Re: [Haskell-cafe] Some thoughts on Type-Directed Name Resolution

2012-02-03 Thread AntC
Kevin Quick quick at sparq.org writes: Currently under H98: f.g-- (both lower case, no space around the dot) Is taken as function composition -- same as (f . g). f. g -- is taken as func composition (f . g) f .g -- is taken as func composition (f . g)

Re: [Haskell-cafe] Adding Html formatting to formlets

2012-02-03 Thread Alberto G. Corona
Hi Jeremy If the signature of a formlet or digestive functor is View *format m a * with `*m*` a monad, `*a*` the resulting value and `*format*` the formatting (Usually HTML) then the signatures of the operators for Text.XHtml format are: *() :: Monad m = (Html - Html) - View Html m a -

Re: [Haskell-cafe] Again, version conflicting problem with cabal-install

2012-02-03 Thread Magicloud Magiclouds
Yes and probably a runtime crash even if passed the compile. But I think if we let it stay the way it is, the hackage empire would be down any minute. All big hackages are depending on many other hackages by many other authors. So big chance that the top hackage cannot be installed (like I

Re: [Haskell-cafe] Again, version conflicting problem with cabal-install

2012-02-03 Thread Andres Löh
Hi. On Fri, Feb 3, 2012 at 7:44 AM, Ivan Lazar Miljenovic ivan.miljeno...@gmail.com wrote: On 3 February 2012 17:29, Magicloud Magiclouds magicloud.magiclo...@gmail.com wrote: Thank you. The document does say it more clearly than me. But still, currently, ghc only gives me one option: cannot

Re: [Haskell-cafe] Cabal-1.10.1.0 and bytestring-0.9.2.1 hackage problem.

2012-02-03 Thread Ketil Malde
Alan Pogrebinschi alan...@gmail.com writes: That Cabal-1.10.1.0 bug seems to be back, now with bytestring-0.9.2.1 just uploaded to hackage. Thanks for the link! I was banging my head on against the virtual wall, since all I'm getting is: % cabal install -v biopsl Reading

Re: [Haskell-cafe] Cabal-1.10.1.0 and bytestring-0.9.2.1 hackage problem.

2012-02-03 Thread Erik Hesselink
Same workaround as last time works I.e:  tar -f ~/.cabal/packages/hackage.haskell.org/00-index.tar --delete bytestring/0.9.2.1 This will only work until the next 'cabal update', right? Does anyone have a better workaround? This is the cabal-install shipped with Ubuntu 12.04 (i.e. the

Re: [Haskell-cafe] Some thoughts on Type-Directed Name Resolution

2012-02-03 Thread Gábor Lehel
On Fri, Feb 3, 2012 at 10:30 AM, AntC anthony_clay...@clear.net.nz wrote: You seem to be not alone in wanting some special syntax for applying field selectors (see other posts on this thread). H98 field selectors don't do this, they're just functions. And there's me bending over backwards to

Re: [Haskell-cafe] Exceeding OS limits for simultaneous socket connections

2012-02-03 Thread Matthew Farkas-Dyck
Rob Stewart wrote: transmitting thousands of messages to each other, sometimes within a small period of time. Either SCTP or UDP seems far more appropriate than TCP (which I assume, hopefully safely, to be at work here) for this task. ___

Re: [Haskell-cafe] Some thoughts on Type-Directed Name Resolution

2012-02-03 Thread Steve Horne
On 03/02/2012 11:13, Gábor Lehel wrote: The first problem is that mixing prefix and postfix function application within the same line makes it harder to read. When you read code to try to understand what it does, the direction you like to go in is here's some object, first do this to it, then do

[Haskell-cafe] Conduit experiment: Is this correct?

2012-02-03 Thread Ertugrul Söylemez
Hello there, I'm trying to build a server for testing the conduit and network-conduit packages. As a contrived example the goal is to pick the first three lines from the client and send them back without the line feeds. After that, I'd like to switch to a simple echo server. This is the code:

Re: [Haskell-cafe] Some thoughts on Type-Directed Name Resolution

2012-02-03 Thread AntC
Gábor Lehel illissius at gmail.com writes: On Fri, Feb 3, 2012 at 10:30 AM, AntC anthony_clayden at clear.net.nz wrote: You seem to be not alone in wanting some special syntax for applying field selectors (see other posts on this thread). H98 field selectors don't do this, they're just

Re: [Haskell-cafe] Some thoughts on Type-Directed Name Resolution

2012-02-03 Thread Ertugrul Söylemez
Steve Horne sh006d3...@blueyonder.co.uk wrote: There's a proposal at the moment to add support for TDNR to Haskell - to leverage the power of the dot (e.g. for intellisense). http://hackage.haskell.org/trac/haskell-prime/wiki/TypeDirectedNameResolution I'm not sure whether this should really

Re: [Haskell-cafe] Conduit experiment: Is this correct?

