On 2 Jan 2008, at 5:49 AM, Yitzchak Gale wrote:
Hi Andrew,
Andrew Bromage wrote:
I still say it "isn't a set" in the same way that a group "isn't a
set".
Haskell data types have structure that is respected by Haskell
homomorphisms. Sets don't.
Ah, that's certainly true. But what is that a
On 31 Dec 2007, at 1:33 PM, Achim Schneider wrote:
Jonathan Cast <[EMAIL PROTECTED]> wrote:
On 31 Dec 2007, at 10:43 AM, Achim Schneider wrote:
Achim Schneider <[EMAIL PROTECTED]> wrote:
That's not specified though, the runtime could choose to let +
force the two chunks
On 31 Dec 2007, at 10:43 AM, Achim Schneider wrote:
Achim Schneider <[EMAIL PROTECTED]> wrote:
That's not specified though, the runtime could choose to let + force
the two chunks the different way round.
And that is probably also the reason why [1..] == [1..] is _|_.
Is "Something that can
On 30 Dec 2007, at 11:16 AM, Cristian Baboi wrote:
On Sun, 30 Dec 2007 19:02:11 +0200, Jonathan Cast
<[EMAIL PROTECTED]> wrote:
On 30 Dec 2007, at 10:54 AM, Cristian Baboi wrote:
On Sun, 30 Dec 2007 18:39:51 +0200, Jonathan Cast
<[EMAIL PROTECTED]> wrote:
On 30 Dec 2007,
On 30 Dec 2007, at 11:12 AM, Cristian Baboi wrote:
On Sun, 30 Dec 2007 19:10:44 +0200, Daniel Fischer
<[EMAIL PROTECTED]> wrote:
Am Sonntag, 30. Dezember 2007 17:55 schrieb Cristian Baboi:
On Sun, 30 Dec 2007 18:34:08 +0200, Daniel Fischer
<[EMAIL PROTECTED]> wrote:
> True, but again, what
On 30 Dec 2007, at 11:10 AM, Cristian Baboi wrote:
In section 4.3.3., chapter 4: Structured types and the semantics of
pattern-matching, by S.Peyton Jones and Philip Wadler, there is
this equation:
Eval[[\(s p1 p2 ... pt).E]] (s a1 a2 ...at) = Eval[[\p1 ... \pt.E]]
a1 ... at
The text s
On 30 Dec 2007, at 10:54 AM, Cristian Baboi wrote:
On Sun, 30 Dec 2007 18:39:51 +0200, Jonathan Cast
<[EMAIL PROTECTED]> wrote:
On 30 Dec 2007, at 10:14 AM, Cristian Baboi wrote:
On Sat, 29 Dec 2007 21:49:16 +0200, Jonathan Cast
<[EMAIL PROTECTED]> wrote:
On 29 Dec 2007
On 30 Dec 2007, at 10:14 AM, Cristian Baboi wrote:
On Sat, 29 Dec 2007 21:49:16 +0200, Jonathan Cast
<[EMAIL PROTECTED]> wrote:
On 29 Dec 2007, at 5:01 AM, Cristian Baboi wrote:
By portable I mean: works on the same machine, with the same OS,
but with different Haskell implemen
On 29 Dec 2007, at 9:31 PM, alex wrote:
Hi there.
If someone can tell me why I am getting type ambiguity
in the following code:
class (Ord s, Num s) => Scalar s where
zero :: s
class Metric m where
delta :: Scalar s => m -> m -> s
(=~):: m -> m -> Bool
On 29 Dec 2007, at 2:18 PM, Miguel Mitrofanov wrote:
ok, please compute 2^2^30 before continuing discussion.
Just for the record: I don't think your computer is able to compute
2^(2^30).
Certainly not at the moment (not with memory loads the way they are
now).
jcc
On 29 Dec 2007, at 5:01 AM, Cristian Baboi wrote:
On Sat, 29 Dec 2007 02:08:14 +0200, Jonathan Cast
<[EMAIL PROTECTED]> wrote:
How can one make portable dynamic libraries then ?
If by portable you mean, works on /both/ OSs, then GHC-specific
should be portable enough for you..
On 29 Dec 2007, at 11:40 AM, Achim Schneider wrote:
Andrew Coppin <[EMAIL PROTECTED]> wrote:
Interesting... So you're claiming that humans have powers of
deduction beyond what computers possess? ;-)
They would be programming us if otherwise, wouldn't they?
