Re: [Haskell-cafe] ANN: attempt-0.0.0
On Sun, Oct 25, 2009 at 4:51 PM, Michael Snoyman mich...@snoyman.com wrote: Comments are most welcome. I would like this to be a suitable replacement for the ubiquitous Maybe, (Either String) and ad-hoc Result data types so often used to report a failure. I'd be very happy to improve the package for the general community. I haven't actually tried writing code with this, just read the api docs. The api makes a lot of sense to me. I'm a Python/Ruby guy. I see Haskell as short like Python, almost fast like C. Your attempt monad thing _makes_ _sense_ to me. One little nit I guess. Python had string as exception for awhile, now they discourage that. There seems to be a historical pattern where the right way to throw exceptions changes from throwing strings to throwing real exception objects. Would it be possible to skip the string one here? Are extensible exceptions too cumbersome for some cases? -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Time for a new logo?
On Tue, Dec 16, 2008 at 9:47 PM, Jeff Wheeler j...@nokrev.com wrote: [1]: http://media.nokrev.com/junk/haskell-logos/logo1.png [2]: http://media.nokrev.com/junk/haskell-logos/logo2.png Oops, I meant to post on list. If you play with the angles and vary the stroke thicknesses you'll probably get a friendlier look, vs. the military/airline look these have now. The first '' doesn't have to be the same thickness as the lambda. Just another $0.02 us. Thanks for running with it. Those look like I imagined. What I like about the design is anybody can draw it in 5 strokes and it's unmistakably what it is. Sharpie, pencil, even spray paint all work. You could make your own hat or t-shirt and wear it to an important event, or a wedding. You could tag a rival cube farm wall to declare some kind of office war. X monad could have a variant of this logo too. X= (That's how I originally thought of it, just was too lazy to post it anywhere. Sorry about that.) -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Time for a new logo?
My $0.02 us: Apologies for ascii art, and hopefully gmail doesn't munge this: \\ \\ \\ \\ \| \\ \\ --- \\ \\ // / \ // / \ \| // / /\\ --- // / / \\ -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] The Gtk Clutter API
http://www.clutter-project.org/ What is the degree-of-difficulty for creating Haskell bindings for Clutter? Is it simple to extend gtk2hs to cover it? Or has it been done and I just don't see it? Thanks. -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Hmm, what license to use?
On Wed, Oct 1, 2008 at 4:00 PM, Don Stewart [EMAIL PROTECTED] wrote: And keep dividing our compiler teams' efforts, while single-implementation languages conquer :) Seems like Haskell has a pretty clear story about which is the right implementation for general purpose use. I don't see a Scheme problem here. -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] New Category Theory Intros
These category theory intros were new to me. Thought others here might care. http://golem.ph.utexas.edu/category/2008/08/new_structures_for_physics_i.html -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: [Haskell] Another First course in Haskell
On Sat, Aug 23, 2008 at 8:41 AM, Johannes Waldmann [EMAIL PROTECTED] wrote: (*) that's the main problem I see with Hutton's book http://www.cs.nott.ac.uk/~gmh/book.htmlhttp://www.cs.nott.ac.uk/%7Egmh/book.html: it has Declaring types and classes as chapter 10 (of 13 total). I think that's way off - and it leaves readers (students) with the impression that declarative programming basically deals with (functions on) lists. This may have been true in the 70s/80s (LISP, Prolog), but it certainly shouldn't be true today. Recall the proverb Get your data structures correct first, and the rest of the program will write itself. (David Jones, cited in John Bentley: More Programming Pearls) I think this is independent of language and paradigm. If functions on lists isn't the thing, what is the thing? Data structures isn't a very satisfactory answer for a n00b like me, because it doesn't capture Haskell's distinctive. I've had this same sense, but in a vague newbie way. This also seems to reflect a growing dissatisfaction with the prelude. Back in the day lazy lists were the thing and the Prelude seems to largely reflect that. Now it's something else I can't possibly articulate. But I can definitely see it trying to replace a significant amount of prelude functionality. Witness that nobody loves strings anymore because ByteStrings are cooler. The stream/fusion lists are way cooler than the stock lists. etc. Or I have no idea what I'm talking about. -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] BLAS Solve Example
On Wed, Jul 23, 2008 at 2:12 AM, Alberto Ruiz [EMAIL PROTECTED] wrote: $ ghci solve.hs *Main sol 3 | [-5.511e-2,0.3,0.2776] I was hoping for rational solutions. If I were a true jedi master I'd write my own solver, which might be the right thing to do. All I know so far is gauss' method. Probably I'd learn something implementing the back substitution. hmm Thanks. -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: Hayoo! beta 0.2
On Wed, Jul 23, 2008 at 5:04 AM, Timo B. Hübel [EMAIL PROTECTED] wrote: Unfortunately we had to drop the direct links to the source code, as the documentation on Hackage is currently generated without source code. But as soon as this changes, we will include these links again. Someone is working on hscolors for hackage? (Oh how hard that would rock.) -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] BLAS Solve Example
