Daryoush Mehrtash-2 wrote:
I am not sure I follow how the endofunctor gave me the 2nd functor.
As I read the transformation there are two catagories C and D and two
functors F and G between the same two catagories. My problem is that I
only
have one functor between the Hask and List
The question of which column width is right is not a
revealing one -- there is little technical or scientific basis
to prefer 117 to 80.
The line length that we prefer is similarly unenlightening.
The number of people who, when pushing for column widths
greater than 80, choose 132
Felipe Lessa wrote:
On Wed, Apr 22, 2009 at 12:29:05AM +0300, Matti Niemenmaa wrote:
Good to hear that it works for someone else, too. (I don't have a new
enough version of containers installed myself, after upgrading to
6.10.2.) Just bear in mind that some functions won't work.
What exactly
Really, the whole thing makes me wish we had blasphemy laws.
If any person, in speaking or in writing, shall indicate
a preference for column widths other than 80 or indent
characters other than spaces (`0x20`) they shall be
compelled to present some science or be subject to
Hello,
imagine the following situation: You want to implement e.g. Dijkstra's
algorithm to find a shortest path between nodes u and v in a graph. This
algorithm relies heavily on mutating arrays, so the type signature would
look something like
getDistance :: Graph - Node - Node - IO Int
Not
Hi,
consider the following code:
class Foo f where
type Bar f :: *
type Baz f :: *
from :: Bar f - Baz f
to :: Baz f - Bar f
data Tree a b c
= Empty
| Tree b c (Tree a b c) (Tree a b c)
--singleton :: (Foo f) = Bar f - Tree a (Bar f) (Baz
Yes. Use the ST (State Thread) monad. Data.Array.ST, STRef etc.
2009/4/22 Daniel K. anmeldema...@gmail.com:
Hello,
imagine the following situation: You want to implement e.g. Dijkstra's
algorithm to find a shortest path between nodes u and v in a graph. This
algorithm relies heavily on
You may want to read the comments at
http://hackage.haskell.org/trac/ghc/ticket/1897.
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
If you want to do raw IO and repackage it as pure, you can
use `unsafePerformIO` and friends. It is important to use the
`NOINLINE` pragma in that case.
--
Jason Dusek
|...unsafePerformIO...|
On 22 Apr 2009, at 10:38, Daniel K. wrote:
Hello,
imagine the following situation: You want to implement e.g.
Dijkstra's algorithm to find a shortest path between nodes u and v
in a graph. This algorithm relies heavily on mutating arrays, so the
type signature would look something like
On 22 Apr 2009, at 13:07, Jon Fairbairn wrote:
Miguel Mitrofanov miguelim...@yandex.ru writes:
Well, the problem is that every implementor does choose a
subset of standart to implement.
That's what I'm complaining about.
And that's exactly what you (or anybody else) can't do anything
Hello Jason,
Wednesday, April 22, 2009, 1:14:49 PM, you wrote:
there is no any need in unsafePerformIO for array computations - ST
monad is exactly what one need here
If you want to do raw IO and repackage it as pure, you can
use `unsafePerformIO` and friends. It is important to use the
Miguel Mitrofanov miguelim...@yandex.ru writes:
Well, the problem is that every implementor does choose a
subset of standart to implement.
That's what I'm complaining about.
It's much worse in JavaScript - essential features working
differently in Internet Explorer, Firefox, Opera, and
Does anyone have any comments on the following criticism of some difficulties
with FFI, including IO, in Haskell:
http://groups.google.com/group/comp.lang.functional/msg/6d650c086b2c8a49?hl=en
In particular, is it not always possible to write IO libraries safely in
Haskell?
--
Dr Jon
On Wed, 2009-04-22 at 11:33 +0200, david48 wrote:
The default should at least be consistent among cabal install, runghc
Setup.hs, installing GHC, Gtk2Hs, and so on.
