Hi Iavor,
In your example using import qualified would also resolve the clash,
although if you were importing two symbols from Text.PrettyPrint you
might like to be able to use the other one unqualified.
In my experience using the current module name for qualification is
pretty rare already, but
The ... foo ... in my example was intended to show that module M does
look up 'foo'.
From: Manuel M T Chakravarty [mailto:c...@cse.unsw.edu.au]
Sent: 25 July 2012 08:26
To: Sittampalam, Ganesh
Cc: Lennart Augustsson; Haskell Prime
Subject: Re: Proposal: Scoping rule change
If Lennart's
rather than being imported from I
- but as it doesn't avoid the need for them in general I'm not sure that
it is worth it.
Ganesh
From: Manuel M T Chakravarty [mailto:c...@cse.unsw.edu.au]
Sent: 25 July 2012 10:25
To: Sittampalam, Ganesh
Cc: Lennart Augustsson; Haskell Prime
Subject: Re
If you're using unqualified and unrestricted imports, there's still the
risk that another module will export something you care about, e.g.
module M where
import I -- currently exports foo
import J -- might be changed in future to export foo
... foo ...
So I think you need to use
Hi,
If I build the code below with -DVER=2, I get a complaint about
PatchInspect (PrimOf p) being missing from the context of
cleverNamedResolve.
This doesn't happen with -DVER=1 or -DVER=3
I presume that type class resolution is operating slightly differently
in the different cases, but it's
Simon Marlow wrote:
Hopefully that explains why sometimes we make breaking changes. If
the
breaking change has a high enough impact, then it becomes worthwhile
to
add backwards compatibility (via warnings / deprecation or whatever).
Of course from the point of view of the user, the
John Smith wrote:
I would like to formally propose that Monad become a subclass of
Applicative, with a call for consensus by 1 February.
I would prefer that we have some proposal like class aliases implemented
before we start fundamental restructuring of basic type classes. This
would help to
Mitar wrote:
Hi!
On Thu, Sep 23, 2010 at 2:19 PM, Christian Maeder
christian.mae...@dfki.de wrote:
I tend to introduce artificial error cases for the Impossible, to
avoid warnings, although the compiler generated error messages are
better to locate the problem.
But this is often
Hi,
I've just been updating darcs 2.5 for GHC 7.0. I had to add about 40
signatures for MonoLocalBinds in about 140 files/30K LOC. Is that about
normal? darcs does make fairly heavy use of rank 2 polymorphism which
leads to quite a lot of local definitions needing to be polymorphic.
Also,
Simon Marlow wrote:
On 02/11/2010 07:37, Sittampalam, Ganesh wrote:
I've just been updating darcs 2.5 for GHC 7.0. I had to add about 40
signatures for MonoLocalBinds in about 140 files/30K LOC. Is that
about normal? darcs does make fairly heavy use of rank 2 polymorphism
which leads to quite
Conor McBride wrote:
Is there some way I can get some more static linking to happen?
I did poke about online a bit and found some remarks to the effect
that GHC got so much more portable after switching to the dynamic
libffi. That sounds great, but tough luck for me.
So, being both
Bit Connor wrote:
On Sat, Oct 16, 2010 at 10:29 AM, Claus Reinke
claus.rei...@talk21.com wrote:
After it catches this error, the function returns (line 376):
return (fail (show e))
The fail is running in the Either monad (The Result type =
Either). This calls the default Monad
Vincent Hanquez wrote:
On Fri, Oct 08, 2010 at 12:54:48PM +0100, Sittampalam, Ganesh wrote:
What's the motivation for this?
Well, I wanted to have a tls/ssl module that integrate nicely with
haskell.
until then the 2 solutions were:
- shelling out to curl: that's not great, usually
Vincent Hanquez wrote:
On Fri, Oct 08, 2010 at 11:14:01AM +0530, C K Kashyap wrote:
Does native mean Haskell only - without FFI?
Native means the implementation is in haskell, and the library is not
using another implementation (in another language) to do the work:
either through FFI as a
Johannes Waldmann wrote:
Is there a conversion guide for switching from base-3 to base-4?