I'm stuck on something that I thought would be easy. I have a matrix and a vector. module Main where import Data.Vector.Dense import Data.Matrix.Dense import BLAS.Matrix.Solve m = listMatrix (2, 3) ([1, 2, 3, 4, 5, 6]::[Double]) v = listVector 2 ([1, 2]::[Double]) main = do ??? Can I use one of the haskell libraries to solve that system? My goal is to automate some tedium on small exercises from the Linear Algebra text by Jim Heffron. -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Haskell Related Reading
I have a trip coming up and might have some reading time. I was hoping to get through some of the classics, bananas and lenses, the essence, etc. So I have a few questions: Bananas and lenses et. al. uses some notation that I don't understand right out of the gate. Is there a good primer on whatever that brand of double bars and arrows means? The essense of functional programming looks good, I could understand it when I skimmed it but can I print it out on US letter? The PDF at citeseer was aligned badly. (Essece seemed like a fabulous intro or chapter 2 on getting used to monads. Better than most stuff on the web. Funny that...) I'm also interested in FRP as it might relate to web programming. Anyone have a recommendation? -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Literal programming in Haskell with rst-literals
2008/6/23 Abhay Parvate [EMAIL PROTECTED]: Hello, You might already know this, but in case you don't: there is another literate style: I had trouble finding the docs on this, as I expected them to be in the ghc user guide. For the record, the relevant docs are in the h98 report: http://www.haskell.org/onlinereport/literate.html And the wiki: http://www.haskell.org/haskellwiki/Literate_programming -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Announce: Fortress talk in New York City
2008/6/13 Jeff Polakow [EMAIL PROTECTED]: There will be a talk on Fortress ( a new OO/Functional language from Sun) on Wednesday June 25 at 6:30pm in Manhattan. Sounds interesting. Any plans to post video? -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] cabal-install failure
Cabal-install is looking good. It now, for the record, has only two deps outside of Cabal-1.4. I installed cabal-install-0.5 on ubuntu with the haskell.org linux binary for ghc 6.8.2. I then tried cabal-install yi Got this output: ... many successful installs ... Registering vty-3.0.1... Reading package info from dist/installed-pkg-config ... done. Saving old package config file... done. Writing new package config file... done. Downloading yi-0.3... [1 of 1] Compiling Main ( Setup.hs, dist/setup/Main.o ) Setup.hs:9:0: Warning: Deprecated use of `showPackageId' (imported from Distribution.Simple, but defined in Distribution.Package): use the Text class instead Linking dist/setup/setup ... Warning: defaultUserHooks in Setup script is deprecated. Configuring yi-0.3... Warning: Instead of 'ghc-options: -DDYNAMIC -DFRONTEND_VTY' use 'cpp-options: -DDYNAMIC -DFRONTEND_VTY' setup: alex version =2.0.1 3 is required but it could not be found. cabal: Error: some packages failed to install: yi-0.3 failed during the configure step. The exception was: exit: ExitFailure 1 Is this a cabal problem of package problem? I would have expected it to fail immediately instead of discover this problem so far into process. Thanks. -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: cabal and platform-independent haskell installation management (again) (Re: Re: Ubuntu and ghc)
On Wed, Jun 4, 2008 at 7:48 PM, Duncan Coutts [EMAIL PROTECTED] wrote: On Wed, 2008-06-04 at 17:22 +0200, Achim Schneider wrote: The question, IMHO, seems to be How would a package manager for a posix-compilant kinetic look like? http://nixos.org/index.html How well does that coexist with other OS's? Could I have it manage only specific applications in it's store and trust the OS for the rest? -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: cabal and platform-independent haskell installation management (again) (Re: [Haskell-cafe] Re: Ubuntu and ghc)
On Wed, Jun 4, 2008 at 10:14 AM, Claus Reinke [EMAIL PROTECTED] wrote: - it isn't sufficient to worry about installation management, one has to worry about integration, lifetime and uninstall management as well. in short, maintain the dependency graphs over any of install/upgrade/uninstall. It's sufficient to worry about the problem at hand. Everything you've mentioned can be done incrementally once the depsolver is happy. After that it's quite likely that the set of people who care about lifetimes and integration stuff will intersect with the people who want to work on said stuff. -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [ANNOUNCE] git-darcs-import 0.1
On Sun, Jun 1, 2008 at 2:44 PM, Bertram Felgenhauer [EMAIL PROTECTED] wrote: Hi, I'm pleased to announce yet another tool for importing darcs repositories to git. Unlike darcs2git [1] and darcs-to-git [2], it's written in Haskell, on top of the darcs2 source code. The result is a much faster program - it can convert the complete ghc 6.9 branch (without libraries) in less than 15 minutes on my slightly dated machine (Athlon XP 2500+), which is quite fast [3]. Incremental updates work, too. What's the appeal of this? I personally love git, but I thought all the cool kids at this school used darcs and that was that. -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Rewrite class with fundeps in pure h98?
I thought that I should be able to write something like the toHtml
function below with pure H98, but when I went to write it I ended up
needing fundeps. Is there a way to express this without using any
extensions?