If GHC is installed in /home/myusername/local,
Where you choose to install ghc is not related.
what does cabal install
Jon Harrop wrote:
Does anyone have any comments on the following criticism of some
difficulties with FFI, including IO, in Haskell:
http://groups.google.com/group/comp.lang.functional/msg/6d650c086b2c8a49?hl=en
That post conflates two separate questions.
1) binding to foreign libraries
On Wed, Apr 22, 2009 at 12:32 AM, Duncan Coutts duncan.cou...@worc.ox.ac.uk
wrote:
On Tue, 2009-04-21 at 12:31 +0200, david48 wrote:
For what it's worth, It's bothered me often enough that cabal doesn't
install globally by default that I had to reinstall ghc in order to
solve package
On Wed, Apr 22, 2009 at 12:06 PM, Duncan Coutts duncan.cou...@worc.ox.ac.uk
wrote:
On Wed, 2009-04-22 at 11:33 +0200, david48 wrote:
The default should at least be consistent among cabal install, runghc
Setup.hs, installing GHC, Gtk2Hs, and so on.
If GHC is installed in
Hello Jon,
Wednesday, April 22, 2009, 1:54:58 PM, you wrote:
Does anyone have any comments on the following criticism of some difficulties
with FFI, including IO, in Haskell:
http://groups.google.com/group/comp.lang.functional/msg/6d650c086b2c8a49?hl=en
In particular, is it not always
Am Dienstag, 21. April 2009 17:18 schrieb Patai Gergely:
What about evaluation time? If I remember correctly, the values
of signals depend on the time when the signal expressions are
evaluated. So evaluating them multiple times might lead to
different behavior. Is this correct?
It is.
On Wed, 2009-04-22 at 12:26 +0200, david48 wrote:
On Wed, Apr 22, 2009 at 12:06 PM, Duncan Coutts
duncan.cou...@worc.ox.ac.uk wrote:
On Wed, 2009-04-22 at 11:33 +0200, david48 wrote:
The default should at least be consistent among cabal
install, runghc
The default should at least be consistent among cabal install, runghc
Setup.hs, installing GHC, Gtk2Hs, and so on.
If GHC is installed in /home/myusername/local, what does cabal install
--global ?
___
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
Maurício wrote:
according the several style guides, lines shouldn't be too long
(longer than 78 characters).
Since Haskell is usually nice to parse, wouldn't it be
interesting to replace a pretty printer program for layout
manuals? I saw in your first link that the teacher provided
a tool
On Wed, 2009-04-22 at 12:21 +0200, david48 wrote:
Do you know what the problem was exactly? It's possible to get
problems with overlap between the user and global package dbs,
but the exact same problems can also happen just within the
global package db.
On Wed, Apr 22, 2009 at 1:01 PM, Duncan Coutts
duncan.cou...@worc.ox.ac.ukwrote:
On Wed, 2009-04-22 at 12:21 +0200, david48 wrote:
Lines starting with -- are comments. You need to uncomment the prefix
line for it to have an effect.
Man do I feel dumb now :)
David.
Am Mittwoch 22 April 2009 12:06:37 schrieb Duncan Coutts:
On Wed, 2009-04-22 at 11:33 +0200, david48 wrote:
The default should at least be consistent among cabal install, runghc
Setup.hs, installing GHC, Gtk2Hs, and so on.
If GHC is installed in /home/myusername/local,
Where you choose
On Wed, Apr 22, 2009 at 2:06 PM, Duncan Coutts
duncan.cou...@worc.ox.ac.ukwrote:
On Wed, 2009-04-22 at 11:33 +0200, david48 wrote:
The default should at least be consistent among cabal install, runghc
Setup.hs, installing GHC, Gtk2Hs, and so on.
If GHC is installed in
On Wed, Apr 22, 2009 at 2:49 AM, michael rice nowg...@yahoo.com wrote:
How do I get the x out of Just x?
Hi Michael,
in your code you're using Maybe to inform the caller of safeDivision
about an exceptional situation. This way, you made a full coverage of
all the input cases and nothing is left
Hi Claus,
thanks for your elaborations. I'm still not convinced that a common name
(e.g. TT :. Tr :. Tu :. Te) is a better interface than a common import
(e.g. TypeLevel.Bool.True). In both cases, the authors of all modules
have to actively collaborate, either to define common names, or to
It makes sense, once you understand the terminology.