I don't know...
I'm probably mor
On 29 Dec 2007, at 10:14 AM, Ben Franksen wrote:
Jonathan Cast wrote:
On 28 Dec 2007, at 3:13 PM, Ben Franksen wrote:
Bulat Ziganshin wrote:
Hello Yitzchak,
Thursday, December 27, 2007, 12:10:21 PM, you wrote:
In particular,
two functions are equal only if they produce
the same value for
On 29 Dec 2007, at 6:39 AM, Cristian Baboi wrote:
On Sat, 29 Dec 2007 13:30:03 +0200, Luke Palmer
<[EMAIL PROTECTED]> wrote:
On Dec 29, 2007 11:14 AM, Cristian Baboi
<[EMAIL PROTECTED]> wrote:
In The Implementation of Functional Programming Languages by S.P.
Jones,
section 2.5.3, page 32
On 28 Dec 2007, at 12:08 PM, Cristian Baboi wrote:
On Fri, 28 Dec 2007 19:18:33 +0200, ChrisK
<[EMAIL PROTECTED]> wrote:
This thread is obviously a source of much fun. I will play too.
Well, it starts with Wikipedia ... :-)
What is the definition of an entry point in Haskell ?
"Haske
On 28 Dec 2007, at 8:42 AM, Cristian Baboi wrote:
On Fri, 28 Dec 2007 16:34:23 +0200, apfelmus
<[EMAIL PROTECTED]> wrote:
Jules Bean wrote:
Cristian Baboi wrote:
But I guess it won't work because the compiler will optimize it
and the call will disappear.
I'm not quite sure what you're tr
On 28 Dec 2007, at 8:21 AM, Cristian Baboi wrote:
On Fri, 28 Dec 2007 16:10:15 +0200, Jules Bean
<[EMAIL PROTECTED]> wrote:
It won't work because haskell functions can't have side-effects.
I'm not quite sure what you're trying to say here.
Jules
What I am trying to say is:
- storing som
On 28 Dec 2007, at 4:40 AM, Cristian Baboi wrote:
On Fri, 28 Dec 2007 12:01:51 +0200, Miguel Mitrofanov
<[EMAIL PROTECTED]> wrote:
[1 .. ] and x=1:x are maximal ?
Yes.
How can a Haskell implementation recognize a maximal value ?
x=1:x for example.
It can't.
jcc
___
On 28 Dec 2007, at 4:20 AM, Cristian Baboi wrote:
Thank you.
This is what I understand so far:
- the maximal values is what is usually called data
Incorrect. Total functions are maximal.
- the non maximal are what is usually called code
Incorrect. `Non maximal' expressions are just e
On 28 Dec 2007, at 4:10 AM, Cristian Baboi wrote:
On Fri, 28 Dec 2007 12:01:51 +0200, Miguel Mitrofanov
<[EMAIL PROTECTED]> wrote:
It sounds like a limit. xn --> x for n --> :-)
Yeah, that's right.
If xn is monotone, then I only have to worry when it is not
bounded, right ?
How can
On 28 Dec 2007, at 3:37 AM, Cristian Baboi wrote:
Thank you.
It sounds like a limit. xn --> x for n --> :-)
I could say that LUBs are colimits, not limits, but I won't :)
More seriously, I don't like the calculus --> notation in this
context; these are suprema, not lims.
How can I get
On 28 Dec 2007, at 2:08 AM, Cristian Baboi wrote:
On Thu, 27 Dec 2007 20:46:24 +0200, Jonathan Cast
<[EMAIL PROTECTED]> wrote:
Preference doesn't come into it. By definition, the denotations
of Haskell functions are monotone continous functions on pointed
complete partial or
On 28 Dec 2007, at 1:15 AM, Cristian Baboi wrote:
On Thu, 27 Dec 2007 17:39:25 +0200, Jonathan Cast
<[EMAIL PROTECTED]> wrote:
Haskell is not a computer programming language; Haskell
implementations are not required to run on computers. Haskell is
a formal notation for compu
On 28 Dec 2007, at 1:12 AM, Cristian Baboi wrote:
On Thu, 27 Dec 2007 17:35:54 +0200, Jonathan Cast
<[EMAIL PROTECTED]> wrote:
Only on Von Neuman machines. Haskell implementations are not
required to run on Von Neuman machines. That's why the language
is called
On 28 Dec 2007, at 3:13 PM, Ben Franksen wrote:
Bulat Ziganshin wrote:
Hello Yitzchak,
Thursday, December 27, 2007, 12:10:21 PM, you wrote:
In particular,
two functions are equal only if they produce
the same value for every input, and in general it is
impossible for a computer to check that.
