Re: [Haskell-cafe] Haskell Logo Macbook Decal

2013-10-02 Thread Tikhon Jelvis
I've heard good things about teespring. I gather it's like a kickstarter but specifically for t-shirts. They seem to have some procedures[1] in place specifically for non-profit organizations, which might be a good option for supporting haskell.org. [1]: http://teespring.com/solutions (confusingly

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Heinrich Apfelmus
Ryan Newton wrote: Here are some examples: - data Foo = Bar | Baz instance Eq Foo where _ == _ = True instance Ord Foo where compare Bar Bar = EQ compare Bar Baz = LT compare _ _ = error "I'm partial!"

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Tom Ellis
On Wed, Oct 02, 2013 at 11:24:39AM +0200, Heinrich Apfelmus wrote: > I'm not sure whether the Eq instance you mention is actually > incorrect. I had always understood that Eq denotes an equivalence > relation, not necessarily equality on the constructor level. There's a difference between impl

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Roman Cheplyaka
* Heinrich Apfelmus [2013-10-02 11:24:39+0200] > In other words, equality of abstract data types is different from > equality of algebraic data types (constructors). I don't think you'll > ever be able to avoid this proof obligation that the public API of an > abstract data type preserves equivale

Re: [Haskell-cafe] Poll & plea: State of GUI & graphics libraries in Haskell

2013-10-02 Thread Atze Dijkstra
Hi, as for wxHaskell, it is currently maintained at https://github.com/wxHaskell/wxHaskell, compilable with wxWidgets 2.9.5 and GHC 7.6. Work is underway to fix various bugs introduced over time by changes in wxWidgets, but we (i.e. https://github.com/wxHaskell?tab=members) hope to release & a

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Tillmann Rendel
Hi, Roman Cheplyaka wrote: It still seems to fit nicely into Safe Haskell. If you are the implementor of an abstract type, you can do whatever you want in the Eq instance, declare your module as Trustworthy, and thus take the responsibility for soundness of that instance w.r.t. your public API.

Re: [Haskell-cafe] Roshask

2013-10-02 Thread Tijn van der Zant
Hi, I'm trying to get things up and running but I keep having problems with the following. When I follow the instructions on https://github.com/acowley/roshask/wiki/Getting-Started I run into the following: tijn@tt:~/MyPackage$ roshask dep Looking for ["std_msgs"], dependencies of /home/tijn/MyP

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Roman Cheplyaka
* Tillmann Rendel [2013-10-02 13:19:38+0200] > Hi, > > Roman Cheplyaka wrote: > >It still seems to fit nicely into Safe Haskell. If you are the > >implementor of an abstract type, you can do whatever you want in the Eq > >instance, declare your module as Trustworthy, and thus take the > >responsi

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Stijn van Drongelen
I do think something has to be done to have an Eq and Ord with more strict laws. * Operators in Eq and Ord diverge iff any of their parameters are bottom. * The default definitions of (/=), (<), (>) and `compare` are law. * (==) is reflexive and transitive * (<=) is antisymmetric ((x <= y && y <=

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Niklas Haas
On Wed, 2 Oct 2013 15:46:42 +0200, Stijn van Drongelen wrote: > I do think something has to be done to have an Eq and Ord with more strict > laws. > > * Operators in Eq and Ord diverge iff any of their parameters are bottom. > * The default definitions of (/=), (<), (>) and `compare` are law. >

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Colin Adams
Only for meanings of "better" which do not imply as good performance. On 2 October 2013 14:46, Stijn van Drongelen wrote: > I do think something has to be done to have an Eq and Ord with more strict > laws. > > * Operators in Eq and Ord diverge iff any of their parameters are bottom. > * The de

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Stijn van Drongelen
On Wed, Oct 2, 2013 at 3:49 PM, Niklas Haas wrote: > On Wed, 2 Oct 2013 15:46:42 +0200, Stijn van Drongelen > wrote: > > I do think something has to be done to have an Eq and Ord with more > strict > > laws. > > > > * Operators in Eq and Ord diverge iff any of their parameters are bottom. > > *

Re: [Haskell-cafe] Poll & plea: State of GUI & graphics libraries in Haskell

2013-10-02 Thread Sylvain HENRY
Hi, The best low-level foundation libraries that I know of are the Enlightenment Foundation Libraries (EFL) [1,2]. They are cross-platform : they support many backends (X11, OpenGL, framebuffer...) and are used on desktops and mobile devices (even to provide games on the French Free ISP box).