Thanks.
Michael
--- On Wed, 4/22/09, Cristiano Paris fr...@theshire.org wrote:
From: Cristiano Paris fr...@theshire.org
Subject: Re: [Haskell-cafe] Getting the x out
To: michael rice nowg...@yahoo.com
Cc: haskell-cafe@haskell.org
Date:
Hi Neil,
I just tried out Hoogle for the first time and it works great.
It seems there are a lot of resources available for Haskell; it just takes time
to find out about them and how they work.
Thanks.
Michael
--- On Wed, 4/22/09, Neil Mitchell ndmitch...@gmail.com wrote:
From: Neil
Installing executable(s) in /home/david/.cabal/bin
why the hell would cabal install binaries in a subdirectory of a
hidden directory. Why not /home/david/bin or /home/david/local/bin ?
Yes, this is clearly suboptimal but getting agreement on where to put it
has not proved easy. There are users
Just exploring. How to load?
Michael
[mich...@localhost ~]$ ghci Data.Complex
GHCi, version 6.10.1: http://www.haskell.org/ghc/ :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer ... linking ... done.
Loading package base ... linking ... done.
no location info:
2009/4/22 michael rice nowg...@yahoo.com:
Just exploring. How to load?
Michael
[mich...@localhost ~]$ ghci Data.Complex
GHCi, version 6.10.1: http://www.haskell.org/ghc/ :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer ... linking ... done.
Loading
Tillmann Rendel ren...@cs.au.dk wrote:
Hi Claus,
thanks for your elaborations. I'm still not convinced that a common
name (e.g. TT :. Tr :. Tu :. Te) is a better interface than a common
import (e.g. TypeLevel.Bool.True). In both cases, the authors of all
modules have to actively
Richard O'Keefe o...@cs.otago.ac.nz wrote:
On 21 Apr 2009, at 11:36 pm, Achim Schneider wrote:
Richard O'Keefe o...@cs.otago.ac.nz wrote:
Some of the right questions are
- how many potential whatever users would need to have
whatever installed on _some_ machine they do NOT
That's absurd. You have no way to access private source code, so any
decision on what features to exclude from future versions of Haskell
must necessarily look at publicly accessible source code. The only
alternative is to continuously add, and never remove, features from
Haskell, even
thanks for your elaborations. I'm still not convinced that a common name
(e.g. TT :. Tr :. Tu :. Te) is a better interface than a common import
(e.g. TypeLevel.Bool.True). In both cases, the authors of all modules
have to actively collaborate, either to define common names, or to
define common
Claus Reinke claus.rei...@talk21.com wrote:
[...]
+1. That, and better error messages: A Verbose-Consequences flag in the
config (on by default), resulting in strings like Binaries have been
installed to $HOME/.cabal/bin and _not_ symlinked. $HOME/.cabal/bin is
not in your $PATH: You will not
network. Therefore, duplication and merging of identical
expressions only affects the performance unless they are
hidden in the input signal of a latcher.
But isn't the latter a fundamental problem?
Of course it is, but I said afterwards that this can be resolved by
sampling 'more
in case anyone stumbles over my ad-hoc notations, that should have been:
module A[type label] where x = undefined :: label
module B[type label] where x = undefined :: label
module C[type label] where
import A[label]
import B[label]
ok = [A.x,B.x]
assuming that:
- 'module X[types]' means a
Richard O'Keefe et all wrote:
[n+k patterns]
I'd like to add my two cents: Assuming that UHC's roadmap strives to be
H'-compilant in the future, and n+k patterns aren't going to be in H',
why bother implementing them?
Also, assuming that current H98 code will be ported to H', shouldn't
n+k
Jason Dusek jason.du...@gmail.com wrote:
Really, the whole thing makes me wish we had blasphemy laws.