On 28 Dec 2007, at 7:15 AM, Cristian Baboi wrote:
But I guess it won't work because the compiler will optimize it and
the call will disappear.
On Fri, 28 Dec 2007 14:58:53 +0200, Cristian Baboi
<[EMAIL PROTECTED]> wrote:
Here is how I want print to be in Haskell
print :: (a->b) -> (a->b
On 27 Dec 2007, at 8:38 PM, Albert Y. C. Lai wrote:
Achim Schneider wrote:
[n..] == [m..], the first thing I notice is
n == m && n+1 == m+1
, which already expresses all of infinity in one instance and can be
trivially cancelled to
n == m
, which makes the whole darn thing only _|_ if n or m is
On 27 Dec 2007, at 4:54 PM, Achim Schneider wrote:
Jonathan Cast <[EMAIL PROTECTED]> wrote:
_|_ is the denotation of every Haskell expression whose
denotation is _|_.
Mu.
Why take away _|_?
Because, when zenning about
instance (Eq a) => Eq [a] where
[] == []
On 27 Dec 2007, at 12:20 PM, Achim Schneider wrote:
Jonathan Cast <[EMAIL PROTECTED]> wrote:
On 27 Dec 2007, at 10:44 AM, Achim Schneider wrote:
Wolfgang Jeltsch <[EMAIL PROTECTED]> wrote:
Am Donnerstag, 27. Dezember 2007 16:34 schrieb Cristian Baboi:
I'll have to tru
On 27 Dec 2007, at 10:44 AM, Achim Schneider wrote:
Wolfgang Jeltsch <[EMAIL PROTECTED]> wrote:
Am Donnerstag, 27. Dezember 2007 16:34 schrieb Cristian Baboi:
I'll have to trust you, because I cannot test it.
let x=(1:x); y=(1:y) in x==y .
I also cannot test this:
let x=(1:x); y=1:1:y in x
On 27 Dec 2007, at 9:57 AM, Cristian Baboi wrote:
Good to know. I intended to use Haskell for algorithms, but it
seems it is not so good at them.
Very sad. The entire point of Haskell is that it allows the user to
transcend the algorithm as a way of expressing computations.
I hope someda
On 27 Dec 2007, at 9:47 AM, Cristian Baboi wrote:
I don't know. I'm a beginner in Haskell, and I down't know
about T.
You mean they cannot ?
I was under the impression that the purpose of computers cannot
be fulfiled if we cannot get the result of computations out of
the computers.
H
On 27 Dec 2007, at 9:41 AM, Cristian Baboi wrote:
On Thu, 27 Dec 2007 17:39:25 +0200, Jonathan Cast
<[EMAIL PROTECTED]> wrote:
On 27 Dec 2007, at 6:51 AM, Cristian Baboi wrote:
On Thu, 27 Dec 2007 14:42:37 +0200, Bulat Ziganshin
<[EMAIL PROTECTED]> wrote:
Hello Cristia
On 27 Dec 2007, at 9:34 AM, Cristian Baboi wrote:
I'll have to trust you, because I cannot test it.
let x=(1:x); y=(1:y) in x==y .
I also cannot test this:
let x=(1:x); y=1:1:y in x==y
Correct. You could try proving it.
Or you could try proving that these expressions are equal to _|_.
On 27 Dec 2007, at 8:53 AM, Cristian Baboi wrote:
On Thu, 27 Dec 2007 16:50:10 +0200, Lennart Augustsson
<[EMAIL PROTECTED]> wrote:
Absolutly. Every expression in Haskell denotes a value.
Now, we've not agreed what "value" means, but to me it is a value. :)
It is one value, or several ?
On 27 Dec 2007, at 8:28 AM, Cristian Baboi wrote:
How about x below:
let x=(1:x) in x ?
Is x a single value in Haskell ?
