I have started the Graham Scan Algorithm exercise. I'm getting tripped
up by the sortByCotangent* function.
Here's what I have so far
data Direction = DStraight
| DLeft
| DRight
deriving (Eq,Show)
type PointXY = (Double,Double)
calcTurn :: PointXY -
Hi all,
Is there a Haskell-Expect module? Something that would allow me to
control an external Unix program via its stdin/stdout/stderr?
Cheers,
Erik
--
-
Erik de Castro Lopo
Hi Erik,
Is there a Haskell-Expect module? Something that would allow me to
control an external Unix program via its stdin/stdout/stderr?
System.Process does what you want, I think:
http://hackage.haskell.org/packages/archive/process/1.0.1.1/doc/html/System-Process.html
Thanks
Neil
Massimiliano Gubinelli wrote:
Hi,
what about avoid the use of the unfold over the tree and construct it
directly (e.g. see http://hpaste.org/13919#a3)?
Nice solution!
I wonder if there is (an
easy) possibility to construct the tree lazily so that output start
immediately for large trees.
Am Montag, 19. Januar 2009 09:32 schrieb Michael Litchard:
I have started the Graham Scan Algorithm exercise. I'm getting tripped
up by the sortByCotangent* function.
Here's what I have so far
data Direction = DStraight
| DLeft
| DRight
david48 wrote:
Apfelmus, Heinrich wrote:
Hm, what about the option of opening Bird's Introduction on Functional
Programming using Haskell in the section about fold? Monoid is on page
62 in the translated copy I've got here.
I don't think that I would try to learn a programming language, for
Am Montag, 19. Januar 2009 10:17 schrieb Daniel Fischer:
Am Montag, 19. Januar 2009 09:32 schrieb Michael Litchard:
I have started the Graham Scan Algorithm exercise. I'm getting tripped
up by the sortByCotangent* function.
Here's what I have so far
data Direction = DStraight
Hi everyone,
I have a general program design question, but I can't really think of
good examples so it will be a bit vague. There was a discussion on Show
not long ago which brought up the problem that there are several ways to
show a data structure, and it depends on the context (or should I
As for multiple Monoid or Functor instances, simply define a newtype,
as it is done in Data.Monoid.
What part of your question does that answer and what part doesn't it?
2009/1/19 Patai Gergely patai_gerg...@fastmail.fm:
Hi everyone,
I have a general program design question, but I can't really
Hello!
I wouldn't use either. It seems like it complicates things quite a lot and it
looks like this could be solved more simply by setting up the data types or
organizing functions differently.
Is there a specific problem that you're solving or are you just curious about
different return
John Ky newho...@gmail.com writes:
Hi,
Possibly a silly question but is it possible to have a function that has a
different return type based on it's first argument?
Are you sure that's what you really want?
For instance
data Person = Person { name :: String, ... }
data Business =
Brandon S. Allbery KF8NH wrote:
On 2009 Jan 18, at 13:47, Matti Niemenmaa wrote:
3. Coadjute keeps track of command line arguments (see docs for
details): for me this is really a killer feature, I don't know of
anything else which does this.
It's been done many times before; it never
2009/1/18 Matti Niemenmaa matti.niemenmaa+n...@iki.fi:
Announcing the release of Coadjute, version 0.0.1!
[...]
Portability is striven towards in two ways:
Is it intended to work on Windows? (I don't want to spend time
downloading and trying to set it up if it was never intended to be
On Mon, Jan 19, 2009 at 3:58 AM, Patai Gergely patai_gerg...@fastmail.fmwrote:
However, there are other type classes that are too general to assign
such concrete uses to. For instance, if a data structure can have more
than one meaningful (and useful) Functor or Monoid instance,
As a side
John Ky newho...@gmail.com wrote in article
bd4fcb030901181744i2b26172bv2328974ff911f...@mail.gmail.com in
gmane.comp.lang.haskell.cafe:
data Person = Person { name :: String, ... }
data Business = Business { business_number :: Int, ...}
key person = name person
key business =
Paul Moore wrote:
2009/1/18 Matti Niemenmaa matti.niemenmaa+n...@iki.fi:
Announcing the release of Coadjute, version 0.0.1!