If any person, in speaking or in writing, shall indicate
a preference for column widths other than 80 or indent
characters other than spaces (`0x20`) they shall be
haxr will no longer compile from cabal because of the dependency
marked HTTP 1.0. The current version of the library requires HTTP
4000.0.0 as it stands. Can it be updated real quick in hackage?
-- Jeff
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Haskell-Cafe mailing list
Another reason for the 80 character limit: some developers have very
poor eyesight, which can be overcome with large monitors and large
fonts. This won't work if you have to scroll the code.
Regards,
John A. De Goes
N-BRAIN, Inc.
The Evolution of Collaboration
http://www.n-brain.net|
I've found that some developers have very poor taste in shirts as well,
therefore Haskell should have a dress code
Sorry I'm not buying 80 characters as a way to address bad eyesight. ;-) I
think there's supposed to be technology in the editors to deal with that...
just as we can try to find
I think you can pass --preference=HTTP==3001.1.5 to cabal-install
0.6.2, try
cabal install haxr --preference=HTTP==3001.1.5
Cheers Christian
Jeff Heard wrote:
haxr will no longer compile from cabal because of the dependency
marked HTTP 1.0. The current version of the library requires HTTP
Hi Jeff,
I have an updated and _seemingly_ working version of the haxr codebase,
but haven't had a chance to test it more than a gentle poke at the tires.
Will see if I can upload commit the bits.
--sigbjorn
On 4/22/2009 07:37, Jeff Heard wrote:
haxr will no longer compile from cabal
I've been working through this example from:
http://en.wikibooks.org/wiki/Haskell/Understanding_monads
I understand what they're doing all the way up to the definition of (), which
duplicates Prelude function (). To continue following the example, I need to
know how to override the Prelude ()
I think
import Prelude hiding (())
does that.
-Ross
On Apr 22, 2009, at 11:44 AM, michael rice wrote:
I've been working through this example from:
http://en.wikibooks.org/wiki/Haskell/Understanding_monads
I understand what they're doing all the way up to the definition of
(), which
You can try at the top
Import Prelude hiding ()
On Wed, Apr 22, 2009 at 10:44 AM, michael rice nowg...@yahoo.com wrote:
I've been working through this example from:
http://en.wikibooks.org/wiki/Haskell/Understanding_monads
I understand what they're doing all the way up to the definition of
On Wed, Apr 22, 2009 at 1:28 PM, Victor Nazarov
asviraspossi...@gmail.comwrote:
Ubuntu/Debian policy seems to be installation into /var/lib/cabal . So it's
clear that the whole hierarchy is managed by single tool cabal. Drawback is
that you should add /var/lib/cabal/bin into your PATH.
I want to use hpc to check that the ASN.1 library tests cover all the code.
When I run it with a set of tests that I *know* don't test certain things, it
reports that they have been covered i.e. there are not coloured in the markup
that hpc produces. I would have expected a lot of yellow.
It
Be aware that the do unsugars to (Prelude.), not your (), even if
you hide (Prelude.):
import Prelude hiding (())
m f = error Call me!
main = putStrLn . show $ do [3,4]
[5]
The desugaring of the do { [3,4]; [5] } is (Prelude.) [3,4] [5] =
[5,5], whereas you might
True enough -- if you really want to redefine the monadic operator,
you have to use
{-# LANGUAGE NoImplicitPrelude #-}
import Prelude hiding ((), (=), return)
or something like it, although Michael's example didn't appear to be
going quite that far.
-Ross
On Apr 22, 2009, at 12:37 PM,
I remember reading some website, that dons (probably) posted once. I'd
like to find them again for a report I'm doing. So, if you know of any
astronomy websites that talk about projects using haskell, please let
me know.
thanks
Michael Litchard
___
2009/4/22 Michael Litchard mich...@schmong.org:
I remember reading some website, that dons (probably) posted once. I'd
like to find them again for a report I'm doing. So, if you know of any
astronomy websites that talk about projects using haskell, please let
me know.
thanks
Michael
2009/04/22 Miguel Mitrofanov miguelim...@yandex.ru:
It's arrogant and disrespectful on the part of the
implementors to say that they know better than the committee
what features should be part of the language.