(let x=1:x in x) is. x went out of scope a couple of lines back.
jcc
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On 27 Dec 2007, at 8:08 AM, Cristian Baboi wrote:
On Thu, 27 Dec 2007 14:02:36 +0200, Lennart Augustsson
<[EMAIL PROTECTED]> wrote:
Comparing functions is certainly possible in Haskell, but there's no
standard function that does it.
If course, it might not terminate, but the same is true for
On 27 Dec 2007, at 6:51 AM, Cristian Baboi wrote:
On Thu, 27 Dec 2007 14:42:37 +0200, Bulat Ziganshin
<[EMAIL PROTECTED]> wrote:
Hello Cristian,
Thursday, December 27, 2007, 12:19:08 PM, you wrote:
Yes, but one can store the result of an operation to disk except
in the
particular case t
On 27 Dec 2007, at 4:57 AM, Cristian Baboi wrote:
On Thu, 27 Dec 2007 12:40:22 +0200, Yitzchak Gale <[EMAIL PROTECTED]>
wrote:
I wrote:
On the other hand, functions are members of types
that are just like any other Haskell type. They are
first-class in that sense.
Cristian Baboi wrote:
I
On 26 Dec 2007, at 12:30 PM, Peter Verswyvelen wrote:
Well I certainly hope the standard defines that both fred and bob
will only
be evaluated once, because my programs depend on that :)
If your programs depend on lazy evaluation, they can't be Haskell
98. Any complete reduction method is
On 18 Dec 2007, at 7:28 AM, [EMAIL PROTECTED] wrote:
Concerning the subject: "The End" of WHAT?
Cristian Baboi writes:
Reinier Lamers wrote:
Cristian Baboi wrote:
Haskell strengts as I see them:
...
- it has a compiler
...
Is there anything you would like to add ?
Higher-order functions
On 17 Dec 2007, at 7:39 AM, David Menendez wrote:
On Dec 17, 2007 8:51 AM, Bayley, Alistair
<[EMAIL PROTECTED]> wrote:
As an aside, I was wondering exactly what the differences are between
newtype and data i.e. between
> newtype A a = A a
and
> data A a = A a
According to:
http://www.has
On 16 Dec 2007, at 9:47 AM, Dominic Steinitz wrote:
Jonathan Cast wrote:
On 16 Dec 2007, at 3:21 AM, Dominic Steinitz wrote:
Do you have a counter-example of (.) not being function
composition in
the categorical sense?
Let bot be the function defined by
bot :: alpha -> beta
bot =
On 16 Dec 2007, at 3:21 AM, Dominic Steinitz wrote:
Do you have a counter-example of (.) not being function
composition in
the categorical sense?
Let bot be the function defined by
bot :: alpha -> beta
bot = bot
By definition,
(.) = \ f -> \ g -> \ x -> f (g x)
Then
bot . id
= ((\ f
On 16 Dec 2007, at 2:23 AM, Dominic Steinitz wrote:
keep in mind that Haskell "composition" (.)
is not really composition in the category-theoretic
sense, because it adds extra laziness. Use this
Do you have a counter-example of (.) not being function composition in
the categorical sense?
Le
On 14 Dec 2007, at 1:21 AM, Jules Bean wrote:
Evan Laforge wrote:
it seems that script may be not terminated if its output isn't
read, so
better code should be
(_, h, g, _) <- runInteractiveCommand "script params"
result <- hGetLine h
hGetContents h >>= evaluate.length
hGetContents g >>= ev
On 10 Dec 2007, at 11:33 AM, Dan Weston wrote:
Questioning apfelmus definitely gives me pause, but...
> id :: a -> a-- "arity" 1
> id = ($) :: (a -> b) -> (a -> b) -- "arity" 2
I agree with the arities given above (but without quotes) and see
no ill-definedness to
On 7 Dec 2007, at 12:39 PM, Dan Weston wrote:
Luke Palmer wrote:
On Dec 7, 2007 7:57 PM, Luke Palmer <[EMAIL PROTECTED]> wrote:
On Dec 7, 2007 7:41 PM, Dan Weston <[EMAIL PROTECTED]> wrote:
Luke Palmer wrote:
You can project the compile time numbers into runtime ones:
Yes, that works well if
On 3 Dec 2007, at 4:19 PM, Dan Piponi wrote:
On Dec 3, 2007 3:54 PM, Ben Franksen <[EMAIL PROTECTED]> wrote:
I don't buy this. As has been noted by others before, IO is a very
special
case, in that it can't be defined in Haskell itself, and there is no
evaluation function runIO :: IO a -> a.
