Re: [Haskell-cafe] Re: Re: Re: Do expression definition

On 9/17/10 4:04 PM, Ben Franksen wrote: wren ng thornton wrote: Note that when compilers do CPS conversion, everything is converted into let-binding and continuations (i.e., longjump/goto with value passing). It's just dual to the everything-is-lambda world, nothing special. Do you know a good

[Haskell-cafe] Re: OpenGL Speed!

On 09/18/10 07:49, Mats Klingberg wrote: > On Friday September 17 2010 19.53.01, Lie Ryan wrote: >> It depends. Updating 800x600 screen at 24-bit color 30 times per second >> requires 800*600*24*30 = 34560 bytes/s = 329 MB/s which is larger > > Shouldn't that be bits/s, or 800*600*3*30 = 41 MB

Re: [Haskell-cafe] example in "All about Monads"

On 9/17/10 12:48 PM, ender wrote: my question is, why not define the function father and mother as type of father::Maybe Sheep -> Maybe Sheep? this can also clean the code and it avoid the additional function comb Do note that `comb` is giving you a natural way of creating those functions:

Re: [Haskell-cafe] Re: Re: Re: Full strict functor by abusing Haskell exceptions

On 9/17/10 4:39 PM, Ben Franksen wrote: Thanks for the link. What I actually wanted was a mathematical definition, though. From the TMR article I gather that a pointed functor could be defined as an endo-functor F: C -> C together with a natural transformation pure: Id -> F where Id:

Re: [Haskell-cafe] Unified Haskell login

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 9/17/10 17:43 , Brandon S Allbery KF8NH wrote: > On 9/17/10 05:27 , Neil Davies wrote: >> Why not use kerberos? > Mind, we use Kerberos heavily around here... but we have the infrastructure > that uses it. Web application space is *not* something

Re: [Haskell-cafe] Re: OpenGL Speed!

On Friday September 17 2010 19.53.01, Lie Ryan wrote: > It depends. Updating 800x600 screen at 24-bit color 30 times per second > requires 800*600*24*30 = 34560 bytes/s = 329 MB/s which is larger Shouldn't that be bits/s, or 800*600*3*30 = 41 MB/s? Mats Klingberg _

Re: [Haskell-cafe] Unified Haskell login

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 9/17/10 05:27 , Neil Davies wrote: > Why not use kerberos? > > We find it works for us, integrates with web (natively or via WebAuth), > remote command execution (remctl) and ssh - widely used, scales brilliantly. 1. Kerberos is only authenticatio

Re: [Haskell-cafe] Curious why "cabal upgrade parsec" not installing latest version

Ivan, Duncan, Thank you both very much for your kind help and comments. I'm really impressed with the quality of help at Haskell Cafe, and Cabal really has worked great for me; I'll just avoid "upgrade" in the future. Anyone: So, to get a clean start with my library situation I will delete my ".

[Haskell-cafe] Re: Re: Re: Full strict functor by abusing Haskell exceptions

Román González wrote: > On Thu, Sep 16, 2010 at 2:12 PM, Ben Franksen > wrote: > >> Sjoerd Visscher wrote: >> > But StrictIncl can't be a pointed functor, only endofunctors can be >> > pointed. >> >> Could someone tell me what exactly a pointed functor is? I googled but >> did not find a definitio

Re: [Haskell-cafe] types for parsing a tree

On 16 sep 2010, at 05:42, Jared Jennings wrote: > On Fri, Sep 10, 2010 at 2:00 PM, S. Doaitse Swierstra > wrote: >> I show how this can be done using uu-parsinglib. Note that we have sevral >> parsers, each having its own type: > > Thanks for such a complete example, Doaitse! Unfortunately I h

Re: [Haskell-cafe] Stateful DSLs

Type families can be used to great effect in this area. For instance, in Potential (http://potential-lang.org) we use two tricks for making sure that the combinators in our EDSL are are obeying our rules for composition: (a) We use type families as type-level functions for describing how state

Re: [Haskell-cafe] translating bidirectional fundeps to TFs

On Friday 17 September 2010 4:04:26 pm Gábor Lehel wrote: > What I would *want* to write is this: > > class (Mutable (Thawed a), Frozen (Thawed a) ~ a) => Immutable a where > type Thawed a :: * > thaw :: a -> Thawed a > > class (Immutable (Frozen a), Thawed (Frozen a) ~ a) => Mutable a wh

[Haskell-cafe] ANN: happstack-auth-0.2

Hey! I'd like to announce the release of happstack-auth-0.2 [1]. It offers an easy (and secure) way to implement user authentication for Happstack web applications with a lot of high level functions and a solid Happstack-State back-end. The original project got started by MightyByte, until I