It's arrogant and disrespectful on the part of the committee
to say that they know
2009/04/22 Achim Schneider bars...@web.de:
Jason Dusek jason.du...@gmail.com wrote:
Really, the whole thing makes me wish we had blasphemy laws.
I'll definitely add it to the list of questions should I ever
conduct a job interview. Just to test how much backing people
have for their zeal.
OK, new release of haxr available via hackage; compilable with ghc-6.10.1
(but may very well have bootstrap issues with 6.10.2 due to 'time'
dependency)
http://hackage.haskell.org/cgi-bin/hackage-scripts/package/haxr
enjoy
--sigbjorn
Sigbjorn Finne wrote:
Hi Jeff,
I have an updated and
On Wed, Apr 22, 2009 at 1:17 PM, Deniz Dogan deniz.a.m.do...@gmail.com wrote:
2009/4/22 Michael Litchard mich...@schmong.org:
Could this be what you meant?
http://www.absoluteastronomy.com/topics/Haskell_(programming_language)
Deniz Dogan
That being just a Wikipedia mirror, seems pretty
On 22 Apr 2009, at 21:19, Jason Dusek wrote:
2009/04/22 Miguel Mitrofanov miguelim...@yandex.ru:
It's arrogant and disrespectful on the part of the
implementors to say that they know better than the committee
what features should be part of the language.
It's arrogant and disrespectful on
On Wed, Apr 22, 2009 at 10:19 AM, Jason Dusek jason.du...@gmail.com wrote:
2009/04/22 Miguel Mitrofanov miguelim...@yandex.ru:
It's arrogant and disrespectful on the part of the
implementors to say that they know better than the committee
what features should be part of the language.
On Mon, Apr 20, 2009 at 8:44 AM, Tillmann Rendel ren...@cs.au.dk wrote:
However, I would prefer the following Coq-like syntax:
data Maybe a =
| Just a
| Nothing
Of course, Coq's inductive syntax is just GADT form:
Inductive Maybe a :=
| Just : a - Maybe a
| Nothing : Maybe a.
data
You can hide () from the implicit import of Prelude using:
import Prelude hiding (())
Kind regards,
Thomas
michael rice wrote:
I've been working through this example from:
http://en.wikibooks.org/wiki/Haskell/Understanding_monads
I understand what they're doing all the way up to the
michael rice wrote:
Got it! I figured there must be some way to unpack it.
If you peek at the thread about getting a value out of IO [1], you will
see some similarities. If you look at my response [2], you will see that
the functions I suggested for IO are exactly the same as the functions
Here's what I get:
[mich...@localhost ~]$ ghci
GHCi, version 6.10.1: http://www.haskell.org/ghc/ :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer ... linking ... done.
Loading package base ... linking ... done.
Prelude import Prelude hiding (())
I've just uploaded version 0.12.1.0 of dataenc with the following (visible)
changes compared to the previous version (0.12):
- implementation of a bunch of new encodings:
- xxencode
- hexadecimal
- quoted-printable
- python escaping
- url encoding
- squashing of a bug in the
On Wed, Apr 22, 2009 at 1:47 PM, michael rice nowg...@yahoo.com wrote:
Here's what I get:
[mich...@localhost ~]$ ghci
GHCi, version 6.10.1: http://www.haskell.org/ghc/ :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer ... linking ... done.
Loading package
On Mon, Apr 20, 2009 at 2:54 PM, Peter Verswyvelen bugf...@gmail.comwrote:
I find this very confusing. Is the documentation of seq wrong (should be
weak head normal form)?
Yes. Weak head normal form is really the only *essential* one. The popular
runtimes do not know how to reduce under a
I was reading the explanation of GADTs on the
wikihttp://en.wikibooks.org/wiki/Haskell/GADT ,
and but can't make any sense of the examples.
Sure I understand what a GADT is, but I'm looking for practical examples,
and the ones on the wiki seem to show what you *cannot* do with them...