I noticed that ghc-HEAD (6.13) comes with base-4.3 (and no base-3).
This will break an awful lot of packages (?), in fact the breakage
starts with cabal-install (since it depends on HTTP which depends
Ketil Malde wrote:
Robin KAY komad...@gekkou.co.uk writes:
the redirects and ignore the original URLs [2]. Using a 302 Found
redirect instead might produce better results, at least for Google
But the page you point to suggests 302 is discouraged, and says they
don't help for the other
Mark Wotton wrote:
Perhaps cabal should print a warning if you have a Setup.hs file,
_and_ try to use Simple? It'd at least give the hint that they're
unhappy together.
I think it should instead verify that Setup.hs is consistent with a
Simple build. I don't know how much variation exists,
Simon Peyton-Jones wrote:
A new Job entitles 'WANTED Haskell Developer - Investment Banking -
Openings in London, NY and Asia' has been submitted by Carrington Fox
(http://cufp.org/user/121). It will remain unavailable to general
users until it is reviewed and published by one of our
Stephen Tetley wrote:
I suspect the difference between the ML module system vs. typeclasses
will be as important as lazy vs. strict. As a style point, Ocaml
programmers don't seem too prone to combinator mania - so I think
golf is a bit less popular over there.
Both the lack of laziness
Sebastian Fischer wrote:
Dear GHC experts,
Certain behaviour when using
{-# LANGUAGE GADTs, TypeFamilies #-}
surprises me. The following is accepted by GHC 6.12.1:
data GADT a where
BoolGADT :: GADT Bool
foo :: GADT a - a - Int
foo BoolGADT True = 42
Sebastian Fischer wrote:
With GADTs, the specific choice of constructor is what gives you the
type matching functionality.
My intention was to use a GADT as data family instance (hence, I
wrote it in GADT style and it was accepted as such). Can't GADTs be
used as data family instances?
Simon Marlow wrote:
I came to the conclusion that counting nesting layers doesn't solve
the problem: the wormhole still exists in the form of nested unmasks.
That is, a library function could always escape out of a masked
context by writing
unmask $ unmask $ unmask $ ...
enough
Ivan Miljenovic wrote:
5) No-one is convincing anyone else to their point of view, so we
have a stale mate.
Would allowing pseudonyms but requiring them to be explicitly marked as
such be an acceptable compromise?
Ganesh
Günther Schmidt wrote:
Is there a listing of sorts for all Haskell-relevant blogs?
http://planet.haskell.org
Ganesh
===
Please access the attached hyperlink for an important electronic
communications disclaimer:
Try darcs optimize --reorder in your repo, or pull your patch into a freshly
got repo. (Annoying internal detail of darcs - it probably won't use the tag
unless it's clean, which requires that any patches not included in the tag
should be after it in the repo order)
-Original Message-
Nick Bowler wrote:
*** Idea #3 ***
Use a multi-parameter type class:
We couldn't go down this route until MPTCs themselves are added to the
language, which I think is unlikely to be soon as the whole fundeps/type
families issue is still unresolved.
Ganesh
Lennart Augustsson wrote:
Of course unary minus should bind tighter than any infix operator.
I remember suggesting this when the language was designed, but the
Haskell committee was very set against it (mostly Joe Fasel I think).
Are there archives of this discussion anywhere?
Cheers,
Tom Lokhorst wrote:
Also, I wonder if there is some efficient way of implementing the
Lazy class, perhaps by having the Force method using runtime code
generation to override itself. I don't know if this is possible, but
I vaguely remember the Dynamic Language Runtime on .NET doing
something
Gwern Branwen wrote:
On Wed, Feb 3, 2010 at 8:14 PM, Henk-Jan van Tuyl hjgt...@chello.nl
wrote:
On Wed, 03 Feb 2010 23:34:34 +0100, Neil Mitchell
ndmitch...@gmail.com
wrote:
Hi Gwern,
Please update: haskell-src-exts - haskell-src **Unknown**
This project was an unqualified success.
