I don't know enough about the details to know if :l and :r do
exactly the same things in ghci.
SM I don't either. But experimentation suggests that the only
SM difference is that :r doesn't need an argument (which in the case
SM of haskell-mode doesn't make any difference since the arg is
SM
Brian Hulley wrote:
Haskell is designed so
that any attempt at abstracting mutable local state will infect the
entire program (modulo use of a highly dangerous function whose
semantics is entirely unclear, depending on the vagaries of evaluation
strategy of the particular compiler)
(Your
Indeed! Getting the library numerics to do the Right Thing is something that
can only be done by people who know about numerics. People who build compilers
aren't, alas. It's quite a specialised subject, and very easy to screw up.
And there's performance to worry about too in the common
LOL. Yeah you are correct I guess. Oh well ;-)
-Original Message-
From: Bulat Ziganshin [mailto:[EMAIL PROTECTED]
Sent: Thursday, August 09, 2007 7:30 AM
To: Peter Verswyvelen
Cc: Donn Cave; haskell-cafe@haskell.org
Subject: Re[2]: [Haskell-cafe] Pure functional GUI (was a regressive
On Thu, 2007-08-09 at 08:59 +0800, Hugh Perkins wrote:
To be fair, GTK is pretty standard. This is so even for big name
gc'd imperative languages such as C#. Sure, you can use Windows.Forms
in C#, but you often wouldnt, because of the patent burden.
Also, gtk in partnership with glade rocks!
Hi
I am practicing writing code in haskell, by solving problems at this
site. http://spoj.pl.
The problem http://spoj.pl/problems/FASHION , is pretty simple.
1. Given two lists A,B , of N numbers, sort them and take sum of products.
i.e. Sum ai * bi
I wrote a code, but seems to give Time
j.vimal:
Hi
I am practicing writing code in haskell, by solving problems at this
site. http://spoj.pl.
The problem http://spoj.pl/problems/FASHION , is pretty simple.
1. Given two lists A,B , of N numbers, sort them and take sum of products.
i.e. Sum ai * bi
I wrote a code, but
* Vimal wrote:
Beginning of CODE
loop t function
| t == 1 = do function
| otherwise = do { function; loop (t - 1) function }
prod [] [] = 0
prod (a:as) (b:bs) = a*b + prod as bs
prod = sum . zipWith (*)
to_int :: [String] - [Integer]
to_int [] = []
to_int (x:xs) = (read x) : to_int
David Roundy wrote:
On Wed, Aug 08, 2007 at 02:20:39PM -0400, Paul Hudak wrote:
As long as the sugar has a pretty obvious desugaring (which I seem to
recall it did), I don't see how it's likely to make things worse. And
Some people are arguing that the desugaring isn't obvious.
Although I
For what it's worth from a Haskell newbie (and from someone who's been doing
FP since November, mainly in Scala.)
I really like Haskell's purity and having the clear separation between zero
side effects and monads is most excellent.
It was quite a brain change to program functionally. It took a
@Donald:
Thanks for the link.
prod = sum . zipWith (*)
This is the slow part. Prelude.read ist really slow.
Futhermore use the recusion pattern again:
to_int = map read
What is n used for?
@Lutz:
Those are some nice tricks... Thanks!
Now, the 'n' is for getting the number of numbers in
I wrote a code, but seems to give Time limit exceeded!
??
Your code writes
15 to stdout which is correct (with the example given on the page)..
You have to explain what you mean by seems to give Time limit exceeded
loop t function
Does already exist.
sequence $ replicate 10 function
is a much
Hello,
I had defined the follwing data type:
data Step = Step Id Scenario Action State Response
How can I define Step as an Eq Instance, in such way that two steps are
equals if they have the same Id (Id is defined as a synonimous for the String
type).
I tried the following code, but
rodrigo.bonifacio wrote:
instance Eq Step where
Step id1 scenario1 action1 state1 response1 == Step id2 scenario2 action2 state2 response2 = id == id
_ == _ = False
Almost. You just used 'id' and 'id' when you meant 'id1' and 'id2'.
instance Eq Step where
Step id1 scenario1 action1
On 8/9/07, Marc Weber [EMAIL PROTECTED] wrote:
I wrote a code, but seems to give Time limit exceeded!