For
On Wed, Apr 22, 2009 at 3:30 PM, Peter Verswyvelen bugf...@gmail.comwrote:
I was reading the explanation of GADTs on the
wikihttp://en.wikibooks.org/wiki/Haskell/GADT ,
and but can't make any sense of the examples.
Sure I understand what a GADT is, but I'm looking for practical examples,
Gleb Alexeyev wrote:
You may want to read the comments at
http://hackage.haskell.org/trac/ghc/ticket/1897.
Wow that's subtle... Thanks a lot!
--
Früher hieß es ja: Ich denke, also bin ich.
Heute weiß man: Es geht auch so.
- Dieter Nuhr
___
I'm having difficulty to understand the difference between WHNF and HNF.
Is this
explanationhttp://encyclopedia2.thefreedictionary.com/Weak+Head+Normal+Form
the
correct one? Or is WHNF and HNF equivalent in Haskell land?
The GHC documentation of seq says:
Evaluates its first argument to head
On Wed, Apr 22, 2009 at 2:30 PM, Peter Verswyvelen bugf...@gmail.com wrote:
I was reading the explanation of GADTs on the wiki , and but can't make any
sense of the examples.
Sure I understand what a GADT is, but I'm looking for practical examples,
and the ones on the wiki seem to show what
Yeah that's what I also thought. I tried it first in GHCi, and I got a type
error. I tried it again, and it works now. I must have forgotten to reload
the file or something, cause I made the wrong conclusion. Duh, mea culpa.
On Wed, Apr 22, 2009 at 11:48 PM, Luke Palmer lrpal...@gmail.com wrote:
Here F is the identity functor, and G is the list functor. And yes, C=D=
category of (a subset of) Haskell types.
Are you saying the function that goes from list functor to singleton funtor
is a natural transformation?
But aren't they functors to different subset of Haskell Types?
The Haskell
Am Mittwoch 22 April 2009 23:30:35 schrieb Peter Verswyvelen:
I was reading the explanation of GADTs on the
wikihttp://en.wikibooks.org/wiki/Haskell/GADT ,
and but can't make any sense of the examples.
Sure I understand what a GADT is, but I'm looking for practical examples,
and the ones on
Am Mittwoch 22 April 2009 23:57:08 schrieb Peter Verswyvelen:
I'm having difficulty to understand the difference between WHNF and HNF.
Is this
explanationhttp://encyclopedia2.thefreedictionary.com/Weak+Head+Normal+For
m the
correct one? Or is WHNF and HNF equivalent in Haskell land?
The GHC
On Wednesday 22 April 2009, Peter Verswyvelen wrote:
I'm having difficulty to understand the difference between WHNF and HNF.
Is this
explanationhttp://encyclopedia2.thefreedictionary.com/Weak+Head+Normal+For
m the
correct one? Or is WHNF and HNF equivalent in Haskell land?
The GHC
Peter Verswyvelen wrote:
The GHC documentation of seq says:
Evaluates its first argument to head normal form, and then returns its
second argument as the result.
I think this should be weak head normal form. I don't think you have
any means to evaluate under a binder in Haskell.
The weak in
On Wed, Apr 22, 2009 at 03:14:03PM -0700, Daryoush Mehrtash wrote:
The Haskell Wikibooks also says the same thing:
Functors in Haskell are from Hask to func, where func is the
subcategory of Hask defined on just that functor's types. E.g. the
list functor goes from Hask to Lst,
On Wed, 2009-04-22 at 13:20 +0200, david48 wrote:
On Wed, Apr 22, 2009 at 1:01 PM, Duncan Coutts
duncan.cou...@worc.ox.ac.uk wrote:
On Wed, 2009-04-22 at 12:21 +0200, david48 wrote:
Lines starting with -- are comments. You need to uncomment the
On 22 Apr 2009, at 8:09 pm, Jason Dusek wrote:
Really, the whole thing makes me wish we had blasphemy laws.