The idea was to take a remotely Dom-like tree and flatten it into a
string, but not require any particular string type. Mostly I'm ripping
off HStringTemplate for the fun of it.
{-# OPTIONS -fglasgow-exts #-}
module Control.WebWidget where
import Data.Monoid
import Data.String
data (IsString s, Monoid s) = Dom s =
Element s [Attr s] [Dom s] |
Text s
data (IsString s, Monoid s) = Attr s = Attr s s
class (Monoid s, IsString s) = HTML d s | d - s where
toHtml :: d - s
instance (Monoid s, IsString s) = HTML (Dom s) s where
toHtml (Element name attrs children) =
mconcat [
fromString ,
name,
mconcat $ map toHtml attrs,
fromString ,
mconcat $ map toHtml children,
fromString /,
name,
fromString ]
toHtml (Text s) = s
instance (Monoid s, IsString s) = HTML (Attr s) s where
toHtml (Attr key value) =
mconcat [
fromString ',
key,
fromString '=',
value,
fromString ' ]
--
Darrin
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Re: [Haskell-cafe] Damnit, we need a CPAN.
On Thu, May 29, 2008 at 11:47 AM, Neil Mitchell [EMAIL PROTECTED] wrote: , a cabal-inst that can install from darcs (or at least from a local directory) Yes, that would be lovely! While we're on the subject, why does searchpath get as little attention as it does? It seems to work reasonably well for HAppS. -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Damnit, we need a CPAN.
On Thu, May 29, 2008 at 4:31 PM, Thomas Hartman [EMAIL PROTECTED] wrote: I've been playing a lot with searchpath lately, for doing happs quickstart installation as described on happs.org. Searchpath works great when it works, which usually means -- when the module map file is up to date and pointing everywhere to the right place. When the module map file is out of date though, the error messages for missing dependencies that you would get from searchpath are not as good as the error messages you'd get from a cabal configure. Makes me wonder if searchpath and a good module map file wouldn't be a good way to bootstrap cabal-install. -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] So how do people pronounce 'cabal' around here?
2008/5/28 Clifford Beshers [EMAIL PROTECTED]: But if you say it that way, you get kicked out of the cabal. I thought the first rule was There is no cabal. Oh wait, that's Debian. Oh wait... aa! -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: Re: [Haskell-cafe] Aren't type system extensions fun? [Further analysis]
On Tue, May 27, 2008 at 3:40 PM, Kim-Ee Yeoh [EMAIL PROTECTED] wrote: Let's fill in the type variable: (x - x) - (Char, Bool) == forall x. (x - x) - (Char, Bool) == x_t - (x - x) - (Char, Bool), where x_t is the hidden type-variable, not unlike the reader monad. As you've pointed out, callER chooses x_t, say Int when passing in (+1) :: Int - Int, which obviously would break \f - (f 'J', f True). What we want is the callEE to choose x_t since callEE needs to instantiate x_t to Char and Bool. What we want is (x_t - x - x) - (Char, Bool). But that's just (forall x. x - x) - (Char, Bool). Nice. That's the first time any of this really made sense to me. Is it possible to construct valid argument for that function? -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] GHC predictability
On Tue, May 13, 2008 at 2:20 AM, Don Stewart [EMAIL PROTECTED] wrote: Note the use of strict pairs. Key to ensuring the accumulators end up in registers.The performance difference here is due to fold (and all left folds) not fusing in normal build/foldr fusion. The vector version runs about the same speed as unoptimsed C. These tricks going into Real World Haskell? When you say someone needs to get familiar with the STG paper it scares me (a beginner) off a little, an I've been making an effort to approach the papers. I could barely understand the Fusion one and getting familiar with compiler internals sounds like something I'd not be ready for. Probably if I really looked at ghc-core I'd be pleasantly surprised but I'm totally biased against even looking. Gcc is hard to read, thus ghc is also. So while you are right about all this when you say it, I think your goal is to persuade. RWH has some of the best practical prose I've read yet. Well done there. Hopefully chapter 26 will be crammed full of this stuff? -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] I am new to haskell
On Thu, May 8, 2008 at 2:59 AM, Benjamin L. Russell [EMAIL PROTECTED] wrote: * Kees Doets and Jan van Eijck: The Haskell Road to Logic, Maths and Programming, As someone approaching haskell with very rusty math skills, this book has been invaluable. My haskell skills are (mostly) beyond what the text is covering, but I'm dutifully working through the math problems as doing it (partway through chapter 4 now, yay!) has sharpened my thinking already. The end result is that I can already sort of read some of the Haskell research papers like the Fusion one. Also, Jan van Eijck is pretty responsive and untangled my mind from time to time. -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: Interesting critique of OCaml
2008/5/8 Donnie Jones [EMAIL PROTECTED]: I would be interested to see an article on Haskell in the same light as this Ocaml article, aka a constructive criticism of Haskell. http://www.drmaciver.com/2008/02/tell-us-why-your-language-sucks/ -- Darrin ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