[...]
Portability is striven towards in two ways:
Is it intended to work on Windows? (I don't want to spend time
downloading and trying to set it up if it was never
Alexandr,
Thanks for sending me this question about unicode and regex-pcre. I will
share with the mailing list. This is an encoding issue.
From the haddock documentation for regex-pcre:
http://hackage.haskell.org/packages/archive/regex-pcre/0.94.1/doc/html/Text-Regex-PCRE.html
Using the
2009/1/19 Luke Palmer lrpal...@gmail.com:
As a side curiosity, I would love to see an example of any data structure
which has more than one Functor instance. Especially those which have more
than one useful functor instance.
(,) ?
-Antoine
___
2009/1/19 Luke Palmer lrpal...@gmail.com:
On Mon, Jan 19, 2009 at 3:58 AM, Patai Gergely patai_gerg...@fastmail.fm
wrote:
However, there are other type classes that are too general to assign
such concrete uses to. For instance, if a data structure can have more
than one meaningful (and
Am Montag, 19. Januar 2009 14:31 schrieb Antoine Latter:
2009/1/19 Luke Palmer lrpal...@gmail.com:
As a side curiosity, I would love to see an example of any data structure
which has more than one Functor instance. Especially those which have
more than one useful functor instance.
(,) ?
Am Montag, den 19.01.2009, 14:47 +0100 schrieb Daniel Fischer:
Am Montag, 19. Januar 2009 14:31 schrieb Antoine Latter:
2009/1/19 Luke Palmer lrpal...@gmail.com:
As a side curiosity, I would love to see an example of any data structure
which has more than one Functor instance. Especially
Excerpts from Matti Niemenmaa's message of Sun Jan 18 19:47:46 +0100 2009:
Henning Thielemann wrote:
Matti Niemenmaa schrieb:
Announcing the release of Coadjute, version 0.0.1!
Web site: http://iki.fi/matti.niemenmaa/coadjute/
Hackage:
I finally installed cabal-install in windows.. I had a copy of sh.exe for
windows time ago so I could use bootstrap. The only additional thing needed
is wget(http://users.ugent.be/~bpuype/wget/).
finally I moved the resulting cabal.exe to ghc/bin
2009/1/19 Duncan Coutts
Nicolas Pouillard wrote:
Excerpts from Matti Niemenmaa's message of Sun Jan 18 19:47:46 +0100 2009:
3. Coadjute keeps track of command line arguments (see docs for
details): for me this is really a killer feature, I don't know of
anything else which does this.
ocamlbuild does
The desugaring of (, a) would involve some type level lambda, and
that's not something that is available (yet).
-- Lennart
On Mon, Jan 19, 2009 at 1:49 PM, Holger Siegel holgersiege...@yahoo.de wrote:
Am Montag, den 19.01.2009, 14:47 +0100 schrieb Daniel Fischer:
Am Montag, 19. Januar 2009
What guidelines should one follow to make Haskell code least-strict?
--
Robin
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Robin Green wrote:
What guidelines should one follow to make Haskell code least-strict?
Obviously the use of seq and bang-patterns make code more strict.
Code is strict when it evaluates values to determine a pattern match. So
avoiding that makes code lazier. Values are evaluated when
C:\Documents and Settings\Administratorcabal install plugins
Resolving dependencies...
cabal: dependencies conflict: ghc-6.10.1 requires Cabal ==1.6.0.1 however
Cabal-1.6.0.1 was excluded because plugins-1.3.1 requires Cabal ==1.4.*
2009/1/19 Alberto G. Corona agocor...@gmail.com
I finally
Do really pluigins needs Cabal (=1.4 1.5) ???
