermines the type system as
> beginners often write functions which return ⊥ where they should either be
> returning a Maybe or Either String, or expressing the violated precondition
> in the type system so it can be tested at compile time. What am I missing?
>
> On Wed,
Maybe it's just me, but I've thought that being non-strict just means that it's
possible for a function to produce some value even if it's argument doesn't; in
other words, that it's possible to have "f (_|_) ≠ (_|_)". If there was no such
thing as (_|_), what would non-strictness mean?
On 16 N
The fact that nobody bothered to write one down doesn't mean there isn't one.
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Nov 16, 2011, в 13:07, Andrew Butterfield
написал(а):
>
> On 16 Nov 2011, at 08:46, Ertugrul Soeylemez wrote:
>
>>
>> But I think, despite the well-founded denotational semantics of Haskell,
>>
In Russian we have the same problem: there is no such thing as a usual
translation of the word "kind". Seems to me that russian Haskell programmers
mostly use an English word adapted to the Russian language: "кайнды" (kaindy).
So, I think, you can do the same thing in German, just name them "Kin
Well, I usually use whatever comes handy, but I'm sure there are other
approaches — like, for example, trying something almost unusable first.
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05.11.2011, в 21:17, Grigory Sarnitskiy написал(а):
> If you are to describe a system, which consists of several subsystems, how do
Can't be done. Even if this particular module doesn't contain "instance Class
Type", it's quite possible that the said instance would be defined in another
module, about which this one knows nothing about.
On the other hand, what would you do with that information?
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26.10.2011
Yeah, I was going to mention Smalltalk too, as one of the languages NOT using
plain text to store programs — which led to a very strong boundary between ST
and other world, not doing any favors to the first.
The idea of using some non-plaintext-based format to store programs appeared
lots of ti
Control.Arrow.Transformer.State.StateArrow?
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11.10.2011, в 17:02, Captain Freako написал(а):
> Hi all,
>
> Is the Arrow-based re-definition of `StateT' included somewhere in the
> `Control.Arrow.' stack, or do you put the code into your program explicitly?
>
> Thanks,
> -db
data Renderer = Renderer {destroy :: IO (); render :: SystemOutput -> IO ()}
newtype Initializer = Initializer {initialize :: IO Renderer}
Отправлено с iPad
03.09.2011, в 14:15, "M. George Hansen" написал(а):
> Greetings,
>
> I'm a Python programmer who is relatively new to Haskell, so go easy
Ehm... what? How can you do such a replacement without losing, for example,
functions like this:
f (KI s h) i = snd $ h i $ fst $ h i s
Отправлено с iPad
24.08.2011, в 11:43, o...@okmij.org написал(а):
>
>> I had simplified the type to make the plumbing simpler. My intention
>> was to inclu
Your MathExpression data type has nothing to do with numbers of any kind. Your
"Float" data constructor doesn't mean that float numbers are a part of your
type; instead it means that you have a SINGLE value of type MathExpression, and
this value is named "Float".
You should modify your data dec
p :: (forall o. M o -> M o) -> ...
Отправлено с iPad
19.08.2011, в 16:06, Anupam Jain написал(а):
> Hi all,
>
> Suppose I have a compound data type -
>
> data M o = M (String,o)
>
> Now, I can define a function that works for ALL M irrespective of o. For
> example -
>
> f :: M o -> M o
> f
Not so sure; his company's website is under construction for more than a year
and after brief google'ing I still don't understand even what kind of business
are they supposed to be in. Seems more likely that it's actually Andrew who
does the spamming.
Отправлено с iPad
14.08.2011, в 21:18, Bra
I remember myself complaining about how when one says something stupid and
corrects himself in a few minutes, it's the first message that attracts all the
attention, not the second one.
Отправлено с iPhone
Jun 22, 2011, в 8:42, Alex Rozenshteyn написал(а):
> Funny, I didn't hear anyone say "C
Yeah, seems to work too.
Отправлено с iPhone
Jun 20, 2011, в 10:55, "Corey O'Connor" написал(а):
> Not just a proposal any more. :-) GHC 7.0 does not generalize local let
> bindings in some situations. See here for information:
> http://hackage.haskell.org/trac/ghc/blog/LetGeneralisationInGhc
Well, Haskell is fun, isn't it? And that's what iPhone is perfect for: fun.
Back when I had iPod Touch 1G (jailbroken, of course), I used to run Hugs on
it. Now I would love to see a Haskell interpreter in the App Store — which, by
the way, is possible; as there are Scheme interpreters there, wh
I fail to understand why instantiating a four-argument class with five
arguments seems obvious to you.
Отправлено с iPhone
Jun 12, 2011, в 12:37, Patrick Browne написал(а):
> class (Surfaces v o, Paths a b (v o)) => Vehicles v o a b where
>
>
> -- I do not know how to make an instance of Veh
> 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
Yes, I'm following it too, and it seems to me that Harper just allows his
dislike for Haskell to take advantage of his judgement. Monads as a way to deal
with laziness are a very common misconception.
Отправлено с iPhone
May 2, 2011, в 11:54, Ketil Malde написал(а):
>
> I'm following Harper'
It would be, if only it checked the (necessary) types during compile time. As
it is now, it seems like a claim that C is lazy just because any pointer can be
null.
Отправлено с iPhone
Apr 27, 2011, в 13:30, Henning Thielemann
написал(а):
>
> I like to apply for the quote of the week. :-)
>
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