On 26 Nov 2007, at 10:48 AM, Henning Thielemann wrote:
I wonder whether it is a typical mistake of beginners
to write 'return' within a do-block (that is, not at the end)
and if it is possible to avoid this mistake by clever typing.
In a proper monad 'return' can be fused with subsequent action
On 24 Nov 2007, at 9:09 PM, Brent Yorgey wrote:
On Nov 24, 2007 10:55 PM, Conal Elliott <[EMAIL PROTECTED]> wrote:
why care about trailing whitespace?
Probably because it looks bad in darcs patch summaries (trailing
whitespace --> little red dollar signs). Unless there's another
reason I do
On 22 Nov 2007, at 11:16 AM, Andrew Coppin wrote:
Aaron Denney wrote:
On 2007-11-21, Andrew Coppin <[EMAIL PROTECTED]> wrote:
In short, lots of Haskell-related things seem to be extremely
Unix-centric and downright unfriendly towards anybody trying to set
things up on Windows. If I didn't alr
On 22 Nov 2007, at 10:17 AM, Maurí cio wrote:
Hi,
If I have two computations a->IO b
and b->IO c, can I join them to
get an a->IO c computation? I imagine
something like a liftM dot operator.
This is called Kleisli composition, by the way; it's defined as (>=>)
in Control.Monad.
jcc
On 17 Nov 2007, at 8:04 PM, PR Stanley wrote:
Hi
okay, so $! is a bit like $ i.e. the equivalent of putting
parentheses around the righthand expression. I'm still not sure of
the difference between $ and $!. Maybe it's because I don't
understand the meaning of "strict application". While w
On 14 Nov 2007, at 4:32 PM, Shachaf Ben-Kiki wrote:
On Nov 14, 2007 4:27 PM, Justin Bailey <[EMAIL PROTECTED]> wrote:
It's:
f $! x = x `seq` f x
That is, the argument to the right of $! is forced to evaluate, and
then that value is passed to the function on the left. The function
itself is
On 13 Nov 2007, at 11:03 PM, Jules Bean wrote:
Just to be clear: my proposal is that if you want it to go faster
you do
ghci foo.hi
or
ghci foo.o
... so you still have the option to run on compiled code.
My suggestion is simply that "ghci foo.hs" is an instruction to
load source code (si
On 7 Nov 2007, at 12:40 PM, Tim Newsham wrote:
Data.Maybe has functions for processing Maybe's but nothing useful
for creating maybe. I think the following would be a very useful
addition, a guarded function:
guarded :: (a -> Bool) -> (a -> b) -> a -> Maybe b
guarded p f x | p x
On 7 Nov 2007, at 11:26 AM, Donn Cave wrote:
I have been working on a little Java project lately at work, by way
of an introduction to the language, and naturally I often have cause
to regret that it isn't Haskell instead.
But in the specific matter I'm wrestling with, the Java library's OOP
m
get into, and not very polite.
Jonathan Cast wrote:
Nope. newStdGen is specified in terms of split, which means it
leaves the random generator in a state independent of the generator
it returns. Perfectly safe. (I think you think you used getStdGen).
I was referring to randoms and randomRs
On 6 Nov 2007, at 6:00 AM, Yitzchak Gale wrote:
There is still a problem here - my code (and also
all of the previous posters, I think) clobbers the random
generator, rendering it unusable for future calculations.
In this case that is probably not a problem, but it
is a bad habit to get into, a
On Tue, 2007-11-06 at 10:32 +1030, Levi Stephen wrote:
> Hi,
>
> I'm was wondering how most people work during when designing a functional
> program. Do you create data structures/types first? Do you work from some
> type
> signatures?
>
> For example, take a blog. Is the first step likely to
On Mon, 2007-11-05 at 20:12 +, Andrew Coppin wrote:
> Hi folks.
>
> Take a look at this:
>
> render :: IOArray Point Colour -> (Point -> Colour) -> IO ()
> render framebuffer fn = mapM_ (\p -> writeArray framebuffer p (fn p))
> all_points
>
> How do I alter this to compute fn in multip
On Mon, 2007-11-05 at 20:11 +, Alex Young wrote:
> Hi all,
>
> I'm new to Haskell, and don't quite understand how IO and lazy
> evaluation work together yet. In order to improve my understanding, I
> thought I'd try to knock together a translation of a fairly simple
> problem I can code up
On Fri, 2007-11-02 at 15:43 -0400, Jeff Polakow wrote:
>
> Hello,
>
> > > Just a bit of minor academic nitpicking...