C:\Documents and Settings\Administratorcabal install plugins
Resolving dependencies...
cabal: dependencies conflict: ghc-6.10.1 requires Cabal ==1.6.0.1 however
Cabal-1.6.0.1 was excluded because plugins-1.3.1 requires Cabal ==1.4.*
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA512
2009/1/19 Alberto G. Corona :
-BEGIN PGP SIGNATURE-
Version: GnuPG v1.4.9 (GNU/Linux)
iEYEAREKAAYFAkl0uKYACgkQvpDo5Pfl1oJ30wCfQzX80TulZxyyLLyaAcU/LPVc
PPMAoJl8tjhfrlWwoQ9yVGXlXStMDs+O
=lf6T
-END PGP SIGNATURE-
Do really pluigins
On Mon, Jan 19, 2009 at 4:48 PM, Robin Green gree...@greenrd.org wrote:
What guidelines should one follow to make Haskell code least-strict?
There was a great Cafe discussion started by Henning on just this. He
provided this link:
http://www.haskell.org/haskellwiki/Maintaining_laziness
As a side curiosity, I would love to see an example of any data structure
which has more than one Functor instance. Especially those which have
more than one useful functor instance.
data Record a b = R { field1 :: a, field2 :: b }
If I want to use fmap to transform either field, I have to
Quoth Neil Mitchell ndmitch...@gmail.com:
Is there a Haskell-Expect module? Something that would allow me to
control an external Unix program via its stdin/stdout/stderr?
System.Process does what you want, I think:
It might not. Expect uses pseudottys (cf. openpty()), and select().
The cabal file still includes the vty dependency, but simply removing it
made it compile.
--
From: Simon Michael si...@joyful.com
Sent: Sunday, January 18, 2009 7:04 PM
To: Sebastian Sylvan sebastian.syl...@gmail.com
Cc: hled...@googlegroups.com;
agocorona:
Do really pluigins needs Cabal (=1.4 1.5) ???
C:\Documents and Settings\Administratorcabal install plugins
Resolving dependencies...
cabal: dependencies conflict: ghc-6.10.1 requires Cabal ==1.6.0.1 however
Cabal-1.6.0.1 was excluded because plugins-1.3.1 requires
On 2009 Jan 19, at 3:47, Neil Mitchell wrote:
Is there a Haskell-Expect module? Something that would allow me to
control an external Unix program via its stdin/stdout/stderr?
System.Process does what you want, I think:
Is anyone else interested in forming a Haskell WikiProject on Wikipedia,
to collaborate on improving and maintaining the coverage and quality of
articles on Haskell-related software and topics (broadly defined)? Not
just programming topics specific to Haskell, but also ones of interest
to the
On Mon, 19 Jan 2009 17:36:30 +
Thomas DuBuisson thomas.dubuis...@gmail.com wrote:
On Mon, Jan 19, 2009 at 4:48 PM, Robin Green gree...@greenrd.org
wrote:
What guidelines should one follow to make Haskell code least-strict?
There was a great Cafe discussion started by Henning on just
greenrd:
Is anyone else interested in forming a Haskell WikiProject on Wikipedia,
to collaborate on improving and maintaining the coverage and quality of
articles on Haskell-related software and topics (broadly defined)? Not
just programming topics specific to Haskell, but also ones of
Hello,
The multitude of newtypes in the Monoid module are a good indication
that the Monoid class is not a good fit for the class system (it is
ironic that discussing it resulted in such a huge thread recently :-).
How I'd approach the situation that you describe would depend on
the context
Manlio Perillo wrote:
Brandon S. Allbery KF8NH ha scritto:
...in theory. In practice GHC needs help with circular imports, and
some cycles might be impossible to resolve.
This is interesting.
Where can I find some examples?
Is this explained in the Real World Haskell book?
I have no
* Robin Green gree...@greenrd.org [2009-01-19 18:46:43+]
Here's a good example to start with. The article on Eager evaluation
could do with some improvement - and possibly should be merged into the
Lazy evaluation article, I'm not sure:
http://en.wikipedia.org/wiki/Eager_evaluation
I
On Mon, 2009-01-19 at 10:59 -0800, Iavor Diatchki wrote:
Hello,
The multitude of newtypes in the Monoid module are a good indication
that the Monoid class is not a good fit for the class system
I would say rather that the class system is not a good fit for Monoid.