The problem with interfaces as a replacement for type classes is that
they only provide dispatch based on the specific type of the first
argument (i.e. the receiver).
Type classes allow you to dispatch based on return type, and on the
instantiations of generic parameters. Neither of these things
Ivan Lazar Miljenovic wrote:
Martijn van Steenbergen mart...@van.steenbergen.nl writes:
Another solution is to build your applications using Cabal and
specify your dependency on mtl in the cabal file.
But until we have cabal ghci, this completely fails for actual
hacking purposes...
Just
Obviously source code documentation would be nice, but why is it
show-stopping?
Ivan Lazar Miljenovic wrote:
I really feel that bug 1720 [1] is a show-stopping bug for darcs,
especially since it means that building Haddock for darcs with
GHC-6.12.* isn't possible.
[1]
\a b - Left a `amb` Right b
From: haskell-cafe-boun...@haskell.org
[mailto:haskell-cafe-boun...@haskell.org] On Behalf Of Jamie Morgenstern
Sent: 21 December 2009 16:50
To: Benedikt Huber
Cc: haskell-cafe@haskell.org
Subject: [Haskell-cafe] Re: no sparks?
Thank
Dave Bayer wrote:
There's clearly something wrong with this picture. A Rorschach blot
test as to what's wrong, but I see people overreaching, if I have to
wait weeks for a simple install tool, then months for the Haskell
Platform to be ready.
Hopefully future GHC releases will go more
Gregory Crosswhite wrote:
Tom Tobin wrote:
The 3 clause BSD license is officially a GPL compatible license.
See:
http://www.gnu.org/licenses/license-list.html#GPLCompatibleLicenses
It is within the terms of the GPL to link GPL code to a bunch of BSD3
code as long as you abide by
Simon Marlow wrote:
This is a game for the whole family! We don't care how much progress
you make on each ticket, just as long as someone has taken a look and
moved the ticket forward in some way. For example, you might check
for duplicates, update the metadata, ask for more information
To install a package from local sources, just run 'cabal install' in the
directory with the package's .cabal file.
Tony Morris wrote:
I don't want to have to upload every time I make a minor change as I
am working. Surely there is an easier way.
Martijn van Steenbergen wrote:
Tony Morris
Ross Paterson wrote:
On Mon, Nov 02, 2009 at 02:05:01PM +, Simon Marlow wrote:
You need array 0.3.0.0 which comes with GHC 6.12rc1, but is
(probably) not on Hackage yet.
No it isn't: array-0.3.0.0 will be defined by what's released in GHC
6.12.
That creates a timing problem, given that
Ian Lynagh wrote:
You already have the array 0.3.0.0 package if you installed the RC.
The problem is that the darcs.cabal file says: build-depends:
[...] array = 0.1 0.3,
[...]
so it's not using it.
Oh, I see. Sorry for the noise - I got
Simon Peyton-Jones wrote:
Fortunately, I don't think a lot of people use the feature in anger.
Please yell if you *are* using impredicative polymorphism for
something serious. But if you are, we need to think of a workaround.
The current situation seems unsustainable.
I think darcs is
Simon Marlow wrote:
The current dilemma we're facing with the 6.12.1 release is this:
cabal-install still needs to be ported to the new version of Cabal,
Duncan is snowed under and doesn't have time to work on it, but
without cabal-install people can't easily test 6.12.1 RC and we can't
test
Martijn van Steenbergen wrote:
wren ng thornton wrote:
Another nice
thing this suggests is the ability to use underscore as a pattern for
when you know the compiler will infer the type but it's too complex
to want to write out (e.g. while experimenting).
I'd love this!
F# has this and I
I think Sigbjorn's binding (http://haskell.forkio.com/dotnet/
http://haskell.forkio.com/dotnet/ as linked below) is the most
complete and likely to work, but it's still just a binding not a
compiler backend.