2012-02-03 Thread Michael Snoyman
2012/2/3 Ertugrul Söylemez e...@ertes.de: Hello there, I'm trying to build a server for testing the conduit and network-conduit packages.  As a contrived example the goal is to pick the first three lines from the client and send them back without the line feeds.  After that, I'd like to

Re: [Haskell-cafe] Some thoughts on Type-Directed Name Resolution

2012-02-03 Thread Gábor Lehel
On Fri, Feb 3, 2012 at 2:37 PM, AntC anthony_clay...@clear.net.nz wrote: Do people really write code with huge pile-ups of functions prefix upon prefix? Wouldn't that be confusing even when it's unidirectional? Not really. Pipeline-like chains where you apply each function to the result of the

Re: [Haskell-cafe] Again, version conflicting problem with cabal-install

2012-02-03 Thread Magicloud Magiclouds
Glad to hear that. I will checkout the trunk and try. On Fri, Feb 3, 2012 at 6:20 PM, Andres Löh andres.l...@googlemail.com wrote: Hi. On Fri, Feb 3, 2012 at 7:44 AM, Ivan Lazar Miljenovic ivan.miljeno...@gmail.com wrote: On 3 February 2012 17:29, Magicloud Magiclouds

Re: [Haskell-cafe] Conduit experiment: Is this correct?

2012-02-03 Thread yi huang
2012/2/3 Michael Snoyman mich...@snoyman.com 2012/2/3 Ertugrul Söylemez e...@ertes.de: Hello there, I'm trying to build a server for testing the conduit and network-conduit packages. As a contrived example the goal is to pick the first three lines from the client and send them back

Re: [Haskell-cafe] Some thoughts on Type-Directed Name Resolution

2012-02-03 Thread AntC
Gábor Lehel illissius at gmail.com writes: On Fri, Feb 3, 2012 at 2:37 PM, AntC anthony_clayden at clear.net.nz wrote: Do people really write code with huge pile-ups of functions prefix upon prefix? Wouldn't that be confusing even when it's unidirectional? Not really. Pipeline-like

Re: [Haskell-cafe] Again, version conflicting problem with cabal-install

2012-02-03 Thread Jason Dagit
In my experience the diamond of death is typically because: * You install package A that uses C-0.1 * Someone uploads C-0.2 to hackage * Later you 'cabal update', this does not rebuild A to use C-0.2, even though it could. * You install package B that uses C, and cabal builds it with C-0.2

Re: [Haskell-cafe] Conduit experiment: Is this correct?

2012-02-03 Thread Ertugrul Söylemez
Michael Snoyman mich...@snoyman.com wrote: In this particular case, it will work due to the implementation of snk. In general, however, you're correct: you should not use the same sink twice. I haven't thought about it much yet, but my initial recommendation would be to create a new Conduit

Re: [Haskell-cafe] Some thoughts on Type-Directed Name Resolution

2012-02-03 Thread Donn Cave
Quoth AntC anthony_clay...@clear.net.nz, ... We're on the slippery slope! Where will it end? And now that I've found it, I so love: customer.lastName.tail.head.toUpper-- Yay! ... compared to present practice, with where dot is function composition only -

Re: [Haskell-cafe] Again, version conflicting problem with cabal-install

2012-02-03 Thread Magicloud Magiclouds
I think this could be gone with cabal-dev only if A has a new version or the compiled one that could use C-0.2 or caba-dev could ignore the version constraint. So it is kind of an old binary problem. It could also be resolved by reinstall A to use C-0.2 with cabal-install. The problem I met is

Re: [Haskell-cafe] Conduit experiment: Is this correct?

2012-02-03 Thread Felipe Almeida Lessa
On Fri, Feb 3, 2012 at 1:38 PM, yi huang yi.codepla...@gmail.com wrote: Since Sink works in a CPS fashion, by which i mean every step it return a new push close pair, i think it can be used multiple time. Actually, this is exactly why it *can't* be used multiple times. Cheers! -- Felipe.

Re: [Haskell-cafe] Again, version conflicting problem with cabal-install

2012-02-03 Thread Andres Löh
I am just wanting an option (ignore versions) to take that risk in develop environment. A controlled way of ignoring version constraints (mainly upper bounds, actually) is certainly on my TODO list for the new solver. The main issue to work out is a good way how to control the disabled bounds

Re: [Haskell-cafe] Again, version conflicting problem with cabal-install

2012-02-03 Thread Felipe Almeida Lessa
On Fri, Feb 3, 2012 at 2:22 PM, Andres Löh andres.l...@googlemail.com wrote: A controlled way of ignoring version constraints (mainly upper bounds, actually) is certainly on my TODO list for the new solver. The main issue to work out is a good way how to control the disabled bounds via the

Re: [Haskell-cafe] Again, version conflicting problem with cabal-install

2012-02-03 Thread Andres Löh
Hi.  --force-allow=foo-1.3 with the semantics that all dependencies on foo will be changed to allow foo-1.3 to be chosen. Would that be ok? Other suggestions? Can't this be integrated with the current --constraint flag? It could be, but ... If the constraint is able to be satisfied

Re: [Haskell-cafe] Conduit experiment: Is this correct?