??
Your code writes
15 to stdout which is correct (with the example given on the page)..
You have to explain what you mean by seems to give Time limit
exceeded
I think Vimal is referring
Dougal Stanton, Thu, 9 Aug 2007 16:57:26 +0100:
Is there a reason why automatic derivation of Ord without Eq doesn't
do the sensible thing and just derive Eq anyway?
newtype Id a = Id { a :: String }
deriving (Read, Show, Eq, Ord)
newtype Ego a = Ego { b :: String }
(sorry, forgot the subject on my first post)
In the following code which uses template haskell, how can I get back the
macro-expanded code generated from
$(inferStartState ''MyState)
I *can* recover the macro-expanded code for
$(cnst 1 x)
using a debugging technique bulat describes on
I would say that qualifies as a bug because it relays an error from compile
time to run time.
Andreas
- Original Message -
From: Dougal Stanton [EMAIL PROTECTED]
To: haskell-cafe haskell-cafe@haskell.org
Sent: Thursday, August 09, 2007 5:57 PM
Subject: [Haskell-cafe] Derivation of Eq
Note that this code isn't more successful, clearly I have
misunderstood one requirement :
import qualified Data.ByteString.Char8 as B
import Data.List (unfoldr)
main = B.interact $ hot
hot = B.unlines . map (B.pack . show) . processList . tail . unfoldr readInt1
readInt1 cs = do
(n, cs') -
I wrote:
instance Eq Ego = Eq Ord where ...
This should have been
instance Eq (Ego a) = Ord (Ego a)
Malte
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On 09/08/07, Thomas Hartman [EMAIL PROTECTED] wrote:
(sorry, forgot the subject on my first post)
In the following code which uses template haskell, how can I get back the
macro-expanded code generated from
$(inferStartState ''MyState)
I just recently used ghc -ddump-splices to debug
Duncan Coutts wrote:
On Thu, 2007-08-09 at 08:59 +0800, Hugh Perkins wrote:
uestion on using gtk from haskell: how easy is it to integrate
with glade? ie, can we directly bind glade form elements to haskell
variables? How easy is it to bind events to glade form elements from
within
Which of these is likely to go faster?
type Quad = (Bool,Bool)
foo (r,t) =
let
x = if r ...
y = if t ...
in ...
data Quad = BL | BR | TL | TR
foo q =
let
x = if q == TL | q == TR ...
y = if q == BR | q == TR ...
in ...
(Unless somebody has a better
Hi folks.
I'm trying to write a Mandelbrot generator, and I've having a few
problems with precision.
First of all, currently I'm just using Double to represent coordinates.
Can anybody tell me what the smallest value you can represent with one
is? (Not including denormals.)
(I've built a
I was writing some haskell code for fun to solve some knights and knaves
problems, and I have troubles with
http://en.wikipedia.org/wiki/Knights_and_knaves#Question_3
So knights always tell the truth and knaves always lie. John and Bill are
two persons, but you don't know what they are, and you
On 09/08/07, Andrew Coppin [EMAIL PROTECTED] wrote:
Which of these is likely to go faster?
type Quad = (Bool,Bool)
foo (r,t) =
let
x = if r ...
y = if t ...
in ...
data Quad = BL | BR | TL | TR
foo q =
let
x = if q == TL | q == TR ...
y
On Thu, Aug 09, 2007 at 07:12:12PM +0100, Sebastian Sylvan wrote:
{-#OPTIONS -funbox-strict-fields #-}
data Quad = Quad !Bool !Bool
foo True True = ...
foo True False =
... etc...
The GHC option just causese GHC to unbox primitive types when they're
strict in the data type, and
Andreas Marth wrote:
I would say that qualifies as a bug because it relays an error from compile
time to run time.