From: haskell-cafe-boun...@haskell.org
Neil Brown wrote:
Can anyone tell me how to fix this? I don't think that changing to
always use Control.Exception would fix this, because I need to give a
different type for catch in base-3 to base-4, so there's still the
incompatibility to be dealt with.
Simon Marlow wrote:
I suggest if we stick with the independent repo approach that we have
some automation to check that changes are indeed getting pushed
upstream.
Agreed. Can you think of an easy way to automate it?
How about a cronjob that runs
darcs send upstream-repo --to=some-list
Simon Marlow wrote:
On 27/08/2009 11:18, Sittampalam, Ganesh wrote:
Simon Marlow wrote:
I suggest if we stick with the independent repo approach that we
have some automation to check that changes are indeed getting
pushed upstream.
Agreed. Can you think of an easy way to automate
Simon Marlow wrote:
Simon Marlow wrote:
I suggest if we stick with the independent repo approach that we
have some automation to check that changes are indeed getting
pushed upstream.
[snip unhelpful suggestion from me]
Yes, it tells you that you've screwed up, rather than telling you
Hi,
Just to chime in with the spate of job advertisements, the Global Modelling and
Analytics Group (GMAG) at Credit Suisse is once again looking to hire
functional programmers.
The group consists of about 130 people worldwide. The majority of the group are
mathematicians engaged in
Hi,
Just to chime in with the spate of job advertisements, the Global Modelling and
Analytics Group (GMAG) at Credit Suisse is once again looking to hire
functional programmers.
The group consists of about 130 people worldwide. The majority of the group are
mathematicians engaged in
What would preOrder foldr/foldl mean? What about preOrder (reverse . map) and
preOrder (map . reverse) ?
Another option would be for map to take a strategy as a parameter, sort of
like Control.Parallel.Strategies.
Peter Verswyvelen wrote:
Well, in DDC I believe the order is left to right.
Cale Gibbard wrote:
There was a great related idea on #haskell the other day: Make
explicit qualification unnecessary whenever there is a *unique*
choice of module qualifications from those imported which would make
the expression typecheck. Ambiguities would still need to be
qualified, but
(To be clear, this about Cale's proposal, not simonpj's one)
Johannes Waldmann wrote:
Sittampalam, Ganesh wrote:
... it would make it substantially less likely that subexpressions
could be abstracted into a separate declaration without giving a type
signature to fix the type of the new
perms = sortByM (const [True,False])
This doesn't seem right, since the comparison function is inconsistent
and moreover the results will depend on the sorting algorithm chosen.
Ganesh
===
Please access the attached
Sebastian Fischer wrote:
On Jul 28, 2009, at 11:06 AM, Sittampalam, Ganesh wrote:
perms = sortByM (const [True,False])
and moreover the results will depend on the sorting algorithm chosen.
Is it only that different sorting algorithms enumerate all
permutations in different orders
Ian Lynagh wrote:
Hi all,
I've made a ticket and proposal page for making the labelled field
syntax stricter, e.g. making this illegal:
data A = A {x :: Int}
y :: Maybe A
y = Just A {x = 5}
+1: The precedence here is an ugly wart. It's particularly annoying when
teaching
Niklas Broberg wrote:
I believe, Language.Haskell.Pretty can properly output haskell code
(and the GHC API should be able to do so, too. Does the GHC API
output tabs?)
Surely you mean Language.Haskell.Exts.Pretty, right? ;-)
The haskell-src-exts library does not (yet) support full
One can use the following style of GADT definition, which avoids the
type variables in the declaration:
{-# LANGUAGE GADTs, KindSignatures #-}
module GADT where
data Foo :: * - * where
Foo :: Int - Foo Int
Iavor Diatchki wrote:
Hello,
Sorry for responding so late---I just saw the thread.