Proposals for local
On Fri, Jan 16, 2009 at 06:42:46AM -0800, eyal.lo...@gmail.com wrote:
Closed-unqualified import:
import Data.Map(Map, lookup)
One problem with this style is that you can get lots of conflicts from
your VCS if you have multiple people working on the same module.
Thanks
Ian
Donn Cave wrote:
Quoth Neil Mitchell ndmitch...@gmail.com:
Is there a Haskell-Expect module? Something that would allow me to
control an external Unix program via its stdin/stdout/stderr?
System.Process does what you want, I think:
It might not. Expect uses pseudottys (cf.
rocon...@theorem.ca wrote:
I noticed the Bool datatype isn't well documented. Since Bool is not
a common English word, I figured it could use some haddock to help
clarify it for newcomers.
My only problem with it is that it's called Bool, while every other
programming language on Earth
Is it possible to earn money using Haskell? Does anybody here actually
do this?
Inquiring minds want to know... ;-)
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http://www.haskell.org/mailman/listinfo/haskell-cafe
http://www.haskell.org/haskellwiki/Haskell_in_industry could be of interest
to you
On Mon, Jan 19, 2009 at 2:34 PM, Andrew Coppin
andrewcop...@btinternet.comwrote:
Is it possible to earn money using Haskell? Does anybody here actually do
this?
Inquiring minds want to know... ;-)
On Mon, 2009-01-19 at 19:33 +, Andrew Coppin wrote:
rocon...@theorem.ca wrote:
I noticed the Bool datatype isn't well documented. Since Bool is not
a common English word, I figured it could use some haddock to help
clarify it for newcomers.
My only problem with it is that it's
On Mon, Jan 19, 2009 at 11:34 AM, Andrew Coppin andrewcop...@btinternet.com
wrote:
Is it possible to earn money using Haskell? Does anybody here actually do
this?
Inquiring minds want to know... ;-)
I'm using it at work in simulations... not shipping anything with it yet,
but we do ship
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA512
On Mon, Jan 19, 2009 at 1:46 PM, Robin Green wrote:
Is anyone else interested in forming a Haskell WikiProject on Wikipedia,
to collaborate on improving and maintaining the coverage and quality of
articles on Haskell-related software and topics
Barclays Capital use it for Equity Derivative modeling and pricing - it's a
small team at the moment, but the whole project is in Haskell.
I don't work on it myself so I couldn't give you any details (plus I would
get fired for blabbing!), I work in an adjacent group. Haskell certainly
lends
And of course, there's at least half a dozen people on this list at
working at Galois.
And all documented on the wiki,
http://haskell.org/haskellwiki/Haskell_in_industry
See you guys at CUFP 09!
http://cufp.galois.com/
-- Don
pbeadling:
Barclays Capital use it for Equity
Hi,
On Mon, Jan 19, 2009 at 11:06 AM, Jonathan Cast
jonathancc...@fastmail.fm wrote:
On Mon, 2009-01-19 at 10:59 -0800, Iavor Diatchki wrote:
Hello,
The multitude of newtypes in the Monoid module are a good indication
that the Monoid class is not a good fit for the class system
I would say
This is one of the shortcomings of haskell not to mention other programming
languages. Mathemathicist would find it very annoying.
Instead of
instance Monoid Integer where
mappend = (+)
mempty = 0
instance Monoid Integer where
mappend = (*)
mempty = 1
which is not legal and the
On Mon, Jan 19, 2009 at 9:10 AM, ChrisK hask...@list.mightyreason.com wrote:
Consider that the order of pattern matching can matter as well, the simplest
common case being zip:
zip xs [] = []
zip [] ys = []
zip (x:xs) (y:ys) = (x,y) : zip xs ys
If you are obsessive about least-strictness
On Mon, Jan 19, 2009 at 11:33 AM, Andrew Coppin
andrewcop...@btinternet.com wrote:
My only problem with it is that it's called Bool, while every other
programming language on Earth calls it Boolean. (Or at least, the languages
that *have* a name for it...)