It doesn't relay anything to run time - ghci has to _compile_ the
expressions you give it too. If you _compile something_ successfully,
you will know that _it_ will not fail in
On 8/9/07, Chaddaï Fouché [EMAIL PROTECTED] wrote:
I get Wrong answer with the following code for the same problem...
Is there something strange in this code :
This problem description is not worded very well. You have to figure out
the matching that maximizes the sum of hotnesses; you don't
Donn Cave wrote:
(I have a soft spot for O'Haskell, but
alas I must be nearly alone on that.)
You are /not/ alone :-) I always found it very sad that O'Haskell and also
its sucessor Timber (with all the good real-time stuff added) died
the 'quick death' of most research languages.
Cheers
On 09/08/07, Stefan O'Rear [EMAIL PROTECTED] wrote:
On Thu, Aug 09, 2007 at 07:12:12PM +0100, Sebastian Sylvan wrote:
{-#OPTIONS -funbox-strict-fields #-}
data Quad = Quad !Bool !Bool
foo True True = ...
foo True False =
... etc...
The GHC option just causese GHC to unbox
Indeed - the *hard* part seems to be figuring out how to run Glade on
Windoze...
I did not dare to ask this question because I could not believe this was
hard... So anybody know how to do this? Run Glade on Window$?
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On
On 8/9/07, rodrigo.bonifacio [EMAIL PROTECTED] wrote:
Hi all.
I want to overload the operator ^ for working instead of the following
+++ operator:
(+++) :: String - [[String]] - [[String]]
x +++ y = [ x:e | e-y ]
How can I overload the ^ operator?
import Prelude hiding ( (^) ) -- this
On Thu, Aug 09, 2007 at 04:02:05PM +1200, ok wrote:
On 9 Aug 2007, at 8:41 am, David Roundy wrote:
I may be stating the obvious here, but I strongly prefer the do syntax.
It's nice to know the other also, but the combination of do +indenting
makes complicated code much clearer than the nested
David Roundy wrote:
Several times since reading the beginning of this discussion I've wished I
had the new syntax so I could write something like:
do if predicateOnFileContents (- readFile foo) then ...
instead of either
do contents - readFile foo
if predicateOnFileContents
On Thu, Aug 09, 2007 at 02:08:20PM +0100, Jules Bean wrote:
David Roundy wrote:
On Wed, Aug 08, 2007 at 02:20:39PM -0400, Paul Hudak wrote:
As long as the sugar has a pretty obvious desugaring (which I seem to
recall it did), I don't see how it's likely to make things worse. And
Some
On 8/9/07, Benjamin Franksen [EMAIL PROTECTED] wrote:
Donn Cave wrote:
(I have a soft spot for O'Haskell, but
alas I must be nearly alone on that.)
You are /not/ alone :-) I always found it very sad that O'Haskell and also
its sucessor Timber (with all the good real-time stuff added) died
On Thu, Aug 09, 2007 at 08:45:14PM +0200, Benjamin Franksen wrote:
David Roundy wrote:
Several times since reading the beginning of this discussion I've wished I
had the new syntax so I could write something like:
do if predicateOnFileContents (- readFile foo) then ...
instead of
On 8/9/07, Brent Yorgey [EMAIL PROTECTED] wrote:
On 8/9/07, Chaddaï Fouché [EMAIL PROTECTED] wrote:
I get Wrong answer with the following code for the same problem...
Is there something strange in this code :
This problem description is not worded very well. You have to figure out
the
I would say both.
The stuff under Examples in the repo should all run with 8.8. (I think
currently it doesn't.)
The stuff in the wiki should say what is 8.8, what is 8.4, and obviously
also give examples that work.
The advantage of the wiki is you can make a change that propogates to the
David Menendez wrote:
On 8/9/07, Benjamin Franksen [EMAIL PROTECTED] wrote:
Donn Cave wrote:
(I have a soft spot for O'Haskell, but
alas I must be nearly alone on that.)
You are /not/ alone :-) I always found it very sad that O'Haskell and
also
its sucessor Timber (with all the good
Hi,
The following link is broken.
http://www.haskell.org/hawiki/HaskellDbTutorial
Edward Ing
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2007/8/9, Peter Verswyvelen [EMAIL PROTECTED]:
Indeed - the *hard* part seems to be figuring out how to run Glade on
Windoze...