Roel van Dijk wrote:
On Mon, Jul 20, 2009 at 1:27 PM, Roel van
Dijkvandijk.r...@gmail.com wrote:
I think the tuple sections are a great idea! It also makes tuple
types and constructors more alike:
x :: (,) String Double
x = (,) Pi 3.14159
I just realised this is already in GHC :-) But
Bulat Ziganshin wrote:
Hello Ganesh,
Tuesday, July 14, 2009, 11:59:00 AM, you wrote:
I don't have any strong opinion about whether there should be a
library standard or not, but if there is a standard, how about
putting the entire thing (perhaps including the Prelude) under the
prefix
Simon Marlow wrote:
On 20/06/2009 21:46, Ganesh Sittampalam wrote:
If I'm right, is it really sensible for every handle to have this
finalizer? Closing a pipe has externally visible side effects beyond
just the release of resources, so it doesn't seem like it should
happen
Duncan Coutts wrote:
Niklas's and my point is
that the list of language extensions in Language.Haskell.Exceptions
are differences from H98 so it should be MonoPatBinds to get the
difference not NoMonoPatBinds to restore H98.
In practise, since ghc uses MonoPatBinds by default it'd
Martijn van Steenbergen wrote:
Consider the function inTwain that splits a list of even length
evenly into two sublists:
inTwain Hello world!
(Hello ,world!)
Is it possible to implement inTwain such that the recursion is done
by one of the standard list folds?
Does this help?
There are multiple possible classes that you might want under different
circumstances (I think the most interesting issue is whether the class
(==), () etc is in has a fundep from the type of the thing being
compared to the type of the boolean), but if NoImplicitPrelude (or some
other extension)
Sebastiaan Visser wrote:
On May 27, 2009, at 1:49 AM, Conal Elliott wrote:
Hi Tom,
I've been working on another code-generating graphics compiler,
generating GPU code. As always, I run into the problem of efficient
common subexpression elimination. In Pan, Vertigo Pajama, I used
lazy
Elliott
Sent: 27 May 2009 16:14
To: Sittampalam, Ganesh
Cc: Haskell Cafe
Subject: Re: [Haskell-cafe] I love purity, but it's killing me.
In my experience [1], observable sharing using GHC's stable
names is a pretty effective solution to this problem.
Plus unsafePerformIO and weak references
Simon Peyton-Jones wrote:
NoMatchErr.hs:20:11:
Couldn't match expected type `Memo d'
against inferred type `Memo d1'
NB: `Memo' is a (non-injective) type function
In the second argument of `(.)', namely `appl'
In the expression: abst . appl
In the
Nicolas Pouillard wrote:
Excerpts from Ryan Ingram's message of Tue May 19 10:23:01 +0200 2009:
To be fair, you can do this with some extensions; I first saw this in
a paper on Oleg's site [1]. Here's some sample code:
This seems like the same trick as the rmonad package:
Martin Hofmann wrote:
It is pretty clear, that the following is not a valid Haskell pattern:
foo (x:x:xs) = x:xs
My questions is _why_ this is not allowed. IMHO, the semantics should
be
clear: The pattern is expected to succeed, iff 'x' is each time bound
to the same term.
How do you
Conor McBride wrote:
On 15 May 2009, at 09:11, Sittampalam, Ganesh wrote:
but then pattern matching can introduce Eq constraints which some
might see as a bit odd.
Doesn't seem that odd to me. Plenty of other language features come
with constraints attached.
It's the introduction
Peter Gammie wrote:
On 13/05/2009, at 6:43 PM, Bayley, Alistair wrote:
From: glasgow-haskell-users-boun...@haskell.org
[mailto:glasgow-haskell-users-boun...@haskell.org] On Behalf Of
Peter Gammie
The semantics I want is:
- use the Cabal-built objects/hi files in dist/build if they're
rocon...@theorem.ca wrote:
I think that use of the mtl should be deprecated so that we move on
to improved monad transformer libraries. Having the mtl in the
Haskell Platform does the opposite by further entrenching its use,
possibly to the point where we may not be able to get rid of it for
Wolfgang Jeltsch wrote:
Am Freitag, 8. Mai 2009 18:43 schrieb Jason Dagit:
If you wanted to work on this, I would encourage you to read more
about patch theory[1,2,3,4] and also try out libdarcs[5].