[Haskell-cafe] Re: Re: Re: Do expression definition

wren ng thornton wrote: > On 9/16/10 4:59 PM, Ben Franksen wrote: >> even though we always have >> >>(\x -> e) y == let x = y in e >> >> which means that let can be translated to lambda, the converse is not >> true, > > Not exactly. Note that when compilers do CPS conversion, everything is >

[Haskell-cafe] translating bidirectional fundeps to TFs

Now that the new typechecking awesomeness has been committed to GHC HEAD, theoretically all of the things one can express with FunctionalDependencies (bar overlap) should now be expressible with TypeFamilies as well. This got me to thinking how this might actually be done. Here's an example of a

Re: [Haskell-cafe] Re: "Introducing The Monads" Presentation Slides

Hi all, I just resubmitted the slides to Reddit at : http://www.reddit.com/r/haskell/comments/dfcux/introducing_the_monads_a_practical_tour_of/ I don't see how to delete the old submission at : http://www.reddit.com/r/haskell/comments/dfazp/introducing_the_monads_a_practical_tour_of/ If the moder

[Haskell-cafe] Re: "Introducing The Monads" Presentation Slides

aditya siram wrote: Ok, I feel dumb. I have the slides hosted elsewhere now and I can't figure out how to change the Reddit link. Any help is appreciated! You can't change the link on Reddit, but you can delete the old submission and make a new one. Regards, Heinrich Apfelmus -- http://apf

Re: [Haskell-cafe] Re: OpenGL Speed!

On Fri, Sep 17, 2010 at 7:53 PM, Lie Ryan wrote: > It depends. Updating 800x600 screen at 24-bit color 30 times per second > requires 800*600*24*30 = 34560 bytes/s = 329 MB/s which is larger > than the size of typical Video Memory, and the first version of PCI > Express (introduced 2003) is on

Re: [Haskell-cafe] "Introducing The Monads" Presentation Slides

Ok, I feel dumb. I have the slides hosted elsewhere now and I can't figure out how to change the Reddit link. Any help is appreciated! -deech On Fri, Sep 17, 2010 at 1:16 PM, Matthias Kilian wrote: > On Fri, Sep 17, 2010 at 12:54:29PM -0500, aditya siram wrote: >> Slides shared and Reddited! Feed

Re: [Haskell-cafe] Re: OpenGL Speed!

On a modern PC, this is no problem at all. We are actually doing this with a 1920 x 1080 x 32-bit bitmap, at 60 FPS, on a 2-year old PC You can easily test your GPU <-> CPU bandwidth using this tool: http://sourceforge.net/projects/gpubench On Fri, Sep 17, 2010 at 7:53 PM, Lie Ryan wrote: > O

[Haskell-cafe] Re: Stateful DSLs

Hi Edward, thanks that is very interesting. If these should turn out not to be usable for some reason, do you happen to know of alternatives? Günther Am 17.09.10 19:49, schrieb Edward Z. Yang: Excerpts from Günther Schmidt's message of Fri Sep 17 13:27:45 -0400 2010: I'd want to create a ED

Re: [Haskell-cafe] "Introducing The Monads" Presentation Slides

On Fri, Sep 17, 2010 at 12:54:29PM -0500, aditya siram wrote: > Slides shared and Reddited! Feedback is very welcome! > > http://www.reddit.com/r/haskell/comments/dfazp/introducing_the_monads_a_practical_tour_of/ Oh, come on. A site where you need a flash player to download (or view) a PDF? This

Re: [Haskell-cafe] Re: Re: Full strict functor by abusing Haskell exceptions

On Thu, Sep 16, 2010 at 2:12 PM, Ben Franksen wrote: > Sjoerd Visscher wrote: > > But StrictIncl can't be a pointed functor, only endofunctors can be > > pointed. > > Could someone tell me what exactly a pointed functor is? I googled but did > not find a definition. > Here you will find what a Po

Re: [Haskell-cafe] Unified Haskell login

Excerpts from Neil Davies's message of Fri Sep 17 05:27:34 -0400 2010: > Why not use kerberos? > > We find it works for us, integrates with web (natively or via > WebAuth), remote command execution (remctl) and ssh - widely used, > scales brilliantly. MIT uses Kerberos and it is quite nice to

Re: [Haskell-cafe] "Introducing The Monads" Presentation Slides

Slides shared and Reddited! Feedback is very welcome! http://www.reddit.com/r/haskell/comments/dfazp/introducing_the_monads_a_practical_tour_of/ -deech On Fri, Sep 17, 2010 at 12:38 PM, Ersin Er wrote: > http://www.slideshare.net/ ? > > and perhaps a link via http://www.reddit.com/r/haskell/ > >

Re: [Haskell-cafe] A new cabal odissey: cabal-1.8 breaking its ownneck by updating its dependencies

On the topic of cabal odisseys: I think it would help to document (prominently) what Cabal fundamentally doesn't (try to) do, to avoid optimistic expectations (and hence the surprises when Cabal doesn't meet those expectations), and to point out the design choices behind many bug tickets (even

[Haskell-cafe] Re: OpenGL Speed!

