[Haskell-cafe] Impredicative types and Lens?

2013-09-08 Thread Artyom Kazak
Here’s a small example, which, when compiled, gives an error. Why? {-# LANGUAGE FlexibleInstances, ImpredicativeTypes, TemplateHaskell #-} import Control.Lens class Item a where name :: a - String instance Item (String, Int) where name = fst

Re: [Haskell-cafe] ANN: set-cover solves Sudoku, Soma cube, 8 Queens etc.

2013-09-08 Thread Johannes Waldmann
Henning Thielemann lemming at henning-thielemann.de writes: .. package set-cover for solving exact set cover problems. http://hackage.haskell.org/package/set-cover It's hard to evaluate whether one could use the library because there's essentially no visible documentation. E.g., what does

[Haskell-cafe] FLTK GUI Binding in progress. Call for participation.

2013-09-08 Thread aditya siram
Hi all, I'm working on a FLTK [1] GUI binding [2]. The attraction of FLTK is that it is portable across many platforms, meaning it is easy to: 1. provide a binary for your application that works without installing anything else. eg. no need to install X on Mac. Just double-click! 2. develop on

Re: [Haskell-cafe] Impredicative types and Lens?

2013-09-08 Thread Edward Kmett
You can't write that lens by hand, so it isn't surprising that the template haskell can't generate it either. =) ImpredicativeTypes don't work all that well. -Edward On Sun, Sep 8, 2013 at 9:49 AM, Artyom Kazak y...@artyom.me wrote: Here’s a small example, which, when compiled, gives an

[Haskell-cafe] ANN: unix-bytestring 0.3.7

2013-09-08 Thread wren ng thornton
-- unix-bytestring 0.3.7 The unix-bytestring package offers a full selection of Unix/Posix-specific functions for reading and writing ByteStrings to Fds. --

Re: [Haskell-cafe] FLTK GUI Binding in progress. Call for participation.

2013-09-08 Thread John Lask
On 9/09/2013 7:09 AM, aditya siram wrote: Hi all, I'm working on a FLTK [1] GUI binding [2]. The attraction of FLTK is that there is an existing binding on hackage: hs-fltk library: Binding to GUI library FLTK which I understand is quite serviceable. Perhaps effort could be directed on