> > >
> > > > Yeah. After all, the "uniqueness constraint" has a theory with
> an
> > > > excellent pedigree (IIUC linear logic, whose proof theory Clean
> uses
> > > > here,
On Fri, 2007-11-02 at 14:41 -0400, Jeff Polakow wrote:
>
> Hello,
>
> Just a bit of minor academic nitpicking...
>
> > Yeah. After all, the "uniqueness constraint" has a theory with an
> > excellent pedigree (IIUC linear logic, whose proof theory Clean uses
> > here, goes back at least to th
On Fri, 2007-11-02 at 11:56 -0400, Brandon S. Allbery KF8NH wrote:
> On Nov 2, 2007, at 11:51 , Jonathan Cast wrote:
>
> >> I will grant that hiding *World / RealWorld# inside IO is cleaner
> >> from a practical standpoint, though. Just not from a semantic one.
> >
On Fri, 2007-11-02 at 08:35 -0400, Brandon S. Allbery KF8NH wrote:
> On Nov 2, 2007, at 6:35 , apfelmus wrote:
>
> > during function evaluation. Then, we'd need a "purity lemma" that
> > states that any function not involving the type *World as in- and
> > output is indeed pure, which may be
On Thu, 2007-11-01 at 21:42 +, Jon Fairbairn wrote:
> "Hugh Perkins" <[EMAIL PROTECTED]> writes:
>
> > On 10/26/07, John Meacham <[EMAIL PROTECTED]> wrote:
> >> Heh, the plethora of pdf papers on Haskell is part of what originally
> >> brought me to respect it. Something about that metafont pa
On Thu, 2007-10-25 at 19:59 -0200, Maurício wrote:
> Hi,
>
> Today, if I write:
>
> [a:[b] | a<-"ab" , b<-"12"]
>
> I get:
>
> ["a1","a2","b1","b2"]
>
> Are there any guarantees that I'll never
> get ["a1","b1","a2","b2"] instead, i.e.,
> that the first list will always be the
> last one to
On Fri, 2007-10-19 at 02:45 +0200, [EMAIL PROTECTED]
wrote:
> PR Stanley writes:
>
> > One of the reasons I'm interested in Wikipedia and Wikibook is because
> > you're more likely to find Latex source code used for typesetting the
> > maths.
> > Latex is the one and only 100% tool right now.
>
On Fri, 2007-10-12 at 19:33 -0400, Brandon S. Allbery KF8NH wrote:
> On Oct 12, 2007, at 18:35 , Albert Y. C. Lai wrote:
>
> > You are not expected to be convinced this, but it seems
> > continuations completely characterize system programming. :)
>
> Didn't someone already prove all monads can
On Fri, 2007-10-19 at 23:57 +0800, TJ wrote:
> Henning Thielemann:
> > > class Renderable a where
> > > render :: a -> RasterImage
> > >
> > > scene :: Renderable a => [a]
> >
> > This signature is valid, but it means that all list elements must be of
> > the same Renderable type.
>
> Yes, that'
On Fri, 2007-10-19 at 00:02 +0200, [EMAIL PROTECTED]
wrote:
> Dan Weston writes:
>
> > ... now I am totally flummoxed:
> >
> > thm1 :: (a -> a) -> a
> > thm1 f = let x = f x in x
> >
> > > thm1 (const 1)
> > 1
> >
> > I *thought* that the theorem ((a => a) => a) is not derivable (after all,
On Fri, 2007-10-12 at 13:52 -0400, Steve Schafer wrote:
> On Fri, 12 Oct 2007 18:24:38 +0100, you wrote:
>
> >I was actually thinking more along the lines of a programming language
> >where you can just write
> >
> > head :: (n > 1) => List n x -> x
> >
> > tail :: List n x -> List (n-1) x
> >
On Fri, 2007-10-12 at 11:00 +1300, ok wrote:
> On 11 Oct 2007, at 4:06 pm, Tom Davies basically asked for
> something equivalent to Ada's
> type T is new Old_T;
> which introduces a *distinct* type T that has all the operations and
> literals of Old_T. In functional terms, suppose there is a
On Wed, 2007-10-10 at 21:45 -0400, Brandon S. Allbery KF8NH wrote:
> On Oct 10, 2007, at 20:14 , Michael Vanier wrote:
>
> > I haven't been following this discussion closely, but here's an
> > idea: use reverse psychology.