Is libdarcs the same as the darcs library package on Hackage (which
exports the darcs API)?
Brandon S. Allbery KF8NH wrote:
On May 8, 2009, at 16:31 , Sittampalam, Ganesh wrote:
Brandon S. Allbery KF8NH wrote:
Unless it catches exceptions itself (which strikes me as a bad idea;
it becomes a trivial way to ignore exceptions, leading to bad
programming practices) either they're
Stephan Friedrichs wrote:
When looking for an xor function, I found one in Data.Bits but
couldn't use it for Bool, because Bool is no instance of Bits and of
Num (which would be necessary, because it's class (Num b) = Bits
b). My question is: Why not?
[...]
quite trivial... Why is this
Brandon S. Allbery KF8NH wrote:
On May 8, 2009, at 01:33 , Joe Fredette wrote:
That strikes me as being bad in a I'm violating the Halting Problem
sort of way- but I'm not sure how. Is there some contradictory
construction that could be built from such a function?
I don't think it is;
Brandon S. Allbery KF8NH wrote:
On May 8, 2009, at 13:08 , Sittampalam, Ganesh wrote:
Brandon S. Allbery KF8NH wrote:
and therefore must be in IO. You may be thinking that it would
return a result for _|_, but as described if you fed it _|_ it could
only produce False (if the _|_ has been
seq something like size map that will force a traversal of the entire
tree, and ensure that the result is actually demanded, e.g. when writing
to a TVar:
do ...
let map' = Data.Map.delete key map
size map' `seq` writeTVar tvar map'
...
(Not tested)
Note that this also won't force any
Do your profiling builds with -osuf p_o -hisuf p_hi, and then run a
non-profiling build first. This means that both sets of object/hi files are
available which placates TH.
Ganesh
From: haskell-cafe-boun...@haskell.org
Ryan Ingram wrote:
There was
another talk about compiling Haskell into Excel spreadsheets for
finance, but I can't seem to locate it right now.
It was an ICFP experience report.
http://www.earth.li/~ganesh/research/paradise-icfp08
Ganesh
Richard O'Keefe wrote:
The thing is that it really seems bizarre to see this one feature
singled out for non-implementation.
If I can do the equivalent of n+k patterns by programming in the
*type system*, why *not* in a pattern?
Do you mean by something like the following?
data Z = Z
Jon Fairbairn wrote:
John A. De Goes j...@n-brain.net writes:
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.
This is all entirely beside the
Jon Fairbairn wrote:
Sittampalam, Ganesh ganesh.sittampa...@credit-suisse.com writes:
So I would say that {Haskell 98 - (n+k)} is itself a worthwhile
standard to implement.
It's not a standard. You have to document the difference (waste of
time), programmers have to notice the difference
Miguel Mitrofanov wrote:
Jon Fairbairn wrote on 20.04.2009 13:59:
Achim Schneider bars...@web.de writes:
Jon Fairbairn jon.fairba...@cl.cam.ac.uk wrote:
a...@cs.uu.nl writes:
Utrecht Haskell Compiler -- first release, version 1.0.0
I have this problem too, but I don't understand it because
librsvg-2-2.dll is in the same directory as the rest of the gtk2hs DLLs
- c:/gtk2hs/0.10.0/bin on my system. Yesterday I was also having trouble
with not being able to find the glib DLL but that problem has
mysteriously vanished today
Robin Green wrote:
I am writing some code for citation support in gitit, and all the
#ifdefs I'm using to do conditional compilation are a bit tiresome.
Suppose you have the requirement that a certain feature of your
software be disable-able at compile time, to avoid having to pull in
Are you proposing to ban all implementation-dependent behaviour
everywhere in Haskell? (Or perhaps relegate it all to IO?)
From: haskell-prime-boun...@haskell.org
[mailto:haskell-prime-boun...@haskell.org] On Behalf Of Conal Elliott
Sent: 21 March 2009 00:56
To:
Jon Fairbairn wrote:
semi-rant warning:
This whole badge/logo business seems to me to be an excellent example
of Parkinson's law of triviality (choosing the colour of the
bikeshed). We have a large (too large) number of variations on
relatively few themes and a really sophisticated
I also see a segfault on Windows XP SP2 and GHC 6.10.1, very quick so
I'm fairly sure it's not memory.