If any person, in speaking or in writing, shall indicate
a preference for column widths other than 80 or indent
characters other than spaces (`0x20`) they shall be
Some material I've read on typography -- can't find the
reference now -- suggests ~65 is the best number of characters
per line. The advice was, if your page is larger than that,
you should make columns.
If someone has done some studies with specifically program
text, I'd of course be
OK, I changed the operator from () to (~). When I try to use it I get this:
[mich...@localhost ~]$ ghci rand
GHCi, version 6.10.1: http://www.haskell.org/ghc/ :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer ... linking ... done.
Loading package base ... linking
P.S. We really need such a well written style guide for
haskell. Python has this nice PEP (Python Enhancement
Proposals). Should we start making our own HEP?
We have one: urchin.earth.li/~ian/style/haskell.html
Yes, it's good. We should publicise it more.
Just a tought: I would
michael rice nowg...@yahoo.com wrote:
OK, I changed the operator from () to (~). When I try to use it I
get this:
[mich...@localhost ~]$ ghci rand
GHCi, version 6.10.1: http://www.haskell.org/ghc/__ :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer ...
I'm working from Real World Haskell, trying to install HDBC and
the Sqlite3 driver on Windows XP. It was easy enough to use Cabal
to install HDBC. However, for the Sqlite3 driver things get
fuzzy. I downloaded hdbc-sqlite3_2.1.0.0.zip, but don't know what
I'm supposed to do with it.
Also, it
I'm just copying code from this web page:
http://en.wikibooks.org/wiki/Haskell/Understanding_monads
Using their initial seed I get this:
*Main rollDie 362354 ~ (rollDie ~ rollDie)
interactive:1:0:
Couldn't match expected type `t - (t1, t2)'
against inferred
Claus Reinke wrote:
Installing executable(s) in /home/david/.cabal/bin
why the hell would cabal install binaries in a subdirectory of a
hidden directory. Why not /home/david/bin or /home/david/local/bin ?
Yes, this is clearly suboptimal but getting agreement on where to put it
has not proved
I forgot the type signiture on the last last:
(~) :: (Seed - (a,Seed)) - (Seed - (b,Seed)) - (Seed - (b,Seed))
(~) m n = \seed0 -
let (result1, seed1) = m seed0
(result2, seed2) = n seed1
in (result2, seed2)
With it I get this:
*Main rollDie 362354 ~ (rollDie ~ rollDie)
It's irrelevant, because I _do_ have root access to my machine,
How nice to be you.
Since the argument is entirely about people who _don't_,
your point it?
It is clear that the only sensible default is no default.
Someone else has said it recently and said it much better.
I think the
Maurício wrote:
We have one: urchin.earth.li/~ian/style/haskell.html
Yes, it's good. We should publicise it more.
Just a tought: I would like to see a guide talking about the
code itself, not about the presentation. Maybe this is ignored
because it's difficult. It's easy to get bad code
Richard O'Keefe wrote:
Endusers, of course, might have other preferences, but cabal doesn't
(IMHO) cater to them, directly: It caters to distribution packages (or
windows installers, or whatever), so cabal's default behaviour is quite
irrelevant for those cases.
The clear impression I've
Daryoush Mehrtash-2 wrote:
singleton :: a - [a]
singleton x = [x]
Here F is the identity functor, and G is the list functor. And yes, C=D=
category of (a subset of) Haskell types.
Are you saying the function that goes from list functor to singleton
funtor
is a natural
On 23 Apr 2009, at 2:09 am, John A. De Goes wrote:
That's absurd. You have no way to access private source code,
Right.
so any decision on what features to exclude from future versions of
Haskell must necessarily look at publicly accessible source code.
Wrong. There is no necessarily
On 23 Apr 2009, at 2:24 am, Achim Schneider wrote:
Richard O'Keefe et all wrote:
[n+k patterns]
I'd like to add my two cents: Assuming that UHC's roadmap strives to
be
H'-compilant in the future, and n+k patterns aren't going to be in H',
why bother implementing them?
Haskell' is a
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