I did not dare to ask this question because I could not believe this was
hard... So anybody know how to do this? Run Glade on Window$?
The google knows??
Stefan O'Rear wrote:
On Thu, Aug 09, 2007 at 07:12:12PM +0100, Sebastian Sylvan wrote:
{-#OPTIONS -funbox-strict-fields #-}
data Quad = Quad !Bool !Bool
foo True True = ...
foo True False =
... etc...
The GHC option just causese GHC to unbox primitive types when they're
strict in
(Better view the below in a fixed-width font!)
With all the recent monad discussions, I embarked on trying to clarify
my own thoughts about them, and started to think about things in terms
of just /where/ extra structure is 'understood'.
I think I can explain why 'a-IO b' is better than 'IO
David Roundy wrote:
On Thu, Aug 09, 2007 at 08:45:14PM +0200, Benjamin Franksen wrote:
David Roundy wrote:
Several times since reading the beginning of this discussion I've
wished I
had the new syntax so I could write something like:
do if predicateOnFileContents (- readFile foo) then
On Thu, Aug 09, 2007 at 09:27:23PM +0100, Andrew Coppin wrote:
OOC, in what way is Bool not primitive enough? You mean because it's an
algebraic data type, rather than a bunch of bits in the machine? For that
matter, just how much space does such a type typically use?
Yes.
data Bool = False
Yeah I tried that one, but only the runtime, because I assumed that glade would
be part of it, but I could not find it. I guess I should install the
development version. Windows users look differently at these things, they
expect all tools to be precompiled ;) I'll try again and dig deeper.
Stefan O'Rear wrote:
On Thu, Aug 09, 2007 at 09:27:23PM +0100, Andrew Coppin wrote:
OOC, in what way is Bool not primitive enough? You mean because it's an
algebraic data type, rather than a bunch of bits in the machine? For that
matter, just how much space does such a type typically use?
Radosław Grzanka wrote:
The google knows??
http://gladewin32.sourceforge.net/modules/news/
Ah - most optimal...
Now finally I can try Glade. :-D
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On Thu, 9 Aug 2007 23:06:04 +0200, you wrote:
Is still don't get it completely... Could you give me an extra hint? I'm
getting crazy here, especially because I was really good at this stuff 20
years ago! :)
Here's the reasoning
The first answer could not be no because from that I can infer that
Is there process for submitting functions for consideration for
inclusion into future versions of the standard libraries? For example,
I'd like to see this in Data.List:
extract :: [Int] - [a] - [a]
extract = f 0
where
f _ _ [] = []
f _ [] _ = []
f k nss@(n:ns) (x:xs) = if n == k
2007/8/9, Peter Verswyvelen [EMAIL PROTECTED]:
Yeah I tried that one, but only the runtime, because I assumed that glade
would be part of it, but I could not find it. I guess I should install the
development version. Windows users look differently at these things, they
expect all tools to
Indeed, I missed that. This rules out the first answer is no
But I still keep the 3 other solutions then :(
(John is a knight,Bill is a knight,Yes,No )
(John is a knave ,Bill is a knight,Yes,Yes)
(John is a knave ,Bill is a knave ,Yes,No )
Any more help (or just the solution, I give up) is very
On Thu, Aug 09, 2007 at 02:29:50PM -0700, Chad Scherrer wrote:
Is there process for submitting functions for consideration for
inclusion into future versions of the standard libraries? For example,
I'd like to see this in Data.List:
extract :: [Int] - [a] - [a]
extract = f 0
where
Can I get some help building HaXml (from hackage) under ghc 6.7?
I'm hoping to get HAppS running under 6.7, and use the new debugger to
better understand what's going on under the hood. Eg, when I'm in the h
function, I can take a look at the args and just see what types they are.
(I am
On Thu, Aug 09, 2007 at 06:40:47PM -0400, Thomas Hartman wrote:
Can I get some help building HaXml (from hackage) under ghc 6.7?