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Tom Ellis
On Wed, Oct 02, 2013 at 03:46:42PM +0200, Stijn van Drongelen wrote: > * Operators in Eq and Ord diverge iff any of their parameters are bottom. What's the benefit of this requirement, as opposed to, for example False <= _ = True ... Tom ___ Hask

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Roman Cheplyaka
* Stijn van Drongelen [2013-10-02 15:46:42+0200] > I do think something has to be done to have an Eq and Ord with more strict > laws. > > * Operators in Eq and Ord diverge iff any of their parameters are bottom. This outlaws the Eq instances of lists, trees, and other (co)recursive types. Furth

Re: [Haskell-cafe] Poll & plea: State of GUI & graphics libraries in Haskell

2013-10-02 Thread Conal Elliott
Hi Atze. I'm glad to hear that some work is going into wxHaskell. Do you know about the issue that arose roughly 7-8 years ago that prevented opening more than one top-level window per process? It had to do with a change to initialization techniques, and made wxHaskell no longer useful with GHCi.

Re: [Haskell-cafe] Poll & plea: State of GUI & graphics libraries in Haskell

2013-10-02 Thread Conal Elliott
Hi Paul. Is there a way to use GLFW with GUI elements other than OpenGL display windows, e.g., text boxes and sliders? -- Conal On Tue, Oct 1, 2013 at 11:23 PM, Paul Liu wrote: > Thanks. I've just built GHC HEAD on Mac OS X Lion, and tested by > installing libraries with --enable-shared and lo

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Stijn van Drongelen
On Wed, Oct 2, 2013 at 4:17 PM, Tom Ellis < tom-lists-haskell-cafe-2...@jaguarpaw.co.uk> wrote: > What's the benefit of this requirement, as opposed to, for example > >False <= _ = True > I was trying to cover for void types, where the only sensible definitions are instance Eq Void where

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Stijn van Drongelen
On Wed, Oct 2, 2013 at 6:57 PM, Stijn van Drongelen wrote: > > On Wed, Oct 2, 2013 at 5:36 PM, Roman Cheplyaka wrote: > >> * Stijn van Drongelen [2013-10-02 15:46:42+0200] >> > I do think something has to be done to have an Eq and Ord with more >> strict >> > laws. >> > >> > * Operators in Eq an

Re: [Haskell-cafe] [ANN] lvish 1.0 -- successor to monad-par

2013-10-02 Thread Ben Gamari
Ryan Newton writes: > Hi all, > > I'm pleased to announce the release of our new parallel-programming > library, LVish: > > hackage.haskell.org/package/lvish > > It provides a "Par" monad similar to the monad-par package, but generalizes > the model to include data-structures other than singl

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Mike Meyer
On Wed, Oct 2, 2013 at 5:18 AM, Tom Ellis < tom-lists-haskell-cafe-2...@jaguarpaw.co.uk> wrote: > Are there examples where application programmers would like there so be some > f, a and b such that a == b but f a /= f b (efficiency concerns aside)? I > can't think of any obvious ones. Yes, and we

Re: [Haskell-cafe] Any precedent or plan for guaranteed-safe Eq and Ord instances?

2013-10-02 Thread Carter Schonwald
So i think we can conclude the following 1) things are not perfect currently. But it requires some huge type class changes to have a better story 2) certain types of data types will need to be newtyped to have instances that play nice with Ryans concurrency work. Thats ok. Theres often good reaso

Re: [Haskell-cafe] Poll & plea: State of GUI & graphics libraries in Haskell

2013-10-02 Thread Simon Marlow
Great to hear that we're getting some payoff for the switch to dynamic linking in GHCi. Thanks for testing! Cheers Simon On 02/10/2013 07:23, Paul Liu wrote: Thanks. I've just built GHC HEAD on Mac OS X Lion, and tested by installing libraries with --enable-shared and loading a GLFW program i

