Re: [Haskell-cafe] Haskell showcase in 5 minutes

2012-02-27 Thread Arnaud Bailly
Well, solving knapsack problem in a couple lines of code looks really fun and instructive. Thanks Ertugrul for suggesting Yesod. This is definitely a great tool for creating web applications but I fear that's too much to swallow in 5 minutes. And thanks also Jason for reminding me of the gems one

Re: [Haskell-cafe] Theorems for free!

2012-02-27 Thread Patrick Browne
Wojciech, I apreciate that the example only satisifies rather than proves the theorem. Wadler says “it is possible to conclude that r satisifies the following theorem” "r must work on lists of X for any types X". So does evaluation demonstrate type level satisfiability? Thanks, Pat     O

Re: [Haskell-cafe] Records in Haskell

2012-02-27 Thread Evan Laforge
[ ccing the list because the wiki page was flawed and I made a bunch of changes, hope you don't mind ] > Thanks Evan, but I think that wiki page isn't doing your > proposal justice. There seem to be several typos in critical > places that make it hard to follow (for me at least). Sorry about the

Re: [Haskell-cafe] Haskell showcase in 5 minutes

2012-02-27 Thread roconnor
In less than 5 minutes I can solve NP-Complete problems in restaurant orders: http://www.reddit.com/comments/24p2c/xkcd_does_anyone_else_feel_compelled_to_solve_this/c24pc5 On Mon, 27 Feb 2012, Arnaud Bailly wrote: Hello Cafe, I will be (re)presenting Haskell in a "Batlle Language" event Wed

[Haskell-cafe] Theorems for free!

2012-02-27 Thread Patrick Browne
Hi, Below is my attempt to code the first example from Walder’s Theorems for free! paper. I am not sure about what is being proved. Using the notation from the paper does the proof establish a property of map, r, composition or the relationship between all three?   {-# LANGUAGE ExistentialQu

Re: [Haskell-cafe] Haskell showcase in 5 minutes

2012-02-27 Thread Jason Dagit
On Mon, Feb 27, 2012 at 7:18 AM, Arnaud Bailly wrote: > Hello Cafe, > > I will be (re)presenting Haskell in a "Batlle Language" event Wednesday > evening: A fun and interactive contest where various programming language > champions try to attract as much followers as possible in 5 minutes. > > Hav

Re: [Haskell-cafe] Haskell showcase in 5 minutes

2012-02-27 Thread Ertugrul Söylemez
Arnaud Bailly wrote: > I will be (re)presenting Haskell in a "Batlle Language" event > Wednesday evening: A fun and interactive contest where various > programming language champions try to attract as much followers as > possible in 5 minutes. > > Having successfully experimented the power of liv

[Haskell-cafe] Haskell showcase in 5 minutes

2012-02-27 Thread Arnaud Bailly
Hello Cafe, I will be (re)presenting Haskell in a "Batlle Language" event Wednesday evening: A fun and interactive contest where various programming language champions try to attract as much followers as possible in 5 minutes. Having successfully experimented the power of live coding in a recent