Python: bool
ocaml: bool
C++: bool
On Mon, 2009-01-19 at 12:10 -0800, Iavor Diatchki wrote:
I usually
avoid using the newtype trick as I find it inconvenient: usually
the newtype does not have the same operations as the underlying type
and so it cannot be used directly, and if you are going to wrap thing
just when you
On Mon, 2009-01-19 at 21:18 +0100, Alberto G. Corona wrote:
This is one of the shortcomings of haskell not to mention other
programming languages. Mathemathicist would find it very annoying.
Instead of
instance Monoid Integer where
mappend = (+)
mempty = 0
instance Monoid
---
Haskell Weekly News
http://sequence.complete.org/hwn/20090119
Issue 101 - January 19, 2009
---
Welcome to issue 101 of HWN, a newsletter covering
Haskell's all I use at work, although no-one requires it. I know that
Ravi Nanavati's company uses Haskell pretty exclusively, and there's
also Galois and a couple of financial houses. I was pretty impressed
with the professional turnout for ICFP 2008.
-- Jeff
On Mon, Jan 19, 2009 at 2:34 PM,
I'd prefer something like
Sum :: Monoid Integer
Sum = Monoid {mappend = (+), mempty = 0}
Prod :: Monoid Integer
Prod = Monoid {mappend = (*), mempty = 1}
instance Sum in [some code using mempty and mappend]
On 19 Jan 2009, at 23:18, Alberto G. Corona wrote:
This is one of the shortcomings of
Andrew Coppin wrote:
Is it possible to earn money using Haskell? Does anybody here actually
do this?
Inquiring minds want to know... ;-)
I work for a company that designs, builds, and sells lawn mowers
(hustlerturf.com). We use quite a bit of Haskell, especially as a glue
language for
Is there a reason why the lift function in ReaderT's MonadTrans
instance is implemented as:
instance MonadTrans (ReaderT r) where
lift m = ReaderT $ \_ - m
Instead of just using the monad's return function? Could lift m
be implemented as return m?
instance (Monad m) = Monad (ReaderT
On Mon, Jan 19, 2009 at 01:03:55PM -0800, Daryoush Mehrtash wrote:
lift m = ReaderT $ \_ - m
return a = ReaderT $ \_ - return a
If you look carefully you will see that these are not the same.
-Brent
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LFNW 2009 (http://linuxfestnorthwest.org/) is going to be at the end of
April, and I was wondering if anyone here is going to be there, or possibly a
Haskell-related presentation.
Last year I met ac from #haskell there, but it would be nice if more people
came, especially with the (relatively)
On Mon, Jan 19, 2009 at 01:13:37PM -0800, Jonathan Cast wrote:
(On the other hand, your hunch that lift = return is correct --- so you
get a cookie for that; it's just that return here is neither the return
of the monad for m nor the return of the monad for ReaderT m. It is,
instead, the
Hi all,
I was hoping to introduce my old pal OpenGL
with my new chum, Haskell. I used cabal to
install GLUT on my 64-bit Ubuntu machine with
GHC 6.8.2 (installed via apt-get/synaptic).
I followed the wiki OpenGLTutorial1 until:
ghc -package GLUT HelloWorld.hs -o HelloWorld
at which point my
Have you tried
http://netsuperbrain.com/blog/posts/freeglut-windows-hopengl-hglut/
?
2009/1/20 Paul Keir pk...@dcs.gla.ac.uk:
Hi all,
I was hoping to introduce my old pal OpenGL
with my new chum, Haskell. I used cabal to
install GLUT on my 64-bit Ubuntu machine with
GHC 6.8.2 (installed
Ouch. Sorry, I misread your post: I thought you were having troubles on Windows.
2009/1/20 Eugene Kirpichov ekirpic...@gmail.com:
Have you tried
http://netsuperbrain.com/blog/posts/freeglut-windows-hopengl-hglut/
?