I'm hoping to get HAppS running under 6.7, and use the new debugger to
better understand what's going on under the hood. Eg, when I'm in the h
function, I can
On Thu, Aug 09, 2007 at 11:52:17AM -0700, David Roundy wrote:
On Thu, Aug 09, 2007 at 02:08:20PM +0100, Jules Bean wrote:
*snip*
A third example is with nested dos:
do x - bar y
baz
something $ do foo x
is not the same as
do baz
something $ do foo (- bar y)
On 8/9/07, Benjamin Franksen [EMAIL PROTECTED] wrote:
David Menendez wrote:
There is also RHaskell, which implements an O'Haskell-like system as a
Haskell library.
http://www.informatik.uni-freiburg.de/~wehr/haskell/
Thanks for the pointer, I didn't know about this. Will take a look.
On 10 Aug 2007, at 6:42 am, David Roundy wrote:
do x1 - e1
if x1 then do x2 - e2
xx - if x2 then e3
else do x4 - e4
x5 - e5
e6 x4 x5
e7 xx x1
else
G'day.
Quoting Andrew Coppin [EMAIL PROTECTED]:
First of all, currently I'm just using Double to represent coordinates.
Can anybody tell me what the smallest value you can represent with one
is? (Not including denormals.)
Remember that floating point numbers are stored in three parts.
On Thu, Aug 09, 2007 at 06:37:32PM +0100, Andrew Coppin wrote:
Which of these is likely to go faster?
type Quad = (Bool,Bool)
...
data Quad = BL | BR | TL | TR
...
I'm hoping that the latter one will more more strict / use less space.
But I don't truely know...
The second one will be
On 10 Aug 2007, at 9:37 am, Stefan O'Rear wrote:
http://www.haskell.org/haskellwiki/Library_submissions
I'd like to ask if it's possible to add expm1 and log1p to
the Floating class:
class ... Floating a where
...
exp, log, sqrt :: a - a
expm1, lop1p:: a - a--
On 8/9/07, Chad Scherrer [EMAIL PROTECTED] wrote:
Is there process for submitting functions for consideration for
inclusion into future versions of the standard libraries? For example,
I'd like to see this in Data.List:
I imagine including it in std lib takes a while. Would it be a good
idea
rk:
On 8/9/07, Chad Scherrer [EMAIL PROTECTED] wrote:
Is there process for submitting functions for consideration for
inclusion into future versions of the standard libraries? For example,
I'd like to see this in Data.List:
I imagine including it in std lib takes a while. Would it be a
G'day all.
Quoting Stefan O'Rear [EMAIL PROTECTED]:
In general, GHC doesn't do unboxing. Instead it has a simpler and
more general approach, [...]
I'm not convinced that the phrase more general is appropriate here. :-)
As far as actual heap usage goes, GHC creates single static values for
hughperkins:
Haskell/FP seems to have solved the hardest bit of
threading, which is making it obvious which bits of a
program are parallelizable, and which are not.
Remains to actually parallelize out the programs. Am I
being naive or is this trivial?
Is there some
On Thu, Aug 09, 2007 at 11:09:36PM -0400, [EMAIL PROTECTED] wrote:
Quoting Stefan O'Rear [EMAIL PROTECTED]:
In general, GHC doesn't do unboxing. Instead it has a simpler and
more general approach, [...]
I'm not convinced that the phrase more general is appropriate here. :-)
Not sure where
Hello John,
Friday, August 10, 2007, 5:15:56 AM, you wrote:
data Quad = BL | BR | TL | TR
under jhc (and probably ghc at some point in the future) there is another
very strong advantage to the second one, since it is an enumerated type,
internally it can be represented by a simple unboxed
{-# OPTIONS -fglasgow-exts #-}
-- G'day everyone.
-- This is okay.
f1 :: (?foo :: String) = String
f1 = ?foo
-- So is this.
f2 :: (Show a, ?foo :: a) = a - String
f2 _ = show ?foo
-- Hugs allows this. GHC rejects it on the grounds that a is unused
-- on the right-hand side of the (=). I
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