2012-02-03 Thread Ertugrul Söylemez
Michael Snoyman mich...@snoyman.com wrote: In this particular case, it will work due to the implementation of snk. In general, however, you're correct: you should not use the same sink twice. I haven't thought about it much yet, but my initial recommendation would be to create a new Conduit

[Haskell-cafe] TFPIE: Trends in Functional Programming in Education 2012

2012-02-03 Thread Simon Thompson
[Apologies for multiple postings, Simon.] CALL FOR PAPERS/PRESENTATIONS TFPIE 2012 International Workshop on Trends in Functional Programming in Education 2012 June 11 2012 University of St Andrews, Scotland http://www.cs.ru.nl/P.Achten/TFPIE_2012/TFPIE_2012_home.html The first International

Re: [Haskell-cafe] Some thoughts on Type-Directed Name Resolution

2012-02-03 Thread wren ng thornton
On 2/3/12 6:13 AM, Gábor Lehel wrote: The first problem is that mixing prefix and postfix function application within the same line makes it harder to read. When you read code to try to understand what it does, the direction you like to go in is here's some object, first do this to it, then do

Re: [Haskell-cafe] ANN: combinatorics

2012-02-03 Thread Brent Yorgey
On Fri, Feb 03, 2012 at 01:06:16AM -0500, wren ng thornton wrote: On 2/2/12 6:46 PM, Carter Schonwald wrote: On Thu, Feb 2, 2012 at 4:06 PM, Ivan Lazar Miljenovic wrote: On 3 February 2012 07:11, Brent Yorgey wrote: On Wed, Feb 01, 2012 at 01:53:03AM -0500, wren ng thornton wrote: [2]

Re: [Haskell-cafe] Conduit experiment: Is this correct?

2012-02-03 Thread Erik de Castro Lopo
Ertugrul Söylemez wrote: Thanks a lot. This conduit world is really new to me and feels a bit more complicated than enumerators, but at least I seem to be getting the right intuition. I can assure you that while this may be true for simple cases, it most definitely is not true for at least

Re: [Haskell-cafe] Contributing to http-conduit

2012-02-03 Thread Myles C. Maxfield
Here is the patch to Web.Cookie. I didn't modify the tests at all because they were already broken - they looked like they hadn't been updated since SetCookie only had 5 parameters. I did verify by hand that the patch works, though. Thanks, Myles On Thu, Feb 2, 2012 at 11:26 PM, Myles C.

[Haskell-cafe] ANN: bytestring-lexing 0.4.0

2012-02-03 Thread wren ng thornton
-- bytestring-lexing 0.4.0 The bytestring-lexing package offers efficient reading and packing of common types like Double and Integral types. -- Changes

Re: [Haskell-cafe] ANN: bytestring-lexing 0.4.0

2012-02-03 Thread Erik de Castro Lopo
wren ng thornton wrote: -- Changes (since 0.3.0) * Data.ByteString.Lex.Integral: added the function readDecimal_ :: Integral a = ByteString - a A variant of readDecimal which does not

[Haskell-cafe] how to print out intermediate results in a recursive function?

2012-02-03 Thread Qi Qi
Hello, I have a question;how can I print out the intermediate number lists in a mergesort recursive function like the following one. merge [] ys = ys merge xs [] = xs merge (x:xs) (y:ys) = if x = y then x : merge xs (y:ys) else y : merge (x:xs) ys

Re: [Haskell-cafe] how to print out intermediate results in a recursive function?

2012-02-03 Thread Ivan Lazar Miljenovic
On 5 February 2012 05:23, Qi Qi qiqi...@gmail.com wrote: Hello, I have a question;how can I print out the intermediate number lists in a mergesort recursive function like the following one. You can use the (completely evil and shouldn't be used in production code) Debug.Trace module. merge

Re: [Haskell-cafe] how to print out intermediate results in a recursive function?

2012-02-03 Thread yi huang
You can use trace from Debug.Trace, change the code like this: mergesort l = case trace l l of [] - ... [x] - ... (x:xs) - ... On Sun, Feb 5, 2012 at 2:23 AM, Qi Qi qiqi...@gmail.com wrote: Hello, I have a question;how can I print out the intermediate number lists in a mergesort

Re: [Haskell-cafe] how to print out intermediate results in a recursive function?

2012-02-03 Thread Ozgur Akgun
Hi, There is also this nice trick to use Debug.Trace: merge xs ys | trace (show (xs,ys)) False = undefined -- add this as the first case to merge mergesort xs | trace (show xs) False = undefined -- and this as the first case to mergesort HTH, Ozgur