I agree this should be a bug report.
From: haskell-cafe-boun...@haskell.org
[mailto:haskell-cafe-boun...@haskell.org] On Behalf Of Luke Palmer
Sent: 19 March
Jules Bean wrote:
Thomas Hartman wrote:
http://blog.patch-tag.com/2009/03/09/implicitparams-are-evil-thoughts-
on-adapting-gitit/
I understand there are arguments for using IPs, but after this
experience, the ImplicitParams extension is a code smell for me.
It's not just you. Implicit
As I understand it the current scheme is that you vote for a bug by
adding yourself to the CC list.
From: haskell-cafe-boun...@haskell.org
[mailto:haskell-cafe-boun...@haskell.org] On Behalf Of Peter Verswyvelen
Sent: 12 March 2009 14:27
To: Conal Elliott
Cc:
Ben Lippmeier wrote:
The first thing I would do is replace your isInCircle :: (Floating
a, Ord a) = (a,a) - Bool with isInCircle :: (Double, Double) -
Bool
Can you point me to why that matters?
At the machine level, GHC treats the (Floating a, Ord a) as an extra
argument to the
Jonathan Cast wrote:
On Wed, 2009-02-25 at 10:23 +, John Lato wrote:
4. Cross-platform concerns are something that responsible developers
need to consider, just like localization and i18n. I.e., why
*shouldn't* you think of that?
Sorry, wtf? I have a *responsibility* to design
Dusan Kolar wrote:
Nevertheless, local version does not
work.
Restructure your code like this:
fibL m =
let
allfib = 0:1:[allfib!!n + allfib!!(n+1) | n - [0..]]
in allfib !! m
fibL = let allfib = 0:1:[allfib!!n + allfib!!(n+1) | n - [0..]]
in \m - allfib !! m
i.e. move
Wolfgang Jeltsch wrote:
on http://www.haskell.org/haskellwiki/Hac5/Projects, you can list a
project under Project descriptions and under Experiences. What's
the difference?
A project description is something you plan to work on, and an
experience
is something you could help other people
Henning Thielemann wrote:
On Mon, 16 Feb 2009, Louis Wasserman wrote:
Overnight I had the following thought, which I think could work
rather well. The most basic implementation of the idea is as
follows:
class MonadST s m | m - s where
liftST :: ST s a - m a
instance MonadST s (ST
Well, I think a type system like Clean's that had linear/uniqueness
types could fix the issue by actually checking that the state is
single-threaded (and thus stop you from applying it to a forking
monad). But there's a fundamental operational problem that ST makes
destructive updates, so to
: Louis Wasserman [mailto:wasserman.lo...@gmail.com]
Sent: 16 February 2009 16:01
To: Sittampalam, Ganesh
Cc: Dan Doel; Henning Thielemann; haskell-cafe@haskell.org
Subject: Re: [Haskell-cafe] ANNOUNCE: pqueue-mtl, stateful-mtl
Overnight I had the following thought, which I think could work rather
Oh, I see, every derived monad has to have an 's' in its type somewhere.
From: Louis Wasserman [mailto:wasserman.lo...@gmail.com]
Sent: 16 February 2009 16:17
To: Sittampalam, Ganesh
Cc: Dan Doel; Henning Thielemann; haskell-cafe@haskell.org
Subject: Re
Dan Doel wrote:
Someone already mentioned using Dynamic as an alternate base (for
instance, use a Map of dynamics for underlying storage). Of course,
the implementation of Dynamic in GHC uses unsafeCoerce, just like ST,
so you may not count that.
However, using GADTs, you can implement
Stateful-mtl provides an ST monad transformer,
Is this safe? e.g. does it work correctly on [], Maybe etc?
If not this should be flagged very prominently in the documentation.
Cheers,
Ganesh
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