> >
> > "Haskell -- You're probably not smart enough to understand it."
>
On Thu, 2007-10-11 at 07:57 +, Aaron Denney wrote:
> On 2007-10-11, Jonathan Cast <[EMAIL PROTECTED]> wrote:
> > Yes. I am very eager to criticize your wording. To wit, I'm still
> > failing to understand what your position is. Is it fair to say that
> > yo
On Thu, 2007-10-11 at 11:22 +0200, [EMAIL PROTECTED]
wrote:
> My last word (promise!) on the subject, especially addressed to Jonathan
> Cast, who writes:
>
> > To wit, I'm still failing to understand what your position is.
>
> I quote the Master:
>
> Le
On Thu, 2007-10-11 at 02:11 +0200, [EMAIL PROTECTED]
wrote:
> Jonathan Cast adds 'something' to a discussion about pi.
>
> I commented the statement of Yitzchak Gale, who answered some point
> of Dan Piponi:
>
> >> > A default implementation of pi woul
On Wed, 2007-10-10 at 12:29 +0200, [EMAIL PROTECTED]
wrote:
> ChrisK writes:
>
> > Putting 'pi' in the same class as the trigonometric functions is good
> > design.
>
> If you wish so... But:
> Look, this is just a numeric constant.
> Would you like to have e, the Euler's constant, etc., as wel
On Wed, 2007-10-10 at 10:40 +0200, [EMAIL PROTECTED]
wrote:
> Yitzchak Gale writes:
>
> > Dan Piponi wrote:
> >> The reusability of Num varies inversely with how many
> >> assumptions you make about it.
> >
> > A default implementation of pi would only increase usability,
> > not decrease it.
>
On Tue, 2007-10-09 at 13:07 -0700, Don Stewart wrote:
> jonathanccast:
> > I just noticed that pi doesn't have a default definition in the standard
> > prelude, according to the Haddock docs. Why is this?
>
> $ ghci
> Prelude> :t pi
> pi :: (Floating a) => a
>
> Prelude> pi
>
I just noticed that pi doesn't have a default definition in the standard
prelude, according to the Haddock docs. Why is this?
jcc
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On Fri, 2007-10-05 at 20:19 +, Aaron Denney wrote:
> On 2007-10-05, Peter Verswyvelen <[EMAIL PROTECTED]> wrote:
> > But where is the great IDE Haskell deserves??? :-) Seriously, 99% of the
> > programmers I know don't want to look at it because when they see Emacs
> > or VIM, they say "what
On Wed, 2007-10-03 at 14:47 -0700, Justin Bailey wrote:
> One of the "holes" in real-world Haskell is you never know if a
> library/function is calling unsafePerformIO and you have to trust the
> library author. I recognize the necessity of the function, but should
> it announce itself? unsafePerfo
On Wed, 2007-10-03 at 14:15 +0200, Stephane Bortzmeyer wrote:
> On Wed, Oct 03, 2007 at 12:01:50AM +0200,
> Twan van Laarhoven <[EMAIL PROTECTED]> wrote
> a message of 24 lines which said:
>
> > Lots of people wrote:
> > > I want a UTF-8 bikeshed!
> > > No, I want a UTF-16 bikeshed!
>
> Person
On Wed, 2007-10-03 at 00:01 +0200, Twan van Laarhoven wrote:
> Lots of people wrote:
> > I want a UTF-8 bikeshed!
> > No, I want a UTF-16 bikeshed!
>
> What the heck does it matter what encoding the library uses internally?
+1
jcc
___
Haskell-Cafe
On Tue, 2007-10-02 at 22:05 +0400, Miguel Mitrofanov wrote:
> > I would like to, again, strongly argue against sacrificing
> > compatibility
> > with Linux/BSD/etc. for the sake of compatibility with OS X or
> > Windows.
>
> Ehm? I've used to think MacOS is a sort of BSD...