2009/1/20 Paul Keir pk...@dcs.gla.ac.uk:
Hi all,
I was hoping to
On Mon, 2009-01-19 at 21:31 +, Ross Paterson wrote:
On Mon, Jan 19, 2009 at 01:13:37PM -0800, Jonathan Cast wrote:
(On the other hand, your hunch that lift = return is correct --- so you
get a cookie for that; it's just that return here is neither the return
of the monad for m nor the
On Mon, 2009-01-19 at 12:10 -0800, Iavor Diatchki wrote:
Hi,
On Mon, Jan 19, 2009 at 11:06 AM, Jonathan Cast
jonathancc...@fastmail.fm wrote:
On Mon, 2009-01-19 at 10:59 -0800, Iavor Diatchki wrote:
Hello,
The multitude of newtypes in the Monoid module are a good indication
that the
Hi Bjorn, hi list,
the darcswatch instance I’m running is getting quite big, and it
periodically slows down my server. I managed to get quite an improvement
with this simple patch to my parsing:
Erik de Castro Lopo wrote:
Its proabably a little harder to find a company that wants a
Haskell hacker than it is to find a company where Haskell and
other sane languages can be worked in over time.
I think you're probably right about that. ;-)
I mean, heck, *I* use Haskell at work - and
Andrew Wagner wrote:
http://www.haskell.org/haskellwiki/Haskell_in_industry could be of
interest to you
Hmm, interesting... So lots happening in Portland, Oregon. Lots in
Cambridge, MA. A few things in Europe. And nothing at all in the UK...
___
2009/1/19 Paul Keir pk...@dcs.gla.ac.uk:
I was hoping to introduce my old pal OpenGL
with my new chum, Haskell. I used cabal to
install GLUT on my 64-bit Ubuntu machine with
GHC 6.8.2 (installed via apt-get/synaptic).
I'm sorry, I can't help you with your problem. But I'd recommend you
using
Andrew Coppin wrote:
Andrew Wagner wrote:
http://www.haskell.org/haskellwiki/Haskell_in_industry could be of
interest to you
Hmm, interesting... So lots happening in Portland, Oregon. Lots in
Cambridge, MA. A few things in Europe. And nothing at all in the
UK...
We (Credit Suisse) have
I second Ryan's recommendation of using unamb [1,2,3] to give you unbiased
(symmetric) laziness.
The zip definition could also be written as
zip xs@(x:xs') ys@(y:ys') =
assuming (xs == []) [] `unamb`
assuming (ys == []) [] `unamb`
(x,y) : zip xs' ys'
The 'assuming'
On Mon, 2009-01-19 at 21:04 +, Andrew Coppin wrote:
Erik de Castro Lopo wrote:
Its proabably a little harder to find a company that wants a
Haskell hacker than it is to find a company where Haskell and
other sane languages can be worked in over time.
I think you're probably
On Mon, 2009-01-19 at 20:55 +, Andrew Coppin wrote:
Dan Piponi wrote:
On Mon, Jan 19, 2009 at 11:33 AM, Andrew Coppin
andrewcop...@btinternet.com wrote:
My only problem with it is that it's called Bool, while every other
programming language on Earth calls it Boolean. (Or at
I think that your instance is too specific, although useful for the
particular case of escaping.
I've done my own implementation for fun:
concatMap' :: (Word8 - L.ByteString) - L.ByteString - L.ByteString
concatMap' f s = L.unfoldr p x0
where x0 = (LI.Empty, s, 0, 0)
p (LI.Empty,
Actually, I see a nice pattern here for unamb + pattern matching:
zip xs ys = foldr unamb undefined [p1 xs ys, p2 xs ys, p3 xs ys] where
p1 [] _ = []
p2 _ [] = []
p3 (x:xs) (y:ys) = (x,y) : zip xs ys
Basically, split each pattern out into a separate function (which by
definition
What's the status of overlapping/closed type families? I'm interested
in something like the following, which can currently be implemented in
GHC with Oleg-magic using functional dependencies, but cannot, to my
knowledge, be implemented with type families:
data HTrue = HTrue
data HFalse = HFalse
G'day all.
Quoting Jonathan Cast jonathancc...@fastmail.fm:
(By the way, you *do* have the equations
lift (return x) = return x
[...]
Right. And you could, at least in principle, implement return this
way in all monad transformers.