On 07/30/10 03:37, Nick Bowler wrote: > On 2010-07-29 11:30 -0600, Luke Palmer wrote: >> If you are trying to redraw in realtime, eg. 30 FPS or so, I don't >> think you're going to be able to. There is just not enough GPU >> bandwidth (and probably not enough CPU). > > Updating an 800x600 texture

Re: [Haskell-cafe] Stateful DSLs

Excerpts from Günther Schmidt's message of Fri Sep 17 13:27:45 -0400 2010: > I'd want to create a EDSL where I want to be able to statically ensure > that expressions can only be built according to a particular "state". > > Like in a network application, SMTP client for example, where I can only

Re: [Haskell-cafe] "Introducing The Monads" Presentation Slides

http://www.slideshare.net/ ? and perhaps a link via http://www.reddit.com/r/haskell/ On Fri, Sep 17, 2010 at 20:31, aditya siram wrote: > Hi folks, > I just did a presentation on monads and how to use the basic ones > (IO,Reader,Writer,State,ReaderT,WriterT,StateT) in practice. I thought > the

[Haskell-cafe] "Introducing The Monads" Presentation Slides

Hi folks, I just did a presentation on monads and how to use the basic ones (IO,Reader,Writer,State,ReaderT,WriterT,StateT) in practice. I thought the community might want to look at it. Is there some place I can upload the slides (it's just PDF)? -deech

[Haskell-cafe] Stateful DSLs

Hello, I'd want to create a EDSL where I want to be able to statically ensure that expressions can only be built according to a particular "state". Like in a network application, SMTP client for example, where I can only issue commands if the application is in a certain state. Are there any

Re: [Haskell-cafe] example in "All about Monads"

El sáb, 18-09-2010 a las 00:48 +0800, ender escribió: > > my question is, why not define the function father and mother as type > of father::Maybe Sheep -> Maybe Sheep? this can also > clean the code and it avoid the additional function comb > The composition of these functions would then be nice

[Haskell-cafe] example in "All about Monads"

Hi all: I am a newbie of haskell and I'm reading "All about Monads" right now, I have some question about the example shows in Chapter 2, it says that following code is ugly mothersPaternalGrandfather :: Sheep -> Maybe Sheep mothersPaternalGrand

Re: [Haskell-cafe] Web development work

I have been meaning to add a jobs section to the happstack.com website. It would be nice if haskellers.com had an API so I could syndicate just the happstack related jobs/contractors/etc on happstack.com. That would help bring more exposure to haskellers.com, and would be beneficial for vis

Re: [Haskell-cafe] Unified Haskell login

Why not use kerberos? We find it works for us, integrates with web (natively or via WebAuth), remote command execution (remctl) and ssh - widely used, scales brilliantly. Neil ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haske

Re: [Haskell-cafe] Unified Haskell login

On Fri, 17 Sep 2010 08:47:02 +0200, Michael Snoyman wrote: > Hi cafe, Hi, > Let me preface this by stating that this is purposely a half-baked > idea, a straw man if you will. I'd like to hear what the community > thinks about this. > > I mentioned yesterday that I was planning on building haske

Re: [Haskell-cafe] Re: Re: Do expression definition

On 9/16/10 4:59 PM, Ben Franksen wrote: wren ng thornton wrote: The difference is that, for let-bindings, once you've figured out a type of the variable being bound, then that type can be "generalized". [...] Whereas, lambda-bindings don't get generalized, and so they'll always be monomorphic (a

Re: [Haskell-cafe] Web development work

In theory, I think there would be a lot of overlap. However, I still think a separate site is worthwhile because: * We can focus exclusively on Haskell. * We can make the site streamlined for this specific purpose, as opposed to just a small corner of another website. * We'll probably want to add

Re: [Haskell-cafe] Curious why "cabal upgrade parsec" not installing latest version

On 17 September 2010 04:44, Peter Schmitz wrote: > This gets a little hilarious (but better to laugh than cry). > > Well, I decided to try Parsec version 3 (i.e., 3.1.0) after all [...] > I did "cabal upgrade parsec", which went great. [...] > (This is where I began laughing instead of crying

Re: [Haskell-cafe] Unified Haskell login

On Thu, Sep 16, 2010 at 11:47 PM, Michael Snoyman wrote: > Hi cafe, > > Let me preface this by stating that this is purposely a half-baked > idea, a straw man if you will. I'd like to hear what the community > thinks about this. > > I mentioned yesterday that I was planning on building haskellers.

Re: [Haskell-cafe] Unified Haskell login

On 17 September 2010 15:47, Michael Snoyman wrote: > Hi cafe, > > I mentioned yesterday that I was planning on building haskellers.com. > The first technicality I considered was how login should work. There > are a few basic ideas: > > * Username/password on the site. But who wants to deal with *a