Cocoa, then.
jcc
On Tue, 2007-10-02 at 08:02 -0700, Deborah Goldsmith wrote:
> On Oct 2, 2007, at 5:11 AM, ChrisK wrote:
> > Deborah Goldsmith wrote:
> >
> >> UTF-16 is the native encoding used for Cocoa, Java, ICU, and
> >> Carbon, and
> >> is what appears in the APIs for all of them. UTF-16 is also what's
> >>
On Fri, 2007-09-28 at 11:19 -0700, Chuk Goodin wrote:
> I have a list of lists of pairs of numeric Strings (like this:
> [["2","3"],["1","2"],["13","14"]] etc.) I'd like to change it into a
> list of a list of numbers, but I'm not sure how to go about it. If it
> was just one list, I could use map,
On Thu, 2007-09-27 at 16:57 +0100, Tristan Allwood wrote:
> On Thu, Sep 27, 2007 at 05:31:51PM +0200, apfelmus wrote:
> > Tristan Allwood wrote:
> >> Does anyone know if there is a function that tells you if a haskell
> >> value has been forced or not? e.g. isWHNF :: a -> IO Bool let x =
> >> (map
On Wed, 2007-09-26 at 17:09 -0500, Derek Elkins wrote:
> On Wed, 2007-09-26 at 14:12 -0700, Jonathan Cast wrote:
> > On Wed, 2007-09-26 at 11:43 -0700, Dan Weston wrote:
> > > It seems no one liked idea #2. I still think fix is the wrong name for
> > > this,
On Wed, 2007-09-26 at 14:28 -0700, Dan Piponi wrote:
> On 9/26/07, Lennart Augustsson <[EMAIL PROTECTED]> wrote:
> > Things can go arbitrarily wrong if you misuse unsafePerformIO, you can even
> > subvert the type system.
>
> So...if I was in a subversive kind of mood (speaking hypothetically),
>
On Wed, 2007-09-26 at 11:43 -0700, Dan Weston wrote:
> It seems no one liked idea #2. I still think fix is the wrong name for
> this, maybe limit would be better.
It calculates least fixed points. `fix' is as good a name as any.
`limit' is terrible; the argument to fix, a -> a, is neither a seq
On Wed, 2007-09-26 at 18:46 +0100, Duncan Coutts wrote:
> In message <[EMAIL PROTECTED]> Jonathan Cast <[EMAIL PROTECTED]> writes:
> > On Wed, 2007-09-26 at 09:05 +0200, Johan Tibell wrote:
>
> > > If UTF-16 is what's used by everyone else (how about Java?
On Wed, 2007-09-26 at 09:05 +0200, Johan Tibell wrote:
> > I'll look over the proposal more carefully when I get time, but the
> > most important issue is to not let the storage type leak into the
> > interface.
>
> Agreed,
>
> > From an implementation point of view, UTF-16 is the most efficient
On Tue, 2007-09-25 at 17:19 -0700, Dan Weston wrote:
> One suggestion:
>
> Section 3.6 defines a function "fix":
>
> fix :: Eq x => (x -> x) -> x -> x
>
> fix f x = if x == x' then x else fix f x'
> where x' = f x
>
> This confusingly differs in both type and meaning from the traditio
On Tue, 2007-09-25 at 19:18 +0100, Brian Hulley wrote:
> Brian Hulley wrote:
> > I'm wondering if anyone can shed light on the reason why
> >
> >x # y
> >
> > gets desugared to
> >
> > (#) x y
> >
> > and not
> >
> > (#) y x
> >
>
> > Can anyone think of an example where the current desuga
On Tue, 2007-09-25 at 12:24 +0100, Andrew Coppin wrote:
> Chaddaï Fouché wrote:
> > 2007/9/25, Andrew Coppin <[EMAIL PROTECTED]>:
> >
> >> This is why I found it so surprising - and annoying - that you can't use
> >> a 2-argument function in a point-free expression.
> >>
> >> For example, "zipWi
On Tue, 2007-09-25 at 11:40 +0100, Andrew Coppin wrote:
> Aaron Denney wrote:
> > On 2007-09-25, Andrew Coppin <[EMAIL PROTECTED]> wrote:
> >
> >> OK, *now* I'm puzzled... Why does map . map type-check?
> >>
> >
> > (map . map) = (.) map map
> >
> > (.) :: (a -> b) -> (b -> c) -> a -> c
> >
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