Re: [Haskell-cafe] [ANN] lvish 1.0 -- successor to monad-par

2013-10-02 Thread Carter Schonwald
that may or may not be a bug on the hackage server side, just brought it to duncan's attention and put a ticket for it on trac https://github.com/haskell/hackage-server/issues/119 On Wed, Oct 2, 2013 at 1:05 PM, Ben Gamari wrote: > Ryan Newton writes: > > > Hi all, > > > > I'm pleased to ann

Re: [Haskell-cafe] [ANN] lvish 1.0 -- successor to monad-par

2013-10-02 Thread Carter Schonwald
i mean github On Wed, Oct 2, 2013 at 3:53 PM, Carter Schonwald wrote: > that may or may not be a bug on the hackage server side, > > just brought it to duncan's attention and put a ticket for it on trac > > https://github.com/haskell/hackage-server/issues/119 > > > On Wed, Oct 2, 2013 at 1:05

Re: [Haskell-cafe] Poll & plea: State of GUI & graphics libraries in Haskell

2013-10-02 Thread Paul Liu
No. GLFW does not give you any UI elements, just basic windowing and input handling. Euterpea has a UI layer on top of GLFW that provides text boxes and sliders, etc, entirely written in Haskell. On Wed, Oct 2, 2013 at 8:40 AM, Conal Elliott wrote: > Hi Paul. Is there a way to use GLFW with GUI

[Haskell-cafe] Newclasses

2013-10-02 Thread Wvv
"Newclasses" are not a new vision of classes! Not at all! Newclasses could elegant solve several instance problems! 1) we want to have "partly applied instances", like Parent2Child: Parent a => Child a like instance Applicative m => Monad m where return = pure

Re: [Haskell-cafe] Newclasses

2013-10-02 Thread Stijn van Drongelen
Hi! Your first two cases will be fixed in 7.10, as Applicative finally becomes a superclass of Monad. I haven't really looked at your third case, so I can't comment on that. Your fourth case is something I'd really like to see solved properly (*together* with a better record system), but as you sa

Re: [Haskell-cafe] Poll & plea: State of GUI & graphics libraries in Haskell

2013-10-02 Thread Conal Elliott
Interesting. How are the aesthetics? Can you point me to screen shots? It'd be a lot of work, but one cool project would be to create *beautiful* GUI elements using OpenGL programmable shaders. Given the speed of GPUs, we could afford to put a lot into visual details. A complementary project is d

[Haskell-cafe] ANN: Nomyx 0.3 beta, the game where you can change the rules

2013-10-02 Thread Corentin Dupont
Hello everybody! I released the third beta of Nomyx , the only game where You can change the rules! The second beta was a success. Great players (byorgey, nomeata, Toxaris...) proposed amazing rules, effectively building a nice universe. For example, a banking system in ecu wa

[Haskell-cafe] [ANNOUNCE] Penny - double-entry accounting

2013-10-02 Thread Omari Norman
I'm pleased to make the first public announcement of the availability of Penny, a double-entry command-line accounting system. Penny is inspired by Ledger, an excellent program in its own right. Ledger's websites and sales pitches are much better developed than those for Penny, so first take a loo

Re: [Haskell-cafe] Poll & plea: State of GUI & graphics libraries in Haskell

2013-10-02 Thread Paul Liu
I only managed to find some screenshots from Harley Trung's class projects a few years ago: https://github.com/harleyttd/keyboard-fretboard/blob/master/demo2.png https://github.com/harleyttd/InstrVislizr/blob/master/stereo.png It was nothing fancy, only basic widgets, single font, not skinnable.

Re: [Haskell-cafe] Newclasses

2013-10-02 Thread Wvv
> Your first two cases will be fixed in 7.10, as Applicative finally becomes a superclass of Monad. Sure, newclassses not about Applicative and Monads only. This question is more wider. Must Apply be a superclass of Bind? Must Bind be a superclass of Monad? So, must Monad has 2 superclasses at o

[Haskell-cafe] [ANN] yi-0.7

2013-10-02 Thread Dmitry Ivanov
I'm pleased to announce a new release of Yi, text editor written and extensible in Haskell. This release introduces new vim keybindings emulation. If all goes well, the old one will be deprecated in future. The advantages of the new emulation include support for visual block operations, more cons