Cheers,
Andrew Bromage
Hmm, interesting... So lots happening in Portland, Oregon. Lots in
Cambridge, MA. A few things in Europe. And nothing at all in the UK...
Nothing in the UK? Lets not forget MSR and Well-Typed!
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G'day all.
On Mon, 2009-01-19 at 19:33 +, Andrew Coppin wrote:
My only problem with it is that it's called Bool, while every other
programming language on Earth calls it Boolean. (Or at least, the
languages that *have* a name for it...)
Jonathan Cast commented:
Except C++?
And
I might go - I'll certainly keep an eye on the page. It would be more
likely if I could find a group driving from Portland.
Tom
On Mon, Jan 19, 2009 at 9:25 PM, Shachaf Ben-Kiki shac...@gmail.com wrote:
LFNW 2009 (http://linuxfestnorthwest.org/) is going to be at the end of
April, and I was
I revisited the Strongly typed Heterogeneous Lists paper and read
about the import hierarchy technique. The basic idea is to delay
importing the instances until as late as possible, which prevents the
context simplification. The instances are effectively imported in the
top, Main module.
I'm
Hi all!
Environment: Windows Vista + SP1, GHC 6.10.1.
Description: If use ghci.exe and run separate ghc.exe compiler
process, memory leak in ghci occurred. After exhausting available
memory Vista has no responding.
Steps for reproduce:
1) After run GHCi, process list has 2 processes:
On Mon, Jan 19, 2009 at 3:04 PM, Andrew Coppin
andrewcop...@btinternet.com wrote:
Like many people I'm sure, I'd like to get paid to code stuff in Haskell.
But I can't begin to imagine how you go about doing that...
At Eaton, we're using Haskell to design automotive control systems
(see
On Mon, Jan 19, 2009 at 7:22 PM, a...@spamcop.net wrote:
And perhaps more to the point, Boolean is an adjective, not a noun.
Therefore, it would be better reserved for a typeclass.
There's also John Meacham's Boolean package.
http://repetae.net/recent/out/Boolean.html
class (Heyting a) =
Such a database would help me counter by boss's
argument that it's impossible to find and hire Haskell programmers.
Err, people actually say such things? And they say _we're_ out of touch with
the real world?
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On Mon, Jan 19, 2009 at 6:25 PM, David Menendez d...@zednenem.com wrote:
Are there any instances of Boolean that aren't isomorphic to Bool?
a-Bool for any a. I think.
Though I think it should be called GeorgeBoolean otherwise we might
confuse it for something his father might have invented.
--
G'day all.
Quoting David Menendez d...@zednenem.com:
Are there any instances of Boolean that aren't isomorphic to Bool?
Sure. Two obvious examples:
- The lattice of subsets of a universe set, where or is union
and is intersection and not is complement with respect to the
universe.
-
G'day all.
I wrote:
- Intuitionistic logic systems.
- The truth values of an arbitrary topos (i.e. the points of the
subobject classifier).
Sorry, I misread the question. These are _not_ instances of Boolean
(or at least the latter isn't an instance in general).
Cheers,
Andrew Bromage
On 17 jan 2009, at 22:22, Derek Elkins wrote:
On Thu, 2009-01-15 at 13:40 +0100, Apfelmus, Heinrich wrote:
Eugene Kirpichov wrote:
Well, your program is not equivalent to the C++ version, since it
doesn't bail on incorrect input.
Oops. That's because my assertion
show . read = id
is
On Mon, 2009-01-19 at 22:12 -0500, S. Doaitse Swierstra wrote:
On 17 jan 2009, at 22:22, Derek Elkins wrote:
On Thu, 2009-01-15 at 13:40 +0100, Apfelmus, Heinrich wrote:
Eugene Kirpichov wrote:
Well, your program is not equivalent to the C++ version, since it
doesn't bail on incorrect
On Thu, 2009-01-15 at 18:10 -0500, Cale Gibbard wrote:
My personal preference would be:
class Monoid m where
zero :: m
(++) :: m - m - m
(in the Prelude of course)
- Cale
I've tried doing this (and making more widespread use of typeclassed
operations) by writing my own
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